#!/usr/bin/env python3
"""Command line utility for determining what jstests should run for the given changed files."""
import logging
import os
import re
import sys
from typing import Any, Dict, List, Set

import click
import structlog
from structlog.stdlib import LoggerFactory
from evergreen.api import EvergreenApi, RetryingEvergreenApi
from git import Repo

from shrub.v2 import ShrubProject, BuildVariant

# Get relative imports to work when the package is not installed on the PYTHONPATH.
from buildscripts.patch_builds.change_data import find_changed_files_in_repos, \
    generate_revision_map_from_manifest

if __name__ == "__main__" and __package__ is None:
    sys.path.append(os.path.dirname(os.path.dirname(os.path.abspath(__file__))))

# pylint: disable=wrong-import-position
import buildscripts.resmokelib.parser
import buildscripts.util.read_config as read_config
from buildscripts.burn_in_tests import DEFAULT_REPO_LOCATIONS, create_task_list_for_tests, \
    is_file_a_test_file
from buildscripts.ciconfig.evergreen import (
    EvergreenProjectConfig,
    ResmokeArgs,
    Task,
    parse_evergreen_file,
    Variant,
)
from buildscripts.evergreen_generate_resmoke_tasks import (
    CONFIG_FORMAT_FN,
    DEFAULT_CONFIG_VALUES,
    REQUIRED_CONFIG_KEYS,
    ConfigOptions,
    GenerateSubSuites,
    remove_gen_suffix,
    write_file_dict,
    Suite,
)
from buildscripts.patch_builds.selected_tests_service import SelectedTestsService

structlog.configure(logger_factory=LoggerFactory())
LOGGER = structlog.getLogger(__name__)

TASK_ID_EXPANSION = "task_id"
EVERGREEN_FILE = "etc/evergreen.yml"
EVG_CONFIG_FILE = ".evergreen.yml"
EXTERNAL_LOGGERS = {
    "evergreen",
    "git",
    "urllib3",
}
SELECTED_TESTS_CONFIG_DIR = "selected_tests_config"
RELATION_THRESHOLD = 0

COMPILE_TASK_PATTERN = re.compile(".*compile.*")
CONCURRENCY_TASK_PATTERN = re.compile("concurrency.*")
INTEGRATION_TASK_PATTERN = re.compile("integration.*")
FUZZER_TASK_PATTERN = re.compile(".*fuzz.*")
GENERATE_TASK_PATTERN = re.compile("burn_in.*")
MULTIVERSION_TASK_PATTERN = re.compile(".*multiversion.*")
LINT_TASK_PATTERN = re.compile("lint.*")
STITCH_TASK_PATTERN = re.compile("stitch.*")
EXCLUDE_TASK_PATTERNS = [
    COMPILE_TASK_PATTERN, CONCURRENCY_TASK_PATTERN, INTEGRATION_TASK_PATTERN, FUZZER_TASK_PATTERN,
    GENERATE_TASK_PATTERN, LINT_TASK_PATTERN, MULTIVERSION_TASK_PATTERN, STITCH_TASK_PATTERN
]

CPP_TASK_NAMES = [
    "dbtest",
    "idl_tests",
    "unittests",
]
PUBLISH_TASK_NAMES = [
    "package",
    "publish_packages",
    "push",
]
PYTHON_TESTS = ["buildscripts_test"]
EXCLUDE_TASK_LIST = [
    *CPP_TASK_NAMES,
    *PYTHON_TESTS,
    *PUBLISH_TASK_NAMES,
]


class SelectedTestsConfigOptions(ConfigOptions):
    """Retrieve configuration from a config file."""

    @classmethod
    # pylint: disable=too-many-arguments,W0221
    def from_file(cls, origin_variant_expansions: Dict[str, str],
                  selected_tests_variant_expansions: Dict[str, str], overwrites: Dict[str, Any],
                  required_keys: Set[str], defaults: Dict[str, Any], formats: Dict[str, type]):
        """
        Create an instance of SelectedTestsConfigOptions based on the given config file.

        :param origin_variant_expansions: Expansions of the origin build variant.
        :param selected_tests_variant_expansions: Expansions of the selected-tests variant.
        :param overwrites: Dict of configuration values to overwrite those listed in expansions.
        :param required_keys: Set of keys required by this config.
        :param defaults: Dict of default values for keys.
        :param formats: Dict with functions to format values before returning.
        :return: Instance of SelectedTestsConfigOptions.
        """
        return cls({**origin_variant_expansions, **selected_tests_variant_expansions, **overwrites},
                   required_keys, defaults, formats)

    @property
    def run_tests_task(self):
        """Return name of task name for s3 folder containing generated tasks config."""
        return remove_gen_suffix(self.name_of_generating_task)

    @property
    def run_tests_build_variant(self):
        """Return name of build_variant for s3 folder containing generated tasks config."""
        return self.name_of_generating_build_variant

    @property
    def run_tests_build_id(self):
        """Return name of build_id for s3 folder containing generated tasks config."""
        return self.name_of_generating_build_id

    @property
    def create_misc_suite(self):
        """Whether or not a _misc suite file should be created."""
        return not self.selected_tests_to_run

    @property
    def display_task_name(self):
        """Return the name to use as the display task."""
        return f"{self.task}_{self.variant}"

    @property
    def generated_suite_filename(self):
        """Filename for the generated suite file."""
        return f"{self.suite}_{self.variant}"

    @property
    def gen_task_set(self):
        """Return the set of tasks used to generate this configuration."""
        return set()


def _configure_logging(verbose: bool):
    """
    Configure logging for the application.

    :param verbose: If True set log level to DEBUG.
    """
    level = logging.DEBUG if verbose else logging.INFO
    logging.basicConfig(
        format="[%(asctime)s - %(name)s - %(levelname)s] %(message)s",
        level=level,
        stream=sys.stdout,
    )
    for log_name in EXTERNAL_LOGGERS:
        logging.getLogger(log_name).setLevel(logging.WARNING)


def _find_selected_test_files(selected_tests_service: SelectedTestsService,
                              changed_files: Set[str]) -> Set[str]:
    """
    Request related test files from selected-tests service and filter invalid files.

    :param selected_tests_service: Selected-tests service.
    :param changed_files: Set of changed_files.
    :return: Set of test files returned by selected-tests service that are valid test files.
    """
    test_mappings = selected_tests_service.get_test_mappings(RELATION_THRESHOLD, changed_files)
    return {
        test_file["name"]
        for test_mapping in test_mappings for test_file in test_mapping["test_files"]
        if is_file_a_test_file(test_file["name"])
    }


def _exclude_task(task: Task) -> bool:
    """
    Check whether a task should be excluded.

    :param task: Task to get info for.
    :return: True if this task should be excluded.
    """
    if task.name in EXCLUDE_TASK_LIST or any(
            regex.match(task.name) for regex in EXCLUDE_TASK_PATTERNS):
        LOGGER.debug("Excluding task from analysis because it is not a jstest", task=task.name)
        return True
    return False


def _find_selected_tasks(selected_tests_service: SelectedTestsService, changed_files: Set[str]) -> \
        Set[str]:
    """
    Request tasks from selected-tests and filter out tasks that don't exist or should be excluded.

    :param selected_tests_service: Selected-tests service.
    :param changed_files: Set of changed_files.
    :return: Set of tasks returned by selected-tests service that should not be excluded.
    """
    task_mappings = selected_tests_service.get_task_mappings(RELATION_THRESHOLD, changed_files)
    return {task["name"] for task_mapping in task_mappings for task in task_mapping["tasks"]}


def _find_task(build_variant_config: Variant, task_name: str) -> Task:
    """
    Look up shrub config for task.

    :param build_variant_config: Config of build variant to collect task info from.
    :param task_name: Name of task to get info for.
    :return: Task configuration.
    """
    task = build_variant_config.get_task(task_name)
    if not task:
        task = build_variant_config.get_task(task_name + "_gen")
    return task


def _get_selected_tests_task_config(
        selected_tests_variant_expansions: Dict[str, str]) -> Dict[str, str]:
    """
    Look up task config of the selected tests task.

    :param selected_tests_variant_expansions: Expansions of the selected-tests variant.
    :return: Task configuration values.
    """
    return {
        "name_of_generating_task": selected_tests_variant_expansions["task_name"],
        "name_of_generating_build_variant": selected_tests_variant_expansions["build_variant"],
        "name_of_generating_build_id": selected_tests_variant_expansions["build_id"]
    }


def _get_evg_task_config(
        selected_tests_variant_expansions: Dict[str, str],
        task: Task,
        build_variant_config: Variant,
) -> Dict[str, Any]:
    """
    Look up task config of the task to be generated.

    :param selected_tests_variant_expansions: Expansions of the selected-tests variant.
    :param task: Task to get info for.
    :param build_variant_config: Config of build variant to collect task info from.
    :return: Task configuration values.
    """
    LOGGER.info("Calculating evg_task_config values for task", task=task.name)
    if task.is_generate_resmoke_task:
        task_vars = task.generate_resmoke_tasks_command["vars"]
    else:
        task_vars = task.run_tests_command["vars"]
        task_vars.update({"fallback_num_sub_suites": "1"})

    suite_name = ResmokeArgs.get_arg(task_vars["resmoke_args"], "suites")
    if suite_name:
        task_vars.update({"suite": suite_name})

    # the suites argument will run all tests in a suite even when individual
    # tests are specified in resmoke_args, so we remove it
    resmoke_args_without_suites = ResmokeArgs.remove_arg(task_vars["resmoke_args"], "suites")
    task_vars["resmoke_args"] = resmoke_args_without_suites

    selected_tests_task_config = _get_selected_tests_task_config(selected_tests_variant_expansions)

    return {
        "task_name": task.name, "build_variant": build_variant_config.name, **task_vars,
        **selected_tests_task_config
    }


def _update_config_with_task(evg_api: EvergreenApi, build_variant: BuildVariant,
                             config_options: SelectedTestsConfigOptions,
                             config_dict_of_suites_and_tasks: Dict[str, str]) -> None:
    """
    Generate the suites config and the task shrub config for a given task config.

    :param evg_api: Evergreen API object.
    :param build_variant: Build variant to add tasks to.
    :param shrub_project: Shrub configuration for task.
    :param config_options: Task configuration options.
    :param config_dict_of_suites_and_tasks: Dict of shrub configs and suite file contents.
    """
    task_generator = GenerateSubSuites(evg_api, config_options)
    suites = task_generator.get_suites()

    config_dict_of_suites = task_generator.generate_suites_config(suites)
    config_dict_of_suites_and_tasks.update(config_dict_of_suites)

    task_generator.add_suites_to_build_variant(suites, build_variant)


def _get_task_configs_for_test_mappings(selected_tests_variant_expansions: Dict[str, str],
                                        tests_by_task: Dict[str, Any],
                                        build_variant_config: Variant) -> Dict[str, dict]:
    """
    For test mappings, generate a dict containing task names and their config settings.

    :param selected_tests_variant_expansions: Expansions of the selected-tests variant.
    :param tests_by_task: Dictionary of tests and tasks to run.
    :param build_variant_config: Config of build variant to collect task info from.
    :return: Dict of task names and their config settings.
    """
    evg_task_configs = {}
    for task_name, test_list_info in tests_by_task.items():
        task = _find_task(build_variant_config, task_name)
        if task and not _exclude_task(task):
            evg_task_config = _get_evg_task_config(selected_tests_variant_expansions, task,
                                                   build_variant_config)
            evg_task_config.update({"selected_tests_to_run": set(test_list_info["tests"])})
            evg_task_configs[task.name] = evg_task_config

    return evg_task_configs


def _get_task_configs_for_task_mappings(selected_tests_variant_expansions: Dict[str, str],
                                        related_tasks: List[str],
                                        build_variant_config: Variant) -> Dict[str, dict]:
    """
    For task mappings, generate a dict containing task names and their config settings.

    :param selected_tests_variant_expansions: Expansions of the selected-tests variant.
    :param related_tasks: List of tasks to run.
    :param build_variant_config: Config of build variant to collect task info from.
    :return: Dict of task names and their config settings.
    """
    evg_task_configs = {}
    for task_name in related_tasks:
        task = _find_task(build_variant_config, task_name)
        if task and not _exclude_task(task):
            evg_task_config = _get_evg_task_config(selected_tests_variant_expansions, task,
                                                   build_variant_config)
            evg_task_configs[task.name] = evg_task_config

    return evg_task_configs


def _remove_repo_path_prefix(file_path: str) -> str:
    """
    Remove the repo path prefix from the filepath.

    :param file_path: Path of the changed file.
    :return: Path of the changed file without prefix.
    """
    for repo_path in DEFAULT_REPO_LOCATIONS:
        if repo_path != ".":
            if repo_path.startswith("./"):
                repo_path = repo_path[2:]
                file_path = re.sub(repo_path + "/", '', file_path)
    return file_path


def _get_task_configs(evg_conf: EvergreenProjectConfig,
                      selected_tests_service: SelectedTestsService,
                      selected_tests_variant_expansions: Dict[str, str],
                      build_variant_config: Variant, changed_files: Set[str]) -> Dict[str, Dict]:
    """
    Get task configurations for the tasks to be generated.

    :param evg_conf: Evergreen configuration.
    :param selected_tests_service: Selected-tests service.
    :param selected_tests_variant_expansions: Expansions of the selected-tests variant.
    :param build_variant_config: Config of build variant to collect task info from.
    :param changed_files: Set of changed_files.
    :return: Task configurations.
    """
    task_configs = {}

    related_test_files = _find_selected_test_files(selected_tests_service, changed_files)
    LOGGER.info("related test files found", related_test_files=related_test_files,
                variant=build_variant_config.name)

    if related_test_files:
        tests_by_task = create_task_list_for_tests(related_test_files, build_variant_config.name,
                                                   evg_conf)
        LOGGER.info("tests and tasks found", tests_by_task=tests_by_task)

        test_mapping_task_configs = _get_task_configs_for_test_mappings(
            selected_tests_variant_expansions, tests_by_task, build_variant_config)
        task_configs.update(test_mapping_task_configs)

    related_tasks = _find_selected_tasks(selected_tests_service, changed_files)
    LOGGER.info("related tasks found", related_tasks=related_tasks,
                variant=build_variant_config.name)
    if related_tasks:
        task_mapping_task_configs = _get_task_configs_for_task_mappings(
            selected_tests_variant_expansions, related_tasks, build_variant_config)
        # task_mapping_task_configs will overwrite test_mapping_task_configs
        # because task_mapping_task_configs will run all tests rather than a subset of tests and we
        # should err on the side of running all tests
        task_configs.update(task_mapping_task_configs)

    return task_configs


def remove_task_configs_already_in_build(task_configs: Dict[str, Dict], evg_api: EvergreenApi,
                                         build_variant_config: Variant, version_id: str) -> None:
    """
    Remove the task_configs that exist for tasks that have been pulled into the build manually.

    :param task_configs: The task configurations for the tasks to be generated.
    :param evg_api: Evergreen API object.
    :param build_variant_config: Config of build variant to collect task info from.
    :param version_id: The version_id of the version running selected tests.
    """
    version = evg_api.version_by_id(version_id)

    try:
        build = version.build_by_variant(build_variant_config.name)
    except KeyError:
        LOGGER.debug("No build exists on this build variant for this version yet",
                     variant=build_variant_config.name)
        build = None

    if build:
        tasks_already_in_build = build.get_tasks()
        for task in tasks_already_in_build:
            if task.display_name in task_configs:
                LOGGER.info(
                    "Will not generate task that has already been pulled into the build manually",
                    variant=build_variant_config.name, task_already_in_build=task.display_name)
                del task_configs[task.display_name]


def run(evg_api: EvergreenApi, evg_conf: EvergreenProjectConfig,
        selected_tests_service: SelectedTestsService,
        selected_tests_variant_expansions: Dict[str, str], repos: List[Repo]) -> Dict[str, str]:
    # pylint: disable=too-many-locals
    """
    Run code to select tasks to run based on test and task mappings for each of the build variants.

    :param evg_api: Evergreen API object.
    :param evg_conf: Evergreen configuration.
    :param selected_tests_service: Selected-tests service.
    :param selected_tests_variant_expansions: Expansions of the selected-tests variant.
    :param repos: List of repos containing changed files.
    :return: Dict of files and file contents for generated tasks.
    """
    config_dict_of_suites_and_tasks = {}

    task_id = selected_tests_variant_expansions[TASK_ID_EXPANSION]
    revision_map = generate_revision_map_from_manifest(repos, task_id, evg_api)
    changed_files = find_changed_files_in_repos(repos, revision_map)
    changed_files = {_remove_repo_path_prefix(file_path) for file_path in changed_files}
    LOGGER.info("Found changed files", files=changed_files)

    shrub_project = ShrubProject()
    for build_variant_config in evg_conf.get_required_variants():
        shrub_build_variant = BuildVariant(build_variant_config.name)
        origin_variant_expansions = build_variant_config.expansions

        task_configs = _get_task_configs(evg_conf, selected_tests_service,
                                         selected_tests_variant_expansions, build_variant_config,
                                         changed_files)

        remove_task_configs_already_in_build(task_configs, evg_api, build_variant_config,
                                             selected_tests_variant_expansions["version_id"])

        for task_config in task_configs.values():
            Suite.reset_current_index()
            config_options = SelectedTestsConfigOptions.from_file(
                origin_variant_expansions,
                selected_tests_variant_expansions,
                task_config,
                REQUIRED_CONFIG_KEYS,
                DEFAULT_CONFIG_VALUES,
                CONFIG_FORMAT_FN,
            )
            _update_config_with_task(evg_api, shrub_build_variant, config_options,
                                     config_dict_of_suites_and_tasks)

        shrub_project.add_build_variant(shrub_build_variant)

    config_dict_of_suites_and_tasks["selected_tests_config.json"] = shrub_project.json()
    return config_dict_of_suites_and_tasks


@click.command()
@click.option("--verbose", "verbose", default=False, is_flag=True, help="Enable extra logging.")
@click.option(
    "--expansion-file",
    "expansion_file",
    type=str,
    required=True,
    help="Location of expansions file generated by evergreen.",
)
@click.option(
    "--evg-api-config",
    "evg_api_config",
    default=EVG_CONFIG_FILE,
    metavar="FILE",
    help="Configuration file with connection info for Evergreen API.",
)
@click.option(
    "--selected-tests-config",
    "selected_tests_config",
    required=True,
    metavar="FILE",
    help="Configuration file with connection info for selected tests service.",
)
def main(
        verbose: bool,
        expansion_file: str,
        evg_api_config: str,
        selected_tests_config: str,
):
    """
    Select tasks to be run based on changed files in a patch build.

    :param verbose: Log extra debug information.
    :param expansion_file: Configuration file.
    :param evg_api_config: Location of configuration file to connect to evergreen.
    :param selected_tests_config: Location of config file to connect to elected-tests service.
    """
    _configure_logging(verbose)

    evg_api = RetryingEvergreenApi.get_api(config_file=evg_api_config)
    evg_conf = parse_evergreen_file(EVERGREEN_FILE)
    selected_tests_service = SelectedTestsService.from_file(selected_tests_config)
    repos = [Repo(x) for x in DEFAULT_REPO_LOCATIONS if os.path.isdir(x)]

    buildscripts.resmokelib.parser.set_run_options()

    task_expansions = read_config.read_config_file(expansion_file)

    config_dict_of_suites_and_tasks = run(evg_api, evg_conf, selected_tests_service,
                                          task_expansions, repos)
    write_file_dict(SELECTED_TESTS_CONFIG_DIR, config_dict_of_suites_and_tasks)


if __name__ == "__main__":
    main()  # pylint: disable=no-value-for-parameter