import os
import ox

from django.conf import settings
from django.shortcuts import get_object_or_404

import requests

from oxdjango.http import HttpFileResponse
from item import models
from archive import extract

def extract_source_frame(self, position, format):
    offset = 0
    streams = self.streams()
    for stream in streams:
        if stream.duration + offset < position:
            offset += stream.duration
        else:
            if not stream.file.is_video or not stream.file.info.get('video'):
                return None
            position = position - offset
            path = None
            if stream.file.data:
                height = stream.file.info['video'][0]['height']
                video_path = stream.file.data.path
                path = os.path.join(settings.MEDIA_ROOT, stream.path(),
                                    'source-frames', "%dp" % height, "%s.%s" % (position, format))
                if not os.path.exists(path) and stream.media:
                    extract.frame(video_path, path, position, height, info=stream.file.info)
                if not os.path.exists(path):
                    return None
            return path

def source_frame(request, id, position=None, format="jpg"):
    if format not in ("jpg", "png"):
        format = "jpg"
    content_type = "image/jpeg" if format == "jpg" else "image/png"
    item = get_object_or_404(models.Item, public_id=id)
    if not item.access(request.user):
        return HttpResponseForbidden()
    frame = None
    if not position:
        position = item.poster_frame
    else:
        position = float(position.replace(',', '.'))

    frame = extract_source_frame(item, position, format)
    response = HttpFileResponse(frame, content_type=content_type)
    if request.method == 'OPTIONS':
        response.allow_access()
    return response