#pragma once

#include "services/plc_discovery_gateway.h"

#include <QModbusDevice>
#include <QObject>
#include <QPointer>

#include <cstddef>
#include <cstdint>
#include <functional>
#include <memory>
#include <vector>

class QModbusReply;
class QModbusRtuSerialMaster;

// 使用独立 Qt Modbus RTU 主站逐项探测串口参数，不污染正式 PLC 连接状态
class PlcDiscoveryService final : public QObject, public PlcDiscoveryGateway
{
public:
    explicit PlcDiscoveryService(QObject *parent = nullptr);
    ~PlcDiscoveryService() override;

    PlcCommunicationResult startDiscovery(
        const PlcSerialConfiguration &preferred) override;
    void cancelDiscovery() override;
    bool isDiscovering() const override;
    void setCallbacks(
        std::function<void(const PlcDiscoveryProgress &)> progress_changed,
        std::function<void(const PlcDiscoveryOutcome &)> discovery_finished) override;

private:
    enum class Phase
    {
        Idle,
        Connecting,
        Probing,
        Disconnecting
    };

    // 尝试当前候选参数并等待串口异步打开
    void tryCurrentCandidate();
    // 串口打开后发送只读 D0 探测请求
    void sendProbe();
    // 处理当前 D0 探测结果
    void handleProbeFinished(QModbusReply *reply, std::uint64_t attempt_generation);
    // 释放当前串口，释放完成后进入下一个候选或报告结果
    void disconnectCurrent(bool found);
    // 当前串口完全释放后完成状态迁移
    void continueAfterDisconnect();
    // 报告最终结果并清理搜索状态
    void finishDiscovery(const PlcDiscoveryOutcome &outcome);
    // 处理 Qt Modbus 主站连接状态变化
    void handleDeviceStateChanged(QModbusDevice::State state);

    std::unique_ptr<QModbusRtuSerialMaster> master_;
    std::vector<PlcSerialConfiguration> candidates_;
    std::size_t current_candidate_ = 0;
    QPointer<QModbusReply> pending_reply_;
    Phase phase_ = Phase::Idle;
    bool discovering_ = false;
    bool cancel_requested_ = false;
    bool found_pending_ = false;
    std::uint64_t attempt_generation_ = 0;
    std::function<void(const PlcDiscoveryProgress &)> progress_changed_callback_;
    std::function<void(const PlcDiscoveryOutcome &)> discovery_finished_callback_;
};