import zipfile
from zipfile import BadZipFile
import logging
import datetime
import time
import os
from io import BytesIO
from fractions import Fraction
try:
    import Image
except ImportError:
    from PIL import Image

from django import forms
from django.utils.translation import ugettext_lazy as _
from django.utils.safestring import mark_safe
from django.contrib import messages
from django.core.files.base import ContentFile
from django.contrib.admin import widgets
from django.contrib.gis.geos import Point
from django.conf import settings

import exiftool
from photos.models import LuxImage, LuxGallery
from locations.models import Location

from .utils import resize_image

logger = logging.getLogger('photos.forms')


class GalleryForm(forms.ModelForm):
    class Meta:
        model = LuxGallery
        fields = '__all__'
        widgets = {
            'images': forms.SelectMultiple,
        }

    def __init__(self, *args, **kwargs):
        super(GalleryForm, self).__init__(*args, **kwargs)

        images = LuxImage.objects.all()[:100]
        items = []
        for image in images:
            items.append(
                (image.pk, mark_safe('%sqq%s' % (image.title, image.get_image_name())))
            )
        self.fields['images'].choices = items
        self.fields['images'].allow_tags = True


class UploadZipForm(forms.Form):
    """
        Handles the uploading of a gallery of photos packed in a .zip file
        Creates Gallery object, adds photos with all metadata that's available
    """
    zip_file = forms.FileField()
    title = forms.CharField(label=_('Gallery Title'), max_length=250)
    slug = forms.SlugField(label=_('Gallery Slug'))
    desc = forms.CharField(label=_('Gallery Caption'), widget=forms.Textarea, required=False)
    date = forms.SplitDateTimeField(label=_('Date'), widget=widgets.AdminSplitDateTime)
    is_public = forms.BooleanField(label=_('Is public'), initial=True, required=False, help_text=_('Show on site'))

    def clean_zip_file(self):
        """Open the zip file a first time, to check that it is a valid zip archive.
        We'll open it again in a moment, so we have some duplication, but let's focus
        on keeping the code easier to read!
        """
        zip_file = self.cleaned_data['zip_file']
        try:
            zip = zipfile.ZipFile(zip_file)
        except BadZipFile as e:
            raise forms.ValidationError(str(e))
        bad_file = zip.testzip()
        if bad_file:
            zip.close()
            raise forms.ValidationError('"%s" in the .zip archive is corrupt.' % bad_file)
        zip.close()  # Close file in all cases.
        return zip_file

    def clean_title(self):
        title = self.cleaned_data['title']
        if title and LuxGallery.objects.filter(title=title).exists():
            raise forms.ValidationError(_('A gallery with that title already exists.'))
        return title

    def clean(self):
        cleaned_data = super(UploadZipForm, self).clean()
        if not self['title'].errors:
            # If there's already an error in the title, no need to add another
            # error related to the same field.
            if not cleaned_data.get('title', None) and not cleaned_data['gallery']:
                raise forms.ValidationError(
                    _('Select an existing gallery, or enter a title for a new gallery.'))
        return cleaned_data

    def save(self, request=None, zip_file=None):
        if not zip_file:
            zip_file = self.cleaned_data['zip_file']

        gallery, created = LuxGallery.objects.get_or_create(
            title=self.cleaned_data['title'],
            description=self.cleaned_data['desc'],
            slug=self.cleaned_data['slug'],
            pub_date=self.cleaned_data['date'],
            is_public=self.cleaned_data['is_public']
        )
        zipper = zipfile.ZipFile(zip_file)
        count = 1
        for filename in sorted(zipper.namelist()):
            f, file_extension = os.path.splitext(filename)
            logger.debug('Reading file "{0}".'.format(filename))
            if filename.startswith('__') or filename.startswith('.'):
                logger.debug('Ignoring file "{0}".'.format(filename))
                continue
            if os.path.dirname(filename):
                logger.warning('Ignoring file "{0}" as it is in a subfolder; all images should be in the top '
                               'folder of the zip.'.format(filename))
                if request:
                    messages.warning(request,
                                     _('Ignoring file "{filename}" as it is in a subfolder').format(filename=filename), fail_silently=True)
                continue
            data = zipper.read(filename)

            if not len(data):
                logger.debug('File "{0}" is empty.'.format(filename))
                continue

            # Basic check that we have a valid image.
            try:
                file = BytesIO(data)
                opened = Image.open(file)
                opened.verify()
            except Exception:
                # Pillow (or PIL) doesn't recognize it as an image.
                # If a "bad" file is found we just skip it.
                # But we do flag this both in the logs and to the user.
                logger.error('Could not process file "{0}" in the .zip archive.'.format(
                    filename))
                if request:
                    messages.warning(request,
                                     _('Could not process file "{0}" in the .zip archive.').format(
                                         filename),
                                     fail_silently=True)
                continue

            image = LuxImage(
                pub_date=datetime.datetime.now()
            )
            contentfile = ContentFile(data)
            image.image.save(filename, contentfile)
            image.save()
            gallery.images.add(image)

            with exiftool.ExifTool() as et:
                meta = et.get_metadata(image.image.path)
            et.terminate()
            image.exif_raw = meta
            try:
                image.title = meta["EXIF:ImageDescription"]
            except:
                pass
            try:
                image.caption = meta["EXIF:UserComment"]
            except:
                pass
            try:
                image.exif_lens = meta["MakerNotes:LensType"]
            except:
                try:
                    image.exif_lens = meta["XMP:Lens"]
                except:
                    pass
            try:
                image.point = Point(meta["XMP:GPSLongitude"], meta["XMP:GPSLatitude"], srid=4326)
                try:
                    image.location = Location.objects.filter(geometry__contains=image.point).get()
                except Location.DoesNotExist:
                    pass
            except KeyError:
                pass
            image.exif_aperture = meta["EXIF:FNumber"]
            image.exif_make = meta["EXIF:Make"]
            image.exif_model = meta["EXIF:Model"]
            image.exif_exposure = str(Fraction(float(meta["EXIF:ExposureTime"])).limit_denominator())
            image.exif_iso = meta["EXIF:ISO"]
            image.exif_focal_length = meta["EXIF:FocalLength"]
            fmt_date = time.strptime(meta["EXIF:DateTimeOriginal"], "%Y:%m:%d %H:%M:%S")
            image.exif_date = time.strftime("%Y-%m-%d %H:%M:%S", fmt_date)
            image.height = meta["File:ImageHeight"]
            image.width = meta["File:ImageWidth"]
            image.save()
            count += 1
            img = Image.open(image.image.path)
            base_path = "%s/galleries/" % settings.IMAGES_ROOT
            if img.size[0] > img.size[1]:
                resize_image(img, 2280, None, 65, base_path+'large/', image.get_image_name())
                resize_image(img, 1140, None, 72, base_path+'medium/', image.get_image_name())
                resize_image(img, 720, None, 68, base_path+'small/', image.get_image_name())
            if img.size[1] > img.size[0]:
                resize_image(img, None, 1600, 65, base_path+'large/', image.get_image_name())
                resize_image(img, None, 800, 72, base_path+'medium/', image.get_image_name())
                resize_image(img, None, 460, 60, base_path+'small/', image.get_image_name())

            resize_image(img, 160, None, 68, base_path+'thumb/', image.get_image_name())
        zipper.close()

        if request:
            messages.success(request, _('The photos have been uploaded'))