package com.battery.business.service.impl;

import java.time.Duration;
import java.time.Instant;
import java.time.ZoneId;
import java.util.List;
import java.util.Locale;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;
import org.springframework.dao.DuplicateKeyException;
import org.springframework.stereotype.Service;
import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONObject;
import com.ruoyi.common.exception.ServiceException;
import com.ruoyi.common.utils.StringUtils;
import com.battery.device.api.DeviceAdapterException;
import com.battery.device.api.discovery.DeviceDiscoveryCandidateStore;
import com.battery.device.api.model.AdapterCapabilities;
import com.battery.device.api.registry.AdapterInstanceConfig;
import com.battery.device.api.registry.AdapterRegistryException;
import com.battery.device.api.registry.DeviceAdapterRegistry;
import com.battery.business.domain.TDetectionChannel;
import com.battery.business.domain.TDeviceAdapter;
import com.battery.business.domain.vo.AdapterDiscoveryResult;
import com.battery.business.mapper.TDeviceAdapterMapper;
import com.battery.business.service.DeviceAdapterErrorCodes;
import com.battery.business.service.IDeviceAdapterService;
import com.battery.business.service.impl.DeviceDiscoveryPersistenceService.DiscoverySource;

@Service
public class DeviceAdapterServiceImpl implements IDeviceAdapterService
{
    private static final Logger log = LoggerFactory.getLogger(DeviceAdapterServiceImpl.class);
    private static final String ENABLED = "0";
    private static final String DISABLED = "1";
    private static final String READ_ONLY_CAPABILITIES =
            "{\"discovery\":true,\"realtimeObservation\":true,\"historyDownload\":true,\"control\":false}";
    /**
     * 适配器类型按存储形态划分；BTS 保留给开发模拟器与将来的协议路线（ADR-0065）。
     * `NEWARE_MYSQL` 只能写字面量：battery-business 不依赖 battery-device-neware，
     * 拿不到那边的常量；推式来源的实现就在本模块，所以用它的常量。
     */
    private static final List<String> SUPPORTED_TYPES = List.of("BTS", "NEWARE_MYSQL", PushIngestAdapter.ADAPTER_TYPE);
    /**
     * 通道清单长期存在的来源，候选不按时间过期：直连厂商存储的来源读的是厂商的登记表，
     * 推式来源读的是取数程序上报的拓扑——两者都不是"轮询发现"的结果。
     */
    private static final List<String> PERSISTENT_CANDIDATE_TYPES =
            List.of("NEWARE_MYSQL", PushIngestAdapter.ADAPTER_TYPE);

    private final TDeviceAdapterMapper mapper;
    private final DeviceAdapterRegistry registry;
    private final DeviceDiscoveryPersistenceService persistence;
    private final DeviceDiscoveryCandidateStore candidateStore;

    public DeviceAdapterServiceImpl(TDeviceAdapterMapper mapper, DeviceAdapterRegistry registry,
            DeviceDiscoveryPersistenceService persistence, DeviceDiscoveryCandidateStore candidateStore)
    {
        this.mapper = mapper;
        this.registry = registry;
        this.persistence = persistence;
        this.candidateStore = candidateStore;
    }

    /** 按管理端筛选条件查询适配器及其运行状态。 */
    @Override
    public List<TDeviceAdapter> selectList(TDeviceAdapter query) { return mapper.selectDeviceAdapterList(query); }

    /** 查询适配器详情；实例不存在时抛出稳定业务错误。 */
    @Override
    public TDeviceAdapter selectById(Long adapterId)
    {
        TDeviceAdapter adapter = mapper.selectDeviceAdapterById(adapterId);
        if (adapter == null) throw error("设备适配器实例不存在", DeviceAdapterErrorCodes.NOT_FOUND);
        return adapter;
    }

    /** 幂等注册应用托管的只读适配器；不预写检测柜或通道事实。 */
    @Override
    public TDeviceAdapter ensureManagedAdapter(TDeviceAdapter adapter)
    {
        normalizeAndValidate(adapter);
        rejectDevelopmentSimulatorDatabaseConfig(adapter);
        AdapterCapabilities capabilities = parseCapabilities(adapter.getCapabilities());
        if (capabilities.control())
            throw error("当前里程碑只允许只读设备适配器", DeviceAdapterErrorCodes.INVALID_CONFIG);
        adapter.setStatus(ENABLED);
        adapter.setConnectionStatus("OFFLINE");
        adapter.setDelFlag("0");
        mapper.upsertManagedDeviceAdapter(adapter);
        TDeviceAdapter registered = mapper.selectDeviceAdapterByCode(adapter.getAdapterCode());
        if (registered == null) throw error("托管设备适配器注册失败", DeviceAdapterErrorCodes.NOT_FOUND);
        return registered;
    }

    /** 新增默认禁用的只读适配器配置。 */
    @Override
    public int insert(TDeviceAdapter adapter)
    {
        normalizeAndValidate(adapter);
        rejectDevelopmentSimulatorDatabaseConfig(adapter);
        if (mapper.selectDeviceAdapterByCode(adapter.getAdapterCode()) != null)
            throw error("适配器编码已存在", DeviceAdapterErrorCodes.DUPLICATE_CODE);
        adapter.setCapabilities(READ_ONLY_CAPABILITIES);
        adapter.setStatus(DISABLED);
        adapter.setConnectionStatus("OFFLINE");
        adapter.setDelFlag("0");
        try { return mapper.insertDeviceAdapter(adapter); }
        catch (DuplicateKeyException exception) { throw error("适配器编码已存在", DeviceAdapterErrorCodes.DUPLICATE_CODE); }
    }

    /** 更新配置；已启用实例会同步运行时注册表。 */
    @Override
    public int update(TDeviceAdapter adapter)
    {
        TDeviceAdapter current = selectById(adapter.getAdapterId());
        normalizeAndValidate(adapter);
        adapter.setAdapterCode(current.getAdapterCode());
        adapter.setCapabilities(current.getCapabilities());
        int rows = mapper.updateDeviceAdapter(adapter);
        if (ENABLED.equals(current.getStatus()))
        {
            adapter.setStatus(ENABLED);
            registry.synchronize(toRuntimeConfig(adapter));
        }
        return rows;
    }

    /** 启停适配器并同步其运行时实例。 */
    @Override
    public int changeStatus(Long adapterId, boolean enabled, String updateBy)
    {
        TDeviceAdapter adapter = selectById(adapterId);
        String status = enabled ? ENABLED : DISABLED;
        if (status.equals(adapter.getStatus())) return 1;
        adapter.setStatus(status);
        // 先装配运行时实例：装配失败（例如缺少口令环境变量）时不把状态写成"已启用"，
        // 免得留下"库里启用、运行时没有实例"的假状态。
        registry.synchronize(toRuntimeConfig(adapter));
        return mapper.updateDeviceAdapterStatus(adapterId, status, updateBy);
    }

    /** 执行一次发现和实时观测，将未登记设备写入 Redis 候选。 */
    @Override
    public AdapterDiscoveryResult discover(Long adapterId)
    {
        TDeviceAdapter adapter = selectById(adapterId);
        if (!ENABLED.equals(adapter.getStatus()))
            throw error("设备适配器实例未启用", DeviceAdapterErrorCodes.DISABLED);
        try
        {
            registry.synchronize(toRuntimeConfig(adapter));
            AdapterDiscoveryResult result = persistence.discoverForReception(registry, new DiscoverySource(
                    adapter.getAdapterCode(), adapter.getAdapterId(), adapter.getAdapterName(),
                    adapter.getPollIntervalMs(), PERSISTENT_CANDIDATE_TYPES.contains(adapter.getAdapterType())));
            mapper.updateDiscoverySuccess(adapterId, result.observedAtUtc());
            return result;
        }
        catch (DeviceAdapterException exception)
        {
            persistence.markUnavailable(adapter.getAdapterCode());
            return failDiscovery(adapterId, exception.failureCode(), exception);
        }
        catch (AdapterRegistryException exception)
        {
            persistence.markUnavailable(adapter.getAdapterCode());
            return failDiscovery(adapterId, "ADAPTER_FAILURE", exception);
        }
    }

    /** 查询指定适配器当前未过期的 Redis 发现通道。 */
    @Override
    public List<TDetectionChannel> selectChannels(Long adapterId)
    {
        TDeviceAdapter adapter = selectById(adapterId);
        return candidateStore.snapshot(Instant.now()).cabinets().stream()
                .filter(item -> item.adapterCode().equals(adapter.getAdapterCode()))
                .flatMap(item -> item.channels().stream().map(channel -> {
                    TDetectionChannel value = new TDetectionChannel();
                    value.setAdapterId(adapterId);
                    value.setDevtype(channel.identity().devtype());
                    value.setDevid(channel.identity().devid());
                    value.setSubdevid(channel.identity().subdevid());
                    value.setChlid(channel.identity().chlid());
                    value.setDisplayNo(channel.identity().subdevid() + "-" + channel.identity().chlid());
                    value.setOnlineStatus(channel.online() ? "ONLINE" : "OFFLINE");
                    value.setWorkStatus(channel.workStatus().name());
                    value.setLastSeenAtUtc(channel.observedAt());
                    value.setStatus("0");
                    return value;
                }))
                .toList();
    }

    /** 启动时恢复所有已启用适配器的运行时注册。 */
    @Override
    public void synchronizeEnabledAdapters()
    {
        for (TDeviceAdapter adapter : mapper.selectEnabledDeviceAdapters())
        {
            try
            {
                registry.synchronize(toRuntimeConfig(adapter));
            }
            catch (RuntimeException exception)
            {
                // 单行配置有问题（例如没放凭据文件、口令键名写错）不得拦住后端启动：
                // 既写日志，也按发现失败的同一路径落到这一行，使"忘了配"在启动后立刻是列表里可见的一行。
                log.warn("设备适配器实例装配失败 adapterCode={}：{}", adapter.getAdapterCode(), exception.getMessage());
                mapper.updateDiscoveryFailure(adapter.getAdapterId(), startupFailureCode(exception),
                        exception.getMessage());
            }
        }
    }

    /**
     * 装配失败写进实例行的错误码：适配器自己给出分类（例如凭据缺失、连接失败）时用它，
     * 否则记为配置问题——启动阶段的装配失败基本都是配置造成的。
     */
    private static String startupFailureCode(RuntimeException exception)
    {
        return exception instanceof DeviceAdapterException deviceFailure && !deviceFailure.failureCode().isBlank()
                ? deviceFailure.failureCode() : "INVALID_CONFIG";
    }

    /** 轮询达到周期的已启用适配器，并持久化失败状态后继续调度。 */
    @Override
    public void pollDueAdapters()
    {
        Instant now = Instant.now();
        for (TDeviceAdapter adapter : mapper.selectEnabledDeviceAdapters())
        {
            Instant lastAttempt = adapter.getLastAttemptAtUtc();
            if (lastAttempt != null && Duration.between(lastAttempt, now).toMillis() < adapter.getPollIntervalMs()) continue;
            try
            {
                // 设备发现必须持续执行；暂停接收只由 discoverNow 中的 receivingIdentities 控制实时快照请求。
                discover(adapter.getAdapterId());
            }
            catch (ServiceException ignored) { /* 失败状态已持久化，下一轮按周期重试。 */ }
        }
    }

    private AdapterDiscoveryResult failDiscovery(Long adapterId, String errorCode, RuntimeException exception)
    {
        mapper.updateDiscoveryFailure(adapterId, errorCode, exception.getMessage());
        throw error("设备发现失败：" + exception.getMessage(), DeviceAdapterErrorCodes.DISCOVERY_FAILED);
    }

    private void normalizeAndValidate(TDeviceAdapter adapter)
    {
        adapter.setAdapterCode(StringUtils.trim(adapter.getAdapterCode()));
        adapter.setAdapterName(StringUtils.trim(adapter.getAdapterName()));
        adapter.setAdapterType(StringUtils.trim(adapter.getAdapterType()).toUpperCase(Locale.ROOT));
        adapter.setHost(StringUtils.trim(adapter.getHost()));
        adapter.setTimezoneId(StringUtils.trim(adapter.getTimezoneId()));
        adapter.setSourceConfig(StringUtils.trim(adapter.getSourceConfig()));
        adapter.setRemark(StringUtils.trim(adapter.getRemark()));
        if (!SUPPORTED_TYPES.contains(adapter.getAdapterType()))
            throw error("不支持的适配器类型", DeviceAdapterErrorCodes.UNSUPPORTED_TYPE);
        if (!Boolean.TRUE.equals(adapter.getReadOnly()))
            throw error("当前里程碑只允许只读设备适配器", DeviceAdapterErrorCodes.INVALID_CONFIG);
        try
        {
            if (adapter.getPort() == null || adapter.getPort() < 1 || adapter.getPort() > 65535
                    || adapter.getPollIntervalMs() == null || adapter.getPollIntervalMs() < 1000
                    || StringUtils.isBlank(adapter.getAdapterCode()) || StringUtils.isBlank(adapter.getAdapterName())
                    || StringUtils.isBlank(adapter.getHost())) throw new IllegalArgumentException();
            ZoneId.of(adapter.getTimezoneId());
        }
        catch (RuntimeException exception)
        {
            throw error("设备适配器配置不正确", DeviceAdapterErrorCodes.INVALID_CONFIG);
        }
    }

    private void rejectDevelopmentSimulatorDatabaseConfig(TDeviceAdapter adapter)
    {
        if (registry.contains(adapter.getAdapterCode()) && mapper.selectDeviceAdapterByCode(adapter.getAdapterCode()) == null)
            throw error("该适配器由运行环境装配，不能写入数据库", DeviceAdapterErrorCodes.INVALID_CONFIG);
    }

    private AdapterInstanceConfig toRuntimeConfig(TDeviceAdapter adapter)
    {
        return new AdapterInstanceConfig(adapter.getAdapterCode(), adapter.getAdapterType(), adapter.getHost(),
                adapter.getPort(), adapter.getPollIntervalMs(), adapter.getTimezoneId(),
                ENABLED.equals(adapter.getStatus()), parseCapabilities(adapter.getCapabilities()),
                parseSourceConfig(adapter.getSourceConfig()));
    }

    /** 来源形态配置只承载非敏感项；连接口令由环境变量或启动参数提供，不入库。 */
    private static java.util.Map<String, String> parseSourceConfig(String sourceConfig)
    {
        if (StringUtils.isBlank(sourceConfig)) return java.util.Map.of();
        JSONObject value = JSON.parseObject(sourceConfig);
        if (value == null) return java.util.Map.of();
        java.util.Map<String, String> result = new java.util.LinkedHashMap<>();
        value.forEach((key, item) -> {
            if (item != null) result.put(String.valueOf(key), String.valueOf(item));
        });
        return result;
    }

    private AdapterCapabilities parseCapabilities(String capabilities)
    {
        JSONObject value = JSON.parseObject(capabilities);
        if (value == null) throw error("设备适配器能力配置不正确", DeviceAdapterErrorCodes.INVALID_CONFIG);
        return new AdapterCapabilities(value.getBooleanValue("discovery"),
                value.getBooleanValue("realtimeObservation"), value.getBooleanValue("historyDownload"),
                value.getBooleanValue("control"));
    }

    private ServiceException error(String message, int code) { return new ServiceException(message, code); }
}