#!/usr/bin/env python3

"""
Doorlockd -- Binary Kitchen's smart door opener

Copyright (c) Binary Kitchen e.V., 2018-2019

Author:
  Thomas Schmid <tom@binary-kitchen.de>

This work is licensed under the terms of the GNU GPL, version 2.  See
the LICENSE file in the top-level directory.

This program is distributed in the hope that it will be useful, but WITHOUT
ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or FITNESS
FOR A PARTICULAR PURPOSE.  See the GNU General Public License for more
details.
"""

import sys
import argparse
import socket
import curses

from enum import Enum, auto
from threading import Thread,Timer

from pydoorlock.Config import Config
from pydoorlock.Protocol import Protocol

cfg = Config('doorlockd')

class State(Enum):
    RED = auto()
    GREEN = auto()
    YELLOW = auto()

class Source(Enum):
    BUTTON = auto()
    EMERGENCY = auto()
    TIMEOUT = auto()
    COMM = auto()

class NetworkWorker(Thread):
    def __init__(self, client, logic):
        Thread.__init__(self)
        self.client = client
        self.logic = logic

    def run(self):
            while True:
                try:
                    rec = self.client.recv(1).decode() 
                    if rec == Protocol.STATE_SWITCH_RED.value:
                        self.logic.update_state(State.RED, Source.COMM)
                    elif rec == Protocol.STATE_SWITCH_GREEN.value:
                        self.logic.update_state(State.GREEN, Source.COMM)
                    elif rec == Protocol.STATE_SWITCH_YELLOW.value:
                        self.logic.update_state(State.YELLOW, Source.COMM)
                except socket.error:
                    print("socket error")
                    return

class Watchdog:
    def __init__(self, timeout, timeoutHandler=None):
        self.timeout = timeout
        self.handler = timeoutHandler if timeoutHandler is not None else self.defaultHandler
        self.timer = Timer(self.timeout, self.handler)

    def defaultHandler(self):
        pass

    def start(self):
        self.timer.start()

    def stop(self):
        self.timer.cancel()

    def reset(self):
        self.timer.cancel()
        self.timer = Timer(self.timeout, self.handler)
        self.timer.start()

class DoorlockLogic:
    def __init__(self, client, timeout, initialState=State.RED):
        self.state = initialState
        self.client = client
        self.watchdog = Watchdog(timeout, self.watchdog_handler)
        self.watchdog.start()

    def update_state(self,new_state,source):
        self.watchdog.reset()
        if new_state == self.state:
            return

        self.state = new_state
        choices = {State.RED: Protocol.STATE_SWITCH_RED.value,
                   State.GREEN: Protocol.STATE_SWITCH_GREEN.value,
                   State.YELLOW: Protocol.STATE_SWITCH_YELLOW.value}
        ret = choices.get(self.state)

        if source == Source.BUTTON:
            self.client.send(ret.upper())
        elif source == Source.EMERGENCY:
            self.client.send(Protocol.EMERGENCY.value)
        elif source == Source.TIMEOUT:
            self.client.send(ret)

    def watchdog_handler(self):
        self.update_state(State.RED, Source.TIMEOUT)

def main(args):
    server = socket.socket(socket.AF_INET, socket.SOCK_STREAM)
    server.bind(('localhost', cfg.int("SIMULATE_SERIAL_PORT")))
    server.listen(1)
    client, addr = server.accept()
    try:
        while True:
            logic = DoorlockLogic(client, args.timeout)
            NetworkWorker(client, logic).start()

            while True:
                rec = input("input desired state (l=lock, u=unlock, p=present, e=emergency unlock)...")
                if rec=='l':
                    logic.update_state(State.RED, Source.BUTTON)
                elif rec=='u':
                    logic.update_state(State.GREEN, Source.BUTTON)
                elif rec=='p':
                    logic.update_state(State.YELLOW, Source.BUTTON)
                elif rec=='e':
                    logic.update_state(State.GREEN, Source.EMERGENCY)
                else:
                    print("Invalid command ""{}""".format(rec))
    finally:
        print("closing")
        client.close()
        server.close()

if __name__ == '__main__':
    parser = argparse.ArgumentParser(description = 'Provide a simulated doorlock serial connection over tcp/ip')
    parser.add_argument('-t', '--timeout', help='specify watchdog timeout interval', type=float, default=5.0)
    args = parser.parse_args()
    try:
        main(args)
    except KeyboardInterrupt as e:
        sys.exit(0)