/* -*- c-file-style: "java"; indent-tabs-mode: nil; tab-width: 4; fill-column: 78 -*-
 * Copyright 2007 Google Inc.
 *
 * This program 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 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 this program; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301,
 * USA.
*/

/* Authors: Manos Renieris, Fergus Henderson */

#include <config.h>

#include <string.h>
#include <stdlib.h>
#include <stdio.h>

#include <sys/stat.h>
#include <sys/types.h>
#include <sys/socket.h>
#include <sys/un.h>

#include <netinet/in.h>
#include <netinet/tcp.h>

#include "distcc.h"
#include "trace.h"
#include "rpc.h"
#include "clinet.h"
#include "exitcode.h"
#include "util.h"
#include "hosts.h"
#include "include_server_if.h"

static int dcc_count_slashes(const char *path);
static int dcc_count_leading_dotdots(const char *path);
static int dcc_categorize_file(const char *include_server_filename);

/* The include server puts all files in its own special directory,
 * which is n path components long, where n = INCLUDE_SERVER_DIR_DEPTH
 */
#define INCLUDE_SERVER_DIR_DEPTH 3

/** Talks to the include server, over the AF_UNIX socket specified
 * in env variable INCLUDE_SERVER_PORT. If all goes well,
 * it returns the array of files in @p files and returns 0;
 * if anything goes wrong, it returns a non-zero value.
 */

int dcc_talk_to_include_server(char **argv, char ***files)
{
    char *include_server_port;
    int fd;
    struct sockaddr_un sa;

    int ret;
    char *stub;

    /* for testing purposes, if INCLUDE_SERVER_STUB is set,
       use its value rather than the include server */
    stub = getenv("INCLUDE_SERVER_STUB");
    if (stub != NULL) {
        ret = dcc_tokenize_string(stub, files);
        rs_log_warning("INCLUDE_SERVER_STUB is set to '%s'; "
                       "ignoring include server",
                       dcc_argv_tostr(*files));
        return ret;
    }

    include_server_port = getenv("INCLUDE_SERVER_PORT");
    if (include_server_port == NULL) {
        rs_log_warning("INCLUDE_SERVER_PORT not set - "
                       "did you forget to run under 'pump'?");
        return 1;
    }

    if (strlen(include_server_port) >= ((int)sizeof(sa.sun_path) - 1)) {
        rs_log_warning("$INCLUDE_SERVER_PORT is longer than %ld characters",
                       ((long) sizeof(sa.sun_path) - 1));
        return 1;
    }

    strcpy(sa.sun_path, include_server_port);
    sa.sun_family = AF_UNIX;

    if (dcc_connect_by_addr((struct sockaddr *) &sa, sizeof(sa), &fd))
        return 1;

    /* TODO? switch include_server to use more appropriate token names */
    if (dcc_x_cwd(fd) ||
        dcc_x_argv(fd, "ARGC", "ARGV", argv) ||
        dcc_r_argv(fd, "ARGC", "ARGV", files)) {
        rs_log_warning("failed to talk to include server '%s'",
                       include_server_port);
        dcc_close(fd);
        /* We are failing anyway, so we can ignore
           the return value of dcc_close() */
        return 1;
    }

    if (dcc_close(fd)) {
        return 1;
    }

    if (dcc_argv_len(*files) == 0) {
        rs_log_warning("include server gave up analyzing");
        return 1;
    }
    return 0;
}

/* The include server puts all files in its own special directory,
 * which is n path components long, where n = INCLUDE_SERVER_DIR_DEPTH
 * The original file should drop those components.
 * Also, we need to strip the .lzo and .lzo.abs suffixes.
 */
int dcc_get_original_fname(const char *fname, char **original_fname)
{
    int i;
    char *work, *alloced_work, *extension;

    alloced_work = work = strdup(fname);
    if (work == NULL)
        return EXIT_OUT_OF_MEMORY;

    /* Since all names are supposed to be absolute, they start with
     * a slash. We are trying to drop INCLUDE_SERVER_DIR_DEPTH path
     * components, so we start right after the first slash, and we look
     * for a slash, and then we skip that slash and look for a slash, etc.
     */

    for (i = 0; i < INCLUDE_SERVER_DIR_DEPTH; ++i) {
        work = strchr(work + 1, '/');
        if (work == NULL) {
            return 1;
        }
    }

    /* This code removes an abs extension if it's there, and
       then a .lzo extension if it's there. As a result
       a .lzo.abs extension is removed, but not a .abs.lzo
       extension.
     */
    extension = dcc_find_extension(work);
    if (extension && (strcmp(extension, ".abs") == 0)) {
        *extension = '\0';
    }
    extension = dcc_find_extension(work);
    if (extension && (strcmp(extension, ".lzo") == 0)) {
        *extension = '\0';
    }

    *original_fname = strdup(work);
    if (*original_fname == NULL) {
        free(alloced_work);
        return EXIT_OUT_OF_MEMORY;
    }
    free(alloced_work);
    return 0;
}

/**
 * This implements the --scan_includes option.
 * Talks to the include server, and prints the results to stdout.
 */
int
dcc_approximate_includes(struct dcc_hostdef *host, char **argv)
{
    char **files;
    int i;
    int ret;

    if (host->cpp_where != DCC_CPP_ON_SERVER) {
        rs_log_error("'--scan_includes' specified, "
                     "but distcc wouldn't have used include server "
                     "(make sure hosts list includes ',cpp' option?)");
        return EXIT_DISTCC_FAILED;
        //return 0;
    }

    if ((ret = dcc_talk_to_include_server(argv, &files))) {
        rs_log_error("failed to get includes from include server");
        return ret;
    }

    for (i = 0; files[i]; i++) {
        if ((ret = dcc_categorize_file(files[i])))
            return ret;
    }

    return 0;
}

/*
 * A subroutine of dcc_approximate_includes().
 * Take a filename output from the include server,
 * convert the filename back so that it refers to the original source tree
 * (as opposed to the include server's mirror tree),
 * categorize it as SYSTEMDIR, DIRECTORY, SYMLINK, or FILE,
 * and print the category and original name to stdout.
 * For SYMLINKs, also print out what the symlink points to.
 */
static int
dcc_categorize_file(const char *include_server_filename) {
    char *filename;
    int is_symlink = 0;
    int is_forced_directory = 0;
    int is_system_include_directory = 0;
    char link_target[MAXPATHLEN + 1];
    int ret;

    if ((ret = dcc_is_link(include_server_filename, &is_symlink)))
        return ret;

    if (is_symlink)
        if ((ret = dcc_read_link(include_server_filename, link_target)))
            return ret;

    if ((ret = dcc_get_original_fname(include_server_filename, &filename))) {
        rs_log_error("dcc_get_original_fname failed");
        return ret;
    }

    if (str_endswith("/forcing_technique_271828", filename)) {
        /* Replace "<foo>/forcing_technique_271818" with "<foo>". */
        filename[strlen(filename) - strlen("/forcing_technique_271828")]
            = '\0';
        is_forced_directory = 1;
    }

    if (is_symlink) {
        int leading_dotdots = dcc_count_leading_dotdots(link_target);
        is_system_include_directory =
            leading_dotdots > 0 &&
            leading_dotdots > dcc_count_slashes(filename) &&
            strcmp(link_target + 3 * leading_dotdots - 1, filename) == 0;
    }

    printf("%-9s %s\n", is_system_include_directory ? "SYSTEMDIR" :
                        is_forced_directory         ? "DIRECTORY" :
                        is_symlink                  ? "SYMLINK" :
                                                      "FILE",
                        filename);

    return 0;
}

/* Count the number of slashes in a path. */
static int
dcc_count_slashes(const char *path)
{
    int i;
    int count = 0;
    for (i = 0; path[i]; i++) {
        if (path[i] == '/')
            count++;
    }
    return count;
}

/* Count the number of leading "../" references in a path. */
static int
dcc_count_leading_dotdots(const char *path)
{
    int count = 0;
    while (str_startswith("../", path)) {
        path += 3;
        count++;
    }
    return count;
}