# -*- coding: utf-8 -*-
#
# Copyright © 2012 - 2017 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/>.
#
"""Helper classes for management commands."""

import logging

from django.core.management.base import BaseCommand, CommandError
from django.db import transaction

from weblate.lang.models import Language
from weblate.trans.models import Unit, SubProject, Translation
from weblate.logger import LOGGER


class WeblateCommand(BaseCommand):
    def execute(self, *args, **options):
        """Wrapper to configure logging prior execution."""
        verbosity = int(options['verbosity'])
        if verbosity > 1:
            LOGGER.setLevel(logging.DEBUG)
        elif verbosity == 1:
            LOGGER.setLevel(logging.INFO)
        else:
            LOGGER.setLevel(logging.ERROR)
        super(WeblateCommand, self).execute(*args, **options)

    def handle(self, *args, **options):
        """
        The actual logic of the command. Subclasses must implement
        this method.
        """
        raise NotImplementedError()


class WeblateComponentCommand(WeblateCommand):
    """Command which accepts project/component/--all params to process."""
    def add_arguments(self, parser):
        parser.add_argument(
            '--all',
            action='store_true',
            dest='all',
            default=False,
            help='process all components'
        )
        parser.add_argument(
            'component',
            nargs='*',
            help='Slug <project/component> of component to process'
        )

    def get_units(self, **options):
        """Return list of units matching parameters."""
        if options['all']:
            return Unit.objects.all()
        return Unit.objects.filter(
            translation__subproject__in=self.get_subprojects(**options)
        )

    def iterate_units(self, **options):
        """Memory effective iteration over units."""
        units = self.get_units(**options).order_by('pk')
        count = units.count()
        if not count:
            return

        current = 0
        last = units.order_by('-pk')[0].pk
        done = 0
        step = 1000

        # Iterate over chunks
        while current < last:
            self.stdout.write(
                'Processing {0:.1f}%'.format(done * 100.0 / count),
            )
            with transaction.atomic():
                step_units = units.filter(
                    pk__gt=current
                )[:step].prefetch_related(
                    'translation__language',
                    'translation__subproject',
                    'translation__subproject__project',
                )
                for unit in step_units:
                    current = unit.pk
                    done += 1
                    yield unit
        self.stdout.write('Operation completed')

    def get_translations(self, **options):
        """Return list of translations matching parameters."""
        return Translation.objects.filter(
            subproject__in=self.get_subprojects(**options)
        )

    def get_subprojects(self, **options):
        """Return list of components matching parameters."""
        if options['all']:
            # all components
            result = SubProject.objects.all()
        elif len(options['component']) == 0:
            # no argumets to filter projects
            self.stderr.write(
                'Please specify either --all '
                'or at least one <project/component>'
            )
            raise CommandError('Nothing to process!')
        else:
            # start with none and add found
            result = SubProject.objects.none()

            # process arguments
            for arg in options['component']:
                # do we have also component?
                parts = arg.split('/')

                # filter by project
                found = SubProject.objects.filter(project__slug=parts[0])

                # filter by component if available
                if len(parts) == 2:
                    found = found.filter(slug=parts[1])

                # warn on no match
                if found.count() == 0:
                    self.stderr.write(
                        '"{0}" did not match any components'.format(arg)
                    )
                    raise CommandError('Nothing to process!')

                # merge results
                result |= found

        return result

    def handle(self, *args, **options):
        """
        The actual logic of the command. Subclasses must implement
        this method.
        """
        raise NotImplementedError()


class WeblateLangCommand(WeblateComponentCommand):
    """
    Command accepting additional language parameter to filter
    list of languages to process.
    """
    def add_arguments(self, parser):
        super(WeblateLangCommand, self).add_arguments(parser)
        parser.add_argument(
            '--lang',
            action='store',
            dest='lang',
            default=None,
            help='Limit only to given languages (comma separated list)'
        )

    def get_units(self, **options):
        """Return list of units matching parameters."""
        units = super(WeblateLangCommand, self).get_units(**options)

        if options['lang'] is not None:
            units = units.filter(
                translation__language__code=options['lang']
            )

        return units

    def get_translations(self, **options):
        """Return list of translations matching parameters."""
        result = super(WeblateLangCommand, self).get_translations(
            **options
        )

        if options['lang'] is not None:
            langs = options['lang'].split(',')
            result = result.filter(language_code__in=langs)

        return result

    def handle(self, *args, **options):
        """
        The actual logic of the command. Subclasses must implement
        this method.
        """
        raise NotImplementedError()


class WeblateTranslationCommand(BaseCommand):
    """Command with target of one translation."""

    def add_arguments(self, parser):
        parser.add_argument(
            'project',
            help='Slug of project'
        )
        parser.add_argument(
            'component',
            help='Slug of component'
        )
        parser.add_argument(
            'language',
            help='Slug of language'
        )

    def get_translation(self, **options):
        """Get translation object"""
        try:
            component = SubProject.objects.get(
                project__slug=options['project'],
                slug=options['component'],
            )
        except SubProject.DoesNotExist:
            raise CommandError('No matching translation component found!')
        try:
            return Translation.objects.get(
                subproject=component,
                language__code=options['language'],
            )
        except Translation.DoesNotExist:
            if 'add' in options and options['add']:
                language = Language.objects.fuzzy_get(options['language'])
                if component.add_new_language(language, None):
                    return Translation.objects.get(
                        subproject=component,
                        language=language,
                    )
            raise CommandError('No matching translation project found!')

    def handle(self, *args, **options):
        """
        The actual logic of the command. Subclasses must implement
        this method.
        """
        raise NotImplementedError()
