from django.db import models
from django.utils import timezone
from django.contrib.contenttypes.fields import GenericForeignKey
from django.contrib.contenttypes.models import ContentType

class InfoItem(models.Model):
    class __meta__:
        abstract = True
    name = models.CharField(max_length=255)
    expire_date = models.DateTimeField(blank=True,null=True) # None means never expiring item

    def get_template_url(self):
        raise NotImplementedError("inheriting classes must implement get_template_url")
    def get_edit_template_url(self):
        raise NotImplementedError("inheriting classes must implement get_template_url")

    def get_dict(self):
        return {
            'name': self.name,
            'template_url': self.get_template_url(),
            'edit_template_url': self.get_edit_template_url(),
            'options': {}
        }
    def __str__(self):
        return self.name

class ABBInfoItem(InfoItem):
    def get_template_url(self):
        return "/static/html/abb.html"
    def get_edit_template_url(self):
        return "/static/html/generic_edit.html"

class ImageInfoItem(InfoItem):
    img = models.ImageField(upload_to="infoimages/")

    def get_template_url(self):
        #get param to avoid angular from optimizing same template with different options
        return "/static/html/generic_image.html?img={}".format(self.name) 

    def get_edit_template_url(self):
        return "/static/html/generic_image_edit.html"

    def get_dict(self):
        d = super().get_dict()
        d["options"] = {'img': self.img.url}
        return d
    
class ExternalImageInfoItem(InfoItem):
    url = models.TextField()

    def get_template_url(self):
        return "/static/html/generic_image.html?img={}".format(self.name)

    def get_edit_template_url(self):
        return "/static/html/generic_external_image_edit.html"

    def get_dict(self):
        d = super().get_dict()
        d["options"] = {'img': self.url}
        return d

class InfoInstance(models.Model):
    rotation = models.ForeignKey('Rotation', related_name='instances')
    duration = models.FloatField(default=15.0) # seconds
    # generic relation to somekind of InfoItem
    item_id = models.PositiveIntegerField()
    item_type = models.ForeignKey(ContentType,on_delete=models.CASCADE)
    item = GenericForeignKey('item_type','item_id')

    def get_dict(self):
        return {
            'item': self.item.get_dict(),
            'duration': self.duration,
        }
    def __str__(self):
        return "{}: {} ({}s)".format(self.rotation.name, self.item.name, self.duration)

class Rotation(models.Model):
    name = models.CharField(max_length=255)
    
    def get_dict(self):
        # exclude expired items from rotation (note: using tricky syntax to avoid excluding items with no expire_date)
        now = timezone.now()
        instances = self.instances.all()
        filtered = filter(lambda i: (i.item.expire_date or now) >= now, list(instances))
        instance_list = list(map(lambda i:i.get_dict(), filtered))

        return {
            'name': self.name,
            'instances': instance_list,
        }

    def __str__(self):
        return self.name

class ABBJob(models.Model):
    sw_id = models.IntegerField(default=-1)
    title = models.CharField(max_length=255)
    QR = models.CharField(max_length=255, default="")
    created = models.DateTimeField(default=timezone.now)

    def get_dict(self):
        return {
            "title": self.title,
            "QR": self.QR,
        }

    def __str__(self):
        return self.title