# GNU MediaGoblin -- federated, autonomous media hosting
# Copyright (C) 2011 MediaGoblin contributors.  See AUTHORS.
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import mediagoblin.mg_globals as mg_globals
import uuid
from os.path import splitext
from cgi import FieldStorage

from werkzeug.utils import secure_filename

from mediagoblin.db.util import ObjectId
from mediagoblin.tools.text import cleaned_markdown_conversion, convert_to_tag_list_of_dicts
from mediagoblin.tools.translate import pass_to_ugettext as _
from mediagoblin.tools.response import render_to_response, redirect
from mediagoblin.decorators import require_active_login
from mediagoblin.submit import forms as submit_forms, security
from mediagoblin.process_media import process_media, mark_entry_failed
from mediagoblin.messages import add_message, SUCCESS


@require_active_login
def submit_start(request):
    """
    First view for submitting a file.
    """
    submit_form = submit_forms.SubmitStartForm(request.POST)

    if request.method == 'POST' and submit_form.validate():
        if not (request.POST.has_key('file')
                and isinstance(request.POST['file'], FieldStorage)
                and request.POST['file'].file):
            submit_form.file.errors.append(
                _(u'You must provide a file.'))
        elif not security.check_filetype(request.POST['file']):
            submit_form.file.errors.append(
                _(u"The file doesn't seem to be an image!"))
        else:
            filename = request.POST['file'].filename

            # create entry and save in database
            entry = request.db.MediaEntry()
            entry['_id'] = ObjectId()
            entry['title'] = (
                unicode(request.POST['title'])
                or unicode(splitext(filename)[0]))

            entry['description'] = unicode(request.POST.get('description'))
            entry['description_html'] = cleaned_markdown_conversion(
                entry['description'])

            entry['license'] = (
                unicode(request.POST.get('license'))
                or '')
            
            entry['media_type'] = u'image' # heh
            entry['uploader'] = request.user['_id']

            # Process the user's folksonomy "tags"
            entry['tags'] = convert_to_tag_list_of_dicts(
                                request.POST.get('tags'))

            # Generate a slug from the title
            entry.generate_slug()

            # Now store generate the queueing related filename
            queue_filepath = request.app.queue_store.get_unique_filepath(
                ['media_entries',
                 unicode(entry['_id']),
                 secure_filename(filename)])

            # queue appropriately
            queue_file = request.app.queue_store.get_file(
                queue_filepath, 'wb')

            with queue_file:
                queue_file.write(request.POST['file'].file.read())

            # Add queued filename to the entry
            entry['queued_media_file'] = queue_filepath

            # We generate this ourselves so we know what the taks id is for
            # retrieval later.
            # (If we got it off the task's auto-generation, there'd be a risk of
            # a race condition when we'd save after sending off the task)
            task_id = unicode(uuid.uuid4())
            entry['queued_task_id'] = task_id

            # Save now so we have this data before kicking off processing
            entry.save(validate=True)

            # Pass off to processing
            #
            # (... don't change entry after this point to avoid race
            # conditions with changes to the document via processing code)
            try:
                process_media.apply_async(
                    [unicode(entry['_id'])], {},
                    task_id=task_id)
            except BaseException as exc:
                # The purpose of this section is because when running in "lazy"
                # or always-eager-with-exceptions-propagated celery mode that
                # the failure handling won't happen on Celery end.  Since we
                # expect a lot of users to run things in this way we have to
                # capture stuff here.
                #
                # ... not completely the diaper pattern because the exception is
                # re-raised :)
                mark_entry_failed(entry[u'_id'], exc)
                # re-raise the exception
                raise

            add_message(request, SUCCESS, _('Woohoo! Submitted!'))

            return redirect(request, "mediagoblin.user_pages.user_home",
                            user = request.user['username'])

    return render_to_response(
        request,
        'mediagoblin/submit/start.html',
        {'submit_form': submit_form,
         'app_config': mg_globals.app_config})