// 文件名: mqtt_client.cpp
#include "mqtt_client.h"
#include "spdlog/spdlog.h"

MqttClient::MqttClient(const std::string& server_uri, const std::string& client_id)
    : client_(server_uri, client_id) {

    conn_opts_.set_clean_session(true);
    conn_opts_.set_automatic_reconnect(true);

    // <<< MODIFIED: 修改连接成功的回调逻辑 >>>
    // 这个回调现在会先打印日志，然后检查并调用外部设置的回调函数
    client_.set_connected_handler([this](const std::string& cause) {
        spdlog::info("MQTT client connected: {}", cause);
        // 如果外部设置了回调函数，就调用它
        if (m_connected_handler) {
            m_connected_handler(cause);
        }
    });

    client_.set_connection_lost_handler([](const std::string& cause) {
        spdlog::error("MQTT connection lost: {}", cause);
    });
    
    spdlog::info("MQTT client created for broker at {}", server_uri);
}

void MqttClient::connect() {
    try {
        spdlog::info("Connecting to MQTT broker...");
        client_.connect(conn_opts_)->wait();
    } catch (const mqtt::exception& exc) {
        spdlog::error("Failed to connect to MQTT broker: {}", exc.what());
        throw;
    }
}

void MqttClient::disconnect() {
    try {
        spdlog::info("Disconnecting from MQTT broker...");
        client_.disconnect()->wait();
    } catch (const mqtt::exception& exc) {
        spdlog::error("Error disconnecting from MQTT broker: {}", exc.what());
    }
}

void MqttClient::publish(const std::string& topic, const std::string& payload, int qos, bool retained) {
    if (!client_.is_connected()) {
        spdlog::warn("MQTT client is not connected. Cannot publish message.");
        return;
    }
    try {
        auto msg = mqtt::make_message(topic, payload, qos, retained);
        client_.publish(msg)->wait_for(std::chrono::seconds(2));
        spdlog::debug("Published message to topic '{}': {}", topic, payload);
    } catch (const mqtt::exception& exc) {
        spdlog::error("Failed to publish to topic '{}': {}", topic, exc.what());
    }
}

void MqttClient::subscribe(const std::string& topic, int qos) {
     if (!client_.is_connected()) {
        spdlog::warn("MQTT client is not connected. Cannot subscribe to topic.");
        return;
    }
    try {
        spdlog::info("Subscribing to topic '{}' with QoS {}", topic, qos);
        client_.subscribe(topic, qos)->wait();
    } catch (const mqtt::exception& exc) {
        spdlog::error("Failed to subscribe to topic '{}': {}", topic, exc.what());
    }
}

void MqttClient::set_message_callback(message_callback cb) {
    client_.set_message_callback(std::move(cb));
}

// <<< MODIFIED: 新增方法的实现 >>>
void MqttClient::set_connected_handler(connection_handler cb) {
    m_connected_handler = std::move(cb);
}

bool MqttClient::is_connected() const {
    return client_.is_connected();
}