#!/usr/bin/python3

from pixels import TermLEDs
import board
import neopixel
import json
import os
import sys
import time
from pathlib import Path

import pyinotify, threading
import paho.mqtt.subscribe as subscribe

from pattern import Pattern


lock_reload = threading.Lock()
cond_reload = threading.Condition(lock_reload)
reload = False
ignore_file = False
config = {}
new_config = None


# Monitor config from file

if len(sys.argv) > 1:
    config_file = sys.argv[1]
else:
    config_file = "blinky.json"

if not Path(config_file).is_file():
    print("WARNING: Config file does not exist:", config_file)

def file_thread(file):
    class EventHandler(pyinotify.ProcessEvent):
        def process_IN_CLOSE_WRITE(self, event):
            global reload, new_config, ignore_file
            with lock_reload:
                if ignore_file:
                    print("Ignoring file change")
                    ignore_file = False
                else:
                    print("Triggering file reload")
                    new_config = None
                    reload = True
                    cond_reload.notify_all()

    wm = pyinotify.WatchManager()
    notifier = pyinotify.Notifier(wm, EventHandler())
    wdd = wm.add_watch(file, pyinotify.IN_CLOSE_WRITE)

    notifier.loop()

threading.Thread(target=file_thread, args=[config_file]).start()


# Monitor config from MQTT

class mqtt:
    topic = "blinky/config"
    hostname = "mqtt.jrhoffa.com"
    auth = {'username':"blinky", 'password':"rainbow"}
    tls = {'ca_certs':"/etc/ssl/certs/ca-certificates.crt"}

def mqtt_thread():
    def on_message(client, userdata, message):
        global reload, new_config
        with lock_reload:
            print("Triggering MQTT reload")
            try:
                new_config = json.loads(message.payload)
                reload = True
                cond_reload.notify_all()
            except:
                print("Invalid MQTT config")

    global reload, new_config
    while True:
        print(f"Subscribing to MQTT topic {mqtt.topic}")
        try:
            message = subscribe.simple(mqtt.topic, hostname=mqtt.hostname, auth=mqtt.auth, port=8883, tls=mqtt.tls)
        except Exception as e:
            print("MQTT subscription error:", e)
            message = None
        if not message:
            print("Subscription failed - retrying")
            time.sleep(1)
        else:
            with lock_reload:
                print("Triggering MQTT reload")
                try:
                    new_config = json.loads(message.payload)
                    reload = True
                    cond_reload.notify_all()
                except:
                    print("Invalid MQTT config")


threading.Thread(target=mqtt_thread).start()


### Entry Point ##

framerate = 30

length = None
patterns = None
pixels = None

with lock_reload:
    while True:
        print("Loading config")
        reload = False

        try:
            # If it wasn't delivered, load from file
            new_config = new_config or json.load(open(config_file, 'r'))

            if 'length' in new_config:
                new_length = new_config['length']
                if length != new_length:
                    length = new_length
                    config['length'] = length
                    pixels = neopixel.NeoPixel(board.D18, length, pixel_order=neopixel.RGB, auto_write=False)
                    #pixels = TermLEDs(length)
                    print("String configured")

            patterns = [(pattern.get('length', length), Pattern.from_dict(pattern)) for pattern in new_config['patterns']]
            config['patterns'] = new_config['patterns']
            print("Pattern configured")

        except Exception as e:
            print("Failed to load config:", e)

        finally:
            print("Saving config")
            ignore_file = True
            json.dump(config, open(config_file, 'w'))

        if not length or not pixels or not patterns:
            print("Waiting for valid config")
            while not reload:
                cond_reload.wait()
        else:
            print("Starting animation")
            last = target = time.time()
            while not reload:
                lock_reload.release()

                # Generate and show new light pattern
                pixels[:] = [x for y in (pattern.step(length) for (length, pattern) in patterns) for x in y]
                pixels.show()

                # Go ahead and sleep, maintaining maximum framerate
                target += (1 / framerate)
                now = time.time()
                sleeptime = target - now
                if sleeptime > 0:
                    time.sleep(sleeptime)

                lock_reload.acquire()