#!/usr/bin/env python

# Copyright Mozilla Foundation
#
# Licensed under the Apache License, Version 2.0 (the "License");
# you may not use this file except in compliance with the License.
# You may obtain a copy of the License at
#
# http://www.apache.org/licenses/LICENSE-2.0
#
# Unless required by applicable law or agreed to in writing, software
# distributed under the License is distributed on an "AS IS" BASIS,
# WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
# See the License for the specific language governing permissions and
# limitations under the License.

from __future__ import annotations

import logging
import sys
from argparse import ArgumentParser, RawDescriptionHelpFormatter
from enum import Enum
from importlib.util import module_from_spec, spec_from_file_location
from os.path import abspath
from textwrap import dedent
from traceback import format_exc

from moz.l10n.migrate import all_migrations
from moz.l10n.paths.android_locale import get_android_locale
from moz.l10n.paths.config import L10nConfigPaths
from moz.l10n.paths.discover import L10nDiscoverPaths, MissingSourceDirectoryError

log = logging.getLogger(__name__)

Result = Enum("Result", ("OK", "SKIP", "UNSUPPORTED", "FAIL"))


def cli(args: list[str] | None = None) -> None:
    parser = ArgumentParser(
        description=dedent(
            """
            Apply migrations to localization resources.

            Returns 0 on success, 1 on internal error, or 2 on argument error.
            """
        ),
        formatter_class=RawDescriptionHelpFormatter,
    )
    parser.add_argument(
        "-q", "--quiet", action="store_true", help="only log input argument errors"
    )
    parser.add_argument(
        "-v", "--verbose", action="count", default=0, help="increase logging verbosity"
    )
    parser.add_argument(
        "-n",
        "--dry-run",
        action="store_true",
        help="do not apply changes to file system",
    )
    parser.add_argument(
        "--config", metavar="PATH", type=str, help="path to l10n.toml config file"
    )
    parser.add_argument(
        "--root",
        metavar="PATH",
        type=str,
        help="path to localization root, if --config is not set",
    )
    parser.add_argument(
        "--ref",
        metavar="PATH",
        type=str,
        help="path to localization reference root, if separate from --root",
    )
    parser.add_argument(
        "migration", nargs="+", type=str, help="path to migration module(s)"
    )
    ns = parser.parse_args(args)

    log_level = (
        logging.ERROR
        if ns.quiet
        else (
            logging.WARNING
            if ns.verbose == 0
            else logging.INFO
            if ns.verbose == 1
            else logging.DEBUG
        )
    )
    logging.basicConfig(format="%(message)s", level=log_level)

    try:
        apply_migrations(
            ns.migration,
            config_path=ns.config,
            discover_root=ns.root,
            discover_ref_root=ns.ref,
            dry_run=ns.dry_run,
        )
    except MissingSourceDirectoryError:
        log.error(f"Reference root not found in {ns.ref or ns.root}")
        log.debug(format_exc())
        sys.exit(2)
    except ValueError as err:
        log.error(str(*err.args))
        log.debug(format_exc())
        sys.exit(2)
    except Exception:
        log.warning(format_exc())
        sys.exit(1)


def apply_migrations(
    migration_paths: list[str],
    *,
    config_path: str | None = None,
    discover_root: str | None = None,
    discover_ref_root: str | None = None,
    dry_run: bool = False,
) -> None:
    paths: L10nConfigPaths | L10nDiscoverPaths | None = None
    if config_path:
        if discover_root:
            raise ValueError("--config and --root must not be both set.")
        paths = L10nConfigPaths(
            config_path, locale_map={"android_locale": get_android_locale}
        )
    elif discover_root:
        if discover_ref_root is not None:
            discover_ref_root = abspath(discover_ref_root)
        paths = L10nDiscoverPaths(abspath(discover_root), ref_root=discover_ref_root)

    all_migrations.clear()
    for idx, migration_path in enumerate(migration_paths):
        name = f"migration_{idx}"
        spec = spec_from_file_location(name, migration_path)
        if spec is None or spec.loader is None:
            raise ValueError(f"Loading {migration_path} failed")
        module = module_from_spec(spec)
        sys.modules[name] = module
        try:
            spec.loader.exec_module(module)
        except Exception as err:
            raise ValueError(f"Loading {migration_path} failed") from err
    if not all_migrations:
        raise ValueError("No migrations found")

    for migration in all_migrations:
        if paths is not None:
            migration.set_paths(paths)
        migration.apply(dry_run=dry_run)


if __name__ == "__main__":
    cli()