"""
Helper functions for test tasks
"""


import os
import re
import subprocess

from paver.easy import cmdopts, sh, task

from pavelib.utils.envs import Env
from pavelib.utils.timer import timed
from pavelib.utils.db_utils import get_file_from_s3, upload_to_s3

try:
    from bok_choy.browser import browser
except ImportError:
    browser = None

MONGO_PORT_NUM = int(os.environ.get('EDXAPP_TEST_MONGO_PORT', '27017'))
MINIMUM_FIREFOX_VERSION = 28.0

COVERAGE_CACHE_BUCKET = "edx-tools-coverage-caches"
COVERAGE_CACHE_BASEPATH = "test_root/who_tests_what"
COVERAGE_CACHE_BASELINE = "who_tests_what.{}.baseline".format(os.environ.get('WTW_CONTEXT', 'all'))
WHO_TESTS_WHAT_DIFF = "who_tests_what.diff"


__test__ = False  # do not collect


@task
@timed
def clean_test_files():
    """
    Clean fixture files used by tests and .pyc files
    """
    sh("git clean -fqdx test_root/logs test_root/data test_root/staticfiles test_root/uploads")
    # This find command removes all the *.pyc files that aren't in the .git
    # directory.  See this blog post for more details:
    # http://nedbatchelder.com/blog/201505/be_careful_deleting_files_around_git.html
    sh(r"find . -name '.git' -prune -o -name '*.pyc' -exec rm {} \;")
    sh("rm -rf test_root/log/auto_screenshots/*")
    sh("rm -rf /tmp/mako_[cl]ms")


@task
@timed
def ensure_clean_package_lock():
    """
    Ensure no untracked changes have been made in the current git context.
    """
    sh("""
      git diff --name-only --exit-code package-lock.json ||
      (echo \"Dirty package-lock.json, run 'npm install' and commit the generated changes\" && exit 1)
    """)


def clean_dir(directory):
    """
    Delete all the files from the specified directory.
    """
    # We delete the files but preserve the directory structure
    # so that coverage.py has a place to put the reports.
    sh(f'find {directory} -type f -delete')


@task
@cmdopts([
    ('skip-clean', 'C', 'skip cleaning repository before running tests'),
    ('skip_clean', None, 'deprecated in favor of skip-clean'),
])
@timed
def clean_reports_dir(options):
    """
    Clean coverage files, to ensure that we don't use stale data to generate reports.
    """
    if getattr(options, 'skip_clean', False):
        print('--skip-clean is set, skipping...')
        return

    # We delete the files but preserve the directory structure
    # so that coverage.py has a place to put the reports.
    reports_dir = Env.REPORT_DIR.makedirs_p()
    clean_dir(reports_dir)


@task
@timed
def clean_mongo():
    """
    Clean mongo test databases
    """
    sh("mongo {host}:{port} {repo_root}/scripts/delete-mongo-test-dbs.js".format(
        host=Env.MONGO_HOST,
        port=MONGO_PORT_NUM,
        repo_root=Env.REPO_ROOT,
    ))


def check_firefox_version():
    """
    Check that firefox is the correct version.
    """
    if 'BOK_CHOY_HOSTNAME' in os.environ:
        # Firefox is running in a separate Docker container; get its version via Selenium
        driver = browser()
        capabilities = driver.capabilities
        if capabilities['browserName'].lower() == 'firefox':
            firefox_version_regex = re.compile(r'^\d+\.\d+')
            version_key = 'browserVersion' if 'browserVersion' in capabilities else 'version'
            try:
                firefox_ver = float(firefox_version_regex.search(capabilities[version_key]).group(0))
            except AttributeError:
                firefox_ver = 0.0
        else:
            firefox_ver = 0.0
        driver.close()
        if firefox_ver < MINIMUM_FIREFOX_VERSION:
            raise Exception(
                'Required firefox version not found.\n'
                'Expected: {expected_version}; Actual: {actual_version}.\n\n'
                'Make sure that the edx.devstack.firefox container is up-to-date and running\n'
                '\t{expected_version}'.format(
                    actual_version=firefox_ver,
                    expected_version=MINIMUM_FIREFOX_VERSION
                )
            )
        return

    # Firefox will be run as a local process
    expected_firefox_ver = "Mozilla Firefox " + str(MINIMUM_FIREFOX_VERSION)
    firefox_ver_string = subprocess.check_output("firefox --version", shell=True).strip()
    if isinstance(firefox_ver_string, bytes):
        firefox_ver_string = firefox_ver_string.decode('utf-8')
    firefox_version_regex = re.compile(r"Mozilla Firefox (\d+.\d+)")
    try:
        firefox_ver = float(firefox_version_regex.search(firefox_ver_string).group(1))
    except AttributeError:
        firefox_ver = 0.0

    if firefox_ver < MINIMUM_FIREFOX_VERSION:
        raise Exception(
            'Required firefox version not found.\n'
            'Expected: {expected_version}; Actual: {actual_version}.'.format(
                actual_version=firefox_ver,
                expected_version=expected_firefox_ver
            )
        )


@task
@cmdopts([
    ("compare-branch=", "b", "Branch to compare against, defaults to origin/master"),
])
@timed
def fetch_coverage_test_selection_data(options):
    """
    Set up the datafiles needed to run coverage-driven test selection (who-tests-what)
    """

    try:
        os.makedirs(COVERAGE_CACHE_BASEPATH)
    except OSError:
        pass  # Directory already exists

    sh('git diff $(git merge-base {} HEAD) > {}/{}'.format(
        getattr(options, 'compare_branch', 'origin/master'),
        COVERAGE_CACHE_BASEPATH,
        WHO_TESTS_WHAT_DIFF
    ))
    get_file_from_s3(COVERAGE_CACHE_BUCKET, COVERAGE_CACHE_BASELINE, COVERAGE_CACHE_BASEPATH)


@task
def upload_coverage_to_s3():
    upload_to_s3(
        COVERAGE_CACHE_BASELINE,
        'reports/{}.coverage'.format(os.environ.get('TEST_SUITE', '')),
        COVERAGE_CACHE_BUCKET,
        replace=True,
    )