import logging
import os
from datetime import datetime
import json

from django.db import models

from core.utils import url
from dss import localsettings, settings


class BaseModel(models.Model):
    logger = logging.getLogger('dss')

    object_created = models.DateTimeField(auto_now_add=True)
    object_updated = models.DateTimeField(auto_now=True, db_index=True)

    class Meta:
        abstract = True
        app_label = 'spa'

    def tosimplejson(self):
        return json.dumps(self)

    @classmethod
    def get_lookup(cls, filter_field, transform=None, filter=None):
        if filter is not None:
            filter_dict = {'%s__startswith' % filter_field: filter}
            return cls.objects.all().filter(filter_dict).extra(select=transform)
        else:
            return cls.objects.all()

    def get_image_url(self, image, default):
        try:
            if os.path.isfile(image.path):
                ret = "{0}/{1}".format(settings.MEDIA_URL, image)
                return url.urlclean(ret)
        except Exception as ex:
            pass

        return default

    @classmethod
    def get_lookup_filter_field(cls):
        field_list = cls._meta.get_all_field_names()
        for field in field_list:
            if field.endswith("title") or field.endswith("name") or field.endswith("description"):
                return field
        return "description"

    def base_pre_save(self, sender, instance, created, **kwargs):
        pass

    def clean_image(self, image_field, sender):

        # TODO(fergal.moran@gmail.com): stop tastypie nulling image field if not sent

        if self.__dict__[image_field] == "DONOTSEND":
            try:
                old_instance = sender.objects.get(pk=self.pk)
                if old_instance is not None:
                    self.__dict__[image_field] = old_instance.__dict__[image_field]
            except Exception as ex:
                pass