#from django.db import models
from django.utils.translation import gettext_lazy as _
import django.contrib.auth.models as auth
from django.conf import settings
from django.dispatch import dispatcher
#from django.db.models import signals
#from signals import update_render
from appengine_django.models import BaseModel
from google.appengine.ext import db


class Symbol(BaseModel):
    name = db.StringProperty(_("Name"))
    latex = db.TextProperty(_("Raw LaTeX"))
    unicode = db.TextProperty(_("Unicode Representation"))
    #renderdir = "symbolrenders/"
    #render = models.ImageField(_("Rendered Image"), 
        #upload_to=renderdir, editable=False)

    class Meta:
        get_latest_by = 'name'
    class Admin:
        ordering = ['name']
    
    def _get_pk_val(self):
        return self.key().id()
    def __str__(self):
        return self.name
    def get_absolute_url(self):
        return "/symbol/%s/" % self.id
    def get_admin_url(self):
        return "/admin/symbols/%s/" % self.id

class Variable(BaseModel):
    name = db.StringProperty(_("Name"))
    latex = db.TextProperty(_("Raw LaTeX"))
    unicode = db.TextProperty(_("Unicode Representation"))
    description = db.TextProperty(_("Description"))
    reference = db.TextProperty(_("Reference URL"))
    symbol = db.ReferenceProperty(Symbol)
    isgeneric = db.BooleanProperty(_("Is Generic?"), default=False)

    class Meta:
        get_latest_by = 'name'
    class Admin:
        ordering = ['name']

    def _get_pk_val(self):
        return self.key().id()
    def __str__(self):
        return self.name
    def get_absolute_url(self):
        return "/variable/%s/" % self.id
    def get_admin_url(self):
        return "/admin/variables/%s/" % self.id

class Equation(BaseModel):
    name = db.StringProperty(_("Name"))
    latex = db.TextProperty(_("Raw LaTeX"))
    unicode = db.TextProperty(_("Unicode Representation"))
    description = db.TextProperty(_("Description"))
    created = db.DateTimeProperty(_("Created"), auto_now_add=True)
    updated = db.DateTimeProperty(_("Last Updated"), auto_now_add=True)
    #owner = models.ForeignKey(auth.User, verbose_name=_("Owner"))

    variables = db.ListProperty(db.Key, verbose_name="Variables")
    reference = db.TextProperty(_("Reference URL"))

    class Meta:
        get_latest_by = 'created'
    class Admin:
        ordering = ['created']

    def _get_pk_val(self):
        return self.key().id()
    def __str__(self):
        return self.name
    def get_absolute_url(self):
        return "/equation/%s/" % self.id
    def get_admin_url(self):
        return "/admin/equations/%s/" % self.id
    def update_variables(self):
        """Updates the variables field with all Variable objects found
           in the LaTeX representation."""
        pass # TODO: write

#signals.post_save.connect(update_render, sender=Equation)
#dispatcher.connect(update_render, signal=signals.post_save, sender=Equation)

#from django.contrib import admin

#admin.site.register(Symbol)
#admin.site.register(Variable)
#admin.site.register(Equation)