from __future__ import print_function

import doctest
import logging
import os
import re
import sys

from sqlalchemy import testing
from sqlalchemy.testing import config
from sqlalchemy.testing import fixtures


class DocTest(fixtures.TestBase):
    __requires__ = ("python3",)

    def _setup_logger(self):
        rootlogger = logging.getLogger("sqlalchemy.engine.Engine")

        class MyStream(object):
            def write(self, string):
                sys.stdout.write(string)
                sys.stdout.flush()

            def flush(self):
                pass

        self._handler = handler = logging.StreamHandler(MyStream())
        handler.setFormatter(logging.Formatter("%(message)s"))
        rootlogger.addHandler(handler)

    def _teardown_logger(self):
        rootlogger = logging.getLogger("sqlalchemy.engine.Engine")
        rootlogger.removeHandler(self._handler)

    def _setup_create_table_patcher(self):
        from sqlalchemy.sql import ddl

        self.orig_sort = ddl.sort_tables_and_constraints

        def our_sort(tables, **kw):
            return self.orig_sort(sorted(tables, key=lambda t: t.key), **kw)

        ddl.sort_tables_and_constraints = our_sort

    def _teardown_create_table_patcher(self):
        from sqlalchemy.sql import ddl

        ddl.sort_tables_and_constraints = self.orig_sort

    def setup_test(self):
        self._setup_logger()
        self._setup_create_table_patcher()

    def teardown_test(self):
        self._teardown_create_table_patcher()
        self._teardown_logger()

    def _run_doctest(self, *fnames):
        here = os.path.dirname(__file__)
        sqla_base = os.path.normpath(os.path.join(here, "..", ".."))

        optionflags = (
            doctest.ELLIPSIS
            | doctest.NORMALIZE_WHITESPACE
            | doctest.IGNORE_EXCEPTION_DETAIL
            | _get_allow_unicode_flag()
        )
        runner = doctest.DocTestRunner(
            verbose=None,
            optionflags=optionflags,
            checker=_get_unicode_checker(),
        )
        parser = doctest.DocTestParser()
        globs = {"print_function": print_function}

        for fname in fnames:
            path = os.path.join(sqla_base, "doc/build", fname)
            if not os.path.exists(path):
                config.skip_test("Can't find documentation file %r" % path)
            with open(path, encoding="utf-8") as file_:
                content = file_.read()
                content = re.sub(r"{(?:stop|sql|opensql)}", "", content)

                test = parser.get_doctest(content, globs, fname, fname, 0)
                runner.run(test, clear_globs=False)
                runner.summarize()
                globs.update(test.globs)
                assert not runner.failures

    def test_20_style(self):
        self._run_doctest(
            "tutorial/index.rst",
            "tutorial/engine.rst",
            "tutorial/dbapi_transactions.rst",
            "tutorial/metadata.rst",
            "tutorial/data.rst",
            "tutorial/data_insert.rst",
            "tutorial/data_select.rst",
            "tutorial/data_update.rst",
            "tutorial/orm_data_manipulation.rst",
            "tutorial/orm_related_objects.rst",
        )

    def test_orm(self):
        self._run_doctest("orm/tutorial.rst")

    @testing.emits_warning()
    def test_core(self):
        self._run_doctest("core/tutorial.rst")

    def test_core_operators(self):
        self._run_doctest("core/operators.rst")

    def test_orm_queryguide(self):
        self._run_doctest("orm/queryguide.rst")


# unicode checker courtesy pytest


def _get_unicode_checker():
    """
    Returns a doctest.OutputChecker subclass that takes in account the
    ALLOW_UNICODE option to ignore u'' prefixes in strings. Useful
    when the same doctest should run in Python 2 and Python 3.

    An inner class is used to avoid importing "doctest" at the module
    level.
    """
    if hasattr(_get_unicode_checker, "UnicodeOutputChecker"):
        return _get_unicode_checker.UnicodeOutputChecker()

    import doctest
    import re

    class UnicodeOutputChecker(doctest.OutputChecker):
        """
        Copied from doctest_nose_plugin.py from the nltk project:
            https://github.com/nltk/nltk
        """

        _literal_re = re.compile(r"(\W|^)[uU]([rR]?[\'\"])", re.UNICODE)

        def check_output(self, want, got, optionflags):
            res = doctest.OutputChecker.check_output(
                self, want, got, optionflags
            )
            if res:
                return True

            if not (optionflags & _get_allow_unicode_flag()):
                return False

            else:  # pragma: no cover
                # the code below will end up executed only in Python 2 in
                # our tests, and our coverage check runs in Python 3 only
                def remove_u_prefixes(txt):
                    return re.sub(self._literal_re, r"\1\2", txt)

                want = remove_u_prefixes(want)
                got = remove_u_prefixes(got)
                res = doctest.OutputChecker.check_output(
                    self, want, got, optionflags
                )
                return res

    _get_unicode_checker.UnicodeOutputChecker = UnicodeOutputChecker
    return _get_unicode_checker.UnicodeOutputChecker()


def _get_allow_unicode_flag():
    """
    Registers and returns the ALLOW_UNICODE flag.
    """
    import doctest

    return doctest.register_optionflag("ALLOW_UNICODE")


# increase number to force pipeline run. 1
