# -*- coding: utf-8
from django.core.files.base import ContentFile
from django.core.files import File
from django.core.urlresolvers import reverse
from librarian import DocProvider, IOFile
from librarian.pyhtml import EduModuleFormat
from librarian.pypdf import EduModulePDFFormat
from .models import Lesson, Attachment
from fnpdjango.utils.text.slughifi import slughifi


# TODO: Using sorl.thumbnail for now,
# but this should be done in Librarian,
# directly using convert or PIL as a fallback.
def get_image(src_img_path, width=None,
        default_width=1600, formats=('PNG', 'JPEG', 'GIF')):
    """ Returns an object with `url` and `storage` attributes,
        or None if using the original image is OK.
    """
    
    from PIL import Image
    from sorl.thumbnail import get_thumbnail
    
    # Does it need converting?
    # Yes, if width is given explicitly.
    convert = width is not None
    if not convert:
        # Looks like it doesn't need converting.
        # But let's try opening it and checking its type.
        try:
            simg = Image.open(src_img_path)
        except IOError:
            # It doesn't look like image,
            # but maybe it's convertable to one.
            convert = True
        else:
            if simg.format not in formats:
                # It's an image, but it's in some weird format.
                convert = True
                width = simg.size[0]

    if convert:
        if width is None:
            width = default_width
        return get_thumbnail(src_img_path, '%sx%s' % (width, 10*width))
    else:
        return None


class HtmlFormat(EduModuleFormat):
    IMAGE_FORMATS = ('PNG', 'JPEG', 'GIF')
    DEFAULT_IMAGE_WIDTH = 1600

    def find_attachment(self, slug, fmt):
        lesson_slug = self.wldoc.book_info.url.slug
        try:
            # If already saved, use it.
            att = Attachment.objects.get(lesson__slug=lesson_slug,
                                         slug=slug, ext=fmt)
        except Attachment.DoesNotExist, e:
            # If attached to source IOFile, save now.
            att_name = "%s.%s" % (slug, fmt)
            try:
                att_file = self.wldoc.source.attachments[att_name]
            except KeyError:
                print u"ATTACHMENT MISSING:", att_name
                raise self.MaterialNotFound()
            else:
                lesson = Lesson.objects.get(slug=lesson_slug)
                att = lesson.attachment_set.create(slug=slug, ext=fmt)
                att.file.save(att_name, File(att_file.get_file()))
                return att
        else:
            return att

    def url_for_material(self, slug, fmt):
        return self.find_attachment(slug, fmt).file.url

    def url_for_image(self, slug, fmt, width=None):
        try:
            src_img = self.find_attachment(slug, fmt).file
        except self.MaterialNotFound:
            return ''
        img = get_image(src_img.path, width,
            self.DEFAULT_IMAGE_WIDTH, self.IMAGE_FORMATS)
        return (img or src_img).url

    def text_to_anchor(self, text):
        return slughifi(text)

    def get_forma_url(self, forma):
        return '%s#%s' % (
            reverse('catalogue_lesson', args=['metody']),
            self.text_to_anchor(forma)
        )

    def get_help_url(self, naglowek):
        return '%s%s#%s' % (
            '//edukacjamedialna.edu.pl',
            reverse('info', args=['jak-korzystac/']),
            self.naglowek_to_anchor(naglowek)
        )


class PdfFormat(EduModulePDFFormat):
    IMAGE_FORMATS = ('PNG', 'JPEG', 'GIF')
    DEFAULT_IMAGE_WIDTH = 1600

    def get_image(self, name):
        src_img = super(PdfFormat, self).get_image(name)
        img = get_image(src_img.get_filename(),
                default_width=self.DEFAULT_IMAGE_WIDTH,
                formats=self.IMAGE_FORMATS
            )
        if img:
            return IOFile.from_filename(img.storage.path(img))
        else:
            return src_img


class OrmDocProvider(DocProvider):
    def by_slug(self, slug):
        """Should return a file-like object with a WL document XML."""
        return IOFile.from_filename(Lesson.objects.get(slug=slug).xml_file.path)