summaryrefslogtreecommitdiff
path: root/lisp/erc/erc-backend.el
blob: 0fead116d8fdd3680e54d9aa68bd11004759fdb8 (plain)
1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
570
571
572
573
574
575
576
577
578
579
580
581
582
583
584
585
586
587
588
589
590
591
592
593
594
595
596
597
598
599
600
601
602
603
604
605
606
607
608
609
610
611
612
613
614
615
616
617
618
619
620
621
622
623
624
625
626
627
628
629
630
631
632
633
634
635
636
637
638
639
640
641
642
643
644
645
646
647
648
649
650
651
652
653
654
655
656
657
658
659
660
661
662
663
664
665
666
667
668
669
670
671
672
673
674
675
676
677
678
679
680
681
682
683
684
685
686
687
688
689
690
691
692
693
694
695
696
697
698
699
700
701
702
703
704
705
706
707
708
709
710
711
712
713
714
715
716
717
718
719
720
721
722
723
724
725
726
727
728
729
730
731
732
733
734
735
736
737
738
739
740
741
742
743
744
745
746
747
748
749
750
751
752
753
754
755
756
757
758
759
760
761
762
763
764
765
766
767
768
769
770
771
772
773
774
775
776
777
778
779
780
781
782
783
784
785
786
787
788
789
790
791
792
793
794
795
796
797
798
799
800
801
802
803
804
805
806
807
808
809
810
811
812
813
814
815
816
817
818
819
820
821
822
823
824
825
826
827
828
829
830
831
832
833
834
835
836
837
838
839
840
841
842
843
844
845
846
847
848
849
850
851
852
853
854
855
856
857
858
859
860
861
862
863
864
865
866
867
868
869
870
871
872
873
874
875
876
877
878
879
880
881
882
883
884
885
886
887
888
889
890
891
892
893
894
895
896
897
898
899
900
901
902
903
904
905
906
907
908
909
910
911
912
913
914
915
916
917
918
919
920
921
922
923
924
925
926
927
928
929
930
931
932
933
934
935
936
937
938
939
940
941
942
943
944
945
946
947
948
949
950
951
952
953
954
955
956
957
958
959
960
961
962
963
964
965
966
967
968
969
970
971
972
973
974
975
976
977
978
979
980
981
982
983
984
985
986
987
988
989
990
991
992
993
994
995
996
997
998
999
1000
1001
1002
1003
1004
1005
1006
1007
1008
1009
1010
1011
1012
1013
1014
1015
1016
1017
1018
1019
1020
1021
1022
1023
1024
1025
1026
1027
1028
1029
1030
1031
1032
1033
1034
1035
1036
1037
1038
1039
1040
1041
1042
1043
1044
1045
1046
1047
1048
1049
1050
1051
1052
1053
1054
1055
1056
1057
1058
1059
1060
1061
1062
1063
1064
1065
1066
1067
1068
1069
1070
1071
1072
1073
1074
1075
1076
1077
1078
1079
1080
1081
1082
1083
1084
1085
1086
1087
1088
1089
1090
1091
1092
1093
1094
1095
1096
1097
1098
1099
1100
1101
1102
1103
1104
1105
1106
1107
1108
1109
1110
1111
1112
1113
1114
1115
1116
1117
1118
1119
1120
1121
1122
1123
1124
1125
1126
1127
1128
1129
1130
1131
1132
1133
1134
1135
1136
1137
1138
1139
1140
1141
1142
1143
1144
1145
1146
1147
1148
1149
1150
1151
1152
1153
1154
1155
1156
1157
1158
1159
1160
1161
1162
1163
1164
1165
1166
1167
1168
1169
1170
1171
1172
1173
1174
1175
1176
1177
1178
1179
1180
1181
1182
1183
1184
1185
1186
1187
1188
1189
1190
1191
1192
1193
1194
1195
1196
1197
1198
1199
1200
1201
1202
1203
1204
1205
1206
1207
1208
1209
1210
1211
1212
1213
1214
1215
1216
1217
1218
1219
1220
1221
1222
1223
1224
1225
1226
1227
1228
1229
1230
1231
1232
1233
1234
1235
1236
1237
1238
1239
1240
1241
1242
1243
1244
1245
1246
1247
1248
1249
1250
1251
1252
1253
1254
1255
1256
1257
1258
1259
1260
1261
1262
1263
1264
1265
1266
1267
1268
1269
1270
1271
1272
1273
1274
1275
1276
1277
1278
1279
1280
1281
1282
1283
1284
1285
1286
1287
1288
1289
1290
1291
1292
1293
1294
1295
1296
1297
1298
1299
1300
1301
1302
1303
1304
1305
1306
1307
1308
1309
1310
1311
1312
1313
1314
1315
1316
1317
1318
1319
1320
1321
1322
1323
1324
1325
1326
1327
1328
1329
1330
1331
1332
1333
1334
1335
1336
1337
1338
1339
1340
1341
1342
1343
1344
1345
1346
1347
1348
1349
1350
1351
1352
1353
1354
1355
1356
1357
1358
1359
1360
1361
1362
1363
1364
1365
1366
1367
1368
1369
1370
1371
1372
1373
1374
1375
1376
1377
1378
1379
1380
1381
1382
1383
1384
1385
1386
1387
1388
1389
1390
1391
1392
1393
1394
1395
1396
1397
1398
1399
1400
1401
1402
1403
1404
1405
1406
1407
1408
1409
1410
1411
1412
1413
1414
1415
1416
1417
1418
1419
1420
1421
1422
1423
1424
1425
1426
1427
1428
1429
1430
1431
1432
1433
1434
1435
1436
1437
1438
1439
1440
1441
1442
1443
1444
1445
1446
1447
1448
1449
1450
1451
1452
1453
1454
1455
1456
1457
1458
1459
1460
1461
1462
1463
1464
1465
1466
1467
1468
1469
1470
1471
1472
1473
1474
1475
1476
1477
1478
1479
1480
1481
1482
1483
1484
1485
1486
1487
1488
1489
1490
1491
1492
1493
1494
1495
1496
1497
1498
1499
1500
1501
1502
1503
1504
1505
1506
1507
1508
1509
1510
1511
1512
1513
1514
1515
1516
1517
1518
1519
1520
1521
1522
1523
1524
1525
1526
1527
1528
1529
1530
1531
1532
1533
1534
1535
1536
1537
1538
1539
1540
1541
1542
1543
1544
1545
1546
1547
1548
1549
1550
1551
1552
1553
1554
1555
1556
1557
1558
1559
1560
1561
1562
1563
1564
1565
1566
1567
1568
1569
1570
1571
1572
1573
1574
1575
1576
1577
1578
1579
1580
1581
1582
1583
1584
1585
1586
1587
1588
1589
1590
1591
1592
1593
1594
1595
1596
1597
1598
1599
1600
1601
1602
1603
1604
1605
1606
1607
1608
1609
1610
1611
1612
1613
1614
1615
1616
1617
1618
1619
1620
1621
1622
1623
1624
1625
1626
1627
1628
1629
1630
1631
1632
1633
1634
1635
1636
1637
1638
1639
1640
1641
1642
1643
1644
1645
1646
1647
1648
1649
1650
1651
1652
1653
1654
1655
1656
1657
1658
1659
1660
1661
1662
1663
1664
1665
1666
1667
1668
1669
1670
1671
1672
1673
1674
1675
1676
1677
1678
1679
1680
1681
1682
1683
1684
1685
1686
1687
1688
1689
1690
1691
1692
1693
1694
1695
1696
1697
1698
1699
1700
1701
1702
1703
1704
1705
1706
1707
1708
1709
1710
1711
1712
1713
1714
1715
1716
1717
1718
1719
1720
1721
1722
1723
1724
1725
1726
1727
1728
1729
1730
1731
1732
1733
1734
1735
1736
1737
1738
1739
1740
1741
1742
1743
1744
1745
1746
1747
1748
1749
1750
1751
1752
1753
1754
1755
1756
1757
1758
1759
1760
1761
1762
1763
1764
1765
1766
1767
1768
1769
1770
1771
1772
1773
1774
1775
1776
1777
1778
1779
1780
1781
1782
1783
1784
1785
1786
1787
1788
1789
1790
1791
1792
1793
1794
1795
1796
1797
1798
1799
1800
1801
1802
1803
1804
1805
1806
1807
1808
1809
1810
1811
1812
1813
1814
1815
1816
1817
1818
1819
1820
1821
1822
1823
1824
1825
1826
1827
1828
1829
1830
1831
1832
1833
1834
1835
1836
1837
1838
1839
1840
1841
1842
1843
1844
1845
1846
1847
1848
1849
1850
1851
1852
1853
1854
1855
1856
1857
1858
1859
1860
1861
1862
1863
1864
1865
1866
1867
1868
1869
1870
1871
1872
1873
1874
1875
1876
1877
1878
1879
1880
1881
1882
1883
1884
1885
1886
1887
1888
1889
1890
1891
1892
1893
1894
1895
1896
1897
1898
1899
1900
1901
1902
1903
1904
1905
1906
1907
1908
1909
1910
1911
1912
1913
1914
1915
1916
1917
1918
1919
1920
1921
1922
1923
1924
1925
1926
1927
1928
1929
1930
1931
1932
1933
1934
1935
1936
1937
1938
1939
1940
1941
1942
1943
1944
1945
1946
1947
1948
1949
1950
1951
1952
1953
1954
1955
1956
1957
1958
1959
1960
1961
1962
1963
;;; erc-backend.el --- Backend network communication for ERC

;; Copyright (C) 2004, 2005, 2006, 2007, 2008 Free Software Foundation, Inc.

;; Filename: erc-backend.el
;; Author: Lawrence Mitchell <wence@gmx.li>
;; Created: 2004-05-7
;; Keywords: IRC chat client internet

;; This file is part of GNU Emacs.

;; GNU Emacs is free software; you can redistribute it and/or modify
;; it under the terms of the GNU General Public License as published by
;; the Free Software Foundation; either version 3, or (at your option)
;; any later version.

;; GNU Emacs is distributed in the hope that it will be useful,
;; but WITHOUT ANY WARRANTY; without even the implied warranty of
;; MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
;; GNU General Public License for more details.

;; You should have received a copy of the GNU General Public License
;; along with GNU Emacs; see the file COPYING.  If not, write to the
;; Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
;; Boston, MA 02110-1301, USA.

;;; Commentary:

;; This file defines backend network communication handlers for ERC.
;;
;; How things work:
;;
;; You define a new handler with `define-erc-response-handler'.  This
;; defines a function, a corresponding hook variable, and populates a
;; global hash table `erc-server-responses' with a map from response
;; to hook variable.  See the function documentation for more
;; information.
;;
;; Upon receiving a line from the server, `erc-parse-server-response'
;; is called on it.
;;
;; A line generally looks like:
;;
;; LINE := ':' SENDER ' ' COMMAND ' ' (COMMAND-ARGS ' ')* ':' CONTENTS
;; SENDER := Not ':' | ' '
;; COMMAND := Not ':' | ' '
;; COMMAND-ARGS := Not ':' | ' '
;;
;; This gets parsed and stuffed into an `erc-response' struct.  You
;; can access the fields of the struct with:
;;
;; COMMAND --- `erc-response.command'
;; COMMAND-ARGS --- `erc-response.command-args'
;; CONTENTS --- `erc-response.contents'
;; SENDER --- `erc-response.sender'
;; LINE --- `erc-response.unparsed'
;;
;; WARNING, WARNING!!
;; It's probably not a good idea to destructively modify the list
;; of command-args in your handlers, since other functions down the
;; line may well need to access the arguments too.
;;
;; That is, unless you're /absolutely/ sure that your handler doesn't
;; invoke some other function that needs to use COMMAND-ARGS, don't do
;; something like
;;
;; (while (erc-response.command-args parsed)
;;   (let ((a (pop (erc-response.command-args parsed))))
;;     ...))
;;
;; The parsed response is handed over to
;; `erc-handle-parsed-server-response', which checks whether it should
;; carry out duplicate suppression, and then runs `erc-call-hooks'.
;; `erc-call-hooks' retrieves the relevant hook variable from
;; `erc-server-responses' and runs it.
;;
;; Most handlers then destructure the parsed response in some way
;; (depending on what the handler is, the arguments have different
;; meanings), and generally display something, usually using
;; `erc-display-message'.

;;; TODO:

;; o Generalise the display-line code so that we can use it to
;;   display the stuff we send, as well as the stuff we receive.
;;   Then, move all display-related code into another backend-like
;;   file, erc-display.el, say.
;;
;; o Clean up the handlers using new display code (has to be written
;;   first).

;;; History:

;; 2004/05/10 -- Handler bodies taken out of erc.el and ported to new
;;               interface.

;; 2005-08-13 -- Moved sending commands from erc.el.

;;; Code:

(require 'erc-compat)
(eval-when-compile (require 'cl))
(autoload 'erc-with-buffer "erc" nil nil 'macro)
(autoload 'erc-log "erc" nil nil 'macro)

;;;; Variables and options

(defvar erc-server-responses (make-hash-table :test #'equal)
  "Hashtable mapping server responses to their handler hooks.")

(defstruct (erc-response (:conc-name erc-response.))
  (unparsed "" :type string)
  (sender "" :type string)
  (command "" :type string)
  (command-args '() :type list)
  (contents "" :type string))

;;; User data

(defvar erc-server-current-nick nil
  "Nickname on the current server.
Use `erc-current-nick' to access this.")
(make-variable-buffer-local 'erc-server-current-nick)

;;; Server attributes

(defvar erc-server-process nil
  "The process object of the corresponding server connection.")
(make-variable-buffer-local 'erc-server-process)

(defvar erc-session-server nil
  "The server name used to connect to for this session.")
(make-variable-buffer-local 'erc-session-server)

(defvar erc-session-port nil
  "The port used to connect to.")
(make-variable-buffer-local 'erc-session-port)

(defvar erc-server-announced-name nil
  "The name the server announced to use.")
(make-variable-buffer-local 'erc-server-announced-name)

(defvar erc-server-version nil
  "The name and version of the server's ircd.")
(make-variable-buffer-local 'erc-server-version)

(defvar erc-server-parameters nil
  "Alist listing the supported server parameters.

This is only set if the server sends 005 messages saying what is
supported on the server.

Entries are of the form:
  (PARAMETER . VALUE)
or
  (PARAMETER) if no value is provided.

Some examples of possible parameters sent by servers:
CHANMODES=b,k,l,imnpst - list of supported channel modes
CHANNELLEN=50 - maximum length of channel names
CHANTYPES=#&!+ - supported channel prefixes
CHARMAPPING=rfc1459 - character mapping used for nickname and channels
KICKLEN=160 - maximum allowed kick message length
MAXBANS=30 - maximum number of bans per channel
MAXCHANNELS=10 - maximum number of channels allowed to join
NETWORK=EFnet -  the network identifier
NICKLEN=9 - maximum allowed length of nicknames
PREFIX=(ov)@+ - list of channel modes and the user prefixes if user has mode
RFC2812 - server supports RFC 2812 features
SILENCE=10 - supports the SILENCE command, maximum allowed number of entries
TOPICLEN=160 - maximum allowed topic length
WALLCHOPS - supports sending messages to all operators in a channel")
(make-variable-buffer-local 'erc-server-parameters)

;;; Server and connection state

(defvar erc-server-ping-timer-alist nil
  "Mapping of server buffers to their specific ping timer.")

(defvar erc-server-connected nil
  "Non-nil if the current buffer has been used by ERC to establish
an IRC connection.

If you wish to determine whether an IRC connection is currently
active, use the `erc-server-process-alive' function instead.")
(make-variable-buffer-local 'erc-server-connected)

(defvar erc-server-reconnect-count 0
  "Number of times we have failed to reconnect to the current server.")
(make-variable-buffer-local 'erc-server-reconnect-count)

(defvar erc-server-quitting nil
  "Non-nil if the user requests a quit.")
(make-variable-buffer-local 'erc-server-quitting)

(defvar erc-server-reconnecting nil
  "Non-nil if the user requests an explicit reconnect, and the
current IRC process is still alive.")
(make-variable-buffer-local 'erc-server-reconnecting)

(defvar erc-server-timed-out nil
  "Non-nil if the IRC server failed to respond to a ping.")
(make-variable-buffer-local 'erc-server-timed-out)

(defvar erc-server-banned nil
  "Non-nil if the user is denied access because of a server ban.")
(make-variable-buffer-local 'erc-server-banned)

(defvar erc-server-error-occurred nil
  "Non-nil if the user triggers some server error.")
(make-variable-buffer-local 'erc-server-error-occurred)

(defvar erc-server-lines-sent nil
  "Line counter.")
(make-variable-buffer-local 'erc-server-lines-sent)

(defvar erc-server-last-peers '(nil . nil)
  "Last peers used, both sender and receiver.
Those are used for /MSG destination shortcuts.")
(make-variable-buffer-local 'erc-server-last-peers)

(defvar erc-server-last-sent-time nil
  "Time the message was sent.
This is useful for flood protection.")
(make-variable-buffer-local 'erc-server-last-sent-time)

(defvar erc-server-last-ping-time nil
  "Time the last ping was sent.
This is useful for flood protection.")
(make-variable-buffer-local 'erc-server-last-ping-time)

(defvar erc-server-last-received-time nil
  "Time the last message was received from the server.
This is useful for detecting hung connections.")
(make-variable-buffer-local 'erc-server-last-received-time)

(defvar erc-server-lag nil
  "Calculated server lag time in seconds.
This variable is only set in a server buffer.")
(make-variable-buffer-local 'erc-server-lag)

(defvar erc-server-filter-data nil
  "The data that arrived from the server
but has not been processed yet.")
(make-variable-buffer-local 'erc-server-filter-data)

(defvar erc-server-duplicates (make-hash-table :test 'equal)
  "Internal variable used to track duplicate messages.")
(make-variable-buffer-local 'erc-server-duplicates)

;; From Circe
(defvar erc-server-processing-p nil
  "Non-nil when we're currently processing a message.

When ERC receives a private message, it sets up a new buffer for
this query.  These in turn, though, do start flyspell. This
involves starting an external process, in which case Emacs will
wait - and when it waits, it does accept other stuff from, say,
network exceptions.  So, if someone sends you two messages
quickly after each other, ispell is started for the first, but
might take long enough for the second message to be processed
first.")
(make-variable-buffer-local 'erc-server-processing-p)

(defvar erc-server-flood-last-message 0
  "When we sent the last message.
See `erc-server-flood-margin' for an explanation of the flood
protection algorithm.")
(make-variable-buffer-local 'erc-server-flood-last-message)

(defvar erc-server-flood-queue nil
  "The queue of messages waiting to be sent to the server.
See `erc-server-flood-margin' for an explanation of the flood
protection algorithm.")
(make-variable-buffer-local 'erc-server-flood-queue)

(defvar erc-server-flood-timer nil
  "The timer to resume sending.")
(make-variable-buffer-local 'erc-server-flood-timer)

;;; IRC protocol and misc options

(defgroup erc-server nil
  "Parameters for dealing with IRC servers."
  :group 'erc)

(defcustom erc-server-auto-reconnect t
  "Non-nil means that ERC will attempt to reestablish broken connections.

Reconnection will happen automatically for any unexpected disconnection."
  :group 'erc-server
  :type 'boolean)

(defcustom erc-server-reconnect-attempts 2
  "The number of times that ERC will attempt to reestablish a
broken connection, or t to always attempt to reconnect.

This only has an effect if `erc-server-auto-reconnect' is non-nil."
  :group 'erc-server
  :type '(choice (const :tag "Always reconnect" t)
                 integer))

(defcustom erc-server-reconnect-timeout 1
  "The amount of time, in seconds, that ERC will wait between
successive reconnect attempts.

If a key is pressed while ERC is waiting, it will stop waiting."
  :group 'erc-server
  :type 'number)

(defcustom erc-split-line-length 440
  "*The maximum length of a single message.
If a message exceeds this size, it is broken into multiple ones.

IRC allows for lines up to 512 bytes. Two of them are CR LF.
And a typical message looks like this:

  :nicky!uhuser@host212223.dialin.fnordisp.net PRIVMSG #lazybastards :Hello!

You can limit here the maximum length of the \"Hello!\" part.
Good luck."
  :type 'integer
  :group 'erc-server)

(defcustom erc-server-coding-system (if (and (fboundp 'coding-system-p)
                                             (coding-system-p 'undecided)
                                             (coding-system-p 'utf-8))
                                        '(utf-8 . undecided)
                                      nil)
  "The default coding system for incoming and outgoing text.
This is either a coding system, a cons, a function, or nil.

If a cons, the encoding system for outgoing text is in the car
and the decoding system for incoming text is in the cdr. The most
interesting use for this is to put `undecided' in the cdr. If a
function, it is called with no arguments and should return a
coding system or a cons as described above. Note that you can use
the dynamically bound variable `target' to get the current
target. See `erc-coding-system-for-target'.

If you need to send non-ASCII text to people not using a client that
does decoding on its own, you must tell ERC what encoding to use.
Emacs cannot guess it, since it does not know what the people on the
other end of the line are using."
  :group 'erc-server
  :type '(choice (const :tag "None" nil)
                 coding-system
                 (cons (coding-system :tag "encoding" :value utf-8)
                       (coding-system :tag "decoding" :value undecided))
                 function))

(defcustom erc-encoding-coding-alist nil
  "Alist of target regexp and coding-system pairs to use.
This overrides `erc-server-coding-system' depending on the
current target as returned by `erc-default-target'.

Example: If you know that the channel #linux-ru uses the coding-system
`cyrillic-koi8', then add '(\"#linux-ru\" . cyrillic-koi8) to the
alist."
  :group 'erc-server
  :type '(repeat (cons (string :tag "Target")
                       coding-system)))

(defcustom erc-server-connect-function 'open-network-stream
  "Function used to initiate a connection.
It should take same arguments as `open-network-stream' does."
  :group 'erc-server
  :type 'function)

(defcustom erc-server-prevent-duplicates '("301")
  "*Either nil or a list of strings.
Each string is a IRC message type, like PRIVMSG or NOTICE.
All Message types in that list of subjected to duplicate prevention."
  :type '(choice (const nil) (list string))
  :group 'erc-server)

(defcustom erc-server-duplicate-timeout 60
  "*The time allowed in seconds between duplicate messages.

If two identical messages arrive within this value of one another, the second
isn't displayed."
  :type 'integer
  :group 'erc-server)

;;; Flood-related

;; Most of this is courtesy of Jorgen Schaefer and Circe
;; (http://www.nongnu.org/circe)

(defcustom erc-server-flood-margin 10
  "*A margin on how much excess data we send.
The flood protection algorithm of ERC works like the one
detailed in RFC 2813, section 5.8 \"Flood control of clients\".

  * If `erc-server-flood-last-message' is less than the current
    time, set it equal.
  * While `erc-server-flood-last-message' is less than
    `erc-server-flood-margin' seconds ahead of the current
    time, send a message, and increase
    `erc-server-flood-last-message' by
    `erc-server-flood-penalty' for each message."
  :type 'integer
  :group 'erc-server)

(defcustom erc-server-flood-penalty 3
  "How much we penalize a message.
See `erc-server-flood-margin' for an explanation of the flood
protection algorithm."
  :type 'integer
  :group 'erc-server)

;; Ping handling

(defcustom erc-server-send-ping-interval 30
  "*Interval of sending pings to the server, in seconds.
If this is set to nil, pinging the server is disabled."
  :group 'erc-server
  :type '(choice (const :tag "Disabled" nil)
                 (integer :tag "Seconds")))

(defcustom erc-server-send-ping-timeout 120
  "*If the time between ping and response is greater than this, reconnect.
The time is in seconds.

This must be greater than or equal to the value for
`erc-server-send-ping-interval'.

If this is set to nil, never try to reconnect."
  :group 'erc-server
  :type '(choice (const :tag "Disabled" nil)
                 (integer :tag "Seconds")))

(defvar erc-server-ping-handler nil
  "This variable holds the periodic ping timer.")
(make-variable-buffer-local 'erc-server-ping-handler)

;;;; Helper functions

;; From Circe
(defun erc-split-line (longline)
  "Return a list of lines which are not too long for IRC.
The length is specified in `erc-split-line-length'.

Currently this is called by `erc-send-input'."
  (if (< (length longline)
         erc-split-line-length)
      (list longline)
    (with-temp-buffer
      (insert longline)
      (let ((fill-column erc-split-line-length))
        (fill-region (point-min) (point-max)
                     nil t))
      (split-string (buffer-string) "\n"))))

;; Used by CTCP functions
(defun erc-upcase-first-word (str)
  "Upcase the first word in STR."
  (with-temp-buffer
    (insert str)
    (goto-char (point-min))
    (upcase-word 1)
    (buffer-string)))

(defun erc-server-setup-periodical-ping (buffer)
  "Set up a timer to periodically ping the current server.
The current buffer is given by BUFFER."
  (with-current-buffer buffer
    (and erc-server-ping-handler (erc-cancel-timer erc-server-ping-handler))
    (when erc-server-send-ping-interval
      (setq erc-server-ping-handler (run-with-timer
                                     4 erc-server-send-ping-interval
                                     #'erc-server-send-ping
                                     buffer))
      (setq erc-server-ping-timer-alist (cons (cons buffer
                                                    erc-server-ping-handler)
                                              erc-server-ping-timer-alist)))))

(defun erc-server-process-alive ()
  "Return non-nil when `erc-server-process' is open or running."
  (and erc-server-process
       (processp erc-server-process)
       (memq (process-status erc-server-process) '(run open))))

;;;; Connecting to a server

(defun erc-server-connect (server port buffer)
  "Perform the connection and login using the specified SERVER and PORT.
We will store server variables in the buffer given by BUFFER."
  (let ((msg (erc-format-message 'connect ?S server ?p port)))
    (message "%s" msg)
    (let ((process (funcall erc-server-connect-function
                            (format "erc-%s-%s" server port)
                            nil server port)))
      (message "%s...done" msg)
      ;; Misc server variables
      (with-current-buffer buffer
        (setq erc-server-process process)
        (setq erc-server-quitting nil)
        (setq erc-server-reconnecting nil)
        (setq erc-server-timed-out nil)
        (setq erc-server-banned nil)
        (setq erc-server-error-occurred nil)
        (let ((time (erc-current-time)))
          (setq erc-server-last-sent-time time)
          (setq erc-server-last-ping-time time)
          (setq erc-server-last-received-time time))
        (setq erc-server-lines-sent 0)
        ;; last peers (sender and receiver)
        (setq erc-server-last-peers '(nil . nil)))
      ;; we do our own encoding and decoding
      (when (fboundp 'set-process-coding-system)
        (set-process-coding-system process 'raw-text))
      ;; process handlers
      (set-process-sentinel process 'erc-process-sentinel)
      (set-process-filter process 'erc-server-filter-function)
      (set-process-buffer process buffer)))
  (erc-log "\n\n\n********************************************\n")
  (message "%s" (erc-format-message
            'login ?n
            (with-current-buffer buffer (erc-current-nick))))
  ;; wait with script loading until we receive a confirmation (first
  ;; MOTD line)
  (if (eq erc-server-connect-function 'open-network-stream-nowait)
      ;; it's a bit unclear otherwise that it's attempting to establish a
      ;; connection
      (erc-display-message nil nil buffer "Opening connection..\n")
    (erc-login)))

(defun erc-server-reconnect ()
"Reestablish the current IRC connection.
Make sure you are in an ERC buffer when running this."
  (let ((buffer (erc-server-buffer)))
    (unless (buffer-live-p buffer)
      (if (eq major-mode 'erc-mode)
          (setq buffer (current-buffer))
        (error "Reconnect must be run from an ERC buffer")))
    (with-current-buffer buffer
      (erc-update-mode-line)
      (erc-set-active-buffer (current-buffer))
      (setq erc-server-last-sent-time 0)
      (setq erc-server-lines-sent 0)
      (erc-open erc-session-server erc-session-port erc-server-current-nick
                erc-session-user-full-name t erc-session-password))))

(defun erc-server-filter-function (process string)
  "The process filter for the ERC server."
  (with-current-buffer (process-buffer process)
    (setq erc-server-last-received-time (erc-current-time))
    ;; If you think this is written in a weird way - please refer to the
    ;; docstring of `erc-server-processing-p'
    (if erc-server-processing-p
        (setq erc-server-filter-data
              (if erc-server-filter-data
                  (concat erc-server-filter-data string)
                string))
      ;; This will be true even if another process is spawned!
      (let ((erc-server-processing-p t))
        (setq erc-server-filter-data (if erc-server-filter-data
                                           (concat erc-server-filter-data
                                                   string)
                                         string))
        (while (and erc-server-filter-data
                    (string-match "[\n\r]+" erc-server-filter-data))
          (let ((line (substring erc-server-filter-data
                                 0 (match-beginning 0))))
            (setq erc-server-filter-data
                  (if (= (match-end 0)
                         (length erc-server-filter-data))
                      nil
                    (substring erc-server-filter-data
                               (match-end 0))))
            (erc-parse-server-response process line)))))))

(defsubst erc-server-reconnect-p (event)
  "Return non-nil if ERC should attempt to reconnect automatically.
EVENT is the message received from the closed connection process."
  (or erc-server-reconnecting
      (and erc-server-auto-reconnect
           (not erc-server-banned)
           (not erc-server-error-occurred)
           ;; make sure we don't infinitely try to reconnect, unless the
           ;; user wants that
           (or (eq erc-server-reconnect-attempts t)
               (and (integerp erc-server-reconnect-attempts)
                    (< erc-server-reconnect-count
                       erc-server-reconnect-attempts)))
           (or erc-server-timed-out
               (not (string-match "^deleted" event)))
           ;; open-network-stream-nowait error for connection refused
           (not (string-match "^failed with code 111" event)))))

(defun erc-process-sentinel-2 (event buffer)
  "Called when `erc-process-sentinel-1' has detected an unexpected disconnect."
  (if (not (buffer-live-p buffer))
      (erc-update-mode-line)
    (with-current-buffer buffer
      (let ((reconnect-p (erc-server-reconnect-p event)))
        (erc-display-message nil 'error (current-buffer)
                             (if reconnect-p 'disconnected
                               'disconnected-noreconnect))
        (if (not reconnect-p)
            ;; terminate, do not reconnect
            (progn
              (erc-display-message nil 'error (current-buffer)
                                   'terminated ?e event)
              ;; Update mode line indicators
              (erc-update-mode-line)
              (set-buffer-modified-p nil))
          ;; reconnect
          (condition-case err
              (progn
                (setq erc-server-reconnecting nil)
                (erc-server-reconnect)
                (setq erc-server-reconnect-count 0))
            (error (when (buffer-live-p buffer)
                     (set-buffer buffer)
                     (if (integerp erc-server-reconnect-attempts)
                         (setq erc-server-reconnect-count
                               (1+ erc-server-reconnect-count))
                       (message "%s ... %s"
                                "Reconnecting until we succeed"
                                "kill the ERC server buffer to stop"))
                     (if (numberp erc-server-reconnect-timeout)
                         (run-at-time erc-server-reconnect-timeout nil
                                      #'erc-process-sentinel-2
                                      event buffer)
                       (error (concat "`erc-server-reconnect-timeout`"
                                      " must be a number")))))))))))

(defun erc-process-sentinel-1 (event buffer)
  "Called when `erc-process-sentinel' has decided that we're disconnecting.
Determine whether user has quit or whether erc has been terminated.
Conditionally try to reconnect and take appropriate action."
  (with-current-buffer buffer
    (if erc-server-quitting
        ;; normal quit
        (progn
          (erc-display-message nil 'error (current-buffer) 'finished)
          ;; Update mode line indicators
          (erc-update-mode-line)
          ;; Kill server buffer if user wants it
          (set-buffer-modified-p nil)
          (when erc-kill-server-buffer-on-quit
            (kill-buffer (current-buffer))))
      ;; unexpected disconnect
      (erc-process-sentinel-2 event buffer))))

(defun erc-process-sentinel (cproc event)
  "Sentinel function for ERC process."
  (with-current-buffer (process-buffer cproc)
    (erc-log (format
              "SENTINEL: proc: %S	 status: %S  event: %S (quitting: %S)"
              cproc (process-status cproc) event erc-server-quitting))
    (if (string-match "^open" event)
        ;; newly opened connection (no wait)
        (erc-login)
      ;; assume event is 'failed
      (let ((buf (process-buffer cproc)))
        (erc-with-all-buffers-of-server cproc nil
                                        (setq erc-server-connected nil))
        (when erc-server-ping-handler
          (progn (erc-cancel-timer erc-server-ping-handler)
                 (setq erc-server-ping-handler nil)))
        (run-hook-with-args 'erc-disconnected-hook
                            (erc-current-nick) (system-name) "")
        ;; Remove the prompt
        (goto-char (or (marker-position erc-input-marker) (point-max)))
        (forward-line 0)
        (erc-remove-text-properties-region (point) (point-max))
        (delete-region (point) (point-max))
        ;; Decide what to do with the buffer
        ;; Restart if disconnected
        (erc-process-sentinel-1 event buf)))))

;;;; Sending messages

(defun erc-coding-system-for-target (target)
  "Return the coding system or cons cell appropriate for TARGET.
This is determined via `erc-encoding-coding-alist' or
`erc-server-coding-system'."
  (unless target (setq target (erc-default-target)))
  (or (when target
        (let ((case-fold-search t))
          (catch 'match
            (dolist (pat erc-encoding-coding-alist)
              (when (string-match (car pat) target)
                (throw 'match (cdr pat)))))))
      (and (functionp erc-server-coding-system)
           (funcall erc-server-coding-system))
      erc-server-coding-system))

(defun erc-decode-string-from-target (str target)
  "Decode STR as appropriate for TARGET.
This is indicated by `erc-encoding-coding-alist', defaulting to the value of
`erc-server-coding-system'."
  (unless (stringp str)
    (setq str ""))
  (let ((coding (erc-coding-system-for-target target)))
    (when (consp coding)
      (setq coding (cdr coding)))
    (erc-decode-coding-string str coding)))

;; proposed name, not used by anything yet
(defun erc-send-line (text display-fn)
  "Send TEXT to the current server.  Wrapping and flood control apply.
Use DISPLAY-FN to show the results."
  (mapc (lambda (line)
          (erc-server-send line)
          (funcall display-fn))
        (erc-split-line text)))

;; From Circe, with modifications
(defun erc-server-send (string &optional forcep target)
  "Send STRING to the current server.
If FORCEP is non-nil, no flood protection is done - the string is
sent directly. This might cause the messages to arrive in a wrong
order.

If TARGET is specified, look up encoding information for that
channel in `erc-encoding-coding-alist' or
`erc-server-coding-system'.

See `erc-server-flood-margin' for an explanation of the flood
protection algorithm."
  (erc-log (concat "erc-server-send: " string "(" (buffer-name) ")"))
  (setq erc-server-last-sent-time (erc-current-time))
  (let ((encoding (erc-coding-system-for-target target)))
    (when (consp encoding)
      (setq encoding (car encoding)))
    (if (erc-server-process-alive)
        (erc-with-server-buffer
          (let ((str (concat string "\r\n")))
            (if forcep
                (progn
                  (setq erc-server-flood-last-message
                        (+ erc-server-flood-penalty
                           erc-server-flood-last-message))
                  (erc-log-irc-protocol str 'outbound)
                  (condition-case err
                      (progn
                        ;; Set encoding just before sending the string
                        (when (fboundp 'set-process-coding-system)
                          (set-process-coding-system erc-server-process
                                                     'raw-text encoding))
                        (process-send-string erc-server-process str))
                    ;; See `erc-server-send-queue' for full
                    ;; explanation of why we need this condition-case
                    (error nil)))
              (setq erc-server-flood-queue
                    (append erc-server-flood-queue
                            (list (cons str encoding))))
              (erc-server-send-queue (current-buffer))))
          t)
      (message "ERC: No process running")
      nil)))

(defun erc-server-send-ping (buf)
  "Send a ping to the IRC server buffer in BUF.
Additionally, detect whether the IRC process has hung."
  (if (buffer-live-p buf)
      (with-current-buffer buf
        (if (and erc-server-send-ping-timeout
                 (>
                  (erc-time-diff (erc-current-time)
                                 erc-server-last-received-time)
                  erc-server-send-ping-timeout))
            (progn
              ;; if the process is hung, kill it
              (setq erc-server-timed-out t)
              (delete-process erc-server-process))
          (erc-server-send (format "PING %.0f" (erc-current-time)))))
    ;; remove timer if the server buffer has been killed
    (let ((timer (assq buf erc-server-ping-timer-alist)))
      (when timer
        (erc-cancel-timer (cdr timer))
        (setcdr timer nil)))))

;; From Circe
(defun erc-server-send-queue (buffer)
  "Send messages in `erc-server-flood-queue'.
See `erc-server-flood-margin' for an explanation of the flood
protection algorithm."
  (with-current-buffer buffer
    (let ((now (erc-current-time)))
      (when erc-server-flood-timer
        (erc-cancel-timer erc-server-flood-timer)
        (setq erc-server-flood-timer nil))
      (when (< erc-server-flood-last-message
               now)
        (setq erc-server-flood-last-message now))
      (while (and erc-server-flood-queue
                  (< erc-server-flood-last-message
                     (+ now erc-server-flood-margin)))
        (let ((msg (caar erc-server-flood-queue))
              (encoding (cdar erc-server-flood-queue)))
          (setq erc-server-flood-queue (cdr erc-server-flood-queue)
                erc-server-flood-last-message
                (+ erc-server-flood-last-message
                   erc-server-flood-penalty))
          (erc-log-irc-protocol msg 'outbound)
          (erc-log (concat "erc-server-send-queue: "
                           msg "(" (buffer-name buffer) ")"))
          (when (erc-server-process-alive)
            (condition-case err
                ;; Set encoding just before sending the string
                (progn
                  (when (fboundp 'set-process-coding-system)
                    (set-process-coding-system erc-server-process
                                               'raw-text encoding))
                  (process-send-string erc-server-process msg))
              ;; Sometimes the send can occur while the process is
              ;; being killed, which results in a weird SIGPIPE error.
              ;; Catch this and ignore it.
              (error nil)))))
      (when erc-server-flood-queue
        (setq erc-server-flood-timer
              (run-at-time (+ 0.2 erc-server-flood-penalty)
                           nil #'erc-server-send-queue buffer))))))

(defun erc-message (message-command line &optional force)
  "Send LINE to the server as a privmsg or a notice.
MESSAGE-COMMAND should be either \"PRIVMSG\" or \"NOTICE\".
If the target is \",\", the last person you've got a message from will
be used. If the target is \".\", the last person you've sent a message
to will be used."
  (cond
   ((string-match "^\\s-*\\(\\S-+\\) ?\\(.*\\)" line)
    (let ((tgt (match-string 1 line))
          (s (match-string 2 line)))
      (erc-log (format "cmd: MSG(%s): [%s] %s" message-command tgt s))
      (cond
       ((string= tgt ",")
        (if (car erc-server-last-peers)
            (setq tgt (car erc-server-last-peers))
          (setq tgt nil)))
       ((string= tgt ".")
        (if (cdr erc-server-last-peers)
            (setq tgt (cdr erc-server-last-peers))
          (setq tgt nil))))
      (cond
       (tgt
        (setcdr erc-server-last-peers tgt)
        (erc-server-send (format "%s %s :%s" message-command tgt s)
                         force))
       (t
        (erc-display-message nil 'error (current-buffer) 'no-target))))
    t)
   (t nil)))

;;; CTCP

(defun erc-send-ctcp-message (tgt l &optional force)
  "Send CTCP message L to TGT.

If TGT is nil the message is not sent.
The command must contain neither a prefix nor a trailing `\\n'.

See also `erc-server-send'."
  (let ((l (erc-upcase-first-word l)))
    (cond
     (tgt
      (erc-log (format "erc-send-CTCP-message: [%s] %s" tgt l))
      (erc-server-send (format "PRIVMSG %s :\C-a%s\C-a" tgt l)
                       force)))))

(defun erc-send-ctcp-notice (tgt l &optional force)
  "Send CTCP notice L to TGT.

If TGT is nil the message is not sent.
The command must contain neither a prefix nor a trailing `\\n'.

See also `erc-server-send'."
  (let ((l (erc-upcase-first-word l)))
    (cond
     (tgt
      (erc-log (format "erc-send-CTCP-notice: [%s] %s" tgt l))
      (erc-server-send (format "NOTICE %s :\C-a%s\C-a" tgt l)
                       force)))))

;;;; Handling responses

(defun erc-parse-server-response (proc string)
  "Parse and act upon a complete line from an IRC server.
PROC is the process (connection) from which STRING was received.
PROCs `process-buffer' is `current-buffer' when this function is called."
  (unless (string= string "") ;; Ignore empty strings
    (save-match-data
      (let ((posn (if (eq (aref string 0) ?:)
                      (string-match " " string)
                    0))
            (msg (make-erc-response :unparsed string)))

        (setf (erc-response.sender msg)
              (if (eq posn 0)
                  erc-session-server
                (substring string 1 posn)))

        (setf (erc-response.command msg)
              (let* ((bposn (string-match "[^ \n]" string posn))
                     (eposn (string-match " " string bposn)))
                (setq posn (and eposn
                                (string-match "[^ \n]" string eposn)))
                (substring string bposn eposn)))

        (while (and posn
                    (not (eq (aref string posn) ?:)))
          (push (let* ((bposn posn)
                       (eposn (string-match " " string bposn)))
                  (setq posn (and eposn
                                  (string-match "[^ \n]" string eposn)))
                  (substring string bposn eposn))
                (erc-response.command-args msg)))
        (when posn
      (let ((str (substring string (1+ posn))))
        (push str (erc-response.command-args msg))))

    (setf (erc-response.contents msg)
          (first (erc-response.command-args msg)))

    (setf (erc-response.command-args msg)
          (nreverse (erc-response.command-args msg)))

    (erc-decode-parsed-server-response msg)

    (erc-handle-parsed-server-response proc msg)))))

(defun erc-decode-parsed-server-response (parsed-response)
  "Decode a pre-parsed PARSED-RESPONSE before it can be handled.

If there is a channel name in `erc-response.command-args', decode
`erc-response' according to this channel name and
`erc-encoding-coding-alist', or use `erc-server-coding-system'
for decoding."
  (let ((args (erc-response.command-args parsed-response))
        (decode-target nil)
        (decoded-args ()))
    (dolist (arg args nil)
      (when (string-match "^[#&].*" arg)
        (setq decode-target arg)))
    (when (stringp decode-target)
      (setq decode-target (erc-decode-string-from-target decode-target nil)))
    (setf (erc-response.unparsed parsed-response)
          (erc-decode-string-from-target
           (erc-response.unparsed parsed-response)
           decode-target))
    (setf (erc-response.sender parsed-response)
          (erc-decode-string-from-target
           (erc-response.sender parsed-response)
           decode-target))
    (setf (erc-response.command parsed-response)
          (erc-decode-string-from-target
           (erc-response.command parsed-response)
           decode-target))
    (dolist (arg (nreverse args) nil)
      (push (erc-decode-string-from-target arg decode-target)
            decoded-args))
    (setf (erc-response.command-args parsed-response) decoded-args)
    (setf (erc-response.contents parsed-response)
          (erc-decode-string-from-target
           (erc-response.contents parsed-response)
           decode-target))))

(defun erc-handle-parsed-server-response (process parsed-response)
  "Handle a pre-parsed PARSED-RESPONSE from PROCESS.

Hands off to helper functions via `erc-call-hooks'."
  (if (member (erc-response.command parsed-response)
              erc-server-prevent-duplicates)
      (let ((m (erc-response.unparsed parsed-response)))
        ;; duplicate supression
        (if (< (or (gethash m erc-server-duplicates) 0)
               (- (erc-current-time) erc-server-duplicate-timeout))
            (erc-call-hooks process parsed-response))
        (puthash m (erc-current-time) erc-server-duplicates))
    ;; Hand off to the relevant handler.
    (erc-call-hooks process parsed-response)))

(defun erc-get-hook (command)
  "Return the hook variable associated with COMMAND.

See also `erc-server-responses'."
  (gethash (format (if (numberp command) "%03i" "%s") command)
           erc-server-responses))

(defun erc-call-hooks (process message)
  "Call hooks associated with MESSAGE in PROCESS.

Finds hooks by looking in the `erc-server-responses' hashtable."
  (let ((hook (or (erc-get-hook (erc-response.command message))
                  'erc-default-server-functions)))
    (run-hook-with-args-until-success hook process message)
    (erc-with-server-buffer
      (run-hook-with-args 'erc-timer-hook (erc-current-time)))))

(add-hook 'erc-default-server-functions 'erc-handle-unknown-server-response)

(defun erc-handle-unknown-server-response (proc parsed)
  "Display unknown server response's message."
  (let ((line (concat (erc-response.sender parsed)
                      " "
                      (erc-response.command parsed)
                      " "
                      (mapconcat 'identity (erc-response.command-args parsed)
                                 " "))))
    (erc-display-message parsed 'notice proc line)))


(put 'define-erc-response-handler 'edebug-form-spec
     '(&define :name erc-response-handler
               (name &rest name)
               &optional sexp sexp def-body))

(defmacro* define-erc-response-handler ((name &rest aliases)
                                        &optional extra-fn-doc extra-var-doc
                                        &rest fn-body)
  "Define an ERC handler hook/function pair.
NAME is the response name as sent by the server (see the IRC RFC for
meanings).

This creates:
 - a hook variable `erc-server-NAME-functions' initialized to `erc-server-NAME'.
 - a function `erc-server-NAME' with body FN-BODY.

If ALIASES is non-nil, each alias in ALIASES is `defalias'ed to
`erc-server-NAME'.
Alias hook variables are created as `erc-server-ALIAS-functions' and
initialized to the same default value as `erc-server-NAME-functions'.

FN-BODY is the body of `erc-server-NAME' it may refer to the two
function arguments PROC and PARSED.

If EXTRA-FN-DOC is non-nil, it is inserted at the beginning of the
defined function's docstring.

If EXTRA-VAR-DOC is non-nil, it is inserted at the beginning of the
defined variable's docstring.

As an example:

  (define-erc-response-handler (311 WHOIS WI)
    \"Some non-generic function documentation.\"
    \"Some non-generic variable documentation.\"
    (do-stuff-with-whois proc parsed))

Would expand to:

  (prog2
      (defvar erc-server-311-functions 'erc-server-311
        \"Some non-generic variable documentation.

  Hook called upon receiving a 311 server response.
  Each function is called with two arguments, the process associated
  with the response and the parsed response.
  See also `erc-server-311'.\")

      (defun erc-server-311 (proc parsed)
        \"Some non-generic function documentation.

  Handler for a 311 server response.
  PROC is the server process which returned the response.
  PARSED is the actual response as an `erc-response' struct.
  If you want to add responses don't modify this function, but rather
  add things to `erc-server-311-functions' instead.\"
        (do-stuff-with-whois proc parsed))

    (puthash \"311\" 'erc-server-311-functions erc-server-responses)
    (puthash \"WHOIS\" 'erc-server-WHOIS-functions erc-server-responses)
    (puthash \"WI\" 'erc-server-WI-functions erc-server-responses)

    (defalias 'erc-server-WHOIS 'erc-server-311)
    (defvar erc-server-WHOIS-functions 'erc-server-311
      \"Some non-generic variable documentation.

  Hook called upon receiving a WHOIS server response.

  Each function is called with two arguments, the process associated
  with the response and the parsed response.  If the function returns
  non-nil, stop processing the hook.  Otherwise, continue.

  See also `erc-server-311'.\")

    (defalias 'erc-server-WI 'erc-server-311)
    (defvar erc-server-WI-functions 'erc-server-311
      \"Some non-generic variable documentation.

  Hook called upon receiving a WI server response.
  Each function is called with two arguments, the process associated
  with the response and the parsed response.  If the function returns
  non-nil, stop processing the hook.  Otherwise, continue.

  See also `erc-server-311'.\"))

\(fn (NAME &rest ALIASES) &optional EXTRA-FN-DOC EXTRA-VAR-DOC &rest FN-BODY)"
  (if (numberp name) (setq name (intern (format "%03i" name))))
  (setq aliases (mapcar (lambda (a)
                          (if (numberp a)
                              (format "%03i" a)
                            a))
                        aliases))
  (let* ((hook-name (intern (format "erc-server-%s-functions" name)))
         (fn-name (intern (format "erc-server-%s" name)))
         (hook-doc (format "%sHook called upon receiving a %%s server response.
Each function is called with two arguments, the process associated
with the response and the parsed response.  If the function returns
non-nil, stop processing the hook.  Otherwise, continue.

See also `%s'."
                           (if extra-var-doc
                               (concat extra-var-doc "\n\n")
                             "")
                           fn-name))
         (fn-doc (format "%sHandler for a %s server response.
PROC is the server process which returned the response.
PARSED is the actual response as an `erc-response' struct.
If you want to add responses don't modify this function, but rather
add things to `%s' instead."
                         (if extra-fn-doc
                             (concat extra-fn-doc "\n\n")
                           "")
                         name hook-name))
         (fn-alternates
          (loop for alias in aliases
                collect (intern (format "erc-server-%s" alias))))
         (var-alternates
          (loop for alias in aliases
                collect (intern (format "erc-server-%s-functions" alias)))))
    `(prog2
         ;; Normal hook variable.
         (defvar ,hook-name ',fn-name ,(format hook-doc name))
         ;; Handler function
         (defun ,fn-name (proc parsed)
           ,fn-doc
           ,@fn-body)

       ;; Make find-function and find-variable find them
       (put ',fn-name 'definition-name ',name)
       (put ',hook-name 'definition-name ',name)

       ;; Hashtable map of responses to hook variables
       ,@(loop for response in (cons name aliases)
               for var in (cons hook-name var-alternates)
               collect `(puthash ,(format "%s" response) ',var
                                 erc-server-responses))
       ;; Alternates.
       ;; Functions are defaliased, hook variables are defvared so we
       ;; can add hooks to one alias, but not another.
       ,@(loop for fn in fn-alternates
               for var in var-alternates
               for a in aliases
               nconc (list `(defalias ',fn ',fn-name)
                           `(defvar ,var ',fn-name ,(format hook-doc a))
                           `(put ',var 'definition-name ',hook-name))))))

(define-erc-response-handler (ERROR)
  "Handle an ERROR command from the server." nil
  (setq erc-server-error-occurred t)
  (erc-display-message
   parsed 'error nil 'ERROR
   ?s (erc-response.sender parsed) ?c (erc-response.contents parsed)))

(define-erc-response-handler (INVITE)
  "Handle invitation messages."
  nil
  (let ((target (first (erc-response.command-args parsed)))
        (chnl (erc-response.contents parsed)))
    (multiple-value-bind (nick login host)
        (erc-parse-user (erc-response.sender parsed))
      (setq erc-invitation chnl)
      (when (string= target (erc-current-nick))
        (erc-display-message
         parsed 'notice 'active
         'INVITE ?n nick ?u login ?h host ?c chnl)))))


(define-erc-response-handler (JOIN)
  "Handle join messages."
  nil
  (let ((chnl (erc-response.contents parsed))
        (buffer nil))
    (multiple-value-bind (nick login host)
        (erc-parse-user (erc-response.sender parsed))
      ;; strip the stupid combined JOIN facility (IRC 2.9)
      (if (string-match "^\\(.*\\)?\^g.*$" chnl)
          (setq chnl (match-string 1 chnl)))
      (save-excursion
        (let* ((str (cond
                     ;; If I have joined a channel
                     ((erc-current-nick-p nick)
                      (setq buffer (erc-open erc-session-server erc-session-port
                                             nick erc-session-user-full-name
                                             nil nil
                                             erc-default-recipients chnl
                                             erc-server-process))
                      (when buffer
                        (set-buffer buffer)
                        (erc-add-default-channel chnl)
                        (erc-server-send (format "MODE %s" chnl)))
                      (erc-with-buffer (chnl proc)
                        (erc-channel-begin-receiving-names))
                      (erc-update-mode-line)
                      (run-hooks 'erc-join-hook)
                      (erc-make-notice
                       (erc-format-message 'JOIN-you ?c chnl)))
                     (t
                      (setq buffer (erc-get-buffer chnl proc))
                      (erc-make-notice
                       (erc-format-message
                        'JOIN ?n nick ?u login ?h host ?c chnl))))))
          (when buffer (set-buffer buffer))
          (erc-update-channel-member chnl nick nick t nil nil host login)
          ;; on join, we want to stay in the new channel buffer
          ;;(set-buffer ob)
          (erc-display-message parsed nil buffer str))))))

(define-erc-response-handler (KICK)
  "Handle kick messages received from the server." nil
  (let* ((ch (first (erc-response.command-args parsed)))
         (tgt (second (erc-response.command-args parsed)))
         (reason (erc-trim-string (erc-response.contents parsed)))
         (buffer (erc-get-buffer ch proc)))
    (multiple-value-bind (nick login host)
        (erc-parse-user (erc-response.sender parsed))
      (erc-remove-channel-member buffer tgt)
      (cond
       ((string= tgt (erc-current-nick))
        (erc-display-message
         parsed 'notice buffer
         'KICK-you ?n nick ?u login ?h host ?c ch ?r reason)
        (run-hook-with-args 'erc-kick-hook buffer)
        (erc-with-buffer
            (buffer)
          (erc-remove-channel-users))
        (erc-delete-default-channel ch buffer)
        (erc-update-mode-line buffer))
       ((string= nick (erc-current-nick))
        (erc-display-message
         parsed 'notice buffer
         'KICK-by-you ?k tgt ?c ch ?r reason))
       (t (erc-display-message
             parsed 'notice buffer
             'KICK ?k tgt ?n nick ?u login ?h host ?c ch ?r reason))))))

(define-erc-response-handler (MODE)
  "Handle server mode changes." nil
  (let ((tgt (first (erc-response.command-args parsed)))
        (mode (mapconcat 'identity (cdr (erc-response.command-args parsed))
                         " ")))
    (multiple-value-bind (nick login host)
        (erc-parse-user (erc-response.sender parsed))
      (erc-log (format "MODE: %s -> %s: %s" nick tgt mode))
      ;; dirty hack
      (let ((buf (cond ((erc-channel-p tgt)
                        (erc-get-buffer tgt proc))
                       ((string= tgt (erc-current-nick)) nil)
                       ((erc-active-buffer) (erc-active-buffer))
                       (t (erc-get-buffer tgt)))))
        (with-current-buffer (or buf
                                 (current-buffer))
          (erc-update-modes tgt mode nick host login))
          (if (or (string= login "") (string= host ""))
              (erc-display-message parsed 'notice buf
                                   'MODE-nick ?n nick
                                   ?t tgt ?m mode)
            (erc-display-message parsed 'notice buf
                                 'MODE ?n nick ?u login
                                 ?h host ?t tgt ?m mode)))
      (erc-banlist-update proc parsed))))

(define-erc-response-handler (NICK)
  "Handle nick change messages." nil
  (let ((nn (erc-response.contents parsed))
        bufs)
    (multiple-value-bind (nick login host)
        (erc-parse-user (erc-response.sender parsed))
      (setq bufs (erc-buffer-list-with-nick nick proc))
      (erc-log (format "NICK: %s -> %s" nick nn))
      ;; if we had a query with this user, make sure future messages will be
      ;; sent to the correct nick. also add to bufs, since the user will want
      ;; to see the nick change in the query, and if it's a newly begun query,
      ;; erc-channel-users won't contain it
      (erc-buffer-filter
       (lambda ()
         (when (equal (erc-default-target) nick)
           (setq erc-default-recipients
                 (cons nn (cdr erc-default-recipients)))
           (rename-buffer nn)
           (erc-update-mode-line)
           (add-to-list 'bufs (current-buffer)))))
      (erc-update-user-nick nick nn host nil nil login)
      (cond
       ((string= nick (erc-current-nick))
        (add-to-list 'bufs (erc-server-buffer))
        (erc-set-current-nick nn)
        (erc-update-mode-line)
        (setq erc-nick-change-attempt-count 0)
        (setq erc-default-nicks (if (consp erc-nick) erc-nick (list erc-nick)))
        (erc-display-message
         parsed 'notice bufs
         'NICK-you ?n nick ?N nn)
        (run-hook-with-args 'erc-nick-changed-functions nn nick))
       (t
        (erc-handle-user-status-change 'nick (list nick login host) (list nn))
        (erc-display-message parsed 'notice bufs 'NICK ?n nick
                             ?u login ?h host ?N nn))))))

(define-erc-response-handler (PART)
  "Handle part messages." nil
  (let* ((chnl (first (erc-response.command-args parsed)))
         (reason (erc-trim-string (erc-response.contents parsed)))
         (buffer (erc-get-buffer chnl proc)))
    (multiple-value-bind (nick login host)
        (erc-parse-user (erc-response.sender parsed))
      (erc-remove-channel-member buffer nick)
      (erc-display-message parsed 'notice buffer
                           'PART ?n nick ?u login
                           ?h host ?c chnl ?r (or reason ""))
      (when (string= nick (erc-current-nick))
        (run-hook-with-args 'erc-part-hook buffer)
        (erc-with-buffer
            (buffer)
          (erc-remove-channel-users))
        (erc-delete-default-channel chnl buffer)
        (erc-update-mode-line buffer)
        (when erc-kill-buffer-on-part
          (kill-buffer buffer))))))

(define-erc-response-handler (PING)
  "Handle ping messages." nil
  (let ((pinger (first (erc-response.command-args parsed))))
    (erc-log (format "PING: %s" pinger))
    ;; ping response to the server MUST be forced, or you can lose big
    (erc-server-send (format "PONG :%s" pinger) t)
    (when erc-verbose-server-ping
      (erc-display-message
       parsed 'error proc
       'PING ?s (erc-time-diff erc-server-last-ping-time (erc-current-time))))
    (setq erc-server-last-ping-time (erc-current-time))))

(define-erc-response-handler (PONG)
  "Handle pong messages." nil
  (let ((time (string-to-number (erc-response.contents parsed))))
    (when (> time 0)
      (setq erc-server-lag (erc-time-diff time (erc-current-time)))
      (when erc-verbose-server-ping
        (erc-display-message
         parsed 'notice proc 'PONG
         ?h (first (erc-response.command-args parsed)) ?i erc-server-lag
         ?s (if (/= erc-server-lag 1) "s" "")))
      (erc-update-mode-line))))

(define-erc-response-handler (PRIVMSG NOTICE)
  nil nil
  (let ((sender-spec (erc-response.sender parsed))
        (cmd (erc-response.command parsed))
        (tgt (car (erc-response.command-args parsed)))
        (msg (erc-response.contents parsed)))
    (if (or (erc-ignored-user-p sender-spec)
            (erc-ignored-reply-p msg tgt proc))
        (when erc-minibuffer-ignored
          (message "Ignored %s from %s to %s" cmd sender-spec tgt))
      (let* ((sndr (erc-parse-user sender-spec))
             (nick (nth 0 sndr))
             (login (nth 1 sndr))
             (host (nth 2 sndr))
             (msgp (string= cmd "PRIVMSG"))
             (noticep (string= cmd "NOTICE"))
             ;; S.B. downcase *both* tgt and current nick
             (privp (erc-current-nick-p tgt))
             s buffer
             fnick)
        (setf (erc-response.contents parsed) msg)
        (setq buffer (erc-get-buffer (if privp nick tgt) proc))
        (when buffer
          (with-current-buffer buffer
            ;; update the chat partner info.  Add to the list if private
            ;; message.  We will accumulate private identities indefinitely
            ;; at this point.
            (erc-update-channel-member (if privp nick tgt) nick nick
                                       privp nil nil host login nil nil t)
            (let ((cdata (erc-get-channel-user nick)))
              (setq fnick (funcall erc-format-nick-function
                                   (car cdata) (cdr cdata))))))
        (cond
         ((erc-is-message-ctcp-p msg)
          (setq s (if msgp
                      (erc-process-ctcp-query proc parsed nick login host)
                    (erc-process-ctcp-reply proc parsed nick login host
                                            (match-string 1 msg)))))
         (t
          (setcar erc-server-last-peers nick)
          (setq s (erc-format-privmessage
                   (or fnick nick) msg
                   ;; If buffer is a query buffer,
                   ;; format the nick as for a channel.
                   (and (not (and buffer
                                  (erc-query-buffer-p buffer)
                                  erc-format-query-as-channel-p))
                        privp)
                   msgp))))
        (when s
          (if (and noticep privp)
              (progn
                (run-hook-with-args 'erc-echo-notice-always-hook
                                    s parsed buffer nick)
                (run-hook-with-args-until-success
                 'erc-echo-notice-hook s parsed buffer nick))
            (erc-display-message parsed nil buffer s)))
        (when (string= cmd "PRIVMSG")
          (erc-auto-query proc parsed))))))

;; FIXME: need clean way of specifiying extra hooks in
;; define-erc-response-handler.
(add-hook 'erc-server-PRIVMSG-functions 'erc-auto-query)

(define-erc-response-handler (QUIT)
  nil nil
  (let ((reason (erc-response.contents parsed))
        bufs)
    (multiple-value-bind (nick login host)
        (erc-parse-user (erc-response.sender parsed))
      (setq bufs (erc-buffer-list-with-nick nick proc))
      (erc-remove-user nick)
      (setq reason (erc-wash-quit-reason reason nick login host))
      (erc-display-message parsed 'notice bufs
                           'QUIT ?n nick ?u login
                           ?h host ?r reason))))

(define-erc-response-handler (TOPIC)
  nil nil
  (let* ((ch (first (erc-response.command-args parsed)))
         (topic (erc-trim-string (erc-response.contents parsed)))
         (time (format-time-string "%T %m/%d/%y" (current-time))))
    (multiple-value-bind (nick login host)
        (erc-parse-user (erc-response.sender parsed))
      (erc-update-channel-member ch nick nick nil nil nil host login)
      (erc-update-channel-topic ch (format "%s\C-o (%s, %s)" topic nick time))
      (erc-display-message parsed 'notice (erc-get-buffer ch proc)
                           'TOPIC ?n nick ?u login ?h host
                           ?c ch ?T topic))))

(define-erc-response-handler (WALLOPS)
  nil nil
  (let ((message (erc-response.contents parsed)))
    (multiple-value-bind (nick login host)
        (erc-parse-user (erc-response.sender parsed))
      (erc-display-message
       parsed 'notice nil
       'WALLOPS ?n nick ?m message))))

(define-erc-response-handler (001)
  "Set `erc-server-current-nick' to reflect server settings and display the welcome message."
  nil
  (erc-set-current-nick (first (erc-response.command-args parsed)))
  (erc-update-mode-line)                ; needed here?
  (setq erc-nick-change-attempt-count 0)
  (setq erc-default-nicks (if (consp erc-nick) erc-nick (list erc-nick)))
  (erc-display-message
   parsed 'notice 'active (erc-response.contents parsed)))

(define-erc-response-handler (MOTD 002 003 371 372 374 375)
  "Display the server's message of the day." nil
  (erc-handle-login)
  (erc-display-message
   parsed 'notice (if erc-server-connected 'active proc)
   (erc-response.contents parsed)))

(define-erc-response-handler (376 422)
  nil nil
  (erc-server-MOTD proc parsed)
  (erc-connection-established proc parsed))

(define-erc-response-handler (004)
  nil nil
  (multiple-value-bind (server-name server-version)
      (cdr (erc-response.command-args parsed))
    (setq erc-server-version server-version)
    (setq erc-server-announced-name server-name)
    (erc-update-mode-line-buffer (process-buffer proc))
    (erc-display-message
     parsed 'notice proc
     's004 ?s server-name ?v server-version
     ?U (fourth (erc-response.command-args parsed))
     ?C (fifth (erc-response.command-args parsed)))))

(define-erc-response-handler (005)
  "Set the variable `erc-server-parameters' and display the received message.

According to RFC 2812, suggests alternate servers on the network.
Many servers, however, use this code to show which parameters they have set,
for example, the network identifier, maximum allowed topic length, whether
certain commands are accepted and more.  See documentation for
`erc-server-parameters' for more information on the parameters sent.

A server may send more than one 005 message."
  nil
  (let ((line (mapconcat 'identity
                         (setf (erc-response.command-args parsed)
                               (cdr (erc-response.command-args parsed)))
                         " ")))
    (while (erc-response.command-args parsed)
      (let ((section (pop (erc-response.command-args parsed))))
        ;; fill erc-server-parameters
        (when (string-match "^\\([A-Z]+\\)\=\\(.*\\)$\\|^\\([A-Z]+\\)$"
                            section)
          (add-to-list 'erc-server-parameters
                       `(,(or (match-string 1 section)
                              (match-string 3 section))
                         .
                         ,(match-string 2 section))))))
    (erc-display-message parsed 'notice proc line)))

(define-erc-response-handler (221)
  nil nil
  (let* ((nick (first (erc-response.command-args parsed)))
         (modes (mapconcat 'identity
                           (cdr (erc-response.command-args parsed)) " ")))
    (erc-set-modes nick modes)
    (erc-display-message parsed 'notice 'active 's221 ?n nick ?m modes)))

(define-erc-response-handler (252)
  "Display the number of IRC operators online." nil
  (erc-display-message parsed 'notice 'active 's252
                       ?i (second (erc-response.command-args parsed))))

(define-erc-response-handler (253)
  "Display the number of unknown connections." nil
  (erc-display-message parsed 'notice 'active 's253
                       ?i (second (erc-response.command-args parsed))))

(define-erc-response-handler (254)
  "Display the number of channels formed." nil
  (erc-display-message parsed 'notice 'active 's254
                       ?i (second (erc-response.command-args parsed))))

(define-erc-response-handler (250 251 255 256 257 258 259 265 266 377 378)
  "Generic display of server messages as notices.

See `erc-display-server-message'." nil
  (erc-display-server-message proc parsed))

(define-erc-response-handler (275)
  "Display secure connection message." nil
  (multiple-value-bind (nick user message)
      (cdr (erc-response.command-args parsed))
    (erc-display-message
     parsed 'notice 'active 's275
     ?n nick
     ?m (mapconcat 'identity (cddr (erc-response.command-args parsed))
                   " "))))

(define-erc-response-handler (290)
  "Handle dancer-ircd CAPAB messages." nil nil)

(define-erc-response-handler (301)
  "AWAY notice." nil
  (erc-display-message parsed 'notice 'active 's301
                       ?n (second (erc-response.command-args parsed))
                       ?r (erc-response.contents parsed)))

(define-erc-response-handler (303)
  "ISON reply" nil
  (erc-display-message parsed 'notice 'active 's303
                       ?n (second (erc-response.command-args parsed))))

(define-erc-response-handler (305)
  "Return from AWAYness." nil
  (erc-process-away proc nil)
  (erc-display-message parsed 'notice 'active
                       's305 ?m (erc-response.contents parsed)))

(define-erc-response-handler (306)
  "Set AWAYness." nil
  (erc-process-away proc t)
  (erc-display-message parsed 'notice 'active
                       's306 ?m (erc-response.contents parsed)))

(define-erc-response-handler (307)
  "Display nick-identified message." nil
  (multiple-value-bind (nick user message)
      (cdr (erc-response.command-args parsed))
    (erc-display-message
     parsed 'notice 'active 's307
     ?n nick
     ?m (mapconcat 'identity (cddr (erc-response.command-args parsed))
                   " "))))

(define-erc-response-handler (311 314)
  "WHOIS/WHOWAS notices." nil
  (let ((fname (erc-response.contents parsed))
        (catalog-entry (intern (format "s%s" (erc-response.command parsed)))))
    (multiple-value-bind (nick user host)
        (cdr (erc-response.command-args parsed))
      (erc-update-user-nick nick nick host nil fname user)
      (erc-display-message
       parsed 'notice 'active catalog-entry
       ?n nick ?f fname ?u user ?h host))))

(define-erc-response-handler (312)
  nil nil
  (multiple-value-bind (nick server-host)
      (cdr (erc-response.command-args parsed))
    (erc-display-message
     parsed 'notice 'active 's312
     ?n nick ?s server-host ?c (erc-response.contents parsed))))

(define-erc-response-handler (313)
  "IRC Operator response in WHOIS." nil
  (erc-display-message
   parsed 'notice 'active 's313
   ?n (second (erc-response.command-args parsed))))

(define-erc-response-handler (315 318 323 369)
  ;; 315 - End of WHO
  ;; 318 - End of WHOIS list
  ;; 323 - End of channel LIST
  ;; 369 - End of WHOWAS
  nil nil
  (ignore proc parsed))

(define-erc-response-handler (317)
  "IDLE notice." nil
  (multiple-value-bind (nick seconds-idle on-since time)
      (cdr (erc-response.command-args parsed))
    (setq time (when on-since
                 (format-time-string "%T %Y/%m/%d"
                                     (erc-string-to-emacs-time on-since))))
    (erc-update-user-nick nick nick nil nil nil
                          (and time (format "on since %s" time)))
    (if time
        (erc-display-message
         parsed 'notice 'active 's317-on-since
         ?n nick ?i (erc-sec-to-time (string-to-number seconds-idle)) ?t time)
      (erc-display-message
       parsed 'notice 'active 's317
       ?n nick ?i (erc-sec-to-time (string-to-number seconds-idle))))))

(define-erc-response-handler (319)
  nil nil
  (erc-display-message
   parsed 'notice 'active 's319
   ?n (second (erc-response.command-args parsed))
   ?c (erc-response.contents parsed)))

(define-erc-response-handler (320)
  "Identified user in WHOIS." nil
  (erc-display-message
   parsed 'notice 'active 's320
   ?n (second (erc-response.command-args parsed))))

(define-erc-response-handler (321)
  "LIST header." nil
  (setq erc-channel-list nil)
  (erc-display-message parsed 'notice proc 's321))

(define-erc-response-handler (322)
  "LIST notice." nil
  (let ((topic (erc-response.contents parsed)))
    (multiple-value-bind (channel num-users)
        (cdr (erc-response.command-args parsed))
      (add-to-list 'erc-channel-list (list channel))
      (erc-update-channel-topic channel topic)
      (erc-display-message
       parsed 'notice proc 's322
       ?c channel ?u num-users ?t (or topic "")))))

(define-erc-response-handler (324)
  "Channel or nick modes." nil
  (let ((channel (second (erc-response.command-args parsed)))
        (modes (mapconcat 'identity (cddr (erc-response.command-args parsed))
                          " ")))
    (erc-set-modes channel modes)
    (erc-display-message
     parsed 'notice (erc-get-buffer channel proc)
     's324 ?c channel ?m modes)))

(define-erc-response-handler (329)
  "Channel creation date." nil
  (let ((channel (second (erc-response.command-args parsed)))
        (time (erc-string-to-emacs-time
               (third (erc-response.command-args parsed)))))
    (erc-display-message
     parsed 'notice (erc-get-buffer channel proc)
     's329 ?c channel ?t (format-time-string "%A %Y/%m/%d %X" time))))

(define-erc-response-handler (330)
  nil nil
  ;; FIXME: I don't know what the magic numbers mean.  Mummy, make
  ;; the magic numbers go away.
  ;; No seriously, I have no clue about the format of this command,
  ;; and don't sit on Quakenet, so can't test.  Originally we had:
  ;; nick == (aref parsed 3)
  ;; authaccount == (aref parsed 4)
  ;; authmsg == (aref parsed 5)
  ;; The guesses below are, well, just that. -- Lawrence 2004/05/10
  (let ((nick (second (erc-response.command-args parsed)))
        (authaccount (third (erc-response.command-args parsed)))
        (authmsg (erc-response.contents parsed)))
    (erc-display-message parsed 'notice 'active 's330
                         ?n nick ?a authmsg ?i authaccount)))

(define-erc-response-handler (331)
  "Channel topic." nil
  (let ((channel (second (erc-response.command-args parsed)))
        (topic (erc-response.contents parsed)))
    ;; FIXME: why don't we do anything with the topic? -- Lawrence 2004/05/10
    (erc-display-message parsed 'notice (erc-get-buffer channel proc)
                         's331 ?c channel)))

(define-erc-response-handler (332)
  "TOPIC notice." nil
  (let ((channel (second (erc-response.command-args parsed)))
        (topic (erc-response.contents parsed)))
    (erc-update-channel-topic channel topic)
    (erc-display-message parsed 'notice (erc-get-buffer channel proc)
                         's332 ?c channel ?T topic)))

(define-erc-response-handler (333)
  ;; Who set the topic, and when
  nil nil
  (multiple-value-bind (channel nick time)
      (cdr (erc-response.command-args parsed))
    (setq time (format-time-string "%T %Y/%m/%d"
                                   (erc-string-to-emacs-time time)))
    (erc-update-channel-topic channel
                              (format "\C-o (%s, %s)" nick time)
                              'append)
    (erc-display-message parsed 'notice (erc-get-buffer channel proc)
                         's333 ?c channel ?n nick ?t time)))

(define-erc-response-handler (341)
  "Let user know when an INVITE attempt has been sent successfully."
  nil
  (multiple-value-bind (nick channel)
      (cdr (erc-response.command-args parsed))
    (erc-display-message parsed 'notice (erc-get-buffer channel proc)
                         's341 ?n nick ?c channel)))

(define-erc-response-handler (352)
  "WHO notice." nil
  (multiple-value-bind (channel user host server nick away-flag)
      (cdr (erc-response.command-args parsed))
    (let ((full-name (erc-response.contents parsed))
          hopcount)
      (when (string-match "\\(^[0-9]+ \\)\\(.*\\)$" full-name)
        (setq hopcount (match-string 1 full-name))
        (setq full-name (match-string 2 full-name)))
      (erc-update-channel-member channel nick nick nil nil nil host
                                 user full-name)
      (erc-display-message parsed 'notice 'active 's352
                           ?c channel ?n nick ?a away-flag
                           ?u user ?h host ?f full-name))))

(define-erc-response-handler (353)
  "NAMES notice." nil
  (let ((channel (third (erc-response.command-args parsed)))
        (users (erc-response.contents parsed)))
    (erc-display-message parsed 'notice (or (erc-get-buffer channel proc)
                                            'active)
                         's353 ?c channel ?u users)
    (erc-with-buffer (channel proc)
      (erc-channel-receive-names users))))

(define-erc-response-handler (366)
  "End of NAMES." nil
  (erc-with-buffer ((second (erc-response.command-args parsed)) proc)
    (erc-channel-end-receiving-names)))

(define-erc-response-handler (367)
  "Channel ban list entries" nil
  (multiple-value-bind (channel banmask setter time)
      (cdr (erc-response.command-args parsed))
    ;; setter and time are not standard
    (if setter
        (erc-display-message parsed 'notice 'active 's367-set-by
                             ?c channel
                             ?b banmask
                             ?s setter
                             ?t (or time ""))
      (erc-display-message parsed 'notice 'active 's367
                           ?c channel
                           ?b banmask))))

(define-erc-response-handler (368)
  "End of channel ban list" nil
  (let ((channel (second (erc-response.command-args parsed))))
    (erc-display-message parsed 'notice 'active 's368
                         ?c channel)))

(define-erc-response-handler (379)
  "Forwarding to another channel." nil
  ;; FIXME: Yet more magic numbers in original code, I'm guessing this
  ;; command takes two arguments, and doesn't have any "contents". --
  ;; Lawrence 2004/05/10
  (multiple-value-bind (from to)
      (cdr (erc-response.command-args parsed))
    (erc-display-message parsed 'notice 'active
                         's379 ?c from ?f to)))

(define-erc-response-handler (391)
  "Server's time string" nil
  (erc-display-message
   parsed 'notice 'active
   's391 ?s (second (erc-response.command-args parsed))
   ?t (third (erc-response.command-args parsed))))

(define-erc-response-handler (401)
  "No such nick/channel." nil
  (let ((nick/channel (second (erc-response.command-args parsed))))
    (when erc-whowas-on-nosuchnick
      (erc-log (format "cmd: WHOWAS: %s" nick/channel))
      (erc-server-send (format "WHOWAS %s 1" nick/channel)))
    (erc-display-message parsed '(notice error) 'active
                         's401 ?n nick/channel)))

(define-erc-response-handler (403)
  "No such channel." nil
  (erc-display-message parsed '(notice error) 'active
                       's403 ?c (second (erc-response.command-args parsed))))

(define-erc-response-handler (404)
  "Cannot send to channel." nil
  (erc-display-message parsed '(notice error) 'active
                       's404 ?c (second (erc-response.command-args parsed))))


(define-erc-response-handler (405)
  ;; Can't join that many channels.
  nil nil
  (erc-display-message parsed '(notice error) 'active
                       's405 ?c (second (erc-response.command-args parsed))))

(define-erc-response-handler (406)
  ;; No such nick
  nil nil
  (erc-display-message parsed '(notice error) 'active
                       's406 ?n (second (erc-response.command-args parsed))))

(define-erc-response-handler (412)
  ;; No text to send
  nil nil
  (erc-display-message parsed '(notice error) 'active 's412))

(define-erc-response-handler (421)
  ;; Unknown command
  nil nil
  (erc-display-message parsed '(notice error) 'active 's421
                       ?c (second (erc-response.command-args parsed))))

(define-erc-response-handler (432)
  ;; Bad nick.
  nil nil
  (erc-display-message parsed '(notice error) 'active 's432
                       ?n (second (erc-response.command-args parsed))))

(define-erc-response-handler (433)
  ;; Login-time "nick in use"
  nil nil
  (erc-nickname-in-use (second (erc-response.command-args parsed))
                       "already in use"))

(define-erc-response-handler (437)
  ;; Nick temporarily unavailable (IRCnet)
  nil nil
  (let ((nick/channel (second (erc-response.command-args parsed))))
    (unless (erc-channel-p nick/channel)
      (erc-nickname-in-use nick/channel "temporarily unavailable"))))

(define-erc-response-handler (442)
  ;; Not on channel
  nil nil
  (erc-display-message parsed '(notice error) 'active 's442
                       ?c (second (erc-response.command-args parsed))))

(define-erc-response-handler (461)
  ;; Not enough params for command.
  nil nil
  (erc-display-message parsed '(notice error)  'active 's461
                       ?c (second (erc-response.command-args parsed))
                       ?m (erc-response.contents parsed)))

(define-erc-response-handler (465)
  "You are banned from this server." nil
  (setq erc-server-banned t)
  ;; show the server's message, as a reason might be provided
  (erc-display-error-notice
   parsed
   (erc-response.contents parsed)))

(define-erc-response-handler (474)
  "Banned from channel errors" nil
  (erc-display-message parsed '(notice error) nil
                       (intern (format "s%s"
                                       (erc-response.command parsed)))
                       ?c (second (erc-response.command-args parsed))))

(define-erc-response-handler (475)
  "Channel key needed." nil
  (erc-display-message parsed '(notice error) nil 's475
                       ?c (second (erc-response.command-args parsed)))
  (when erc-prompt-for-channel-key
    (let ((channel (second (erc-response.command-args parsed)))
          (key (read-from-minibuffer
                (format "Channel %s is mode +k.  Enter key (RET to cancel): "
                        (second (erc-response.command-args parsed))))))
      (when (and key (> (length key) 0))
          (erc-cmd-JOIN channel key)))))

(define-erc-response-handler (477)
  nil nil
  (let ((channel (second (erc-response.command-args parsed)))
        (message (erc-response.contents parsed)))
    (erc-display-message parsed 'notice (erc-get-buffer channel proc)
                         (format "%s: %s" channel message))))

(define-erc-response-handler (482)
  nil nil
  (let ((channel (second (erc-response.command-args parsed)))
        (message (erc-response.contents parsed)))
    (erc-display-message parsed '(error notice) 'active 's482
                         ?c channel ?m message)))

(define-erc-response-handler (431 445 446 451 462 463 464 481 483 484 485
                                  491 501 502)
  ;; 431 - No nickname given
  ;; 445 - SUMMON has been disabled
  ;; 446 - USERS has been disabled
  ;; 451 - You have not registered
  ;; 462 - Unauthorized command (already registered)
  ;; 463 - Your host isn't among the privileged
  ;; 464 - Password incorrect
  ;; 481 - Need IRCop privileges
  ;; 483 - You can't kill a server!
  ;; 484 - Your connection is restricted!
  ;; 485 - You're not the original channel operator
  ;; 491 - No O-lines for your host
  ;; 501 - Unknown MODE flag
  ;; 502 - Cannot change mode for other users
  nil nil
  (erc-display-error-notice
   parsed
   (intern (format "s%s" (erc-response.command parsed)))))

;; FIXME: These are yet to be implemented, they're just stubs for now
;; -- Lawrence 2004/05/12

;; response numbers left here for reference

;; (define-erc-response-handler (323 364 365 381 382 392 393 394 395
;;                               200 201 202 203 204 205 206 208 209 211 212 213
;;                               214 215 216 217 218 219 241 242 243 244 249 261
;;                               262 302 342 351 402 407 409 411 413 414 415
;;                               423 424 436 441 443 444 467 471 472 473 KILL)
;;   nil nil
;;   (ignore proc parsed))

(provide 'erc-backend)

;;; erc-backend.el ends here
;; Local Variables:
;; indent-tabs-mode: nil
;; End:

;; arch-tag: a64e6bb7-a780-4efd-8f98-083b18c7c84a