forms.py

# -*- coding: utf-8 -*-
#
# This file is part of FNP-Redakcja, licensed under GNU Affero GPLv3 or later.
# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
#
import re
from urllib2 import urlopen
from django import forms
from django.utils.translation import ugettext_lazy as _
from cover.models import Image

class ImageAddForm(forms.ModelForm):
    class Meta:
        model = Image

class ImageEditForm(forms.ModelForm):
    """Form used for editing a Book."""
    class Meta:
        model = Image
        exclude = ['download_url']


class ReadonlyImageEditForm(ImageEditForm):
    """Form used for not editing a Book."""

    def __init__(self, *args, **kwargs):
        ret = super(ReadonlyImageEditForm, self).__init__(*args, **kwargs)
        for field in self.fields.values():
            field.widget.attrs.update({"readonly": True})
        return ret

    def save(self, *args, **kwargs):
        raise AssertionError, "ReadonlyImageEditForm should not be saved."


class FlickrForm(forms.Form):
    source_url = forms.URLField(label=_('Flickr URL'))

    def clean_source_url(self):
        url = self.cleaned_data['source_url']
        m = re.match(r'(https?://)?(www\.|secure\.)?flickr\.com/photos/(?P<author>[^/]+)/(?P<img>\d+)', url)
        if not m:
            raise forms.ValidationError("It doesn't look like Flickr URL.")
        author_slug, img_id = m.group('author'), m.group('img')
        base_url = "https://www.flickr.com/photos/%s/%s/" % (author_slug, img_id)

        try:
            html = urlopen(url).read().decode('utf-8')
        except:
            raise forms.ValidationError('Error reading page.')
        match = re.search(r'<a href="([^"]*)" rel="license cc:license">Some rights reserved</a>', html)
        try:
            assert match
            license_url = match.group(1)
            self.cleaned_data['license_url'] = license_url
            re_license = re.compile(r'http://creativecommons.org/licenses/([^/]*)/([^/]*)/.*')
            m = re_license.match(license_url)
            assert m
            self.cleaned_data['license_name'] = 'CC %s %s' % (m.group(1).upper(), m.group(2))
        except AssertionError:
            raise forms.ValidationError('Error reading license name.')

        m = re.search(r'<strong class="username">By <a href="[^"]*">([^<]*)</a></strong>', html)
        if m:
            self.cleaned_data['author'] = "%s@Flickr" % m.group(1)
        else:
            raise forms.ValidationError('Error reading author name.')

        m = re.search(r'<h1[^>]*>(.*?)</h1>', html)
        if not m:
            raise forms.ValidationError('Error reading image title.')
        self.cleaned_data['title'] = m.group(1)

        url_size = base_url + "sizes/o/"
        html = urlopen(url_size).read().decode('utf-8')
        m = re.search(r'<div id="allsizes-photo">\s*<img src="([^"]*)"', html)
        if m:
            self.cleaned_data['download_url'] = m.group(1)
        else:
            raise forms.ValidationError('Error reading image URL.')
        return base_url