#include "online_logic_monitor_service.h"

#include <algorithm>
#include <utility>

namespace {

LogicScanResult success()
{
    return {true, LogicScanError::None, {}, {}, {}, {}};
}

LogicScanResult snapshotFailure(const RegisterAddress &address)
{
    return {
        false,
        LogicScanError::RegisterReadFailed,
        "读取 PLC 缓存失败：" + address.toString(),
        {},
        {},
        {}};
}

} // namespace

OnlineLogicMonitorService::OnlineLogicMonitorService(
    RegisterRepository &plc_repository,
    QObject *parent)
    : QObject(parent),
      plc_repository_(plc_repository)
{
}

OnlineLogicMonitorStartResult OnlineLogicMonitorService::start(
    const std::vector<ControlLogic> &logics)
{
    if (state_ == OnlineLogicMonitorState::Running)
    {
        return {false, OnlineLogicMonitorStartError::AlreadyRunning, {}};
    }

    std::vector<ControlLogic> snapshot = logics;
    const LogicScanResult validation = executor_.validate(snapshot);
    if (!validation.succeeded)
    {
        last_error_ = validation;
        state_ = OnlineLogicMonitorState::Faulted;
        emit stateChanged();
        return {false, OnlineLogicMonitorStartError::InvalidLogic, validation};
    }

    std::vector<RegisterAddress> addresses;
    for (const ControlLogic &logic : snapshot)
    {
        if (!logic.enabled)
        {
            continue;
        }
        for (const LadderRung &rung : logic.rungs)
        {
            std::vector<const LogicNode *> nodes;
            if (rung.condition.has_value())
            {
                collectConditionNodes(*rung.condition, &nodes);
            }
            if (rung.output.has_value())
            {
                nodes.push_back(&*rung.output);
            }
            for (const LogicNode *node : nodes)
            {
                collectRegisterAddressesForLogicNode(node->config, &addresses);
            }
        }
    }
    std::sort(
        addresses.begin(), addresses.end(),
        [](const RegisterAddress &left, const RegisterAddress &right)
        {
            return left.area() == right.area()
                ? left.index() < right.index()
                : left.area() == RegisterArea::M;
        });
    addresses.erase(std::unique(addresses.begin(), addresses.end()), addresses.end());

    executor_.resetRuntime();
    working_repository_.clear();
    logic_snapshot_ = std::move(snapshot);
    referenced_addresses_ = std::move(addresses);
    successful_scan_count_ = 0;
    last_error_ = success();
    trace_snapshot_.clear();
    state_ = OnlineLogicMonitorState::Running;
    emit stateChanged();

    const LogicScanResult first_scan = executeOnce();
    if (!first_scan.succeeded)
    {
        return {
            false,
            OnlineLogicMonitorStartError::PlcSnapshotUnavailable,
            first_scan};
    }
    return {true, OnlineLogicMonitorStartError::None, success()};
}

void OnlineLogicMonitorService::stop()
{
    executor_.resetRuntime();
    working_repository_.clear();
    logic_snapshot_.clear();
    referenced_addresses_.clear();
    trace_snapshot_.clear();
    successful_scan_count_ = 0;
    // 主动停止时保留最近一次故障，便于真机退出后继续查看诊断信息
    if (state_ == OnlineLogicMonitorState::Stopped)
    {
        return;
    }
    state_ = OnlineLogicMonitorState::Stopped;
    emit stateChanged();
}

LogicScanResult OnlineLogicMonitorService::executeOnce()
{
    if (state_ != OnlineLogicMonitorState::Running)
    {
        return {
            false,
            LogicScanError::InvalidLogic,
            "真机本地轨迹尚未运行",
            {},
            {},
            {}};
    }

    const LogicScanResult copied = copyPlcSnapshot();
    if (!copied.succeeded)
    {
        enterFault(copied);
        return copied;
    }
    const LogicScanResult result = executor_.executeScan(
        logic_snapshot_, working_repository_, &trace_snapshot_);
    if (!result.succeeded)
    {
        enterFault(result);
        return result;
    }
    ++successful_scan_count_;
    emit scanCompleted();
    return result;
}

OnlineLogicMonitorState OnlineLogicMonitorService::state() const
{
    return state_;
}

std::uint64_t OnlineLogicMonitorService::successfulScanCount() const
{
    return successful_scan_count_;
}

const LogicScanResult &OnlineLogicMonitorService::lastError() const
{
    return last_error_;
}

const LogicTraceSnapshot &OnlineLogicMonitorService::traceSnapshot() const
{
    return trace_snapshot_;
}

LogicScanResult OnlineLogicMonitorService::copyPlcSnapshot()
{
    // 每轮从真实读回缓存重新开始，本地输出不会跨轮污染 PLC 数据
    working_repository_.clear();
    for (const RegisterAddress &address : referenced_addresses_)
    {
        if (address.area() == RegisterArea::M)
        {
            const BitReadResult read = plc_repository_.readBit(address);
            if (!read.succeeded)
            {
                return snapshotFailure(address);
            }
            working_repository_.writeBit(address, read.value);
        }
        else
        {
            const WordReadResult read = plc_repository_.readWord(address);
            if (!read.succeeded)
            {
                return snapshotFailure(address);
            }
            working_repository_.writeWord(address, read.value);
        }
    }
    return success();
}

void OnlineLogicMonitorService::enterFault(const LogicScanResult &error)
{
    executor_.resetRuntime();
    last_error_ = error;
    state_ = OnlineLogicMonitorState::Faulted;
    emit stateChanged();
}