import os

import cherrypy
from mako.template import Template
from mako.lookup import TemplateLookup
import simplejson
import datetime, decimal
from invirt.config import structs as config
from webcommon import State

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)

def external_remote_user_login():
    pass

def require_login():
    """If the user isn't logged in, raise 403 with an error."""
    if cherrypy.request.login is False:
        raise cherrypy.HTTPError(403,
            "You are not authorized to access that resource")

cherrypy.tools.require_login = cherrypy.Tool('on_start_resource', require_login, priority=150)

def remote_user_login():
    """Get the current user based on the SSL or GSSAPI environment variables"""
    environ = cherrypy.request.wsgi_environ
    user = environ.get('REMOTE_USER')
    if user is None:
        return
    else:
        cherrypy.request.login = None # clear what cherrypy put there

    if environ.get('AUTH_TYPE') == 'Negotiate':
        # Convert the krb5 principal into a krb4 username
        if not user.endswith('@%s' % config.kerberos.realm):
            cherrypy.request.login = False # failed to login
        else:
            cherrypy.request.login = user.split('@')[0].replace('/', '.')
    else:
        cherrypy.request.login = user

cherrypy.tools.remote_user_login = cherrypy.Tool('on_start_resource', remote_user_login, priority=50)

def invirtwebstate_init():
    """Initialize the cherrypy.request.state object from Invirt"""
    cherrypy.request.state = State(cherrypy.request.login)

cherrypy.tools.invirtwebstate = cherrypy.Tool('on_start_resource', invirtwebstate_init, priority=100)

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