# Copyright 2014 The Chromium OS Authors. All rights reserved.
# Use of this source code is governed by a BSD-style license that can be
# found in the LICENSE file.

"""Integration tests for cidb.py module."""

from __future__ import print_function

import datetime
import glob
import os
import random
import shutil
import time

from chromite.cbuildbot import constants
from chromite.cbuildbot import metadata_lib
from chromite.lib import cidb
from chromite.lib import clactions
from chromite.lib import cros_build_lib
from chromite.lib import cros_logging as logging
from chromite.lib import cros_test_lib
from chromite.lib import osutils
from chromite.lib import parallel


# pylint: disable=protected-access

# Used to ensure that all build_number values we use are unique.
def _random():
  return random.randint(1, 1000000000)


SERIES_0_TEST_DATA_PATH = os.path.join(
    constants.CHROMITE_DIR, 'cidb', 'test_data', 'series_0')

SERIES_1_TEST_DATA_PATH = os.path.join(
    constants.CHROMITE_DIR, 'cidb', 'test_data', 'series_1')


class CIDBIntegrationTest(cros_test_lib.LocalSqlServerTestCase):
  """Base class for cidb tests that connect to a test MySQL instance."""

  CIDB_USER_ROOT = 'root'
  CIDB_USER_BOT = 'bot'
  CIDB_USER_READONLY = 'readonly'

  CIDB_CREDS_DIR = {
      CIDB_USER_BOT: os.path.join(constants.SOURCE_ROOT, 'crostools', 'cidb',
                                  'cidb_test_bot'),
      CIDB_USER_READONLY: os.path.join(constants.SOURCE_ROOT, 'crostools',
                                       'cidb', 'cidb_test_readonly'),
  }

  def LocalCIDBConnection(self, cidb_user):
    """Create a CIDBConnection with the local mysqld instance.

    Args:
      cidb_user: The mysql user to connect as.

    Returns:
      The created CIDBConnection object.
    """
    creds_dir_path = os.path.join(self.tempdir, 'local_cidb_creds')
    osutils.RmDir(creds_dir_path, ignore_missing=True)
    osutils.SafeMakedirs(creds_dir_path)

    osutils.WriteFile(os.path.join(creds_dir_path, 'host.txt'),
                      self.mysqld_host)
    osutils.WriteFile(os.path.join(creds_dir_path, 'port.txt'),
                      str(self.mysqld_port))
    osutils.WriteFile(os.path.join(creds_dir_path, 'user.txt'), cidb_user)

    if cidb_user in self.CIDB_CREDS_DIR:
      shutil.copy(os.path.join(self.CIDB_CREDS_DIR[cidb_user], 'password.txt'),
                  creds_dir_path)

    return cidb.CIDBConnection(
        creds_dir_path,
        query_retry_args=cidb.SqlConnectionRetryArgs(4, 1, 1.1))

  def _PrepareFreshDatabase(self, max_schema_version=None):
    """Create an empty database with migrations applied.

    Args:
      max_schema_version: The highest schema version migration to apply,
      defaults to None in which case all migrations will be applied.

    Returns:
      A CIDBConnection instance, connected to a an empty database as the
      root user.
    """
    # Note: We do not use the cidb.CIDBConnectionFactory
    # in this module. That factory method is used only to construct
    # connections as the bot user, which is how the builders will always
    # connect to the database. In this module, however, we need to test
    # database connections as other mysql users.

    # Connect to database and drop its contents.
    db = self.LocalCIDBConnection(self.CIDB_USER_ROOT)
    db.DropDatabase()

    # Connect to now fresh database and apply migrations.
    db = self.LocalCIDBConnection(self.CIDB_USER_ROOT)
    db.ApplySchemaMigrations(max_schema_version)

    return db

  def _PrepareDatabase(self):
    """Prepares a database at the latest known schema version.

    If database already exists, do not delete existing database. This
    optimization can save a lot of time, when used by tests that do not
    require an empty database.
    """
    # Connect to now fresh database and apply migrations.
    db = self.LocalCIDBConnection(self.CIDB_USER_ROOT)
    db.ApplySchemaMigrations()

    return db


class CIDBMigrationsTest(CIDBIntegrationTest):
  """Test that all migrations apply correctly."""

  def testMigrations(self):
    """Test that all migrations apply in bulk correctly."""
    self._PrepareFreshDatabase()

  def testIncrementalMigrations(self):
    """Test that all migrations apply incrementally correctly."""
    db = self._PrepareFreshDatabase(0)
    migrations = db._GetMigrationScripts()
    max_version = migrations[-1][0]

    for i in range(1, max_version + 1):
      db.ApplySchemaMigrations(i)

  def testActions(self):
    """Test that InsertCLActions accepts 0-, 1-, and multi-item lists."""
    db = self._PrepareDatabase()
    build_id = db.InsertBuild('my builder', 'chromiumos', _random(),
                              'my config', 'my bot hostname')

    a1 = clactions.CLAction.FromGerritPatchAndAction(
        metadata_lib.GerritPatchTuple(1, 1, True),
        constants.CL_ACTION_PICKED_UP)
    a2 = clactions.CLAction.FromGerritPatchAndAction(
        metadata_lib.GerritPatchTuple(1, 1, True),
        constants.CL_ACTION_PICKED_UP)
    a3 = clactions.CLAction.FromGerritPatchAndAction(
        metadata_lib.GerritPatchTuple(1, 1, True),
        constants.CL_ACTION_PICKED_UP)

    db.InsertCLActions(build_id, [])
    db.InsertCLActions(build_id, [a1])
    db.InsertCLActions(build_id, [a2, a3])

    action_count = db._GetEngine().execute(
        'select count(*) from clActionTable').fetchall()[0][0]
    self.assertEqual(action_count, 3)

    # Test that all known CL action types can be inserted
    fakepatch = metadata_lib.GerritPatchTuple(1, 1, True)
    all_actions_list = [
        clactions.CLAction.FromGerritPatchAndAction(fakepatch, action)
        for action in constants.CL_ACTIONS]
    db.InsertCLActions(build_id, all_actions_list)

  def testWaterfallMigration(self):
    """Test that migrating waterfall from enum to varchar preserves value."""
    self.skipTest('Skipped obsolete waterfall migration test.')
    # This test no longer runs. It was used only to confirm the correctness of
    # migration #41. In #43, the InsertBuild API changes in a way that is not
    # compatible with this test.
    # The test code remains in place for demonstration purposes only.
    db = self._PrepareFreshDatabase(40)
    build_id = db.InsertBuild('my builder', 'chromiumos', _random(),
                              'my config', 'my bot hostname')
    db.ApplySchemaMigrations(41)
    self.assertEqual('chromiumos', db.GetBuildStatus(build_id)['waterfall'])


class CIDBAPITest(CIDBIntegrationTest):
  """Tests of the CIDB API."""

  def testSchemaVersionTooLow(self):
    """Tests that the minimum_schema decorator works as expected."""
    db = self._PrepareFreshDatabase(2)
    with self.assertRaises(cidb.UnsupportedMethodException):
      db.InsertCLActions(0, [])

  def testSchemaVersionOK(self):
    """Tests that the minimum_schema decorator works as expected."""
    db = self._PrepareFreshDatabase(4)
    db.InsertCLActions(0, [])

  def testGetTime(self):
    db = self._PrepareFreshDatabase(1)
    current_db_time = db.GetTime()
    self.assertEqual(type(current_db_time), datetime.datetime)

  def testBuildMessages(self):
    db = self._PrepareFreshDatabase(43)
    self.assertEqual([], db.GetBuildMessages(1))
    master_build_id = db.InsertBuild('builder name',
                                     constants.WATERFALL_TRYBOT,
                                     1,
                                     'master',
                                     'hostname')
    slave_build_id = db.InsertBuild('slave builder name',
                                    constants.WATERFALL_TRYBOT,
                                    2,
                                    'slave',
                                    'slave hostname',
                                    master_build_id=master_build_id)
    db.InsertBuildMessage(master_build_id)
    db.InsertBuildMessage(master_build_id, 'message_type', 'message_subtype',
                          'message_value')
    for i in range(10):
      db.InsertBuildMessage(slave_build_id,
                            'message_type', 'message_subtype', str(i))

    master_messages = db.GetBuildMessages(master_build_id)
    slave_messages = db.GetSlaveBuildMessages(master_build_id)

    self.assertEqual(2, len(master_messages))
    self.assertEqual(10, len(slave_messages))

    mm2 = master_messages[1]
    mm2.pop('timestamp')
    self.assertEqual({'build_id': master_build_id,
                      'build_config': 'master',
                      'waterfall': constants.WATERFALL_TRYBOT,
                      'builder_name': 'builder name',
                      'build_number': 1L,
                      'message_type': 'message_type',
                      'message_subtype': 'message_subtype',
                      'message_value': 'message_value'},
                     mm2)
    sm10 = slave_messages[9]
    sm10.pop('timestamp')
    self.assertEqual({'build_id': slave_build_id,
                      'build_config': 'slave',
                      'waterfall': constants.WATERFALL_TRYBOT,
                      'builder_name': 'slave builder name',
                      'build_number': 2L,
                      'message_type': 'message_type',
                      'message_subtype': 'message_subtype',
                      'message_value': '9'},
                     sm10)

  def testGetKeyVals(self):
    db = self._PrepareFreshDatabase(40)
    # In production we would never insert into this table from a bot, but for
    # testing purposes here this is convenient.
    db._Execute('INSERT INTO keyvalTable(k, v) VALUES '
                '("/foo/bar", "baz"), ("/qux/norf", NULL)')
    self.assertEqual(db.GetKeyVals(), {'/foo/bar': 'baz', '/qux/norf': None})


def GetTestDataSeries(test_data_path):
  """Get metadata from json files at |test_data_path|.

  Returns:
    A list of CBuildbotMetadata objects, sorted by their start time.
  """
  filenames = glob.glob(os.path.join(test_data_path, '*.json'))
  metadatas = []
  for fname in filenames:
    metadatas.append(
        metadata_lib.CBuildbotMetadata.FromJSONString(osutils.ReadFile(fname)))

  # Convert start time values, which are stored in RFC 2822 string format,
  # to seconds since epoch.
  timestamp_from_dict = lambda x: cros_build_lib.ParseUserDateTimeFormat(
      x.GetDict()['time']['start'])

  metadatas.sort(key=timestamp_from_dict)
  return metadatas


class DataSeries0Test(CIDBIntegrationTest):
  """Simulate a set of 630 master/slave CQ builds."""

  def testCQWithSchema44(self):
    """Run the CQ test with schema version 44."""
    self._PrepareFreshDatabase(44)
    self._runCQTest()

  def _runCQTest(self):
    """Simulate a set of 630 master/slave CQ builds.

    Note: This test takes about 2.5 minutes to populate its 630 builds
    and their corresponding cl actions into the test database.
    """
    metadatas = GetTestDataSeries(SERIES_0_TEST_DATA_PATH)
    self.assertEqual(len(metadatas), 630, 'Did not load expected amount of '
                                          'test data')

    bot_db = self.LocalCIDBConnection(self.CIDB_USER_BOT)

    # Simulate the test builds, using a database connection as the
    # bot user.
    self.simulate_builds(bot_db, metadatas)

    # Perform some sanity check queries against the database, connected
    # as the readonly user.
    readonly_db = self.LocalCIDBConnection(self.CIDB_USER_READONLY)

    self._start_and_finish_time_checks(readonly_db)

    build_types = readonly_db._GetEngine().execute(
        'select build_type from buildTable').fetchall()
    self.assertTrue(all(x == ('paladin',) for x in build_types))

    self._cl_action_checks(readonly_db)

    build_config_count = readonly_db._GetEngine().execute(
        'select COUNT(distinct build_config) from buildTable').fetchall()[0][0]
    self.assertEqual(build_config_count, 30)

    # Test the _Select method, and verify that the first inserted
    # build is a master-paladin build.
    first_row = readonly_db._Select('buildTable', 1, ['id', 'build_config'])
    self.assertEqual(first_row['build_config'], 'master-paladin')

    # First master build has 29 slaves. Build with id 2 is a slave
    # build with no slaves of its own.
    self.assertEqual(len(readonly_db.GetSlaveStatuses(1)), 29)
    self.assertEqual(len(readonly_db.GetSlaveStatuses(2)), 0)

    # Make sure we can get build status by build id.
    self.assertEqual(readonly_db.GetBuildStatus(2).get('id'), 2)

    # Make sure we can get build statuses by build ids.
    build_dicts = readonly_db.GetBuildStatuses([1, 2])
    self.assertEqual([x.get('id') for x in build_dicts], [1, 2])

    self._start_and_finish_time_checks(readonly_db)
    self._cl_action_checks(readonly_db)
    self._last_updated_time_checks(readonly_db)

    #| Test get build_status from -- here's the relevant data from
    # master-paladin
    #|          id | status |
    #|         601 | pass   |
    #|         571 | pass   |
    #|         541 | fail   |
    #|         511 | pass   |
    #|         481 | pass   |
    # From 1929 because we always go back one build first.
    last_status = readonly_db.GetBuildHistory('master-paladin', 1)
    self.assertEqual(len(last_status), 1)
    last_status = readonly_db.GetBuildHistory('master-paladin', 5)
    self.assertEqual(len(last_status), 5)
    # Make sure keys are sorted correctly.
    build_ids = []
    for index, status in enumerate(last_status):
      # Add these to list to confirm they are sorted afterwards correctly.
      # Should be descending.
      build_ids.append(status['id'])
      if index == 2:
        self.assertEqual(status['status'], 'fail')
      else:
        self.assertEqual(status['status'], 'pass')

    # Check the sort order.
    self.assertEqual(sorted(build_ids, reverse=True), build_ids)

  def _last_updated_time_checks(self, db):
    """Sanity checks on the last_updated column."""
    # We should have a diversity of last_updated times. Since the timestamp
    # resolution is only 1 second, and we have lots of parallelism in the test,
    # we won't have a distinct last_updated time per row.
    # As the test is now local, almost everything happens together, so we check
    # for a tiny number of distinct timestamps.
    distinct_last_updated = db._GetEngine().execute(
        'select count(distinct last_updated) from buildTable').fetchall()[0][0]
    self.assertTrue(distinct_last_updated > 3)

    ids_by_last_updated = db._GetEngine().execute(
        'select id from buildTable order by last_updated').fetchall()

    ids_by_last_updated = [id_tuple[0] for id_tuple in ids_by_last_updated]

    # Build #1 should have been last updated before build # 200.
    self.assertLess(ids_by_last_updated.index(1),
                    ids_by_last_updated.index(200))

    # However, build #1 (which was a master build) should have been last updated
    # AFTER build #2 which was its slave.
    self.assertGreater(ids_by_last_updated.index(1),
                       ids_by_last_updated.index(2))

  def _cl_action_checks(self, db):
    """Sanity checks that correct cl actions were recorded."""
    submitted_cl_count = db._GetEngine().execute(
        'select count(*) from clActionTable where action="submitted"'
        ).fetchall()[0][0]
    rejected_cl_count = db._GetEngine().execute(
        'select count(*) from clActionTable where action="kicked_out"'
        ).fetchall()[0][0]
    total_actions = db._GetEngine().execute(
        'select count(*) from clActionTable').fetchall()[0][0]
    self.assertEqual(submitted_cl_count, 56)
    self.assertEqual(rejected_cl_count, 8)
    self.assertEqual(total_actions, 1877)

    actions_for_change = db.GetActionsForChanges(
        [metadata_lib.GerritChangeTuple(205535, False)])

    self.assertEqual(len(actions_for_change), 60)
    last_action_dict = dict(actions_for_change[-1]._asdict())
    last_action_dict.pop('timestamp')
    last_action_dict.pop('id')
    self.assertEqual(last_action_dict, {'action': 'submitted',
                                        'build_config': 'master-paladin',
                                        'build_id': 511L,
                                        'change_number': 205535L,
                                        'change_source': 'external',
                                        'patch_number': 1L,
                                        'reason': ''})

  def _start_and_finish_time_checks(self, db):
    """Sanity checks that correct data was recorded, and can be retrieved."""
    max_start_time = db._GetEngine().execute(
        'select max(start_time) from buildTable').fetchall()[0][0]
    min_start_time = db._GetEngine().execute(
        'select min(start_time) from buildTable').fetchall()[0][0]
    max_fin_time = db._GetEngine().execute(
        'select max(finish_time) from buildTable').fetchall()[0][0]
    min_fin_time = db._GetEngine().execute(
        'select min(finish_time) from buildTable').fetchall()[0][0]
    self.assertGreater(max_start_time, min_start_time)
    self.assertGreater(max_fin_time, min_fin_time)

    # For all builds, finish_time should equal last_updated.
    mismatching_times = db._GetEngine().execute(
        'select count(*) from buildTable where finish_time != last_updated'
        ).fetchall()[0][0]
    self.assertEqual(mismatching_times, 0)

  def simulate_builds(self, db, metadatas):
    """Simulate a series of Commit Queue master and slave builds.

    This method use the metadata objects in |metadatas| to simulate those
    builds insertions and updates to the cidb. All metadatas encountered
    after a particular master build will be assumed to be slaves of that build,
    until a new master build is encountered. Slave builds for a particular
    master will be simulated in parallel.

    The first element in |metadatas| must be a CQ master build.

    Args:
      db: A CIDBConnection instance.
      metadatas: A list of CBuildbotMetadata instances, sorted by start time.
    """
    m_iter = iter(metadatas)

    def is_master(m):
      return m.GetDict()['bot-config'] == 'master-paladin'

    next_master = m_iter.next()

    while next_master:
      master = next_master
      next_master = None
      assert is_master(master)
      master_build_id = _SimulateBuildStart(db, master)

      def simulate_slave(slave_metadata):
        build_id = _SimulateBuildStart(db, slave_metadata,
                                       master_build_id,
                                       important=True)
        _SimulateCQBuildFinish(db, slave_metadata, build_id)
        logging.debug('Simulated slave build %s on pid %s', build_id,
                      os.getpid())
        return build_id

      slave_metadatas = []
      for slave in m_iter:
        if is_master(slave):
          next_master = slave
          break
        slave_metadatas.append(slave)

      with parallel.BackgroundTaskRunner(simulate_slave, processes=15) as queue:
        for slave in slave_metadatas:
          queue.put([slave])

      # Yes, this introduces delay in the test. But this lets us do some basic
      # sanity tests on the |last_update| column later.
      time.sleep(1)
      _SimulateCQBuildFinish(db, master, master_build_id)
      logging.debug('Simulated master build %s', master_build_id)


class BuildStagesAndFailureTest(CIDBIntegrationTest):
  """Test buildStageTable functionality."""

  def runTest(self):
    """Test basic buildStageTable and failureTable functionality."""
    self._PrepareDatabase()

    bot_db = self.LocalCIDBConnection(self.CIDB_USER_BOT)

    master_build_id = bot_db.InsertBuild('master build',
                                         constants.WATERFALL_INTERNAL,
                                         _random(),
                                         'master_config',
                                         'master.hostname')

    build_id = bot_db.InsertBuild('builder name',
                                  constants.WATERFALL_INTERNAL,
                                  _random(),
                                  'build_config',
                                  'bot_hostname',
                                  master_build_id=master_build_id)

    build_stage_id = bot_db.InsertBuildStage(build_id,
                                             'My Stage',
                                             board='bunny')

    values = bot_db._Select('buildStageTable', build_stage_id, ['start_time'])
    self.assertEqual(None, values['start_time'])

    bot_db.StartBuildStage(build_stage_id)
    values = bot_db._Select('buildStageTable', build_stage_id,
                            ['start_time', 'status'])
    self.assertNotEqual(None, values['start_time'])
    self.assertEqual(constants.BUILDER_STATUS_INFLIGHT, values['status'])

    bot_db.FinishBuildStage(build_stage_id, constants.BUILDER_STATUS_PASSED)
    values = bot_db._Select('buildStageTable', build_stage_id,
                            ['finish_time', 'status', 'final'])
    self.assertNotEqual(None, values['finish_time'])
    self.assertEqual(True, values['final'])
    self.assertEqual(constants.BUILDER_STATUS_PASSED, values['status'])

    self.assertFalse(bot_db.HasBuildStageFailed(build_stage_id))
    for category in constants.EXCEPTION_CATEGORY_ALL_CATEGORIES:
      e = ValueError('The value was erroneous.')
      bot_db.InsertFailure(build_stage_id, type(e).__name__, str(e), category)
      self.assertTrue(bot_db.HasBuildStageFailed(build_stage_id))

    failures = bot_db.GetSlaveFailures(master_build_id)
    self.assertEqual(len(failures),
                     len(constants.EXCEPTION_CATEGORY_ALL_CATEGORIES))
    for f in failures:
      self.assertEqual(f['build_id'], build_id)

    slave_stages = bot_db.GetSlaveStages(master_build_id)
    self.assertEqual(len(slave_stages), 1)
    self.assertEqual(slave_stages[0]['status'], 'pass')
    self.assertEqual(slave_stages[0]['build_config'], 'build_config')
    self.assertEqual(slave_stages[0]['name'], 'My Stage')

class BuildTableTest(CIDBIntegrationTest):
  """Test buildTable functionality not tested by the DataSeries tests."""

  def testInsertWithDeadline(self):
    """Test deadline setting/querying API."""
    self._PrepareDatabase()
    bot_db = self.LocalCIDBConnection(self.CIDB_USER_BOT)

    build_id = bot_db.InsertBuild('build_name',
                                  constants.WATERFALL_INTERNAL,
                                  _random(),
                                  'build_config',
                                  'bot_hostname',
                                  timeout_seconds=30 * 60)
    # This will flake if the few cidb calls above take hours. Unlikely.
    self.assertLess(10, bot_db.GetTimeToDeadline(build_id))

    build_id = bot_db.InsertBuild('build_name',
                                  constants.WATERFALL_INTERNAL,
                                  _random(),
                                  'build_config',
                                  'bot_hostname',
                                  timeout_seconds=1)
    # Sleep till the deadline expires.
    time.sleep(3)
    self.assertEqual(0, bot_db.GetTimeToDeadline(build_id))

    build_id = bot_db.InsertBuild('build_name',
                                  constants.WATERFALL_INTERNAL,
                                  _random(),
                                  'build_config',
                                  'bot_hostname')
    self.assertEqual(None, bot_db.GetTimeToDeadline(build_id))

    self.assertEqual(None, bot_db.GetTimeToDeadline(build_id))

  def testExtendDeadline(self):
    """Test that a deadline in the future can be extended."""

    self._PrepareDatabase()
    bot_db = self.LocalCIDBConnection(self.CIDB_USER_BOT)

    build_id = bot_db.InsertBuild('build_name',
                                  constants.WATERFALL_INTERNAL,
                                  _random(),
                                  'build_config',
                                  'bot_hostname')
    self.assertEqual(None, bot_db.GetTimeToDeadline(build_id))

    self.assertEqual(1, bot_db.ExtendDeadline(build_id, 1))
    time.sleep(2)
    self.assertEqual(0, bot_db.GetTimeToDeadline(build_id))
    self.assertEqual(0, bot_db.ExtendDeadline(build_id, 10 * 60))
    self.assertEqual(0, bot_db.GetTimeToDeadline(build_id))

    build_id = bot_db.InsertBuild('build_name',
                                  constants.WATERFALL_INTERNAL,
                                  _random(),
                                  'build_config',
                                  'bot_hostname',
                                  timeout_seconds=30 * 60)
    self.assertLess(10, bot_db.GetTimeToDeadline(build_id))

    self.assertEqual(0, bot_db.ExtendDeadline(build_id, 10 * 60))
    self.assertLess(20 * 60, bot_db.GetTimeToDeadline(build_id))

    self.assertEqual(1, bot_db.ExtendDeadline(build_id, 60 * 60))
    self.assertLess(40 * 60, bot_db.GetTimeToDeadline(build_id))


class DataSeries1Test(CIDBIntegrationTest):
  """Simulate a single set of canary builds."""

  def runTest(self):
    """Simulate a single set of canary builds with database schema v44."""
    metadatas = GetTestDataSeries(SERIES_1_TEST_DATA_PATH)
    self.assertEqual(len(metadatas), 18, 'Did not load expected amount of '
                                         'test data')

    # Migrate db to specified version. As new schema versions are added,
    # migrations to later version can be applied after the test builds are
    # simulated, to test that db contents are correctly migrated.
    self._PrepareFreshDatabase(44)

    bot_db = self.LocalCIDBConnection(self.CIDB_USER_BOT)

    def is_master(m):
      return m.GetValue('bot-config') == 'master-release'

    master_index = metadatas.index(next(m for m in metadatas if is_master(m)))
    master_metadata = metadatas.pop(master_index)
    self.assertEqual(master_metadata.GetValue('bot-config'), 'master-release')

    master_id = self._simulate_canary(bot_db, master_metadata)

    for m in metadatas:
      self._simulate_canary(bot_db, m, master_id)

    # Verify that expected data was inserted
    num_boards = bot_db._GetEngine().execute(
        'select count(*) from boardPerBuildTable'
        ).fetchall()[0][0]
    self.assertEqual(num_boards, 40)

    main_firmware_versions = bot_db._GetEngine().execute(
        'select count(distinct main_firmware_version) from boardPerBuildTable'
        ).fetchall()[0][0]
    self.assertEqual(main_firmware_versions, 29)

    # For all builds, finish_time should equal last_updated.
    mismatching_times = bot_db._GetEngine().execute(
        'select count(*) from buildTable where finish_time != last_updated'
        ).fetchall()[0][0]
    self.assertEqual(mismatching_times, 0)

  def _simulate_canary(self, db, metadata, master_build_id=None):
    """Helper method to simulate an individual canary build.

    Args:
      db: cidb instance to use for simulation
      metadata: CBuildbotMetadata instance of build to simulate.
      master_build_id: Optional id of master build.

    Returns:
      build_id of build that was simulated.
    """
    build_id = _SimulateBuildStart(db, metadata, master_build_id)
    metadata_dict = metadata.GetDict()

    # Insert child configs and boards
    for child_config_dict in metadata_dict['child-configs']:
      db.InsertChildConfigPerBuild(build_id, child_config_dict['name'])

    for board in metadata_dict['board-metadata'].keys():
      db.InsertBoardPerBuild(build_id, board)

    for board, bm in metadata_dict['board-metadata'].items():
      db.UpdateBoardPerBuildMetadata(build_id, board, bm)

    db.UpdateMetadata(build_id, metadata)

    status = metadata_dict['status']['status']
    status = _TranslateStatus(status)

    for child_config_dict in metadata_dict['child-configs']:
      # Note, we are not using test data here, because the test data
      # we have predates the existence of child-config status being
      # stored in metadata.json. Instead, we just pretend all child
      # configs had the same status as the main config.
      db.FinishChildConfig(build_id, child_config_dict['name'],
                           status)

    db.FinishBuild(build_id, status)

    return build_id


def _TranslateStatus(status):
  # TODO(akeshet): The status strings used in BuildStatus are not the same as
  # those recorded in CBuildbotMetadata. Use a general purpose adapter.
  if status == 'passed':
    return 'pass'

  if status == 'failed':
    return 'fail'

  return status


def _SimulateBuildStart(db, metadata, master_build_id=None, important=None):
  """Returns build_id for the inserted buildTable entry."""
  metadata_dict = metadata.GetDict()
  # TODO(akeshet): We are pretending that all these builds were on the internal
  # waterfall at the moment, for testing purposes. This is because we don't
  # actually save in the metadata.json any way to know which waterfall the
  # build was on.
  waterfall = 'chromeos'

  build_id = db.InsertBuild(metadata_dict['builder-name'],
                            waterfall,
                            metadata_dict['build-number'],
                            metadata_dict['bot-config'],
                            metadata_dict['bot-hostname'],
                            master_build_id,
                            important=important)

  return build_id


def _SimulateCQBuildFinish(db, metadata, build_id):

  metadata_dict = metadata.GetDict()

  db.InsertCLActions(
      build_id,
      [clactions.CLAction.FromMetadataEntry(e)
       for e in metadata_dict['cl_actions']])

  db.UpdateMetadata(build_id, metadata)

  status = metadata_dict['status']['status']
  status = _TranslateStatus(status)
  # The build summary reported by a real CQ run is more complicated -- it is
  # computed from slave summaries by a master. For sanity checking, we just
  # insert the current builer's summary.
  summary = metadata_dict['status'].get('reason', None)

  db.FinishBuild(build_id, status, summary)


def main(_argv):
  # TODO(akeshet): Allow command line args to specify alternate CIDB instance
  # for testing.
  cros_test_lib.main(module=__name__)