#!/usr/bin/env python

import functools
import importlib
import os
import logging
import json
import socket
import subprocess
import sys
import time
import websocket
import yaml

from threading import Thread
from getopt import getopt

__author__ = 'Fabio Manganiello <info@fabiomanganiello.com>'

#-----------#

curdir = os.path.dirname(os.path.realpath(__file__))
lib_dir = curdir + os.sep + 'lib'
sys.path.insert(0, lib_dir)

DEVICE_ID = None
modules = {}
plugins = {}


def on_open(ws):
    logging.info('Connection opened')


def on_close(ws):
    logging.info('Connection closed')


def on_error(ws, error):
    logging.error(error)


def _init_plugin(plugin, reload=False):
    module_name = 'plugins.{}'.format(plugin)
    if module_name not in modules or reload:
        try:
            modules[module_name] = importlib.import_module(module_name)
        except ModuleNotFoundError as e:
            logging.warn('No such plugin: {}'.format(plugin))
            raise RuntimeError(e)

    # e.g. plugins.music.mpd main class: MusicMpdPlugin
    cls_name = functools.reduce(
        lambda a,b: a.title() + b.title(),
        (plugin.title().split('.'))
    ) + 'Plugin'

    if cls_name not in plugins or reload:
        try:
            plugins[cls_name] = getattr(modules[module_name], cls_name)()
        except AttributeError as e:
            logging.warn('No such class in {}: {}'.format(
                module_name, cls_name))
            raise RuntimeError(e)

    return plugins[cls_name]


def _exec_func(body, retry=True):
    try:
        logging.info('Received push addressed to me: {}'.format(body))
        args = body['args'] if 'args' in body else {}
        if 'plugin' not in body:
            logging.warn('No plugin specified')
            return

        plugin_name = body['plugin']

        try:
            plugin = _init_plugin(plugin_name)
        except RuntimeError as e:  # Module/class not found
            return

        ret = plugin.run(args)
        out = None
        err = None

        if isinstance(ret, list):
            out = ret[0]
            err = ret[1] if len(ret) > 1 else None
        elif ret is not None:
            out = ret

        if out:
            logging.info('Command output: {}'.format(out))

        if err:
            logging.warn('Command error: {}'.format(err))
    except Exception as e:
        logging.exception(e)
        if retry:
            logging.info('Reloading plugin {} and retrying'.format(plugin_name))
            _init_plugin(plugin_name, reload=True)
            _exec_func(body, retry=False)


def _on_push(ws, data):
    global DEVICE_ID

    data = json.loads(data)
    if data['type'] == 'tickle' and data['subtype'] == 'push':
        logging.debug('Received push tickle')
        return

    if data['type'] != 'push':
        return  # Not a push notification

    push = data['push']
    logging.debug('Received push: {}'.format(push))

    if 'body' not in push:
        return

    body = push['body']
    try:
        body = json.loads(body)
    except ValueError as e:
        return

    if 'target' not in body or body['target'] != DEVICE_ID:
        return  # Not for me

    if 'plugin' not in body:
        return  # No plugin specified

    thread = Thread(target=_exec_func, args=(body,))
    thread.start()

def on_push(ws, data):
    try:
        _on_push(ws, data)
    except Exception as e:
        on_error(ws, e)


def main():
    global DEVICE_ID

    DEBUG = False
    config_file = curdir + os.sep + 'config.yaml'

    optlist, args = getopt(sys.argv[1:], 'vh')
    for opt, arg in optlist:
        if opt == '-c':
            config_file = arg
        if opt == '-v':
            DEBUG = True
        elif opt == '-h':
            print('''
Usage: {} [-v] [-h] [-c <config_file>]
    -v  Enable debug mode
    -h  Show this help
    -c  Path to the configuration file (default: ./config.yaml)
'''.format(sys.argv[0]))
            return

    config = {}
    with open(config_file,'r') as f:
        config = yaml.load(f)

    API_KEY = config['pushbullet']['token']
    DEVICE_ID = config['device_id'] \
        if 'device_id' in config else socket.gethostname()

    if 'debug' in config:
        DEBUG = config['debug']

    if DEBUG:
        logging.basicConfig(level=logging.DEBUG)
        websocket.enableTrace(True)
    else:
        logging.basicConfig(level=logging.INFO)

    ws = websocket.WebSocketApp('wss://stream.pushbullet.com/websocket/' +
                                API_KEY,
                                on_message = on_push,
                                on_error = on_error,
                                on_close = on_close)
    ws.on_open = on_open
    ws.run_forever()


if __name__ == '__main__':
    main()