# wikiget - CLI tool for downloading files from Wikimedia sites
# Copyright (C) 2018-2023 Cody Logan and contributors
# SPDX-License-Identifier: GPL-3.0-or-later
#
# Wikiget is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Wikiget is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with Wikiget. If not, see <https://www.gnu.org/licenses/>.

import logging
import os
import sys

from mwclient import APIError, InvalidResponse, LoginError, Site
from requests import ConnectionError, HTTPError
from tqdm import tqdm

import wikiget
from wikiget.file import File
from wikiget.parse import get_dest
from wikiget.validations import verify_hash


def query_api(filename, site_name, args):
    logging.debug(f"User agent: {wikiget.USER_AGENT}")

    # connect to site and identify ourselves
    logging.info(f"Site name: {site_name}")
    try:
        site = Site(site_name, path=args.path, clients_useragent=wikiget.USER_AGENT)
        if args.username and args.password:
            site.login(args.username, args.password)
    except ConnectionError as e:
        # usually this means there is no such site, or there's no network connection,
        # though it could be a certificate problem
        logging.error("Could not connect to specified site")
        logging.debug(e)
        raise
    except HTTPError as e:
        # most likely a 403 forbidden or 404 not found error for api.php
        logging.error(
            "Could not find the specified wiki's api.php. Check the value of --path."
        )
        logging.debug(e)
        raise
    except (InvalidResponse, LoginError) as e:
        # InvalidResponse: site exists, but we couldn't communicate with the API
        # endpoint for some reason other than an HTTP error.
        # LoginError: missing or invalid credentials
        logging.error(e)
        raise

    # get info about the target file
    try:
        file = site.images[filename]
    except APIError as e:
        # an API error at this point likely means access is denied, which could happen
        # with a private wiki
        logging.error(
            "Access denied. Try providing credentials with --username and --password."
        )
        for i in e.args:
            logging.debug(i)
        raise

    return file, site


def prep_download(dl, args):
    filename, dest, site_name = get_dest(dl, args)
    file = File(filename, dest)
    file.object, file.site = query_api(file.name, site_name, args)
    return file


def download(f, args):
    file = f.object
    filename = f.name
    site = f.site
    dest = f.dest

    if file.imageinfo != {}:
        # file exists either locally or at a common repository, like Wikimedia Commons
        file_url = file.imageinfo["url"]
        file_size = file.imageinfo["size"]
        file_sha1 = file.imageinfo["sha1"]

        filename_log = f"Downloading '{filename}' ({file_size} bytes) from {site.host}"
        if args.output:
            filename_log += f" to '{dest}'"
        logging.info(filename_log)
        logging.info(f"{file_url}")

        if os.path.isfile(dest) and not args.force:
            logging.warning(
                f"File '{dest}' already exists, skipping download (use -f to force)"
            )
        else:
            try:
                fd = open(dest, "wb")
            except OSError as e:
                logging.error(
                    "File could not be written. The following error was encountered:"
                )
                logging.error(e)
                sys.exit(1)
            else:
                # download the file(s)
                if args.verbose >= wikiget.STD_VERBOSE:
                    leave_bars = True
                else:
                    leave_bars = False
                with tqdm(
                    leave=leave_bars,
                    total=file_size,
                    unit="B",
                    unit_scale=True,
                    unit_divisor=wikiget.CHUNKSIZE,
                ) as progress_bar:
                    with fd:
                        res = site.connection.get(file_url, stream=True)
                        progress_bar.set_postfix(file=dest, refresh=False)
                        for chunk in res.iter_content(wikiget.CHUNKSIZE):
                            fd.write(chunk)
                            progress_bar.update(len(chunk))

            # verify file integrity and log details
            dl_sha1 = verify_hash(dest)

            logging.info(f"Remote file SHA1 is {file_sha1}")
            logging.info(f"Local file SHA1 is {dl_sha1}")
            if dl_sha1 == file_sha1:
                logging.info("Hashes match!")
                # at this point, we've successfully downloaded the file
                success_log = f"'{filename}' downloaded"
                if args.output:
                    success_log += f" to '{dest}'"
                logging.info(success_log)
            else:
                logging.error("Hash mismatch! Downloaded file may be corrupt.")
                # TODO: log but don't quit while in batch mode
                sys.exit(1)

    else:
        # no file information returned
        logging.error(f"Target '{filename}' does not appear to be a valid file")
        # TODO: log but don't quit while in batch mode
        sys.exit(1)