// 文件名: src/modbus/modbus_rtu_poller_service.cc
#include "modbus_rtu_poller_service.h"
#include "generic_modbus_parser.h" // 使用通用解析器
#include "spdlog/spdlog.h"
#include <chrono>
#include <algorithm> // for std::minmax_element

ModbusRtuPollerService::ModbusRtuPollerService(ModbusRtuDeviceConfig config, ReportDataCallback report_cb)
    : m_config(std::move(config)),
      m_report_callback(std::move(report_cb)) {}

ModbusRtuPollerService::~ModbusRtuPollerService() {
    stop();
}

void ModbusRtuPollerService::start() {
    if (m_thread.joinable()) {
        spdlog::warn("[Modbus RTU Service] Poller for device '{}' is already running.", m_config.device_id);
        return;
    }
    m_stop_flag = false;
    // 启动一个新线程，并将 run() 方法作为入口点
    // 'this' 指针被传递，以便新线程可以调用类的成员函数
    m_thread = std::thread(&ModbusRtuPollerService::run, this);
    spdlog::info("[Modbus RTU Service] Poller for device '{}' started in a background thread.", m_config.device_id);
}

void ModbusRtuPollerService::stop() {
    m_stop_flag = true;
    if (m_thread.joinable()) {
        m_thread.join(); // 等待线程安全退出
        spdlog::info("[Modbus RTU Service] Poller for device '{}' has been stopped.", m_config.device_id);
    }
}

void ModbusRtuPollerService::run() {
    // 检查是否有数据点被配置
    if (m_config.data_points.empty()) {
        spdlog::warn("[Modbus RTU] Device '{}' has no data points configured. Thread will not run.", m_config.device_id);
        return;
    }

    // 设置并打开串口
    if (!m_client.setPortSettings(m_config.port_path, m_config.baud_rate)) {
        spdlog::error("[Modbus RTU] Failed to set up serial port '{}' for device '{}'. Thread exiting.", m_config.port_path, m_config.device_id);
        return;
    }

    // 1. 为了提高效率，我们计算出需要一次性读取的连续寄存器范围
    auto [min_it, max_it] = std::minmax_element(m_config.data_points.begin(), m_config.data_points.end(),
        [](const DataPointConfig& a, const DataPointConfig& b) {
            return a.address < b.address;
        });
    uint16_t start_address = min_it->address;
    uint16_t last_address = max_it->address;
    
    // 考虑多寄存器数据类型（如FLOAT32）会占用额外的寄存器
    if (max_it->type == ModbusDataType::UINT32 || max_it->type == ModbusDataType::INT32 || max_it->type == ModbusDataType::FLOAT32) {
        last_address += 1; // 32位数据占用2个16位寄存器
    }
    uint16_t quantity = last_address - start_address + 1;
    
    spdlog::info("[Modbus RTU] Device '{}' will poll {} registers starting from address {}.", m_config.device_id, quantity, start_address);

    // 线程主循环
    while (!m_stop_flag) {
        try {
            // 2. 一次性读取所有需要的连续寄存器
            std::vector<uint16_t> raw_registers = m_client.readHoldingRegisters(m_config.slave_id, start_address, quantity);
            
            // 3. 将返回的寄存器数组转换为 (地址 -> 值) 的映射，方便解析器按地址查找
            std::map<uint16_t, uint16_t> registers_map;
            for (uint16_t i = 0; i < raw_registers.size(); ++i) {
                registers_map[start_address + i] = raw_registers[i];
            }

            // 4. 使用通用的、配置驱动的解析器进行解析
            nlohmann::json data_j = GenericModbusParser::parse(registers_map, m_config.data_points);

            // 5. 封装成 UnifiedData 结构并上报
            UnifiedData report_data;
            report_data.device_id = m_config.device_id;
            report_data.timestamp_ms = std::chrono::duration_cast<std::chrono::milliseconds>(std::chrono::system_clock::now().time_since_epoch()).count();
            report_data.data_json = data_j.dump();

            if (m_report_callback) {
                m_report_callback(report_data);
            }

        } catch (const std::exception& e) {
            spdlog::error("[Modbus RTU] Error during communication with device '{}': {}", m_config.device_id, e.what());
        }

        // 在本线程中等待，不影响主线程的事件循环
        std::this_thread::sleep_for(std::chrono::milliseconds(m_config.poll_interval_ms));
    }
    
    // 线程退出前关闭串口
    m_client.closePort();
}