# -*- coding: utf-8 -*-
#
# Copyright © 2012 - 2019 Michal Čihař <michal@cihar.com>
#
# This file is part of Weblate <https://weblate.org/>
#
# This program 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.
#
# This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.
#

from __future__ import unicode_literals

from django.conf import settings
from six.moves.urllib.error import HTTPError
from six.moves.urllib.parse import quote

from weblate.machinery.base import MachineTranslation, MissingConfiguration

AMAGAMA_LIVE = 'https://amagama-live.translatehouse.org/api/v1'


class TMServerTranslation(MachineTranslation):
    """tmserver machine translation support."""

    name = 'tmserver'

    def __init__(self):
        """Check configuration."""
        super(TMServerTranslation, self).__init__()
        self.url = self.get_server_url()

    @staticmethod
    def get_server_url():
        """Return URL of a server."""
        if settings.MT_TMSERVER is None:
            raise MissingConfiguration('Not configured tmserver URL')

        return settings.MT_TMSERVER.rstrip('/')

    def convert_language(self, language):
        """Convert language to service specific code."""
        return language.replace('-', '_').lower()

    def download_languages(self):
        """Download list of supported languages from a service."""
        try:
            # This will raise exception in DEBUG mode
            data = self.json_req('{0}/languages/'.format(self.url))
        except HTTPError as error:
            if error.code == 404:
                return []
            raise
        return [
            (src, tgt)
            for src in data['sourceLanguages']
            for tgt in data['targetLanguages']
        ]

    def is_supported(self, source, language):
        """Check whether given language combination is supported."""
        if not self.supported_languages:
            # Fallback for old tmserver which does not export list of
            # supported languages
            return True
        return (source, language) in self.supported_languages

    def download_translations(self, source, language, text, unit, user):
        """Download list of possible translations from a service."""
        url = '{0}/{1}/{2}/unit/{3}'.format(
            self.url,
            quote(source, b''),
            quote(language, b''),
            quote(text[:500].replace('\r', ' ').encode('utf-8'), b''),
        )
        response = self.json_req(url)

        return [
            {
                'text': line['target'],
                'quality': int(line['quality']),
                'service': self.name,
                'source': line['source'],
            }
            for line in response
        ]


class AmagamaTranslation(TMServerTranslation):
    """Specific instance of tmserver ran by Virtaal authors."""

    name = 'Amagama'

    @staticmethod
    def get_server_url():
        return AMAGAMA_LIVE
