# -*- coding: utf-8 -*-
# vi:si:et:sw=4:sts=4:ts=4
# GPL 2013
from __future__ import division, with_statement
import os
import random
from urllib import quote
import json

from django.db import models
from django.core.files.base import ContentFile
from django.db.models.signals import pre_delete
from django.contrib.auth.models import User, Group
from django.conf import settings

import ox
from ox.django import fields

def new_slug():
    current_max = Item.objects.all().count() * 2
    slug = ox.toAZ(random.randint(0, max(10, current_max))).capitalize()
    if Item.objects.all().filter(slug=slug).count() > 0:
        return new_slug()
    return slug

class Item(models.Model):
    created = models.DateTimeField(auto_now_add=True)
    modified = models.DateTimeField(auto_now=True)
    user = models.ForeignKey(User, related_name='items')

    slug = models.SlugField(unique=True, default=new_slug)
    file = models.FileField(upload_to=lambda f, x: f.path(x), max_length=1024)
    filename = models.CharField(max_length=1024)

    overlay = fields.DictField(default={}, editable=True)

    done = models.BooleanField(default=False)

    def editable(self, user):
        if user.is_anonymous():
            return False
        return user.is_staff or self.user == user

    def get_overlay(self):
        return json.dumps(self.overlay)

    def size(self):
        try:
            size = self.file and self.file.size or 0
        except:
            size = 0
        return ox.format_bytes(size)

    def get_absolute_url(self):
        return '%s/%s' % (settings.PREFIX, self.slug)
    
    def get_absolute_pdf_url(self):
        filename = self.filename
        if not filename.endswith('.pdf'):
            filename += '.pdf'
        return '%s/%s' % (self.get_absolute_url(), quote(filename))

    def path(self, filename):
        if len(filename) > 1024:
            filename = os.path.splitext(filename)
            filename = filename[0][:1024-len(filename[-1])-3] + '...' + filename[-1]
        return os.path.join('item', self.slug, filename)

    def __unicode__(self):
        return u"%s/%s" %(self.slug, self.filename)

    def save_chunk(self, chunk, name='data.bin'):
        if not self.done:
            if not self.file:
                if len(name) > 1024:
                    name = os.path.splitext(name)
                    name = name[0][:1024-len(name[-1])-3] + '...' + name[-1]
                self.file.save(name, ContentFile(chunk))
                self.filename = name
                self.save()
                os.chmod(self.file.path, 0644)
            else:
                f = open(self.file.path, 'a')
                f.write(chunk)
                f.close()
            return True
        return False

def delete_file(sender, **kwargs):
    item= kwargs['instance']
    if item.file:
        path = item.file.path
        item.file.delete()
        try:
            os.rmdir(os.path.dirname(path))
        except OSError:
            pass
pre_delete.connect(delete_file, sender=Item)