# -*- coding: utf-8 -*-
from openerp import http
from openerp.http import request
from passlib.context import CryptContext

import os
import jwt
import json
from werkzeug.wrappers import Response

RESOURCES_MAP = None
JWT_SECRET_KEY = '@MjSk$2016?'
JWT_HEADER = 'Authorization'
JWT_HEADER_PREFIX = 'JWT'
CRYPT_CONTEXT = CryptContext(['pbkdf2_sha512', 'md5_crypt'], deprecated=['md5_crypt'])

with open(os.path.dirname(__file__) + '/resources.json') as resources:
    RESOURCES_MAP = json.load(resources)

'''
    Class for manage authentication
'''
class Auth(http.Controller):

    # --------------------------------------------------------------------------
    # Generate JWT token based on username and password field
    # --------------------------------------------------------------------------
    @http.route(['/api/jwt'], type = 'http', auth = 'none', methods = ['POST'], cors = '*')
    def get_jwt(self, **args):
        try:
            user = request.env['res.users'].sudo().search([('login', '=', args['username']), ('active', '=', True)])

            if not user:
                return self.make_response({'error': 'invalid user'}) # bad request

            if not self.get_crypt_context().verify(args['password'], user.password_crypt):
                return self.make_response({'error': 'invalid password'}, status = 400) # bad request

            payload = {
                'uid': user.id,
                'password': args['password']
            }

            encoded = jwt.encode(payload, JWT_SECRET_KEY, algorithm = 'HS256')

            user.write({'jwt_token': encoded})

            return self.make_response({'token': encoded})
        except Exception, e:
            return self.make_response({'error': 'fields required'}, status = 400) # bad request

    # --------------------------------------------------------------------------
    # Check JWT token auth
    # --------------------------------------------------------------------------
    @http.route(['/api/check'], type = 'http', auth = 'none',  methods = ['POST'], cors = '*')
    def check_token(self, **args):
        try:
            user = request.env['res.users'].sudo().search([('jwt_token', '=', args['token'])])

            if not user:
                return self.make_response({'error' : 'invalid token'}, status = 400) # bad request

            decoded = jwt.decode(args['token'], JWT_SECRET_KEY, algorithms = ['HS256'])

            if not self.get_crypt_context().verify(decoded['password'], user.password_crypt):
                return self.make_response({'error' : 'invalid token'}, status = 400) # bad request

            return self.make_response({'token': 'valid'})
        except Exception, e:
            return self.make_response({'error': 'token required'}, status = 400) # bad request

    # --------------------------------------------------------------------------
    # Get context for encryption
    # --------------------------------------------------------------------------
    def get_crypt_context(self):
        return CRYPT_CONTEXT

    # --------------------------------------------------------------------------
    # Make JSON response
    # --------------------------------------------------------------------------
    def make_response(self, data, status = 200):
        return Response(json.dumps(data), status = status, mimetype = 'application/json')


'''
    Class for manage rest api interaction
'''
class ApiManager(http.Controller):

    # --------------------------------------------------------------------------
    # Restify your request
    # --------------------------------------------------------------------------
    @http.route([
                    '/api/<any(customers, leads, opportunities):resource>',
                    '/api/<any(customers, leads, opportunities):resource>/<int:uid>'
                ],
                type = 'http',
                auth = 'none',
                cors = '*')
    def restify(self, resource, uid = None):
        if not self.valid_token():
            return self.make_response({'error': 'denied resource'}, status = 403) # access denied

        if not self.resource_exists(resource):
            return self.make_response({'error': 'resource not available'}, status = 404) # not found

        http_verb = request.httprequest.method

        if http_verb == 'GET':
            return self.http_get(resource, uid)

        if http_verb == 'POST':
            return json.dumps({'verb': 'POST'}, sort_keys = True)

        if http_verb == 'PUT' or http_verb == 'PATCH':
            return json.dumps({'verb': 'PUT OR PATCH'})

        if http_verb == 'DELETE':
            return self.http_delete(resource, uid)

        return self.make_response({'error': 'method not allowed'}, status = 405) # method not allowed

    # --------------------------------------------------------------------------
    # Manage GET request
    # --------------------------------------------------------------------------
    def http_get(self, resource, uid):
        model, filters = self.resource_inflater(resource)
        data = []

        if uid != None:
            filters.append(('id', '=', uid))

        result = request.env[model].sudo().search(filters)

        for item in result:
            data.append(item.dump())

        return self.make_response(data);


    # --------------------------------------------------------------------------
    # Manage DELETE request
    # --------------------------------------------------------------------------
    def http_delete(self, resource, uid):
        if uid == None:
            return self.make_response({'error': 'uid not provided'})

        model, filters = self.resource_inflater(resource)
        result = request.env[model].sudo().browse(uid)

        if not result.exists():
            return self.make_response({'error': 'cannot be deleted'})

        return self.make_response({'response': result.unlink()})

    # --------------------------------------------------------------------------
    # Make JSON response
    # --------------------------------------------------------------------------
    def make_response(self, data, status = 200):
        return Response(json.dumps(data), status = status, mimetype = 'application/json')

    # --------------------------------------------------------------------------
    # Check if resource is available
    # --------------------------------------------------------------------------
    def resource_exists(self, resource):
        try:
            model = RESOURCES_MAP[resource]['module']
            module_name = model.replace('.', '_')

            module = request.env['ir.module.module'].sudo().search([('name', '=', module_name)])

            return True if module.state == 'installed' and len(module) != 0 else False
        except Exception, e:
            return False;

    # --------------------------------------------------------------------------
    # Manage JWT token validity
    # --------------------------------------------------------------------------
    def valid_token(self):
        try:
            auth_header = request.httprequest.headers[JWT_HEADER]

            if not auth_header.startswith(JWT_HEADER_PREFIX):
                return False

            jwt_token = auth_header[4:]

            if not jwt_token:
                return False

            user = request.env['res.users'].sudo().search([('jwt_token', '=', jwt_token)])

            if not user:
                return False

            decoded = jwt.decode(jwt_token, JWT_SECRET_KEY, algorithms = ['HS256'])

            if not self.get_crypt_context().verify(decoded['password'], user.password_crypt):
                return False

            return True
        except Exception, e:
            print e
            return False

    # --------------------------------------------------------------------------
    # Manage GET request
    # --------------------------------------------------------------------------
    def resource_inflater(self, resource):
        try:
            model = RESOURCES_MAP[resource]['model']
            filters = []

            for i in range(len(RESOURCES_MAP[resource]['filters'])):
                filters.append(tuple(RESOURCES_MAP[resource]['filters'][i]))

            return (model, filters)
        except Exception, e:
            return (None, None)

    # --------------------------------------------------------------------------
    # Get context for encryption
    # --------------------------------------------------------------------------
    def get_crypt_context(self):
        return CRYPT_CONTEXT