'''
处理mqtt消息相关
'''

import paho.mqtt.client as mqtt
import time
import threading
import re
import queue
import sys
from queue import Queue, Empty
from concurrent.futures import ThreadPoolExecutor
import signal

import common.sys_comm as sys_comm
from common.sys_comm import LOGDBG, LOGINFO, LOGWARN, LOGERR
from mqtt.mqtt_topics import TOPICS, Topic_Pattern

import mqtt.mqtt_recv as mqtt_recv
import mqtt.mqtt_send as mqtt_send
from mqtt.mqtt_send import mqtt_send_que # 发送队列
# 格式如下
'''
{
    "topic":    "topic/xxxx",
    "msg":      "msg to be send"
}
'''

# ================================
# MQTT 配置
# ================================
MQTT_BROKER = "119.45.12.173"   # MQTT BROKER 地址
MQTT_PORT = 1883                # MQTT 端口
MQTT_USERNAME = "lnradar"       # MQTT 用户名
MQTT_PASSWD = "lnradar"         # MQTT 密码

# ================================
# 全局对象
# ================================
executor = ThreadPoolExecutor(max_workers=8)
mqtt_queue = Queue()   # 消息队列
shutting_down = False

import atexit
atexit.register(lambda: setattr(sys.modules[__name__], 'shutting_down', True))

# ================================
# 辅助函数
# ================================
def check_topic(pattern:str, topic:str) -> bool:
    return bool(re.match(pattern, topic))


# ================================
# 消费者线程
# ================================
class MQTTConsumerThread(threading.Thread):
    def __init__(self):
        super().__init__()
        self.running = True

    def run(self):
        global shutting_down
        while self.running:
            try:
                msg_tuple = mqtt_queue.get(timeout=0.1)  # (client, userdata, msg)
            except Empty:
                if shutting_down:
                    break
                continue

            client, userdata, msg = msg_tuple
            if shutting_down:
                break
            try:
                executor.submit(mqtt_recv.process_message, client, userdata, msg)
            except RuntimeError:
                # 线程池已关闭，忽略
                break



# ================================
# MQTT 回调
# ================================
def on_connect(client:mqtt.Client, userdata, flags, rc):
    if rc == 0:
        LOGINFO("MQTT Connected successfully!")
        client.subscribe(TOPICS.dev_dsp_data)
        # client.subscribe(TOPICS.das_all)
        # client.subscribe(TOPICS.mps_all)
        client.subscribe(TOPICS.las_alarm_plan_update, qos=2)
    else:
        LOGERR(f"MQTT failed to connect, return code {rc}")

def on_message(client, userdata, msg):
    if not shutting_down:
        mqtt_queue.put((client, userdata, msg))  # 放入队列，由消费者线程处理

# ================================
# MQTT 线程类
# ================================
class MQTTClientThread(threading.Thread):
    def __init__(self,):
        threading.Thread.__init__(self)
        self.client:mqtt.Client = mqtt.Client()
        self.publish_status = {}
        self.client.username_pw_set(MQTT_USERNAME, MQTT_PASSWD)
        self.client.on_connect = on_connect
        self.client.on_message = on_message
        self.client.on_publish = self.on_publish

        self.running = True

    def on_publish(self, client, userdata, mid):
        self.publish_status[mid] = "success"

    def send_msg_to_mqtt(self):
        while True:
            time.sleep(0.01)
            try:
                mqtt_msg: dict = mqtt_send_que.get(timeout=0.1)
            except Exception:
                if shutting_down:
                    break
                continue
            try:
                topic = mqtt_msg["topic"]
                msg = mqtt_msg["msg"]
                qos = mqtt_msg.get("qos", 0)
                info = self.client.publish(topic, msg, qos=qos)
                if info.rc == 0:
                    self.publish_status[info.mid] = "pending"
                    if qos == 0:
                        self.publish_status[info.mid] = "success"
                else:
                    LOGDBG(f"send failed: {info.rc}, topic: {topic}, qos: {qos}\nmsg:{msg}")

            except Exception as e:
                LOGERR(f"send error: {e}, topic: {topic}, qos: {qos}\nmsg:{msg}")

    def run(self):
        global shutting_down
        try:
            self.client.connect(MQTT_BROKER, MQTT_PORT, 60)
            LOGINFO("Connecting to MQTT broker...")
            self.client.loop_start()
            self.send_msg_to_mqtt()

        except Exception as e:
            LOGERR(f"MQTT thread encountered an error: {e}")
        finally:
            self.running = False
            self.client.loop_stop()
            self.client.disconnect()
            shutting_down = True


mqtt_client: MQTTClientThread = None
mqtt_consumer: MQTTConsumerThread = None

# ================================
# 退出信号处理
# ================================
def signal_handler(sig, frame):
    global shutting_down
    LOGINFO("Exiting... shutting down MQTT and thread pool")
    shutting_down = True
    mqtt_client.running = False
    mqtt_client.client.loop_stop()
    mqtt_client.client.disconnect()
    mqtt_consumer.running = False
    executor.shutdown(wait=True)
    sys.exit(0)

signal.signal(signal.SIGINT, signal_handler)
signal.signal(signal.SIGTERM, signal_handler)