package com.ruoyi.device.bts;

import java.io.IOException;
import java.io.StringReader;
import java.math.BigDecimal;
import java.time.Instant;
import java.time.ZoneId;
import java.time.format.DateTimeFormatter;
import java.util.ArrayList;
import java.util.List;
import javax.xml.stream.XMLInputFactory;
import javax.xml.stream.XMLStreamConstants;
import javax.xml.stream.XMLStreamReader;
import com.ruoyi.device.model.DeviceWorkStatus;
import com.ruoyi.device.simulator.BtsSimulatorStateStore;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.ChannelState;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.ChannelTombstone;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.CollectorChannelState;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.CollectorHistoryAppend;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.CollectorHistoryFaults;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.CollectorMeasurementRecord;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.CollectorMetricState;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.CollectorRealtimeMeasurement;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.CollectorState;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.DeviceState;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.BtsDeviceProfile;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.BtsHistoryRecord;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.BtsPlaybackState;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.RecentRequest;
import com.ruoyi.device.simulator.BtsSimulatorStateStore.SimulatorState;
import com.ruoyi.device.simulator.InMemoryBtsSimulatorStateStore;
import com.ruoyi.device.simulator.DevelopmentCollectorSimulation;
import com.ruoyi.device.simulator.DevelopmentCollectorSimulation.CollectorAdvance;
import com.ruoyi.device.simulator.DevelopmentCollectorSimulation.CollectorHistoryPage;
import com.ruoyi.device.simulator.DevelopmentCollectorSimulation.CollectorRealtimeSnapshot;

/** 提供由开发后端托管的临时只读 BTS 模拟端点。 */
public final class BtsDevelopmentSimulator implements AutoCloseable
{
    public static final String HOST = "127.0.0.1";
    public static final int DEFAULT_PORT = 15020;
    public static final String ADAPTER_CODE = "dev-sim";
    public static final String ADAPTER_NAME = "dev-sim BTS 模拟器";
    public static final int POLL_INTERVAL_MS = 5000;
    public static final String NEWARE_CT_4008T_5V6A_S1_F = "CT-4008T-5V6A-S1-F";
    public static final String NEWARE_CT_4008TN_5V12A_S1_F = "CT-4008Tn-5V12A-S1-F";

    private static final int MAX_CHANNEL_COUNT = 99;
    private static final int MAX_RECENT_REQUESTS = 20;
    private static final int TOMBSTONE_DISCOVERY_COUNT = 3;

    private final ScriptedBtsTcpSimulator simulator;
    private final BtsSimulatorStateStore stateStore;
    private SimulatorState state;
    private boolean running = true;
    private long observationSequence;
    private final java.util.Map<String, java.util.List<BtsHistoryRecord>> btsHistory = new java.util.LinkedHashMap<>();
    private static final long SIMULATED_RECORD_INTERVAL_SECONDS = 60L;
    private static final DateTimeFormatter BTS_HISTORY_TIME = DateTimeFormatter.ofPattern("yyyy-MM-dd HH.mm.ss")
            .withZone(ZoneId.of("Asia/Hong_Kong"));

    /** 启动仅监听 IPv4 本机回环地址的开发模拟器；传入 0 时由系统分配测试端口。 */
    public BtsDevelopmentSimulator(int port) throws IOException
    {
        this(port, new InMemoryBtsSimulatorStateStore());
    }

    /** 从长期状态恢复后再启动 TCP 服务，避免服务先暴露默认拓扑。 */
    public BtsDevelopmentSimulator(int port, BtsSimulatorStateStore stateStore) throws IOException
    {
        this.stateStore = stateStore;
        state = stateStore.loadOrInitialize(defaultState());
        // 仅清理 Ticket13 之前嵌在主状态中的旧演示历史；独立历史由存储实现保留并继续补采。
        state = stateStore.resetHistoryForDemoStartup(state);
        restoreBtsHistory();
        validateRestoredState();
        stateStore.completeValidatedRestore(state);
        simulator = ScriptedBtsTcpSimulator.responding(port, this::respond);
    }

    public int port()
    {
        return simulator.port();
    }

    /** 新增一台具有独立虚拟 IP 和通道数的开发设备。 */
    public synchronized int addDevice(String ip, int channelCount)
    {
        validateDeviceConfiguration(ip, channelCount, null);
        int deviceId = state.nextDeviceId();
        List<DeviceState> devices = new ArrayList<>(state.devices());
        devices.add(newDevice(deviceId, ip, BtsDeviceProfile.virtual(channelCount)));
        persist(new SimulatorState(BtsSimulatorStateStore.CURRENT_VERSION, devices, state.collectors(),
                deviceId + 1, state.nextCollectorId(), state.tombstones()));
        return deviceId;
    }

    /** 修改开发设备的虚拟地址、通道数和在线状态。 */
    public synchronized void updateDevice(int deviceId, String ip, int channelCount, boolean online)
    {
        DeviceState current = requireDevice(deviceId);
        validateDeviceConfiguration(ip, channelCount, deviceId);
        List<ChannelState> channels = new ArrayList<>(channelCount);
        for (int channelId = 1; channelId <= channelCount; channelId++)
        {
            channels.add(channelId <= current.channels().size()
                    ? current.channels().get(channelId - 1)
                    : new ChannelState(channelId, true, DeviceWorkStatus.STOPPED));
        }
        List<DeviceState> devices = replaceDevice(new DeviceState(deviceId, ip.trim(), online, channels,
                resizeProfile(current.profile(), channelCount)));
        List<ChannelTombstone> tombstones = new ArrayList<>(state.tombstones());
        for (int channelId = channelCount + 1; channelId <= current.channels().size(); channelId++)
            upsertTombstone(tombstones, current.deviceId(), current.ip(), channelId);
        tombstones.removeIf(item -> item.deviceId() == deviceId && item.channelId() <= channelCount);
        persist(new SimulatorState(state.version(), devices, state.collectors(), state.nextDeviceId(),
                state.nextCollectorId(), tombstones));
    }

    /** 使用现场确认的新威检测柜 profile 新增设备，型号之外的控制语义仍保持只读。 */
    public synchronized int addNewareDevice(String ip, String model)
    {
        BtsDeviceProfile profile = newareProfile(model);
        validateDeviceConfiguration(ip, profile.channelCount(), null);
        int deviceId = state.nextDeviceId();
        List<DeviceState> devices = new ArrayList<>(state.devices());
        devices.add(newDevice(deviceId, ip, profile));
        persist(new SimulatorState(state.version(), devices, state.collectors(), deviceId + 1,
                state.nextCollectorId(), state.tombstones()));
        return deviceId;
    }

    /** 将已有模拟设备切换为新威 profile，并按 profile 通道数调整拓扑。 */
    public synchronized void configureNewareProfile(int deviceId, String model)
    {
        DeviceState current = requireDevice(deviceId);
        BtsDeviceProfile profile = newareProfile(model);
        updateDeviceWithProfile(current, profile);
    }

    /** 删除指定开发设备；后续发现响应不再返回它。 */
    public synchronized void deleteDevice(int deviceId)
    {
        DeviceState removed = requireDevice(deviceId);
        List<DeviceState> devices = new ArrayList<>(state.devices());
        devices.removeIf(item -> item.deviceId() == deviceId);
        List<ChannelTombstone> tombstones = new ArrayList<>(state.tombstones());
        BtsDeviceProfile removedProfile = profileFor(removed);
        for (ChannelState channel : removed.channels())
        {
            upsertTombstone(tombstones, removed.deviceId(), removed.ip(), channel.channelId());
            String key = historyKey(removedProfile.devtype(), removed.deviceId(), removedProfile.subDeviceId(),
                    channel.channelId());
            stateStore.deleteBtsHistory(key);
            stateStore.deleteBtsPlaybackState(key);
            btsHistory.remove(key);
        }
        persist(new SimulatorState(state.version(), devices, state.collectors(), state.nextDeviceId(),
                state.nextCollectorId(), tombstones));
    }

    /** 修改指定开发设备的单个通道状态。 */
    public synchronized void updateChannel(int deviceId, int channelId, boolean online,
            DeviceWorkStatus workStatus)
    {
        requireControllableStatus(workStatus);
        DeviceState device = requireDevice(deviceId);
        if (channelId < 1 || channelId > device.channels().size())
            throw new IllegalArgumentException("channelId must be between 1 and " + device.channels().size());
        List<ChannelState> channels = new ArrayList<>(device.channels());
        channels.set(channelId - 1, new ChannelState(channelId, online, workStatus));
        persist(new SimulatorState(state.version(),
                replaceDevice(new DeviceState(deviceId, device.ip(), device.online(), channels, device.profile())), state.collectors(),
                state.nextDeviceId(), state.nextCollectorId(), state.tombstones()));
    }

    /** 新增一台与 BTS 检测柜拓扑隔离的开发采集器。 */
    public synchronized int addCollector(String ip, int channelCount)
    {
        validateCollectorConfiguration(ip, channelCount, null);
        int collectorId = state.nextCollectorId();
        List<CollectorState> collectors = new ArrayList<>(state.collectors());
        collectors.add(newCollector(collectorId, ip, channelCount));
        persist(new SimulatorState(state.version(), state.devices(), collectors, state.nextDeviceId(),
                collectorId + 1, state.tombstones()));
        return collectorId;
    }

    /** 修改开发采集器的虚拟地址、通道数和在线状态。 */
    public synchronized void updateCollector(int collectorId, String ip, int channelCount, boolean online)
    {
        validateCollectorConfiguration(ip, channelCount, collectorId);
        CollectorState current = requireCollector(collectorId);
        List<CollectorState> collectors = new ArrayList<>(state.collectors());
        collectors.replaceAll(item -> item.collectorId() == collectorId
                ? DevelopmentCollectorSimulation.resize(current, ip, channelCount, online, Instant.now())
                : item);
        persist(new SimulatorState(state.version(), state.devices(), collectors, state.nextDeviceId(),
                state.nextCollectorId(), state.tombstones()));
    }

    /** 删除指定开发采集器，不影响检测柜 TCP 发现结果。 */
    public synchronized void deleteCollector(int collectorId)
    {
        CollectorState collector = requireCollector(collectorId);
        List<CollectorState> collectors = new ArrayList<>(state.collectors());
        collectors.removeIf(item -> item.collectorId() == collectorId);
        SimulatorState next = new SimulatorState(state.version(), state.devices(), collectors, state.nextDeviceId(),
                state.nextCollectorId(), state.tombstones());
        stateStore.saveAndDeleteCollectorHistory(next, collector.deviceCode());
        this.state = next;
    }

    /** 配置采集器独立采样频率和历史下载故障场景。 */
    public synchronized void configureCollectorSampling(int collectorId, int sampleIntervalMs,
            CollectorHistoryFaults historyFaults)
    {
        CollectorState current = requireCollector(collectorId);
        replaceCollector(DevelopmentCollectorSimulation.configureSampling(current, sampleIntervalMs, historyFaults));
    }

    /** 配置一个稳定 S 通道的固定或动态演示指标。 */
    public synchronized void configureCollectorChannel(int collectorId, String channelCode,
            List<CollectorMetricState> metrics)
    {
        CollectorState current = requireCollector(collectorId);
        replaceCollector(DevelopmentCollectorSimulation.configureChannel(current, channelCode, metrics));
    }

    /**
     * 模拟现场人工统一开关机：关机停止采样但保留历史，开机后检测柜通道保持待机。
     * 该操作只改变模拟设备事实，不代表系统具备真实设备控制能力。
     */
    public synchronized void setAllDevicesPoweredOn(boolean poweredOn)
    {
        List<DeviceState> devices = state.devices().stream()
                .map(device -> new DeviceState(device.deviceId(), device.ip(), poweredOn,
                        device.channels().stream()
                                .map(channel -> new ChannelState(channel.channelId(), poweredOn,
                                        DeviceWorkStatus.STOPPED))
                                .toList(), device.profile()))
                .toList();
        Instant changedAt = Instant.now();
        List<CollectorState> collectors = state.collectors().stream()
                .map(collector -> DevelopmentCollectorSimulation.resize(collector, collector.ip(),
                        collector.channelCount(), poweredOn, changedAt))
                .toList();
        persist(new SimulatorState(state.version(), devices, collectors, state.nextDeviceId(),
                state.nextCollectorId(), state.tombstones()));
    }

    /** 按每台采集器自己的频率推进实时和历史采样。 */
    public synchronized void advanceCollectors(Instant now)
    {
        boolean hasOnlineCollector = false;
        for (CollectorState collector : state.collectors())
        {
            if (!collector.online()) continue;
            hasOnlineCollector = true;
            break;
        }
        if (!hasOnlineCollector) return;
        List<CollectorState> collectors = new ArrayList<>(state.collectors().size());
        List<CollectorHistoryAppend> historyAppends = new ArrayList<>();
        for (CollectorState collector : state.collectors())
        {
            CollectorAdvance advance = DevelopmentCollectorSimulation.advance(collector, now);
            collectors.add(advance.state());
            if (!advance.appendedRecords().isEmpty())
                historyAppends.add(new CollectorHistoryAppend(collector.deviceCode(), advance.appendedRecords()));
        }
        if (!historyAppends.isEmpty())
            persist(new SimulatorState(state.version(), state.devices(), collectors, state.nextDeviceId(),
                    state.nextCollectorId(), state.tombstones()), historyAppends);
    }

    /** 按墙上时间推进检测柜模拟播放；设备状态和测试接收状态互不影响。 */
    public synchronized void advanceBts(Instant now)
    {
        for (DeviceState device : state.devices())
        {
            if (!device.online()) continue;
            BtsDeviceProfile profile = profileFor(device);
            for (ChannelState channel : device.channels())
            {
                if (!channel.online() || channel.workStatus() != DeviceWorkStatus.WORKING) continue;
                String key = historyKey(profile.devtype(), device.deviceId(), profile.subDeviceId(), channel.channelId());
                BtsPlaybackState playback = playbackState(key, now);
                advanceBtsPlayback(key, profile, playback,
                        profile.currentMaxA().doubleValue() * 0.2d, 3.7d, now);
            }
        }
    }

    /** 设置检测柜通道演示倍速，只接受 1x、60x 和 600x。 */
    public synchronized void setBtsSpeed(int deviceId, int channelId, int speedMultiplier)
    {
        DeviceState device = requireDevice(deviceId);
        requireChannel(device, channelId);
        String key = btsKey(device, channelId);
        BtsPlaybackState current = playbackState(key, Instant.now());
        stateStore.saveBtsPlaybackState(key, new BtsPlaybackState(current.playing(), speedMultiplier,
                current.cycleNo(), current.stepNo(), current.stepName(), current.stepType(), current.simulatedAt(),
                Instant.now(), current.nextSequence(), current.naturallyFinished()));
    }

    /** 开始播放指定检测柜通道的演示时间线。 */
    public synchronized void playBts(int deviceId, int channelId) { setBtsPlaying(deviceId, channelId, true); }
    /** 暂停模拟器时间线，不改变检测柜通道工作事实。 */
    public synchronized void pauseBts(int deviceId, int channelId) { setBtsPlaying(deviceId, channelId, false); }
    /** 从暂停状态恢复模拟器时间线。 */
    public synchronized void resumeBts(int deviceId, int channelId) { setBtsPlaying(deviceId, channelId, true); }

    private void setBtsPlaying(int deviceId, int channelId, boolean playing)
    {
        DeviceState device = requireDevice(deviceId);
        requireChannel(device, channelId);
        String key = btsKey(device, channelId);
        Instant now = Instant.now();
        BtsPlaybackState current = playbackState(key, now);
        if (current.naturallyFinished() && playing) return;
        stateStore.saveBtsPlaybackState(key, new BtsPlaybackState(playing, current.speedMultiplier(), current.cycleNo(),
                current.stepNo(), current.stepName(), current.stepType(), current.simulatedAt(), now,
                current.nextSequence(), current.naturallyFinished()));
    }

    /** 跳转到下一实际工步；不向设备发送控制报文。 */
    public synchronized void nextBtsStep(int deviceId, int channelId)
    {
        DeviceState device = requireDevice(deviceId);
        requireChannel(device, channelId);
        String key = btsKey(device, channelId);
        BtsPlaybackState current = playbackState(key, Instant.now());
        BtsExcelFixture.FixtureRecord next = nextFixtureStep(current.cycleNo(), current.stepNo());
        if (next == null)
        {
            BtsExcelFixture.FixtureRecord last = BtsExcelFixture.record(BtsExcelFixture.recordCount());
            savePlayback(key, new BtsPlaybackState(false, current.speedMultiplier(), last.cycleNo(), last.stepNo(),
                    last.stepName(), last.stepType(), current.simulatedAt(), Instant.now(),
                    BtsExcelFixture.recordCount() + 1L, true));
            return;
        }
        savePlayback(key, new BtsPlaybackState(current.playing(), current.speedMultiplier(), next.cycleNo(), next.stepNo(),
                next.stepName(), next.stepType(), current.simulatedAt(), Instant.now(), next.sequenceId(), false));
    }

    /** 跳转到下一循环的首工步；不补齐当前循环缺失的首尾工步。 */
    public synchronized void nextBtsCycle(int deviceId, int channelId)
    {
        DeviceState device = requireDevice(deviceId);
        requireChannel(device, channelId);
        String key = btsKey(device, channelId);
        BtsPlaybackState current = playbackState(key, Instant.now());
        BtsExcelFixture.FixtureRecord next = BtsExcelFixture.records().stream()
                .filter(item -> item.cycleNo() > current.cycleNo()).findFirst().orElse(null);
        if (next == null)
        {
            BtsExcelFixture.FixtureRecord last = BtsExcelFixture.record(BtsExcelFixture.recordCount());
            savePlayback(key, new BtsPlaybackState(false, current.speedMultiplier(), last.cycleNo(), last.stepNo(),
                    last.stepName(), last.stepType(), current.simulatedAt(), Instant.now(),
                    BtsExcelFixture.recordCount() + 1L, true));
            return;
        }
        savePlayback(key, new BtsPlaybackState(current.playing(), current.speedMultiplier(), next.cycleNo(), next.stepNo(),
                next.stepName(), next.stepType(), current.simulatedAt(), Instant.now(), next.sequenceId(), false));
    }

    /** 清空单通道播放和原始数据，恢复到首循环首工步。 */
    public synchronized void resetBts(int deviceId, int channelId)
    {
        DeviceState device = requireDevice(deviceId);
        requireChannel(device, channelId);
        String key = btsKey(device, channelId);
        btsHistory.remove(key);
        stateStore.deleteBtsHistory(key);
        stateStore.deleteBtsPlaybackState(key);
        savePlayback(key, defaultPlayback(Instant.now()));
    }

    /** 返回播放状态及当前通道的 record、step、cycle 数据。 */
    public synchronized PlaybackSnapshot btsPlayback(int deviceId, int channelId)
    {
        DeviceState device = requireDevice(deviceId);
        requireChannel(device, channelId);
        String key = btsKey(device, channelId);
        BtsPlaybackState state = playbackState(key, Instant.now());
        return new PlaybackSnapshot(deviceId, channelId, state, btsRecords(deviceId, channelId),
                btsSteps(deviceId, channelId), btsCycles(deviceId, channelId));
    }

    /** 返回只追加的检测柜原始 record。 */
    public synchronized List<BtsHistoryRecord> btsRecords(int deviceId, int channelId)
    {
        DeviceState device = requireDevice(deviceId);
        requireChannel(device, channelId);
        return List.copyOf(btsHistoryFor(btsKey(device, channelId)));
    }

    /** 按实际出现的循环和工步汇总 record，不补齐缺失行。 */
    public synchronized List<BtsStepRecord> btsSteps(int deviceId, int channelId)
    {
        java.util.Map<String, BtsStepAccumulator> grouped = new java.util.LinkedHashMap<>();
        for (BtsHistoryRecord item : btsRecords(deviceId, channelId))
        {
            String key = item.cycleNo() + ":" + item.stepNo();
            grouped.computeIfAbsent(key, ignored -> new BtsStepAccumulator(item)).add(item);
        }
        return grouped.values().stream().map(BtsStepAccumulator::finish).toList();
    }

    /** 按实际出现的循环汇总 record，不增加测试结束统计行。 */
    public synchronized List<BtsCycleRecord> btsCycles(int deviceId, int channelId)
    {
        java.util.Map<Integer, BtsCycleAccumulator> grouped = new java.util.LinkedHashMap<>();
        for (BtsHistoryRecord item : btsRecords(deviceId, channelId))
            grouped.computeIfAbsent(item.cycleNo(), ignored -> new BtsCycleAccumulator(item)).add(item);
        return grouped.entrySet().stream().map(entry -> {
            BtsCycleRecord calculated = entry.getValue().finish();
            BtsExcelFixture.CycleSummary expected = BtsExcelFixture.cycle(entry.getKey());
            String recordNo = "CYCLE-" + deviceId + "-" + channelId + "-" + entry.getKey();
            if (expected == null || entry.getValue().count < expected.recordCount())
                return new BtsCycleRecord(recordNo, calculated.cycleNo(), calculated.recordCount(), calculated.startedAt(), calculated.endedAt(),
                        calculated.chargeCapacityAh(), calculated.dischargeCapacityAh(), calculated.chargeEnergyWh(), calculated.dischargeEnergyWh(), calculated.efficiency());
            return new BtsCycleRecord(recordNo, calculated.cycleNo(), expected.recordCount(), calculated.startedAt(),
                    calculated.endedAt(), expected.chargeCapacityAh(), expected.dischargeCapacityAh(),
                    expected.chargeEnergyWh(), expected.dischargeEnergyWh(),
                    efficiency(expected.chargeCapacityAh(), expected.dischargeCapacityAh()));
        }).toList();
    }

    /** 返回采集器最新实时快照；快照与分页历史保持不同读取路径。 */
    public synchronized CollectorRealtimeSnapshot collectorRealtime(int collectorId)
    {
        return DevelopmentCollectorSimulation.realtime(requireCollector(collectorId));
    }

    /** 分页下载采集器模拟历史，并应用已配置的重复、冲突、乱序或缺失场景。 */
    public synchronized CollectorHistoryPage collectorHistory(int collectorId, long offset, int limit)
    {
        CollectorState collector = requireCollector(collectorId);
        return DevelopmentCollectorSimulation.history(collector, stateStore, offset, limit);
    }

    /** 返回控制页需要的运行状态快照。 */
    public synchronized StateSnapshot snapshot()
    {
        List<DeviceSnapshot> deviceSnapshots = state.devices().stream()
                .map(device -> new DeviceSnapshot(device.deviceId(), device.ip(), device.online(), device.profile(),
                        device.channels().stream()
                                .map(channel -> new ChannelSnapshot(channel.channelId(), channel.online(),
                                        channel.workStatus()))
                                .toList()))
                .toList();
        List<CollectorSnapshot> collectorSnapshots = state.collectors().stream()
                .map(collector -> new CollectorSnapshot(collector.collectorId(), collector.deviceCode(),
                        collector.ip(), collector.mac(), collector.name(), collector.manufacturer(),
                        collector.model(), collector.channelCount(), collector.online(), collector.sampleIntervalMs(),
                        collector.channels(), collector.historyFaults(), collector.historyRecordCount(),
                        DevelopmentCollectorSimulation.realtime(collector).measurements()))
                .toList();
        return new StateSnapshot(running, HOST + ":" + port(), deviceSnapshots, collectorSnapshots,
                stateStore.loadRecentRequests());
    }

    /** 人工恢复默认拓扑；这是正常运行中唯一清空长期模拟状态的入口。 */
    public synchronized void reset()
    {
        SimulatorState defaultState = defaultState();
        stateStore.reset(defaultState);
        btsHistory.clear();
        state = defaultState;
    }

    private SimulatorState defaultState()
    {
        return new SimulatorState(BtsSimulatorStateStore.CURRENT_VERSION,
                List.of(newDevice(1, "127.0.0.2", 4)),
                List.of(newCollector(1, "127.0.1.2", 4)), 2, 2, List.of());
    }

    private DeviceState newDevice(int deviceId, String ip, int channelCount)
    {
        return newDevice(deviceId, ip, BtsDeviceProfile.virtual(channelCount));
    }

    private DeviceState newDevice(int deviceId, String ip, BtsDeviceProfile profile)
    {
        List<ChannelState> channels = new ArrayList<>(profile.channelCount());
        for (int channelId = 1; channelId <= profile.channelCount(); channelId++)
            channels.add(new ChannelState(channelId, true, DeviceWorkStatus.STOPPED));
        return new DeviceState(deviceId, ip.trim(), true, channels, profile);
    }

    private CollectorState newCollector(int collectorId, String ip, int channelCount)
    {
        return new CollectorState(collectorId, "dev-sim-collector-" + collectorId,
                ip.trim(), simulatorCollectorMac(collectorId), "dev-sim 采集器 " + collectorId,
                "开发模拟器", "Virtual Collector", channelCount, true);
    }

    private void replaceCollector(CollectorState replacement)
    {
        List<CollectorState> collectors = new ArrayList<>(state.collectors());
        collectors.replaceAll(item -> item.collectorId() == replacement.collectorId() ? replacement : item);
        persist(new SimulatorState(state.version(), state.devices(), collectors, state.nextDeviceId(),
                state.nextCollectorId(), state.tombstones()));
    }

    private String respond(String request)
    {
        String command = readCommand(request);
        recordRequest(command, request);
        return switch (command)
        {
            case "getdevinfo" -> deviceInfoResponse();
            case "inquire" -> observationResponse(request);
            case "inquiredf" -> historyAvailabilityResponse(request);
            case "download" -> historyResponse(request);
            default -> "<bts version=\"1.0\"><cmd>error</cmd></bts>";
        };
    }

    private synchronized void recordRequest(String command, String request)
    {
        List<RecentRequest> recentRequests = new ArrayList<>(stateStore.loadRecentRequests());
        recentRequests.add(0, new RecentRequest(Instant.now(), command, request));
        if (recentRequests.size() > MAX_RECENT_REQUESTS)
            recentRequests = new ArrayList<>(recentRequests.subList(0, MAX_RECENT_REQUESTS));
        stateStore.saveRecentRequests(recentRequests);
    }

    private String readCommand(String request)
    {
        try
        {
            XMLInputFactory factory = XMLInputFactory.newFactory();
            factory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
            factory.setProperty("javax.xml.stream.isSupportingExternalEntities", false);
            XMLStreamReader reader = factory.createXMLStreamReader(new StringReader(request));
            while (reader.hasNext())
            {
                if (reader.next() == XMLStreamConstants.START_ELEMENT && "cmd".equals(reader.getLocalName()))
                    return reader.getElementText().trim();
            }
        }
        catch (Exception exception)
        {
            throw new IllegalArgumentException("Invalid BTS request XML", exception);
        }
        throw new IllegalArgumentException("BTS request does not contain cmd");
    }

    private synchronized String deviceInfoResponse()
    {
        int channelCount = state.devices().stream().mapToInt(device -> device.channels().size()).sum()
                + state.tombstones().size();
        StringBuilder response = new StringBuilder("<bts version=\"1.0\"><cmd>getdevinfo_resp</cmd>")
                .append("<serverip count=\"0\"/><middle count=\"").append(channelCount).append("\">");
        for (DeviceState device : state.devices())
        {
            for (ChannelState channel : device.channels())
            {
                boolean available = device.online() && channel.online();
                appendDiscoveredChannel(response, device.deviceId(), device.ip(), channel.channelId(), available);
            }
        }
        List<ChannelTombstone> remaining = new ArrayList<>();
        for (ChannelTombstone tombstone : state.tombstones())
        {
            appendDiscoveredChannel(response, tombstone.deviceId(), tombstone.ip(), tombstone.channelId(), false);
            if (tombstone.remainingDiscoveries() > 1)
                remaining.add(new ChannelTombstone(tombstone.deviceId(), tombstone.ip(), tombstone.channelId(),
                        tombstone.remainingDiscoveries() - 1));
        }
        if (!remaining.equals(state.tombstones()))
            persist(new SimulatorState(state.version(), state.devices(), state.collectors(), state.nextDeviceId(),
                    state.nextCollectorId(), remaining));
        return response.append("</middle></bts>").toString();
    }

    private void appendDiscoveredChannel(StringBuilder response, int deviceId, String ip, int channelId,
            boolean available)
    {
        // 展示元数据是开发模拟器扩展，不代表真实 BTS 协议必然提供这些属性。
        DeviceState device = state.devices().stream().filter(item -> item.deviceId() == deviceId).findFirst().orElse(null);
        BtsDeviceProfile profile = device == null ? BtsDeviceProfile.virtual(channelId) : profileFor(device);
        response.append("<channel ip=\"").append(ip).append("\" devtype=\"").append(profile.devtype())
                .append("\" devid=\"").append(deviceId).append("\" subdevid=\"").append(profile.subDeviceId())
                .append("\" Channelid=\"").append(channelId).append("\" name=\"").append(profile.name())
                .append("\" manufacturer=\"").append(profile.manufacturer()).append("\" model=\"")
                .append(profile.model()).append("\" serialNumber=\"").append(profile.serialNumber())
                .append("\" firmwareVersion=\"").append(profile.firmwareVersion()).append("\" mac=\"")
                .append(simulatorMac(profile.devtype(), deviceId)).append("\">")
                .append(available).append("</channel>");
    }

    private synchronized String observationResponse(String request)
    {
        long tick = ++observationSequence;
        java.util.Set<String> requested = requestedChannels(request);
        List<ObservedChannel> available = new ArrayList<>();
        for (DeviceState device : state.devices())
            for (ChannelState channel : device.channels())
                if (device.online() && channel.online()
                        && (requested.isEmpty() || requested.contains(device.deviceId() + ":" + channel.channelId())))
                    available.add(new ObservedChannel(device.deviceId(), channel));

        StringBuilder response = new StringBuilder("<bts version=\"1.0\"><cmd>inquire_resp</cmd><list count=\"")
                .append(available.size()).append("\">");
        for (ObservedChannel observed : available)
        {
            ChannelState channel = observed.channel();
            DeviceState device = requireDevice(observed.deviceId());
            BtsDeviceProfile profile = profileFor(device);
            boolean working = channel.workStatus() == DeviceWorkStatus.WORKING;
            double wave = Math.sin((tick + channel.channelId()) * 0.7d);
            double current = working ? clamp(profile.currentMaxA().doubleValue() * (0.18d + wave * 0.02d),
                    profile.currentMinA().doubleValue(), profile.currentMaxA().doubleValue()) : 0d;
            double voltage = clamp(3.7d + wave * 0.01d, profile.voltageMinV().doubleValue(),
                    profile.voltageMaxV().doubleValue());
            String key = historyKey(profile.devtype(), observed.deviceId(), profile.subDeviceId(), channel.channelId());
            BtsPlaybackState playback = playbackState(key, Instant.now());
            double capacity = working ? latestCapacity(key) : 0d;
            double energy = capacity * voltage;
            if (working)
            {
                playback = advanceBtsPlayback(key, profile, playback, current, voltage);
                BtsHistoryRecord latest = latestRecord(key);
                if (latest != null)
                {
                    capacity = latest.capacityAh();
                    energy = latest.energyWh();
                }
            }
            int cycleNo = playback.cycleNo();
            int stepNo = playback.stepNo();
            String stepType = playback.stepType();
            response.append("<inquire dev=\"").append(profile.devtype()).append('-').append(observed.deviceId())
                    .append('-').append(profile.subDeviceId()).append('-').append(channel.channelId())
                    .append("-0\" cycle_id=\"").append(cycleNo).append("\" step_id=\"").append(stepNo)
                    .append("\" step_type=\"").append(stepType).append("\" workstatus=\"")
                    .append(toBtsWorkStatus(channel.workStatus()))
                    .append("\" current=\"").append(decimal(current)).append("\" voltage=\"")
                    .append(decimal(voltage)).append("\" capacity=\"").append(decimal(capacity))
                    .append("\" energy=\"").append(decimal(energy)).append("\" totaltime=\"")
                    .append(working ? tick : 0).append("\" relativetime=\"").append(working ? tick : 0)
                    .append("\" open_or_close=\"0\" log_code=\"0\"/>");
        }
        return response.append("</list></bts>").toString();
    }

    private synchronized String historyAvailabilityResponse(String request)
    {
        java.util.regex.Matcher matcher = java.util.regex.Pattern.compile("<chl\\s+([^>]*)/?>").matcher(request);
        StringBuilder response = new StringBuilder("<bts version=\"1.0\"><cmd>inquiredf_resp</cmd><list>");
        while (matcher.find())
        {
            String attrs = matcher.group(1);
            int devtype = Integer.parseInt(attribute(attrs, "devtype"));
            int devid = Integer.parseInt(attribute(attrs, "devid"));
            int subdevid = Integer.parseInt(attribute(attrs, "subdevid"));
            int chlid = Integer.parseInt(attribute(attrs, "chlid"));
            int count = btsHistoryFor(historyKey(devtype, devid, subdevid, chlid)).size();
            response.append("<chl devtype=\"").append(devtype).append("\" devid=\"").append(devid)
                    .append("\" subdevid=\"").append(subdevid).append("\" chlid=\"").append(chlid)
                    .append("\" testid=\"SIM-").append(devid).append('-').append(chlid).append("\" count=\"")
                    .append(count).append("\">true</chl>");
        }
        return response.append("</list></bts>").toString();
    }

    private synchronized String historyResponse(String request)
    {
        int devtype = Integer.parseInt(attribute(request, "devtype"));
        int devid = Integer.parseInt(attribute(request, "devid"));
        int subdevid = Integer.parseInt(attribute(request, "subdevid"));
        int chlid = Integer.parseInt(attribute(request, "chlid"));
        String testId = attribute(request, "testid");
        long start = Long.parseLong(attribute(request, "startpos"));
        int count = Integer.parseInt(attribute(request, "count"));
        List<BtsHistoryRecord> history = btsHistoryFor(historyKey(devtype, devid, subdevid, chlid));
        int from = (int) Math.min(Math.max(0L, start - 1L), history.size());
        int to = Math.min(history.size(), from + Math.max(1, count));
        StringBuilder response = new StringBuilder("<bts version=\"1.0\"><cmd>download_resp</cmd><download devtype=\"")
                .append(devtype).append("\" devid=\"").append(devid).append("\" subdevid=\"").append(subdevid)
                .append("\" chlid=\"").append(chlid).append("\" testid=\"").append(testId)
                .append("\"><list>");
        for (BtsHistoryRecord item : history.subList(from, to))
            response.append("<data seqid=\"").append(item.sequenceId()).append("\" stepid=\"").append(item.stepNo())
                    .append("\" cycleid=\"").append(item.cycleNo()).append("\" steptype=\"").append(item.stepType()).append("\" atime=\"")
                    .append(BTS_HISTORY_TIME.format(item.deviceTime())).append("\" testtime=\"60000\" volt=\"")
                    .append(decimal(item.voltageV())).append("\" curr=\"").append(decimal(item.currentA()))
                    .append("\" cap=\"").append(decimal(item.capacityAh())).append("\" eng=\"").append(decimal(item.energyWh())).append("\"/>");
        return response.append("</list></download></bts>").toString();
    }

    private String attribute(String xml, String name)
    {
        java.util.regex.Matcher matcher = java.util.regex.Pattern.compile(name + "=\\\"([^\\\"]+)\\\"").matcher(xml);
        if (!matcher.find()) throw new IllegalArgumentException("Missing simulator attribute: " + name);
        return matcher.group(1);
    }

    private String historyKey(int devtype, int devid, int subdevid, int chlid)
    {
        return devtype + ":" + devid + ":" + subdevid + ":" + chlid;
    }

    private void restoreBtsHistory()
    {
        for (DeviceState device : state.devices())
        {
            BtsDeviceProfile profile = profileFor(device);
            for (ChannelState channel : device.channels())
            {
                String key = historyKey(profile.devtype(), device.deviceId(), profile.subDeviceId(), channel.channelId());
                ArrayList<BtsHistoryRecord> restored = new ArrayList<>();
                long offset = 0;
                while (true)
                {
                    var page = stateStore.loadBtsHistoryPage(key, offset, BtsSimulatorStateStore.MAX_HISTORY_BATCH_SIZE);
                    restored.addAll(page.records().stream().map(this::normalizeHistoryRecord).toList());
                    if (!page.hasMore()) break;
                    if (page.nextOffset() <= offset) throw new IllegalStateException("Invalid BTS history page");
                    offset = page.nextOffset();
                }
                if (!restored.isEmpty()) btsHistory.put(key, restored);
            }
        }
    }

    private List<BtsHistoryRecord> btsHistoryFor(String key)
    {
        return btsHistory.getOrDefault(key, List.of());
    }

    private BtsHistoryRecord normalizeHistoryRecord(BtsHistoryRecord item)
    {
        return item.stepName() == null || item.stepName().isBlank()
                ? new BtsHistoryRecord(item.sequenceId(), item.deviceTime(), item.currentA(), item.voltageV(),
                        item.capacityAh(), item.energyWh()) : item;
    }

    private String btsKey(DeviceState device, int channelId)
    {
        BtsDeviceProfile profile = profileFor(device);
        return historyKey(profile.devtype(), device.deviceId(), profile.subDeviceId(), channelId);
    }

    private void requireChannel(DeviceState device, int channelId)
    {
        if (channelId < 1 || channelId > device.channels().size())
            throw new IllegalArgumentException("channelId must be between 1 and " + device.channels().size());
    }

    private BtsPlaybackState playbackState(String key, Instant now)
    {
        BtsPlaybackState stored = stateStore.loadBtsPlaybackState(key);
        if (stored != null) return stored;
        List<BtsHistoryRecord> records = btsHistoryFor(key);
        long next = records.stream().mapToLong(BtsHistoryRecord::sequenceId).max().orElse(0L) + 1L;
        BtsExcelFixture.FixtureRecord first = BtsExcelFixture.record(1);
        BtsPlaybackState created = new BtsPlaybackState(true, 1, first.cycleNo(), first.stepNo(), first.stepName(), first.stepType(),
                now.minusSeconds(SIMULATED_RECORD_INTERVAL_SECONDS), now, next, false);
        stateStore.saveBtsPlaybackState(key, created);
        return created;
    }

    private BtsHistoryRecord latestRecord(String key)
    {
        List<BtsHistoryRecord> records = btsHistoryFor(key);
        return records.isEmpty() ? null : records.get(records.size() - 1);
    }

    private double latestCapacity(String key)
    {
        BtsHistoryRecord latest = latestRecord(key);
        return latest == null ? 0d : latest.capacityAh();
    }

    private BtsPlaybackState advanceBtsPlayback(String key, BtsDeviceProfile profile, BtsPlaybackState current,
            double currentA, double voltageV)
    {
        return advanceBtsPlayback(key, profile, current, currentA, voltageV, Instant.now());
    }

    private BtsPlaybackState advanceBtsPlayback(String key, BtsDeviceProfile profile, BtsPlaybackState current,
            double currentA, double voltageV, Instant now)
    {
        if (!current.playing() || current.naturallyFinished()) return current;
        long elapsedMillis = Math.max(0L, java.time.Duration.between(current.wallClockAt(), now).toMillis())
                * current.speedMultiplier();
        List<BtsHistoryRecord> history = new ArrayList<>(btsHistoryFor(key));
        List<BtsHistoryRecord> appended = new ArrayList<>();
        Instant simulated = current.simulatedAt();
        long sequence = current.nextSequence();
        if (sequence < 1) sequence = 1;
        if (sequence > BtsExcelFixture.recordCount() + 1L)
            sequence = BtsExcelFixture.recordCount() + 1L;
        long lastOffset = sequence == 1 ? -SIMULATED_RECORD_INTERVAL_SECONDS
                : BtsExcelFixture.record(sequence - 1).offsetSeconds();
        long budgetMillis = elapsedMillis;
        while (sequence <= BtsExcelFixture.recordCount())
        {
            BtsExcelFixture.FixtureRecord fixture = BtsExcelFixture.record(sequence);
            long deltaSeconds = fixture.offsetSeconds() - lastOffset;
            long deltaMillis = Math.max(1L, deltaSeconds * 1000L);
            boolean firstRecord = history.isEmpty() && sequence == 1L;
            if (!firstRecord && budgetMillis < deltaMillis) break;
            budgetMillis = Math.max(0L, budgetMillis - deltaMillis);
            simulated = simulated.plusSeconds(deltaSeconds);
            BtsHistoryRecord record = new BtsHistoryRecord(fixture.sequenceId(), simulated, fixture.currentA(), fixture.voltageV(),
                    fixture.capacityAh(), fixture.energyWh(), fixture.cycleNo(), fixture.stepNo(), fixture.stepName(), fixture.stepType());
            history.add(record);
            appended.add(record);
            lastOffset = fixture.offsetSeconds();
            sequence++;
        }
        if (appended.isEmpty()) return current;
        if (history.size() > BtsSimulatorStateStore.MAX_HISTORY_RECORDS)
            history = new ArrayList<>(history.subList(history.size() - (int) BtsSimulatorStateStore.MAX_HISTORY_RECORDS,
                    history.size()));
        BtsExcelFixture.FixtureRecord latest = BtsExcelFixture.record(sequence - 1L);
        boolean finished = sequence > BtsExcelFixture.recordCount();
        BtsPlaybackState next = new BtsPlaybackState(!finished && current.playing(), current.speedMultiplier(),
                latest.cycleNo(), latest.stepNo(), latest.stepName(), latest.stepType(), simulated, now, sequence, finished);
        stateStore.saveBtsPlaybackAndAppendHistory(key, next, appended);
        btsHistory.put(key, history);
        return next;
    }

    private BtsPlaybackState defaultPlayback(Instant now)
    {
        BtsExcelFixture.FixtureRecord first = BtsExcelFixture.record(1);
        return new BtsPlaybackState(true, 1, first.cycleNo(), first.stepNo(), first.stepName(), first.stepType(),
                now.minusSeconds(SIMULATED_RECORD_INTERVAL_SECONDS), now, 1, false);
    }

    private BtsExcelFixture.FixtureRecord nextFixtureStep(int cycleNo, int stepNo)
    {
        return BtsExcelFixture.records().stream()
                .filter(item -> item.cycleNo() > cycleNo || (item.cycleNo() == cycleNo && item.stepNo() > stepNo))
                .findFirst().orElse(null);
    }

    private void savePlayback(String key, BtsPlaybackState playback)
    {
        stateStore.saveBtsPlaybackState(key, playback);
    }

    public record BtsStepRecord(int cycleNo, int stepNo, String stepName, String stepType, long recordCount,
            Instant startedAt, Instant endedAt, double durationSeconds, double capacityAh, double energyWh,
            double startVoltageV, double endVoltageV, double chargePeakVoltageV, double dischargeValleyVoltageV) { }

    public record BtsCycleRecord(String recordNo, int cycleNo, long recordCount, Instant startedAt, Instant endedAt,
            double chargeCapacityAh, double dischargeCapacityAh, double chargeEnergyWh, double dischargeEnergyWh,
            double efficiency) { }

    private static double efficiency(double chargeCapacityAh, double dischargeCapacityAh)
    {
        return chargeCapacityAh > 0d ? dischargeCapacityAh / chargeCapacityAh * 100d : 0d;
    }

    public record PlaybackSnapshot(int deviceId, int channelId, BtsPlaybackState playback,
            List<BtsHistoryRecord> records, List<BtsStepRecord> steps, List<BtsCycleRecord> cycles) { }

    private static final class BtsStepAccumulator
    {
        private final int cycle; private final int step; private final String name; private final String type;
        private long count; private Instant first; private Instant last; private double duration; private double capacity; private double energy;
        private double startVoltage; private double endVoltage; private double chargePeak = Double.NEGATIVE_INFINITY; private double dischargeValley = Double.POSITIVE_INFINITY;
        BtsStepAccumulator(BtsHistoryRecord first) { cycle = first.cycleNo(); step = first.stepNo(); name = first.stepName(); type = first.stepType(); }
        void add(BtsHistoryRecord item) { count++; if (first == null) { first = item.deviceTime(); startVoltage = item.voltageV(); } last = item.deviceTime(); endVoltage = item.voltageV(); duration = first == null ? 0 : Math.max(0, java.time.Duration.between(first, last).toMillis() / 1000d); capacity = item.capacityAh(); energy = item.energyWh(); if (item.currentA() >= 0) chargePeak = Math.max(chargePeak, item.voltageV()); else dischargeValley = Math.min(dischargeValley, item.voltageV()); }
        BtsStepRecord finish() { return new BtsStepRecord(cycle, step, name, type, count, first, last, duration, capacity, energy, startVoltage, endVoltage, chargePeak == Double.NEGATIVE_INFINITY ? 0 : chargePeak, dischargeValley == Double.POSITIVE_INFINITY ? 0 : dischargeValley); }
    }

    private static final class BtsCycleAccumulator
    {
        private final int cycle; private long count; private Instant first; private Instant last;
        private double maximumCapacity = Double.NEGATIVE_INFINITY; private double minimumCapacity = Double.POSITIVE_INFINITY;
        private double chargeEnergy; private double dischargeEnergy;
        BtsCycleAccumulator(BtsHistoryRecord first) { cycle = first.cycleNo(); }
        void add(BtsHistoryRecord item) { count++; if (first == null) first = item.deviceTime(); last = item.deviceTime(); maximumCapacity = Math.max(maximumCapacity, item.capacityAh()); minimumCapacity = Math.min(minimumCapacity, item.capacityAh()); if (item.currentA() >= 0) chargeEnergy = Math.max(chargeEnergy, item.energyWh()); else dischargeEnergy = Math.max(dischargeEnergy, Math.abs(item.energyWh())); }
        BtsCycleRecord finish() { double charge = Math.max(0d, maximumCapacity); double discharge = Math.max(0d, maximumCapacity - minimumCapacity); return new BtsCycleRecord(cycle, count, first, last, charge, discharge, chargeEnergy, dischargeEnergy, efficiency(charge, discharge)); }
    }

    private java.util.Set<String> requestedChannels(String request)
    {
        java.util.Set<String> channels = new java.util.HashSet<>();
        try
        {
            XMLInputFactory factory = XMLInputFactory.newFactory();
            factory.setProperty(XMLInputFactory.SUPPORT_DTD, false);
            factory.setProperty("javax.xml.stream.isSupportingExternalEntities", false);
            XMLStreamReader reader = factory.createXMLStreamReader(new StringReader(request));
            while (reader.hasNext())
            {
                if (reader.next() == XMLStreamConstants.START_ELEMENT && "inquire".equals(reader.getLocalName()))
                {
                    String devid = reader.getAttributeValue(null, "devid");
                    String chlid = reader.getAttributeValue(null, "chlid");
                    if (devid != null && chlid != null) channels.add(devid + ":" + chlid);
                }
            }
            return channels;
        }
        catch (Exception exception)
        {
            throw new IllegalArgumentException("Invalid BTS inquire XML", exception);
        }
    }

    private BtsDeviceProfile profileFor(DeviceState device)
    {
        return device.profile() == null ? BtsDeviceProfile.virtual(device.channels().size()) : device.profile();
    }

    private BtsDeviceProfile resizeProfile(BtsDeviceProfile profile, int channelCount)
    {
        return new BtsDeviceProfile(profile.devtype(), profile.subDeviceId(), profile.name(), profile.manufacturer(),
                profile.model(), profile.serialNumber(), profile.firmwareVersion(), channelCount,
                profile.currentMinA(), profile.currentMaxA(), profile.voltageMinV(), profile.voltageMaxV(),
                profile.sampleIntervalMs());
    }

    private void updateDeviceWithProfile(DeviceState current, BtsDeviceProfile profile)
    {
        int channelCount = profile.channelCount();
        List<ChannelState> channels = new ArrayList<>(channelCount);
        for (int channelId = 1; channelId <= channelCount; channelId++)
            channels.add(channelId <= current.channels().size() ? current.channels().get(channelId - 1)
                    : new ChannelState(channelId, true, DeviceWorkStatus.STOPPED));
        List<DeviceState> devices = replaceDevice(new DeviceState(current.deviceId(), current.ip(), current.online(),
                channels, profile));
        List<ChannelTombstone> tombstones = new ArrayList<>(state.tombstones());
        for (int channelId = channelCount + 1; channelId <= current.channels().size(); channelId++)
            upsertTombstone(tombstones, current.deviceId(), current.ip(), channelId);
        tombstones.removeIf(item -> item.deviceId() == current.deviceId() && item.channelId() <= channelCount);
        persist(new SimulatorState(state.version(), devices, state.collectors(), state.nextDeviceId(),
                state.nextCollectorId(), tombstones));
    }

    private BtsDeviceProfile newareProfile(String model)
    {
        if (NEWARE_CT_4008T_5V6A_S1_F.equals(model))
            return new BtsDeviceProfile(22, 1, "新威 CT-4008T", "新威", model, "SIM-CT4008T-5V6A",
                    "BTS7.5.4", 8, new BigDecimal("-6.000"), new BigDecimal("6.000"), BigDecimal.ZERO,
                    new BigDecimal("5.000"), 100);
        if (NEWARE_CT_4008TN_5V12A_S1_F.equals(model))
            return new BtsDeviceProfile(22, 1, "新威 CT-4008Tn", "新威", model, "SIM-CT4008TN-5V12A",
                    "BTS8.0", 8, new BigDecimal("-12.000"), new BigDecimal("12.000"), BigDecimal.ZERO,
                    new BigDecimal("5.000"), 100);
        throw new IllegalArgumentException("Unsupported Neware simulator model: " + model);
    }

    private double clamp(double value, double minimum, double maximum)
    {
        return Math.max(minimum, Math.min(maximum, value));
    }

    private String decimal(double value)
    {
        return String.format(java.util.Locale.ROOT, "%.3f", value);
    }

    private String toBtsWorkStatus(DeviceWorkStatus status)
    {
        return switch (status)
        {
            case STOPPED -> "stop";
            case WORKING -> "working";
            case PAUSED -> "pause";
            case FINISHED -> "finish";
            default -> throw new IllegalArgumentException("Unsupported simulator work status: " + status);
        };
    }

    private void validateDeviceConfiguration(String ip, int channelCount, Integer currentDeviceId)
    {
        if (!isIpv4(ip)) throw new IllegalArgumentException("Simulator device IP must be a valid IPv4 address");
        if (channelCount < 1 || channelCount > MAX_CHANNEL_COUNT)
            throw new IllegalArgumentException("channelCount must be between 1 and " + MAX_CHANNEL_COUNT);
        boolean duplicate = state.devices().stream()
                .anyMatch(device -> device.ip().equals(ip.trim())
                        && device.deviceId() != (currentDeviceId == null ? -1 : currentDeviceId));
        duplicate = duplicate || state.collectors().stream().anyMatch(collector -> collector.ip().equals(ip.trim()));
        if (duplicate) throw new IllegalArgumentException("Simulator device IP must be unique");
    }

    private void validateCollectorConfiguration(String ip, int channelCount, Integer currentCollectorId)
    {
        if (!isIpv4(ip)) throw new IllegalArgumentException("Simulator collector IP must be a valid IPv4 address");
        if (channelCount < 1 || channelCount > MAX_CHANNEL_COUNT)
            throw new IllegalArgumentException("channelCount must be between 1 and " + MAX_CHANNEL_COUNT);
        boolean duplicate = state.collectors().stream()
                .anyMatch(collector -> collector.ip().equals(ip.trim())
                        && collector.collectorId() != (currentCollectorId == null ? -1 : currentCollectorId));
        duplicate = duplicate || state.devices().stream().anyMatch(device -> device.ip().equals(ip.trim()));
        if (duplicate) throw new IllegalArgumentException("Simulator collector IP must be unique");
    }

    private boolean isIpv4(String ip)
    {
        if (ip == null) return false;
        String[] parts = ip.trim().split("\\.", -1);
        if (parts.length != 4) return false;
        for (String part : parts)
        {
            try
            {
                int value = Integer.parseInt(part);
                if (part.isEmpty() || value < 0 || value > 255) return false;
            }
            catch (NumberFormatException exception)
            {
                return false;
            }
        }
        return true;
    }

    private DeviceState requireDevice(int deviceId)
    {
        return state.devices().stream().filter(item -> item.deviceId() == deviceId).findFirst()
                .orElseThrow(() -> new IllegalArgumentException("Unknown simulator device: " + deviceId));
    }

    private CollectorState requireCollector(int collectorId)
    {
        return state.collectors().stream().filter(item -> item.collectorId() == collectorId).findFirst()
                .orElseThrow(() -> new IllegalArgumentException("Unknown simulator collector: " + collectorId));
    }

    private List<DeviceState> replaceDevice(DeviceState replacement)
    {
        List<DeviceState> devices = new ArrayList<>(state.devices());
        devices.replaceAll(item -> item.deviceId() == replacement.deviceId() ? replacement : item);
        return devices;
    }

    private void upsertTombstone(List<ChannelTombstone> tombstones, int deviceId, String ip, int channelId)
    {
        tombstones.removeIf(item -> item.deviceId() == deviceId && item.channelId() == channelId);
        tombstones.add(new ChannelTombstone(deviceId, ip, channelId, TOMBSTONE_DISCOVERY_COUNT));
    }

    private void persist(SimulatorState nextState)
    {
        // 写穿失败时保留当前内存副本，避免控制页显示未持久化状态。
        stateStore.save(nextState);
        state = nextState;
    }

    private void persist(SimulatorState nextState, List<CollectorHistoryAppend> historyAppends)
    {
        // 主状态与原始历史批次必须一起成功，内存序号才能向前推进。
        stateStore.save(nextState, historyAppends);
        state = nextState;
    }

    private String simulatorMac(int devtype, int devid)
    {
        return String.format("02:44:%02X:%02X:%02X:%02X",
                (devtype >>> 8) & 0xFF, devtype & 0xFF, (devid >>> 8) & 0xFF, devid & 0xFF);
    }

    private String simulatorCollectorMac(int collectorId)
    {
        return String.format("02:43:00:00:%02X:%02X", (collectorId >>> 8) & 0xFF, collectorId & 0xFF);
    }

    private void requireControllableStatus(DeviceWorkStatus status)
    {
        if (status == null || (status != DeviceWorkStatus.STOPPED && status != DeviceWorkStatus.WORKING
                && status != DeviceWorkStatus.PAUSED && status != DeviceWorkStatus.FINISHED))
            throw new IllegalArgumentException("Simulator work status must be STOPPED, WORKING, PAUSED or FINISHED");
    }

    private void validateRestoredState()
    {
        java.util.Set<Integer> deviceIds = new java.util.HashSet<>();
        java.util.Set<Integer> collectorIds = new java.util.HashSet<>();
        java.util.Set<String> ips = new java.util.HashSet<>();
        int maximumDeviceId = 0;
        for (DeviceState device : state.devices())
        {
            if (device.deviceId() < 1 || !deviceIds.add(device.deviceId()) || !isIpv4(device.ip())
                    || !ips.add(device.ip()) || device.channels().isEmpty()
                    || device.channels().size() > MAX_CHANNEL_COUNT)
                throw new IllegalStateException("Invalid BTS simulator device state in Redis");
            if (profileFor(device).channelCount() != device.channels().size())
                throw new IllegalStateException("BTS simulator device profile channel count does not match topology");
            maximumDeviceId = Math.max(maximumDeviceId, device.deviceId());
            for (int index = 0; index < device.channels().size(); index++)
            {
                ChannelState channel = device.channels().get(index);
                if (channel.channelId() != index + 1)
                    throw new IllegalStateException("Invalid BTS simulator channel state in Redis");
                requireControllableStatus(channel.workStatus());
            }
        }
        int maximumCollectorId = 0;
        for (CollectorState collector : state.collectors())
        {
            if (collector.collectorId() < 1 || !collectorIds.add(collector.collectorId())
                    || !isIpv4(collector.ip()) || !ips.add(collector.ip())
                    || collector.channelCount() < 1 || collector.channelCount() > MAX_CHANNEL_COUNT)
                throw new IllegalStateException("Invalid BTS simulator collector state in Redis");
            DevelopmentCollectorSimulation.validate(collector, stateStore);
            maximumCollectorId = Math.max(maximumCollectorId, collector.collectorId());
        }
        java.util.Set<String> tombstoneIds = new java.util.HashSet<>();
        boolean invalidTombstone = state.tombstones().stream().anyMatch(item -> item.deviceId() < 1
                || !isIpv4(item.ip()) || item.channelId() < 1 || item.channelId() > MAX_CHANNEL_COUNT
                || item.remainingDiscoveries() < 1 || item.remainingDiscoveries() > TOMBSTONE_DISCOVERY_COUNT
                || !tombstoneIds.add(item.deviceId() + ":" + item.channelId()));
        if (state.nextDeviceId() <= maximumDeviceId || state.nextCollectorId() <= maximumCollectorId
                || invalidTombstone)
            throw new IllegalStateException("Invalid BTS simulator numbering or tombstone state in Redis");
    }

    @Override
    public synchronized void close() throws Exception
    {
        running = false;
        simulator.close();
    }

    private record ObservedChannel(int deviceId, ChannelState channel) { }

    public record StateSnapshot(boolean running, String listenAddress, List<DeviceSnapshot> devices,
            List<CollectorSnapshot> collectors, List<RecentRequest> recentRequests) { }

    public record DeviceSnapshot(int deviceId, String ip, boolean online, BtsDeviceProfile profile,
            List<ChannelSnapshot> channels) { }

    public record ChannelSnapshot(int channelId, boolean online, DeviceWorkStatus workStatus) { }

    public record CollectorSnapshot(int collectorId, String deviceCode, String ip, String mac, String name,
            String manufacturer, String model, int channelCount, boolean online, int sampleIntervalMs,
            List<CollectorChannelState> channels, CollectorHistoryFaults historyFaults, long historyRecordCount,
            List<CollectorRealtimeMeasurement> latestMeasurements)
    {
        public CollectorSnapshot
        {
            channels = List.copyOf(channels);
            latestMeasurements = List.copyOf(latestMeasurements);
        }
    }

}