import threading, time,json
from rocketmq.client import PushConsumer, ConsumeStatus, Producer, Message


# 官方示例
# https://github.com/apache/rocketmq-client-python/tree/master/samples


"""
使用方法 : 仅限linux环境，目前支持基于Debian的发行版
1. 安装rocketmq-client-cpp（https://github.com/apache/rocketmq-client-python）
wget https://github.com/apache/rocketmq-client-cpp/releases/download/2.0.0/rocketmq-client-cpp-2.0.0.amd64.deb
dpkg -i rocketmq-client-cpp-2.0.0.amd64.deb

2. 安装 rocketmq-client-python
pip install rocketmq-client-python -i http://mirrors.aliyun.com/pypi/simple --trusted-host mirrors.aliyun.com

3. 创建rocketmq主题(如果主题不存在)
rocketmq 控制台创建主题
./mqadmin updateTopic -t alg-response -c DefaultCluster -n 192.168.1.70:9876
./mqadmin updateTopic -t alg-request -c DefaultCluster -n 192.168.1.70:9876

3. 初始化
RocketClient(name_server_address='http://192.168.1.70:8976')
后续在其他文件中直接调用RocketClient类方法，无需再次初始化
RocketClient.start_consuming 监听消息
RocketClient.send_sync  发送消息


"""
ALG_REQ_TOPIC = 'alg-request'  # 算法触发主题
ALG_RESP_TOPIC = 'alg-response'  # 算法运算结果主题


class RocketClient:
    _instance = None
    _lock = threading.Lock()  # 类级锁，确保线程安全
    _producer = None  # 单例生产者
    _name_server_address = None  # NameServer 地址

    def __new__(cls, *args, **kwargs):
        """单例模式实现"""
        with cls._lock:
            if not cls._instance:
                cls._instance = super(RocketClient, cls).__new__(cls)
        return cls._instance

    def __init__(self, name_server_address, producer_group='alg_result_producer'):
        """初始化生产者（仅执行一次）"""
        with self._lock:
            if not self.__class__._producer:
                self.__class__._name_server_address = name_server_address
                self.__class__._producer = Producer(producer_group)
                self.__class__._producer.set_name_server_address(name_server_address)
                self.__class__._producer.start()
                print('start producer')

    @classmethod
    def start_consuming(cls, topic, on_message, consumer_group='alg-req-consumer-group', expression='*'):
        """
        创建消费端
        :param topic: 监听的消息主题
        :param on_message: 收到消息后的回调方法
        :param consumer_group: 消费组
        :param expression: 消息按tag\key过滤，暂不使用
        :return:
        """

        def consumer_thread():
            consumer = PushConsumer(consumer_group)
            consumer.set_name_server_address(cls._name_server_address)
            consumer.subscribe(topic, on_message, expression=expression)
            consumer.start()
            print('listening message at {}'.format(topic))
            # 消费端是守护进程，需要保证主线程持续运行否则收到消息后客户端会退出
            while True:
                time.sleep(3)

        thread = threading.Thread(target=consumer_thread, daemon=True)
        thread.start()

    @classmethod
    def send_msg_sync(cls, msg: Message):
        """
        发送消息
        :param cls:
        :param msg:
        :return:
        """
        cls._producer.send_sync(msg)

    @classmethod
    def send_sync(cls, topic: str, body: str, tags=None, keys=None, ):
        """
        发送消息
        :param cls:
        :param topic:
        :param tags:
        :param keys:
        :param body:
        :return:
        """
        msg = Message(topic)
        if tags:
            msg.set_tags(tags)
        if keys:
            msg.set_keys(keys)
        msg.set_body(body.encode('utf-8'))
        cls._producer.send_sync(msg)
        print(f'[RocketClient] send msg to  {topic}')


if __name__ == '__main__':
    # 初始化
    RocketClient(name_server_address='http://192.168.1.70:9876')


    # 收到消息后的回调方法
    def on_msg(msg):
        try:
            print(f'msgId: {msg.id}, body: {msg.body.decode("utf-8")}')

            # 回复运算结果
            body = {
                'userName':"test",
                'coolingStationName':'一期冷站',
                'deviceName':'1号主机',
                'coolingCapacity': 1926.9,
                'COP':6.35,
                'coolingWaterFlow': 639.2,
                'time': time.time()
            }
            RocketClient.send_sync(ALG_RESP_TOPIC,body=json.dumps(body, ensure_ascii=False))
            return ConsumeStatus.CONSUME_SUCCESS
        except Exception as e:
            print(e)
            return ConsumeStatus.RECONSUME_LATER

    # 监听算法触发消息
    RocketClient.start_consuming(ALG_REQ_TOPIC, on_msg)

    while True:
        cmd = input('输入消息内容 (输入 q 退出): ')
        if cmd == 'q':
            break
        # 发送算法触发消息
        RocketClient.send_sync(ALG_RESP_TOPIC, body=cmd)