#!/usr/bin/python3
import json
import logging
import os
import time
from urllib.parse import unquote

from tornado.httpserver import HTTPServer
from tornado.ioloop import IOLoop, PeriodicCallback

from tornado.web import StaticFileHandler, Application, HTTPError
import tornado.gen
import tornado.web


from recommendation_engine import Engine
from utils import json_dumps, run_async


BANNER_PUBLIC = 'DD recommondation engine'
BANNER = '%s - use POST at / to access JSON-RPC 2.0 endpoint' % BANNER_PUBLIC

logger = logging.getLogger(__name__)


@run_async
def api_task(request, engine, callback):
    try:
        if request['method'] == 'getVideos':
            result = engine.get_videos(**request['params'])
        elif request['method'] == 'getNext':
            result = engine.get_next(**request['params'])
        elif request['method'] == 'getRecommendations':
            result = engine.state
        elif request['method'] == 'setRecommendations':
            result = engine.update_state(request['params'])
        else:
            result = {}
        response = {
            'result': result
        }
    except:
        logger.error('api failed: %s', request, exc_info=True)
        response = {'error': {'code': -32000, 'message': 'Server error'}}
    callback(response)


class RPCHandler(tornado.web.RequestHandler):

    def initialize(self, engine):
        self.engine = engine

    def get(self):
        self.write(BANNER)

    @tornado.gen.coroutine
    def post(self):
        error = None
        request = None
        try:
            request = json.loads(self.request.body.decode())
            if request['method'] not in ('getVideos', 'getNext', 'getRecommendations', 'setRecommendations'):
                raise Exception('unknown method')
        except:
            error = {'error': {'code': -32700, 'message': 'Parse error'}}
        if not error:
            try:
                response = yield tornado.gen.Task(api_task, request, self.engine)
            except:
                logger.error("ERROR: %s", request, exc_info=True)
                error = {'error': {'code': -32000, 'message': 'Server error'}}
        if error:
            response = error
        if request and 'id' in request:
            response['id'] = request['id']
        response['jsonrpc'] = '2.0'
        response = json_dumps(response)
        self.write(response)


def main(prefix='json/'):
    settings = {
        'debug': False,
        'port': 8081,
        'address': '',
        'pandora': 'http://pandora.dmp/api/',
        'pandora_ws': 'ws://pandora.dmp/api/ws/',
        'username': 'dd.re',
        'password': 'dd.re'
    }
    engine = Engine(prefix, **settings)

    handlers = [
        (r'/', RPCHandler, dict(engine=engine)),
    ]
    options = {
        'debug': settings['debug'],
        'gzip': True,
    }
    if settings['debug']:
        log_format = '%(asctime)s:%(levelname)s:%(name)s:%(message)s'
        logging.basicConfig(level=logging.DEBUG, format=log_format)

    app = Application(handlers, **options)
    app.listen(settings['port'], settings['address'])
    main = IOLoop.instance()

    update_cb = PeriodicCallback(engine.update_async, 15*60*1000)
    update_cb.start()
    #main.spawn_callback(update, engine)

    #fixme run periodically
    try:
        main.start()
    except:
        print('shutting down...')


if __name__ == '__main__':
    main()