import os

import cherrypy
from mako.template import Template
from mako.lookup import TemplateLookup
import simplejson
import datetime, decimal

class MakoHandler(cherrypy.dispatch.LateParamPageHandler):
    """Callable which sets response.body."""
    
    def __init__(self, template, next_handler, content_type='text/html; charset=utf-8'):
        self.template = template
        self.next_handler = next_handler
        self.content_type = content_type
    
    def __call__(self):
        env = globals().copy()
        env.update(self.next_handler())
        cherrypy.response.headers['Content-Type'] = self.content_type
        return self.template.render(**env)
        

class MakoLoader(object):
    
    def __init__(self):
        self.lookups = {}
    
    def __call__(self, filename, directories, module_directory=None,
                 collection_size=-1, content_type='text/html; charset=utf-8'):
        # Find the appropriate template lookup.
        key = (tuple(directories), module_directory)
        try:
            lookup = self.lookups[key]
        except KeyError:
            lookup = TemplateLookup(directories=directories,
                                    module_directory=module_directory,
                                    collection_size=collection_size,
                                    default_filters=['decode.utf8'],
                                    input_encoding='utf-8',
                                    output_encoding='utf-8',
                                    )
            self.lookups[key] = lookup
        cherrypy.request.lookup = lookup
        
        # Replace the current handler.
        cherrypy.request.template = t = lookup.get_template(filename)
        cherrypy.request.handler = MakoHandler(t, cherrypy.request.handler, content_type)

main = MakoLoader()
cherrypy.tools.mako = cherrypy.Tool('on_start_resource', main)

class JSONEncoder(simplejson.JSONEncoder):
	def default(self, obj):
		if isinstance(obj, datetime.datetime):
			return str(obj)
		elif isinstance(obj, decimal.Decimal):
			return float(obj)
		else:
			return simplejson.JSONEncoder.default(self, obj)

def jsonify_tool_callback(*args, **kwargs):
    if not cherrypy.request.cached:
        response = cherrypy.response
        response.headers['Content-Type'] = 'text/javascript'
        response.body = JSONEncoder().iterencode(response.body)

cherrypy.tools.jsonify = cherrypy.Tool('before_finalize', jsonify_tool_callback, priority=30)

class View(object):
    _cp_config = {'tools.mako.directories': [os.path.join(os.path.dirname(__file__),'templates')]}