# This file is part of Buildbot.  Buildbot 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, version 2.
#
# 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.
#
# Copyright Buildbot Team Members

import os
import textwrap

import sqlalchemy as sa

from twisted.internet import defer
from twisted.trial import unittest

from buildbot.db.connector import DBConnector
from buildbot.scripts import cleanupdb
from buildbot.test.fake import fakemaster
from buildbot.test.util import db
from buildbot.test.util import dirs
from buildbot.test.util import misc
from buildbot.test.util.decorators import flaky
from buildbot.test.util.misc import TestReactorMixin

from . import test_db_logs

try:
    import lz4
    [lz4]
    hasLz4 = True
except ImportError:
    hasLz4 = False


def mkconfig(**kwargs):
    config = dict(quiet=False, basedir=os.path.abspath('basedir'), force=True)
    config.update(kwargs)
    return config


def patch_environ(case, key, value):
    """
    Add an environment variable for the duration of a test.
    """
    old_environ = os.environ.copy()

    def cleanup():
        os.environ.clear()
        os.environ.update(old_environ)
    os.environ[key] = value
    case.addCleanup(cleanup)


class TestCleanupDb(misc.StdoutAssertionsMixin, dirs.DirsMixin,
                    db.RealDatabaseMixin, TestReactorMixin,
                    unittest.TestCase):

    def setUp(self):
        self.setUpTestReactor()
        self.origcwd = os.getcwd()
        self.setUpDirs('basedir')
        with open(os.path.join('basedir', 'buildbot.tac'), 'wt') as f:
            f.write(textwrap.dedent("""
                from twisted.application import service
                application = service.Application('buildmaster')
            """))
        self.setUpStdoutAssertions()
        self.ensureNoSqliteMemory()

    def tearDown(self):
        os.chdir(self.origcwd)
        self.tearDownDirs()

    def ensureNoSqliteMemory(self):
        # test may use mysql or pg if configured in env
        envkey = "BUILDBOT_TEST_DB_URL"
        if envkey not in os.environ or os.environ[envkey] == 'sqlite://':

            patch_environ(self, envkey, "sqlite:///" + os.path.join(
                self.origcwd, "basedir", "state.sqlite"))

    def createMasterCfg(self, extraconfig=""):
        os.chdir(self.origcwd)
        with open(os.path.join('basedir', 'master.cfg'), 'wt') as f:
            f.write(textwrap.dedent("""
                from buildbot.plugins import *
                c = BuildmasterConfig = dict()
                c['db_url'] = {dburl}
                c['buildbotNetUsageData'] = None
                c['multiMaster'] = True  # don't complain for no builders
                {extraconfig}
            """.format(dburl=repr(os.environ["BUILDBOT_TEST_DB_URL"]),
                       extraconfig=extraconfig)))

    @defer.inlineCallbacks
    def test_cleanup_not_basedir(self):
        res = yield cleanupdb._cleanupDatabase(mkconfig(basedir='doesntexist'))
        self.assertEqual(res, 1)
        self.assertInStdout('invalid buildmaster directory')

    @defer.inlineCallbacks
    def test_cleanup_bad_config(self):
        res = yield cleanupdb._cleanupDatabase(mkconfig(basedir='basedir'))
        self.assertEqual(res, 1)
        self.assertInStdout("master.cfg' does not exist")

    @defer.inlineCallbacks
    def test_cleanup_bad_config2(self):

        self.createMasterCfg(extraconfig="++++ # syntaxerror")
        res = yield cleanupdb._cleanupDatabase(mkconfig(basedir='basedir'))
        self.assertEqual(res, 1)
        self.assertInStdout(
            "encountered a SyntaxError while parsing config file:")
        # config logs an error via log.err, we must eat it or trial will
        # complain
        self.flushLoggedErrors()

    @flaky(bugNumber=4406, onPlatform='win32')
    @defer.inlineCallbacks
    def test_cleanup(self):

        # we reuse RealDatabaseMixin to setup the db
        yield self.setUpRealDatabase(table_names=['logs', 'logchunks', 'steps', 'builds', 'builders',
                                                  'masters', 'buildrequests', 'buildsets',
                                                  'workers'])
        master = fakemaster.make_master(self)
        master.config.db['db_url'] = self.db_url
        self.db = DBConnector(self.basedir)
        self.db.setServiceParent(master)
        self.db.pool = self.db_pool

        # we reuse the fake db background data from db.logs unit tests
        yield self.insertTestData(test_db_logs.Tests.backgroundData)

        # insert a log with lots of redundancy
        LOGDATA = "xx\n" * 2000
        logid = yield self.db.logs.addLog(102, "x", "x", "s")
        yield self.db.logs.appendLog(logid, LOGDATA)

        # test all methods
        lengths = {}
        for mode in self.db.logs.COMPRESSION_MODE:
            if mode == "lz4" and not hasLz4:
                # ok.. lz4 is not installed, don't fail
                lengths["lz4"] = 40
                continue
            # create a master.cfg with different compression method
            self.createMasterCfg("c['logCompressionMethod'] = '%s'" % (mode,))
            res = yield cleanupdb._cleanupDatabase(mkconfig(basedir='basedir'))
            self.assertEqual(res, 0)

            # make sure the compression don't change the data we can retrieve
            # via api
            res = yield self.db.logs.getLogLines(logid, 0, 2000)
            self.assertEqual(res, LOGDATA)

            # retrieve the actual data size in db using raw sqlalchemy
            def thd(conn):
                tbl = self.db.model.logchunks
                q = sa.select([sa.func.sum(sa.func.length(tbl.c.content))])
                q = q.where(tbl.c.logid == logid)
                return conn.execute(q).fetchone()[0]
            lengths[mode] = yield self.db.pool.do(thd)

        self.assertDictAlmostEqual(
            lengths, {'raw': 5999, 'bz2': 44, 'lz4': 40, 'gz': 31})

    def assertDictAlmostEqual(self, d1, d2):
        # The test shows each methods return different size
        # but we still make a fuzzy comparison to resist if underlying libraries
        # improve efficiency
        self.assertEqual(len(d1), len(d2))
        for k in d2.keys():
            self.assertApproximates(d1[k], d2[k], 10)
