from sqlalchemy import MetaData, Table, Column, String, Unicode, Integer, \
    create_engine
from sqlalchemy.testing import fixtures, AssertsExecutionResults, profiling
from sqlalchemy import testing
from sqlalchemy.testing import eq_
from sqlalchemy.util import u
from sqlalchemy.engine.result import RowProxy
import sys

NUM_FIELDS = 10
NUM_RECORDS = 1000

t = t2 = metadata = None


class ResultSetTest(fixtures.TestBase, AssertsExecutionResults):
    __backend__ = True

    @classmethod
    def setup_class(cls):
        global t, t2, metadata
        metadata = MetaData(testing.db)
        t = Table('table', metadata, *[Column('field%d' % fnum, String(50))
                                       for fnum in range(NUM_FIELDS)])
        t2 = Table(
            'table2', metadata, *
            [Column('field%d' % fnum, Unicode(50))
             for fnum in range(NUM_FIELDS)])

    def setup(self):
        metadata.create_all()
        t.insert().execute([dict(('field%d' % fnum, u('value%d' % fnum))
                                 for fnum in range(NUM_FIELDS)) for r_num in
                            range(NUM_RECORDS)])
        t2.insert().execute([dict(('field%d' % fnum, u('value%d' % fnum))
                                  for fnum in range(NUM_FIELDS)) for r_num in
                             range(NUM_RECORDS)])

        # warm up type caches
        t.select().execute().fetchall()
        t2.select().execute().fetchall()

    def teardown(self):
        metadata.drop_all()

    @profiling.function_call_count()
    def test_string(self):
        [tuple(row) for row in t.select().execute().fetchall()]

    @profiling.function_call_count()
    def test_unicode(self):
        [tuple(row) for row in t2.select().execute().fetchall()]

    @profiling.function_call_count()
    def test_raw_string(self):
        stmt = 'SELECT %s FROM "table"' % (
            ", ".join("field%d" % fnum for fnum in range(NUM_FIELDS))
        )
        [tuple(row) for row in testing.db.execute(stmt).fetchall()]

    @profiling.function_call_count()
    def test_raw_unicode(self):
        stmt = "SELECT %s FROM table2" % (
            ", ".join("field%d" % fnum for fnum in range(NUM_FIELDS))
        )
        [tuple(row) for row in testing.db.execute(stmt).fetchall()]

    def test_contains_doesnt_compile(self):
        row = t.select().execute().first()
        c1 = Column('some column', Integer) + \
            Column("some other column", Integer)

        @profiling.function_call_count()
        def go():
            c1 in row
        go()


class ExecutionTest(fixtures.TestBase):
    __backend__ = True

    def test_minimal_connection_execute(self):
        # create an engine without any instrumentation.
        e = create_engine('sqlite://')
        c = e.connect()
        # ensure initial connect activities complete
        c.execute("select 1")

        @profiling.function_call_count()
        def go():
            c.execute("select 1")
        try:
            go()
        finally:
            c.close()

    def test_minimal_engine_execute(self, variance=0.10):
        # create an engine without any instrumentation.
        e = create_engine('sqlite://')
        # ensure initial connect activities complete
        e.execute("select 1")

        @profiling.function_call_count()
        def go():
            e.execute("select 1")
        go()


class RowProxyTest(fixtures.TestBase):
    __requires__ = 'cpython',
    __backend__ = True

    def _rowproxy_fixture(self, keys, processors, row):
        class MockMeta(object):

            def __init__(self):
                pass

        metadata = MockMeta()

        keymap = {}
        for index, (keyobjs, processor, values) in \
                enumerate(list(zip(keys, processors, row))):
            for key in keyobjs:
                keymap[key] = (processor, key, index)
            keymap[index] = (processor, key, index)
        return RowProxy(metadata, row, processors, keymap)

    def _test_getitem_value_refcounts(self, seq_factory):
        col1, col2 = object(), object()

        def proc1(value):
            return value
        value1, value2 = "x", "y"
        row = self._rowproxy_fixture(
            [(col1, "a"), (col2, "b")],
            [proc1, None],
            seq_factory([value1, value2])
        )

        v1_refcount = sys.getrefcount(value1)
        v2_refcount = sys.getrefcount(value2)
        for i in range(10):
            row[col1]
            row["a"]
            row[col2]
            row["b"]
            row[0]
            row[1]
            row[0:2]
        eq_(sys.getrefcount(value1), v1_refcount)
        eq_(sys.getrefcount(value2), v2_refcount)

    def test_value_refcounts_pure_tuple(self):
        self._test_getitem_value_refcounts(tuple)

    def test_value_refcounts_custom_seq(self):
        class CustomSeq(object):

            def __init__(self, data):
                self.data = data

            def __getitem__(self, item):
                return self.data[item]

            def __iter__(self):
                return iter(self.data)
        self._test_getitem_value_refcounts(CustomSeq)