import os
import simplejson as json
from os.path import dirname
import sys
from django.core.management import call_command
import pytest


def pytest_addoption(parser):
    parser.addoption(
        "--runslow",
        action="store_true",
        help="run slow tests",
    )


def pytest_sessionstart(session):
    """
    Set up the test environment.

    Set DJANGO_SETTINGS_MODULE and sets up a test database.

    """
    sys.path.append(dirname(dirname(__file__)))
    os.environ.setdefault("DJANGO_SETTINGS_MODULE", "treeherder.settings")
    from django.conf import settings
    from django.test.simple import DjangoTestSuiteRunner

    # we don't actually let Django run the tests, but we need to use some
    # methods of its runner for setup/teardown of dbs and some other things
    session.django_runner = DjangoTestSuiteRunner()
    # this provides templates-rendered debugging info and locmem mail storage
    session.django_runner.setup_test_environment()
    # support custom db prefix for tests for the main datazilla datasource
    # as well as for the testproj and testpushlog dbs
    prefix = getattr(settings, "TEST_DB_PREFIX", "")
    settings.DATABASES["default"]["TEST_NAME"] = "{0}test_treeherder".format(prefix)

    # this makes celery calls synchronous, useful for unit testing
    settings.CELERY_ALWAYS_EAGER = True
    settings.CELERY_EAGER_PROPAGATES_EXCEPTIONS = True

    # this sets up a clean test-only database
    session.django_db_config = session.django_runner.setup_databases()


def pytest_sessionfinish(session):
    """Tear down the test environment, including databases."""
    session.django_runner.teardown_databases(session.django_db_config)
    session.django_runner.teardown_test_environment()


def pytest_runtest_setup(item):
    """
    Per-test setup.
    - Add an option to run those tests marked as 'slow'
    - Provide cache isolation incrementing the cache key prefix
    - Drop and recreate tables in the master db
    """

    if 'slow' in item.keywords and not item.config.getoption("--runslow"):
        pytest.skip("need --runslow option to run")

    increment_cache_key_prefix()

    # this should provide isolation between tests.
    call_command("init_master_db", interactive=False, skip_fixtures=True)


def pytest_runtest_teardown(item):
    """
    Per-test teardown.

    Roll back the Django ORM transaction and delete all the dbs created
    between tests

    """
    from treeherder.model.models import Datasource

    ds_list = Datasource.objects.all()
    for ds in ds_list:
        ds.delete()


def increment_cache_key_prefix():
    """Increment a cache prefix to effectively clear the cache."""
    from django.core.cache import cache
    cache.key_prefix = ""
    prefix_counter_cache_key = "treeherder-tests-key-prefix-counter"
    try:
        key_prefix_counter = cache.incr(prefix_counter_cache_key)
    except ValueError:
        key_prefix_counter = 0
        cache.set(prefix_counter_cache_key, key_prefix_counter)
    cache.key_prefix = "t{0}".format(key_prefix_counter)


@pytest.fixture()
def initial_data():
    from django.core.management import call_command

    call_command('load_initial_data')


@pytest.fixture()
def jm():
    """ Give a test access to a JobsModel instance. """
    from django.conf import settings
    from treeherder.model.derived.jobs import JobsModel
    model = JobsModel.create(settings.DATABASES["default"]["TEST_NAME"])

    # patch in additional test-only procs on the datasources
    add_test_procs_file(
        model.get_dhub("objectstore"),
        model.get_datasource("objectstore").key,
        "objectstore_test.json",
    )
    add_test_procs_file(
        model.get_dhub("jobs"),
        model.get_datasource("jobs").key,
        "jobs_test.json",
    )

    def fin():
        model.disconnect()

    return model


@pytest.fixture()
def refdata():
    """returns a patched RefDataManager for testing purpose"""

    from treeherder.model.derived import RefDataManager

    refdata = RefDataManager()

    proc_path = os.path.join(
        os.path.abspath(os.path.dirname(__file__)),
        'refdata_test.json'
    )

    add_test_procs_file(refdata.dhub, 'reference', proc_path)
    return refdata


def add_test_procs_file(dhub, key, filename):
    """Add an extra procs file in for testing purposes."""
    test_proc_file = os.path.join(
        os.path.abspath(os.path.dirname(__file__)),
        filename,
    )
    del dhub.procs[key]
    proclist = dhub.data_sources[key]["procs"]
    if not test_proc_file in proclist:
        proclist.append(test_proc_file)
    dhub.data_sources[key]["procs"] = proclist
    dhub.load_procs(key)


@pytest.fixture()
def jobs_ds():
    from django.conf import settings
    from treeherder.model.models import Datasource
    return Datasource.objects.create(
        project=settings.DATABASES["default"]["TEST_NAME"],
        dataset=1,
        contenttype="jobs",
        host="localhost",
    )


@pytest.fixture()
def objectstore_ds():
    from django.conf import settings
    from treeherder.model.models import Datasource
    return Datasource.objects.create(
        project=settings.DATABASES["default"]["TEST_NAME"],
        dataset=1,
        contenttype="objectstore",
        host="localhost",
    )


@pytest.fixture(scope='session')
def sample_data():
    """Returns a SampleData() object"""
    from sampledata import SampleData
    return SampleData()


@pytest.fixture(scope='session')
def test_base_dir():
    return os.path.dirname(__file__)


@pytest.fixture
def sample_resultset(test_base_dir):
    source_file = os.path.join(test_base_dir, "sample_data",
                               "resultset_data.json")

    return json.loads(open(source_file).read())


@pytest.fixture
def test_repository():
    from django.conf import settings
    from treeherder.model.models import Repository

    return Repository.objects.create(
        dvcs_type = "hg",
        name = settings.DATABASES["default"]["TEST_NAME"],
        url = "https://hg.mozilla.org/mozilla-central",
        active_status = "active",
        codebase = "gecko",
        repository_group_id = 1,
        description = ""
    )


@pytest.fixture
def mock_log_parser(monkeypatch):
    from celery import task
    from treeherder.log_parser import tasks

    @task
    def task_mock(*args, **kwargs):
        pass

    monkeypatch.setattr(tasks,
                        'parse_log',
                        task_mock)


@pytest.fixture
def result_set_stored(jm, initial_data, sample_resultset):

    """
    jm.store_result_set_data(
        sample_resultset['revision_hash'],
        sample_resultset['push_timestamp'],
        sample_resultset['revisions']
    )
    """
    jm.store_result_set_data(sample_resultset)

    return sample_resultset


@pytest.fixture(scope='function')
def mock_get_resultset(monkeypatch, result_set_stored):
    from treeherder.etl import common

    def _get_resultset(params):
        for k in params:
            rev = params[k][0]
            params[k] = {
                rev: {
                    'id': 1,
                    'revision_hash': result_set_stored[0]['revision_hash']
                }
            }
        return params

    monkeypatch.setattr(common, 'lookup_revisions', _get_resultset)

@pytest.fixture()
def refdata():
    """returns a patched RefDataManager for testing purpose"""

    import os
    from treeherder.model.derived import RefDataManager
    from tests.conftest import add_test_procs_file

    refdata = RefDataManager()

    proc_path = os.path.join(
        os.path.abspath(os.path.dirname(__file__)),
        'model',
        'derived',
        'test_refdata.json'
    )

    add_test_procs_file(refdata.dhub, 'reference', proc_path)
    return refdata