# -*- coding: utf-8 -*-
import codecs
import datetime
import logging
import os
from django.apps import apps
from django.contrib import messages
from django.core.exceptions import PermissionDenied
from django.urls import reverse_lazy
from django.utils.translation import ugettext as _
from django.views import generic

from .forms import UploadForm

app_config = apps.get_containing_app_config(__package__)
logger = logging.getLogger(__name__)


class UploadView(generic.edit.FormView):
    initial = {
        # 'name': u'heinzel',
        # 'email_address': 'heinzel@heinzelwelt.de',
        # 'group': 'Alte Maschinen',
        # 'title': u'Mein Beitrag',
        # 'description': 'Foobar',
        # 'accepted': True,
    }
    template_name = 'dav_submission/upload_form.html'
    form_class = UploadForm
    success_url = reverse_lazy('dav_submission:success')

    def _sanitize_filename(self, input):
        max_length = None
        discard_chars = u''
        allowed_chars = (u'abcdefghijklmnopqrstuvwxyz'
                         u'äöüß'
                         u'ABCDEFGHIJKLMNOPQRSTUVWXYZ'
                         u'ÄÖÜ'
                         u'0123456789'
                         u'._-')
        non_allowed_substitute = u'_'
        space_substitute = u'_'

        if space_substitute is None:
            space_substitute = non_allowed_substitute

        r = ''
        for c in input:
            if c in discard_chars:
                continue
            elif allowed_chars is not None and c in allowed_chars:
                r += c
            elif allowed_chars is None and c.isalnum():
                r += c
            elif c.isspace():
                r += space_substitute
            else:
                r += non_allowed_substitute

        return r[:max_length]

    def get_context_data(self, **kwargs):
        c = super(UploadView, self).get_context_data(**kwargs)
        c['show_upload_form'] = app_config.settings.enable_upload
        return c

    def form_valid(self, form):
        base_path = app_config.settings.upload_path

        subdir_format_str = u'{datetime}--{title}'
        now = datetime.datetime.now()
        subdir_format_kwargs = {'datetime': now.strftime('%Y-%m-%d--%H%M%S'),
                                'date': now.strftime('%Y-%m-%d'),
                                'time': now.strftime('%H-%M-%S'),
                                'title': form.cleaned_data['title']}
        subdir_name = self._sanitize_filename(
            subdir_format_str.format(**subdir_format_kwargs)
        )
        subdir_path = os.path.join(base_path, subdir_name)

        if os.path.isdir(subdir_path):
            message = _(u'Es gibt bereits einen Beitrag mit dem Titel "%(title)s".') % subdir_format_kwargs
            messages.error(self.request, message)
            form.add_error('title', message)
            return self.render_to_response(self.get_context_data(form=form))

        os.makedirs(subdir_path)

        try:
            metadata_format_str = u"""Absender: {name} <{email_address}>
Gruppe: {group}
Datum: {date} {time}
Titel: {title}
Beschreibung:
{description}
"""
            metadata_format_kwargs = {
                'date': now.strftime('%d.%m.%Y'),
                'time': now.strftime('%H:%M:%S'),
                'name': form.cleaned_data['name'],
                'email_address': form.cleaned_data['email_address'],
                'group': form.cleaned_data['group'],
                'title': form.cleaned_data['title'],
                'description': form.cleaned_data['description'],
            }

            metadata = metadata_format_str.format(**metadata_format_kwargs)
            metadata_file_name = app_config.settings.metadata_file_name
            metadata_file_path = os.path.join(subdir_path, metadata_file_name)

            with codecs.open(metadata_file_path, 'w', encoding='utf-8') as metadata_file:
                metadata_file.write(metadata)
        except Exception as e:
            message = _(u'Jetzt ist irgendwas schief gelaufen.')
            messages.error(self.request, message)
            logger.error('dav_submission.views.UploadView.form_valid(): Catched Exception #2: %s', str(e))
            return super(UploadView, self).form_valid(form)

        try:
            for input_file in form.files.getlist('files'):
                file_name = self._sanitize_filename(input_file.name)
                file_path = os.path.join(subdir_path, file_name)

                if os.path.exists(file_path):
                    message = _(u'Die Datei %(name)s haben wir bereits.') % {'name': input_file.name}
                    messages.error(self.request, message)
                    continue

                with open(file_path, 'wb+') as local_file:
                    for chunk in input_file.chunks():
                        local_file.write(chunk)

                size = os.path.getsize(file_path)
                if size > (1024 * 1024):
                    size_str = u'%s MiB' % ('%.3f' % (size / 1024.0 / 1024.0)).rstrip('0').rstrip('.')
                elif size > 1024:
                    size_str = u'%s KiB' % ('%.3f' % (size / 1024.0)).rstrip('0').rstrip('.')
                else:
                    size_str = u'%d Byte' % size
                message = _(u'Datei erfolgreich hochgeladen: %(name)s (%(size)s)') % {'name': input_file.name,
                                                                                      'size': size_str}
                messages.success(self.request, message)
        except Exception as e:
            message = _(u'Jetzt ist irgendwas schief gelaufen.')
            messages.error(self.request, message)
            logger.error('dav_submission.views.UploadView.form_valid(): Catched Exception #3: %s', str(e))
            return super(UploadView, self).form_valid(form)

        return super(UploadView, self).form_valid(form)

    def post(self, request, *args, **kwargs):
        if not app_config.settings.enable_upload:
            raise PermissionDenied(_(u'Der Upload ist noch nicht freigeschaltet.'))
        return super(UploadView, self).post(request, *args, **kwargs)


class SuccessView(generic.TemplateView):
    template_name = 'dav_submission/success.html'