# testing/assertions.py
# Copyright (C) 2005-2019 the SQLAlchemy authors and contributors
# <see AUTHORS file>
#
# This module is part of SQLAlchemy and is released under
# the MIT License: http://www.opensource.org/licenses/mit-license.php

from __future__ import absolute_import

import contextlib
import re
import warnings

from . import assertsql
from . import config
from . import mock
from . import util as testutil
from .exclusions import db_spec
from .util import fail
from .. import exc as sa_exc
from .. import orm
from .. import pool
from .. import schema
from .. import types as sqltypes
from .. import util
from ..engine import default
from ..engine import url
from ..util import compat
from ..util import decorator


def expect_warnings(*messages, **kw):
    """Context manager which expects one or more warnings.

    With no arguments, squelches all SAWarnings emitted via
    sqlalchemy.util.warn and sqlalchemy.util.warn_limited.   Otherwise
    pass string expressions that will match selected warnings via regex;
    all non-matching warnings are sent through.

    The expect version **asserts** that the warnings were in fact seen.

    Note that the test suite sets SAWarning warnings to raise exceptions.

    """
    return _expect_warnings(sa_exc.SAWarning, messages, **kw)


@contextlib.contextmanager
def expect_warnings_on(db, *messages, **kw):
    """Context manager which expects one or more warnings on specific
    dialects.

    The expect version **asserts** that the warnings were in fact seen.

    """
    spec = db_spec(db)

    if isinstance(db, util.string_types) and not spec(config._current):
        yield
    else:
        with expect_warnings(*messages, **kw):
            yield


def emits_warning(*messages):
    """Decorator form of expect_warnings().

    Note that emits_warning does **not** assert that the warnings
    were in fact seen.

    """

    @decorator
    def decorate(fn, *args, **kw):
        with expect_warnings(assert_=False, *messages):
            return fn(*args, **kw)

    return decorate


def expect_deprecated(*messages, **kw):
    return _expect_warnings(sa_exc.SADeprecationWarning, messages, **kw)


def emits_warning_on(db, *messages):
    """Mark a test as emitting a warning on a specific dialect.

    With no arguments, squelches all SAWarning failures.  Or pass one or more
    strings; these will be matched to the root of the warning description by
    warnings.filterwarnings().

    Note that emits_warning_on does **not** assert that the warnings
    were in fact seen.

    """

    @decorator
    def decorate(fn, *args, **kw):
        with expect_warnings_on(db, assert_=False, *messages):
            return fn(*args, **kw)

    return decorate


def uses_deprecated(*messages):
    """Mark a test as immune from fatal deprecation warnings.

    With no arguments, squelches all SADeprecationWarning failures.
    Or pass one or more strings; these will be matched to the root
    of the warning description by warnings.filterwarnings().

    As a special case, you may pass a function name prefixed with //
    and it will be re-written as needed to match the standard warning
    verbiage emitted by the sqlalchemy.util.deprecated decorator.

    Note that uses_deprecated does **not** assert that the warnings
    were in fact seen.

    """

    @decorator
    def decorate(fn, *args, **kw):
        with expect_deprecated(*messages, assert_=False):
            return fn(*args, **kw)

    return decorate


@contextlib.contextmanager
def _expect_warnings(
    exc_cls, messages, regex=True, assert_=True, py2konly=False
):

    if regex:
        filters = [re.compile(msg, re.I | re.S) for msg in messages]
    else:
        filters = messages

    seen = set(filters)

    real_warn = warnings.warn

    def our_warn(msg, *arg, **kw):
        if isinstance(msg, exc_cls):
            exception = msg
            msg = str(exception)
        elif arg:
            exception = arg[0]
        else:
            exception = None
        if not exception or not issubclass(exception, exc_cls):
            return real_warn(msg, *arg, **kw)

        if not filters:
            return

        for filter_ in filters:
            if (regex and filter_.match(msg)) or (
                not regex and filter_ == msg
            ):
                seen.discard(filter_)
                break
        else:
            real_warn(msg, *arg, **kw)

    with mock.patch("warnings.warn", our_warn):
        yield

    if assert_ and (not py2konly or not compat.py3k):
        assert not seen, "Warnings were not seen: %s" % ", ".join(
            "%r" % (s.pattern if regex else s) for s in seen
        )


def global_cleanup_assertions():
    """Check things that have to be finalized at the end of a test suite.

    Hardcoded at the moment, a modular system can be built here
    to support things like PG prepared transactions, tables all
    dropped, etc.

    """
    _assert_no_stray_pool_connections()


_STRAY_CONNECTION_FAILURES = 0


def _assert_no_stray_pool_connections():
    global _STRAY_CONNECTION_FAILURES

    # lazy gc on cPython means "do nothing."  pool connections
    # shouldn't be in cycles, should go away.
    testutil.lazy_gc()

    # however, once in awhile, on an EC2 machine usually,
    # there's a ref in there.  usually just one.
    if pool._refs:

        # OK, let's be somewhat forgiving.
        _STRAY_CONNECTION_FAILURES += 1

        print(
            "Encountered a stray connection in test cleanup: %s"
            % str(pool._refs)
        )
        # then do a real GC sweep.   We shouldn't even be here
        # so a single sweep should really be doing it, otherwise
        # there's probably a real unreachable cycle somewhere.
        testutil.gc_collect()

    # if we've already had two of these occurrences, or
    # after a hard gc sweep we still have pool._refs?!
    # now we have to raise.
    if pool._refs:
        err = str(pool._refs)

        # but clean out the pool refs collection directly,
        # reset the counter,
        # so the error doesn't at least keep happening.
        pool._refs.clear()
        _STRAY_CONNECTION_FAILURES = 0
        warnings.warn(
            "Stray connection refused to leave " "after gc.collect(): %s" % err
        )
    elif _STRAY_CONNECTION_FAILURES > 10:
        assert False, "Encountered more than 10 stray connections"
        _STRAY_CONNECTION_FAILURES = 0


def eq_regex(a, b, msg=None):
    assert re.match(b, a), msg or "%r !~ %r" % (a, b)


def eq_(a, b, msg=None):
    """Assert a == b, with repr messaging on failure."""
    assert a == b, msg or "%r != %r" % (a, b)


def ne_(a, b, msg=None):
    """Assert a != b, with repr messaging on failure."""
    assert a != b, msg or "%r == %r" % (a, b)


def le_(a, b, msg=None):
    """Assert a <= b, with repr messaging on failure."""
    assert a <= b, msg or "%r != %r" % (a, b)


def is_instance_of(a, b, msg=None):
    assert isinstance(a, b), msg or "%r is not an instance of %r" % (a, b)


def is_true(a, msg=None):
    is_(a, True, msg=msg)


def is_false(a, msg=None):
    is_(a, False, msg=msg)


def is_(a, b, msg=None):
    """Assert a is b, with repr messaging on failure."""
    assert a is b, msg or "%r is not %r" % (a, b)


def is_not_(a, b, msg=None):
    """Assert a is not b, with repr messaging on failure."""
    assert a is not b, msg or "%r is %r" % (a, b)


def in_(a, b, msg=None):
    """Assert a in b, with repr messaging on failure."""
    assert a in b, msg or "%r not in %r" % (a, b)


def not_in_(a, b, msg=None):
    """Assert a in not b, with repr messaging on failure."""
    assert a not in b, msg or "%r is in %r" % (a, b)


def startswith_(a, fragment, msg=None):
    """Assert a.startswith(fragment), with repr messaging on failure."""
    assert a.startswith(fragment), msg or "%r does not start with %r" % (
        a,
        fragment,
    )


def eq_ignore_whitespace(a, b, msg=None):
    a = re.sub(r"^\s+?|\n", "", a)
    a = re.sub(r" {2,}", " ", a)
    b = re.sub(r"^\s+?|\n", "", b)
    b = re.sub(r" {2,}", " ", b)

    assert a == b, msg or "%r != %r" % (a, b)


def assert_raises(except_cls, callable_, *args, **kw):
    try:
        callable_(*args, **kw)
        success = False
    except except_cls:
        success = True

    # assert outside the block so it works for AssertionError too !
    assert success, "Callable did not raise an exception"


def assert_raises_return(except_cls, callable_, *args, **kw):
    ret_err = None
    try:
        callable_(*args, **kw)
        success = False
    except except_cls as err:
        success = True
        ret_err = err

    # assert outside the block so it works for AssertionError too !
    assert success, "Callable did not raise an exception"
    return ret_err


def assert_raises_message(except_cls, msg, callable_, *args, **kwargs):
    try:
        callable_(*args, **kwargs)
        assert False, "Callable did not raise an exception"
    except except_cls as e:
        assert re.search(msg, util.text_type(e), re.UNICODE), "%r !~ %s" % (
            msg,
            e,
        )
        print(util.text_type(e).encode("utf-8"))


class AssertsCompiledSQL(object):
    def assert_compile(
        self,
        clause,
        result,
        params=None,
        checkparams=None,
        dialect=None,
        checkpositional=None,
        check_prefetch=None,
        use_default_dialect=False,
        allow_dialect_select=False,
        literal_binds=False,
        schema_translate_map=None,
    ):
        if use_default_dialect:
            dialect = default.DefaultDialect()
        elif allow_dialect_select:
            dialect = None
        else:
            if dialect is None:
                dialect = getattr(self, "__dialect__", None)

            if dialect is None:
                dialect = config.db.dialect
            elif dialect == "default":
                dialect = default.DefaultDialect()
            elif dialect == "default_enhanced":
                dialect = default.StrCompileDialect()
            elif isinstance(dialect, util.string_types):
                dialect = url.URL(dialect).get_dialect()()

        kw = {}
        compile_kwargs = {}

        if schema_translate_map:
            kw["schema_translate_map"] = schema_translate_map

        if params is not None:
            kw["column_keys"] = list(params)

        if literal_binds:
            compile_kwargs["literal_binds"] = True

        if isinstance(clause, orm.Query):
            context = clause._compile_context()
            context.statement.use_labels = True
            clause = context.statement
        elif isinstance(clause, orm.persistence.BulkUD):
            with mock.patch.object(clause, "_execute_stmt") as stmt_mock:
                clause.exec_()
                clause = stmt_mock.mock_calls[0][1][0]

        if compile_kwargs:
            kw["compile_kwargs"] = compile_kwargs

        c = clause.compile(dialect=dialect, **kw)

        param_str = repr(getattr(c, "params", {}))

        if util.py3k:
            param_str = param_str.encode("utf-8").decode("ascii", "ignore")
            print(
                ("\nSQL String:\n" + util.text_type(c) + param_str).encode(
                    "utf-8"
                )
            )
        else:
            print(
                "\nSQL String:\n"
                + util.text_type(c).encode("utf-8")
                + param_str
            )

        cc = re.sub(r"[\n\t]", "", util.text_type(c))

        eq_(cc, result, "%r != %r on dialect %r" % (cc, result, dialect))

        if checkparams is not None:
            eq_(c.construct_params(params), checkparams)
        if checkpositional is not None:
            p = c.construct_params(params)
            eq_(tuple([p[x] for x in c.positiontup]), checkpositional)
        if check_prefetch is not None:
            eq_(c.prefetch, check_prefetch)


class ComparesTables(object):
    def assert_tables_equal(self, table, reflected_table, strict_types=False):
        assert len(table.c) == len(reflected_table.c)
        for c, reflected_c in zip(table.c, reflected_table.c):
            eq_(c.name, reflected_c.name)
            assert reflected_c is reflected_table.c[c.name]
            eq_(c.primary_key, reflected_c.primary_key)
            eq_(c.nullable, reflected_c.nullable)

            if strict_types:
                msg = "Type '%s' doesn't correspond to type '%s'"
                assert isinstance(reflected_c.type, type(c.type)), msg % (
                    reflected_c.type,
                    c.type,
                )
            else:
                self.assert_types_base(reflected_c, c)

            if isinstance(c.type, sqltypes.String):
                eq_(c.type.length, reflected_c.type.length)

            eq_(
                {f.column.name for f in c.foreign_keys},
                {f.column.name for f in reflected_c.foreign_keys},
            )
            if c.server_default:
                assert isinstance(
                    reflected_c.server_default, schema.FetchedValue
                )

        assert len(table.primary_key) == len(reflected_table.primary_key)
        for c in table.primary_key:
            assert reflected_table.primary_key.columns[c.name] is not None

    def assert_types_base(self, c1, c2):
        assert c1.type._compare_type_affinity(c2.type), (
            "On column %r, type '%s' doesn't correspond to type '%s'"
            % (c1.name, c1.type, c2.type)
        )


class AssertsExecutionResults(object):
    def assert_result(self, result, class_, *objects):
        result = list(result)
        print(repr(result))
        self.assert_list(result, class_, objects)

    def assert_list(self, result, class_, list_):
        self.assert_(
            len(result) == len(list_),
            "result list is not the same size as test list, "
            + "for class "
            + class_.__name__,
        )
        for i in range(0, len(list_)):
            self.assert_row(class_, result[i], list_[i])

    def assert_row(self, class_, rowobj, desc):
        self.assert_(
            rowobj.__class__ is class_, "item class is not " + repr(class_)
        )
        for key, value in desc.items():
            if isinstance(value, tuple):
                if isinstance(value[1], list):
                    self.assert_list(getattr(rowobj, key), value[0], value[1])
                else:
                    self.assert_row(value[0], getattr(rowobj, key), value[1])
            else:
                self.assert_(
                    getattr(rowobj, key) == value,
                    "attribute %s value %s does not match %s"
                    % (key, getattr(rowobj, key), value),
                )

    def assert_unordered_result(self, result, cls, *expected):
        """As assert_result, but the order of objects is not considered.

        The algorithm is very expensive but not a big deal for the small
        numbers of rows that the test suite manipulates.
        """

        class immutabledict(dict):
            def __hash__(self):
                return id(self)

        found = util.IdentitySet(result)
        expected = {immutabledict(e) for e in expected}

        for wrong in util.itertools_filterfalse(
            lambda o: isinstance(o, cls), found
        ):
            fail(
                'Unexpected type "%s", expected "%s"'
                % (type(wrong).__name__, cls.__name__)
            )

        if len(found) != len(expected):
            fail(
                'Unexpected object count "%s", expected "%s"'
                % (len(found), len(expected))
            )

        NOVALUE = object()

        def _compare_item(obj, spec):
            for key, value in spec.items():
                if isinstance(value, tuple):
                    try:
                        self.assert_unordered_result(
                            getattr(obj, key), value[0], *value[1]
                        )
                    except AssertionError:
                        return False
                else:
                    if getattr(obj, key, NOVALUE) != value:
                        return False
            return True

        for expected_item in expected:
            for found_item in found:
                if _compare_item(found_item, expected_item):
                    found.remove(found_item)
                    break
            else:
                fail(
                    "Expected %s instance with attributes %s not found."
                    % (cls.__name__, repr(expected_item))
                )
        return True

    def sql_execution_asserter(self, db=None):
        if db is None:
            from . import db as db

        return assertsql.assert_engine(db)

    def assert_sql_execution(self, db, callable_, *rules):
        with self.sql_execution_asserter(db) as asserter:
            result = callable_()
        asserter.assert_(*rules)
        return result

    def assert_sql(self, db, callable_, rules):

        newrules = []
        for rule in rules:
            if isinstance(rule, dict):
                newrule = assertsql.AllOf(
                    *[assertsql.CompiledSQL(k, v) for k, v in rule.items()]
                )
            else:
                newrule = assertsql.CompiledSQL(*rule)
            newrules.append(newrule)

        return self.assert_sql_execution(db, callable_, *newrules)

    def assert_sql_count(self, db, callable_, count):
        self.assert_sql_execution(
            db, callable_, assertsql.CountStatements(count)
        )

    def assert_multiple_sql_count(self, dbs, callable_, counts):
        recs = [
            (self.sql_execution_asserter(db), db, count)
            for (db, count) in zip(dbs, counts)
        ]
        asserters = []
        for ctx, db, count in recs:
            asserters.append(ctx.__enter__())
        try:
            return callable_()
        finally:
            for asserter, (ctx, db, count) in zip(asserters, recs):
                ctx.__exit__(None, None, None)
                asserter.assert_(assertsql.CountStatements(count))

    @contextlib.contextmanager
    def assert_execution(self, db, *rules):
        with self.sql_execution_asserter(db) as asserter:
            yield
        asserter.assert_(*rules)

    def assert_statement_count(self, db, count):
        return self.assert_execution(db, assertsql.CountStatements(count))
