# Part of Odoo. See LICENSE file for full copyright and licensing details.
import argparse
import io
import urllib.parse
import sys
import zipfile
from functools import partial
from pathlib import Path

import requests

from . import Command
from .server import report_configuration
from ..service.db import dump_db, exp_drop, exp_db_exist, exp_duplicate_database, exp_rename, restore_db
from ..tools import config

eprint = partial(print, file=sys.stderr, flush=True)

class Db(Command):
    """ Create, drop, dump, load databases """
    name = 'db'

    def run(self, cmdargs):
        """Command-line version of the database manager.

        Doesn't provide a `create` command as that's not useful. Commands are
        all filestore-aware.
        """
        parser = argparse.ArgumentParser(
            prog=f'{Path(sys.argv[0]).name} {self.name}',
            description=self.__doc__.strip()
        )
        parser.add_argument('-c', '--config')
        parser.add_argument('-D', '--data-dir')
        parser.add_argument('--addons-path')
        parser.add_argument('-r', '--db_user')
        parser.add_argument('-w', '--db_password')
        parser.add_argument('--pg_path')
        parser.add_argument('--db_host')
        parser.add_argument('--db_port')
        parser.add_argument('--db_sslmode')
        parser.set_defaults(func=lambda _: exit(parser.format_help()))

        subs = parser.add_subparsers()
        load = subs.add_parser(
            "load", help="Load a dump file.",
            description="Loads a dump file into odoo, dump file can be a URL. "
                 "If `database` is provided, uses that as the database name. "
                 "Otherwise uses the dump file name without extension.")
        load.set_defaults(func=self.load)
        load.add_argument(
            '-f', '--force', action='store_const', default=False, const=True,
            help="delete `database` database before loading if it exists"
        )
        load.add_argument(
            '-n', '--neutralize', action='store_const', default=False, const=True,
            help="neutralize the database after restore"
        )
        load.add_argument(
            'database', nargs='?',
            help="database to create, defaults to dump file's name "
                 "(without extension)"
        )
        load.add_argument('dump_file', help="zip or pg_dump file to load")

        dump = subs.add_parser(
            "dump", help="Create a dump with filestore.",
            description="Creates a dump file. The dump is always in zip format "
                        "(with filestore), to get a no-filestore format use "
                        "pg_dump directly.")
        dump.set_defaults(func=self.dump)
        dump.add_argument('database', help="database to dump")
        dump.add_argument(
            'dump_path', nargs='?', default='-',
            help="if provided, database is dumped to specified path, otherwise "
                 "or if `-`, dumped to stdout",
        )

        duplicate = subs.add_parser("duplicate", help="Duplicate a database including filestore.")
        duplicate.set_defaults(func=self.duplicate)
        duplicate.add_argument(
            '-f', '--force', action='store_const', default=False, const=True,
            help="delete `target` database before copying if it exists"
        )
        duplicate.add_argument(
            '-n', '--neutralize', action='store_const', default=False, const=True,
            help="neutralize the target database after duplicate"
        )
        duplicate.add_argument("source")
        duplicate.add_argument("target", help="database to copy `source` to, must not exist unless `-f` is specified in which case it will be dropped first")

        rename = subs.add_parser("rename", help="Rename a database including filestore.")
        rename.set_defaults(func=self.rename)
        rename.add_argument(
            '-f', '--force', action='store_const', default=False, const=True,
            help="delete `target` database before renaming if it exists"
        )
        rename.add_argument('source')
        rename.add_argument("target", help="database to rename `source` to, must not exist unless `-f` is specified, in which case it will be dropped first")

        drop = subs.add_parser("drop", help="Delete a database including filestore")
        drop.set_defaults(func=self.drop)
        drop.add_argument("database", help="database to delete")

        args = parser.parse_args(cmdargs)

        config.parse_config([
            val
            for k, v in vars(args).items()
            if v is not None
            if k in ['config', 'data_dir', 'addons_path'] or k.startswith(('db_', 'pg_'))
            for val in [
                '--data-dir' if k == 'data_dir'\
                    else '--addons-path' if k == 'addons_path'\
                    else f'--{k}',
                v,
            ]
        ])
        # force db management active to bypass check when only a
        # `check_db_management_enabled` version is available.
        config['list_db'] = True
        report_configuration()

        args.func(args)

    def load(self, args):
        db_name = args.database or Path(args.dump_file).stem
        self._check_target(db_name, delete_if_exists=args.force)

        url = urllib.parse.urlparse(args.dump_file)
        if url.scheme:
            eprint(f"Fetching {args.dump_file}...", end='')
            r = requests.get(args.dump_file, timeout=10)
            if not r.ok:
                exit(f" unable to fetch {args.dump_file}: {r.reason}")

            eprint(" done")
            dump_file = io.BytesIO(r.content)
        else:
            eprint(f"Restoring {args.dump_file}...")
            dump_file = args.dump_file

        if not zipfile.is_zipfile(dump_file):
            exit("Not a zipped dump file, use `pg_restore` to restore raw dumps,"
                 " and `psql` to execute sql dumps or scripts.")

        restore_db(db=db_name, dump_file=dump_file, copy=True, neutralize_database=args.neutralize)

    def dump(self, args):
        if args.dump_path == '-':
            dump_db(args.database, sys.stdout.buffer)
        else:
            with open(args.dump_path, 'wb') as f:
                dump_db(args.database, f)

    def duplicate(self, args):
        self._check_target(args.target, delete_if_exists=args.force)
        exp_duplicate_database(args.source, args.target, neutralize_database=args.neutralize)

    def rename(self, args):
        self._check_target(args.target, delete_if_exists=args.force)
        exp_rename(args.source, args.target)

    def drop(self, args):
        if not exp_drop(args.database):
            exit(f"Database {args.database} does not exist.")

    def _check_target(self, target, *, delete_if_exists):
        if exp_db_exist(target):
            if delete_if_exists:
                exp_drop(target)
            else:
                exit(f"Target database {target} exists, aborting.\n\n"
                     f"\tuse `--force` to delete the existing database anyway.")