#!/usr/bin/python

import os
import pdb
import copy
import sys
import json
import re
from django.template import Context, Template

blacklist = ['SingletonModel','PlCoreBase']

# Django set up

sys.path.append('.')
os.environ.setdefault("DJANGO_SETTINGS_MODULE", "xos.settings")
from django.db.models.fields.related import ForeignKey, ManyToManyField

def singular(foo, keys):
	for k in keys:
		if (foo==k+'es'):
			return k
		elif (foo==k+'s'):
			return k
	raise Exception('Plural to singular error for %s'%foo)

g = globals()

def enum_classes(apps):
    model_classes = []
    for app in apps:
            app = app + ".models"
            models_module = __import__(app)
            for part in app.split(".")[1:]:
                if hasattr(models_module, "PlCoreBase"):
                    break
                models_module = getattr(models_module,part)

            PlCoreBase = getattr(models_module,"PlCoreBase")

            for classname in dir(models_module):
                    c = getattr(models_module, classname, None)
                    if type(c)==type(PlCoreBase) and c.__name__ not in blacklist:
                            model_classes.append(c)

    return model_classes

class GenObj(object):
	def __str__(self):
		return str(self.model.__name__.lower())

	def __init__(self, m):
		self.model = m
		self.props = []
		self.refs = []
		self.plural_name = None

	def plural(self):
		if (self.plural_name):
			return self.plural_name
		else:
			name = str(self)
			if (name.endswith('s')):
				return name+'es'
			else:
				return name+'s'

        def singular(self):
            return str(self)

        def rest_name(self):
            # These are things that either for historic reasons or due to incorrect naming,
            # got called something different than the autogen thinks they should be
            # called.
            REST_FIXUP = {'controllernetworkses': 'controllernetworks',
                            'controllerimageses': 'controllerimages',
                            'controllersliceses': 'controllerslices',
                            'controlleruserses': 'controllerusers',
                            'sitedeploymentses': 'sitedeployments',
                            'siteroles': 'site_roles',
                            'sliceprivileges': 'slice_privileges',
                            'sliceroles': 'slice_roles',
                            }
            return REST_FIXUP.get(self.plural(), self.plural())

	def camel(self):
		name = str(self.model.__name__)
		return name
		
class Generator(dict):
	def all(self):
		return self.values()
	
	def regex(self, r):
		filtered = filter(lambda o:re.match(r,str(o)), self.values())
		return filtered

	def add_object(self, o):
		obj = GenObj(o)
		fields = o._meta.fields
		self[str(obj).lower()]=obj

	def compute_links(self):
		for obj in self.values():
			#if (str(obj)=='network'):
			#	pdb.set_trace()
			fields = obj.model._meta.fields
			for f in fields:
				if (f and f.rel):
					to_name = str(f.rel.to)
				else:
					to_name = None

				if type(f)==ForeignKey and to_name and to_name in self.keys():
					refobj = self[f.to_name]

					if (str(obj)=='slice' and f.to_name=='networks'):
						obj.refs.append(refobj)
					related_name = f.related_query_name()
					if (related_name!='+' and related_name.lower()!=str(obj).lower()):
						cobj = copy.deepcopy(obj)
						cobj.multi = True
						cobj.plural_name = related_name
						refobj.refs.append(cobj)
				else:
					obj.props.append(f.name)

			m2m = obj.model._meta.many_to_many
			for f in m2m:
				try:
					related_model_name = f.m2m_reverse_field_name()
				except:
					related_model_name = f.m2m_db_table().rsplit('_',1)[-1]

				related_name = f.related_query_name()
				if related_model_name in self.keys():
                                        #print "XXX1", obj, f, related_name, related_model_name
					refobj = self[related_model_name]
					cobj = copy.deepcopy(obj)
					cobj.multi=True
					refobj.refs.append(cobj)

                                # deal with upgradeFrom_rel_+
                                if (related_name.endswith("+")):
                                    continue

				if (related_name!='+' and related_name.lower()!=str(obj).lower()):
                                        #print "XXX2", obj, f, related_name, related_model_name, refobj.plural_name
                                        refobj = self[related_model_name]
					cobj = copy.deepcopy(refobj)
					cobj.multi = True

					obj.refs.append(cobj)


def main():
        if len(sys.argv)==3:
            apps = [x.strip() for x in sys.argv[1].split(",")]
            output = sys.argv[2]
        elif len(sys.argv)==2:
            apps = ["core"]
            output = sys.argv[1]
        else:
	    print 'Usage: modelgen <output_template>'
            print 'Alternative Usage: modelgen <app> <output_template>'
	    exit(1)

	generator = Generator()

	models = enum_classes(apps)

	for m in models:
		generator.add_object(m)

	generator.compute_links()
	template_contents = open(output).read()
	template = Template(template_contents)
	context = Context({'generator':generator})
	print template.render(context)


if (__name__=='__main__'):
	main()