package com.ruoyi.config;

import java.math.BigDecimal;
import java.time.Instant;
import java.util.ArrayList;
import java.util.List;
import java.util.concurrent.TimeUnit;
import org.springframework.data.redis.core.RedisTemplate;
import org.springframework.stereotype.Component;
import com.alibaba.fastjson2.JSON;
import com.alibaba.fastjson2.JSONArray;
import com.alibaba.fastjson2.JSONObject;
import com.ruoyi.device.simulator.BtsSimulatorStateStore;
import com.ruoyi.device.model.DeviceWorkStatus;

/** 将开发模拟器完整状态写入 Redis，主状态不设置普通 TTL。 */
@Component
public class RedisBtsSimulatorStateStore implements BtsSimulatorStateStore
{
    static final String STATE_KEY = "dev:bts-simulator:state:v1";
    static final String RECENT_REQUESTS_KEY = "dev:bts-simulator:recent-requests:v1";
    private static final long RECENT_REQUESTS_TTL_HOURS = 1;

    private final RedisTemplate<Object, Object> redisTemplate;

    public RedisBtsSimulatorStateStore(RedisTemplate<Object, Object> redisTemplate)
    {
        this.redisTemplate = redisTemplate;
    }

    @Override
    public SimulatorState loadOrInitialize(SimulatorState defaultState)
    {
        Object stored = redisTemplate.opsForValue().get(STATE_KEY);
        if (stored != null) return parseState(stored);
        String initial = JSON.toJSONString(defaultState);
        if (Boolean.TRUE.equals(redisTemplate.opsForValue().setIfAbsent(STATE_KEY, initial))) return defaultState;
        stored = redisTemplate.opsForValue().get(STATE_KEY);
        if (stored == null) throw new IllegalStateException("BTS simulator state initialization lost in Redis");
        return parseState(stored);
    }

    @Override
    public void save(SimulatorState state)
    {
        redisTemplate.opsForValue().set(STATE_KEY, JSON.toJSONString(state));
    }

    @Override
    public List<RecentRequest> loadRecentRequests()
    {
        Object stored = redisTemplate.opsForValue().get(RECENT_REQUESTS_KEY);
        if (stored == null) return List.of();
        return List.copyOf(JSON.parseArray(stored.toString(), RecentRequest.class));
    }

    @Override
    public void saveRecentRequests(List<RecentRequest> requests)
    {
        redisTemplate.opsForValue().set(RECENT_REQUESTS_KEY, JSON.toJSONString(requests),
                RECENT_REQUESTS_TTL_HOURS, TimeUnit.HOURS);
    }

    @Override
    public void reset(SimulatorState defaultState)
    {
        redisTemplate.delete(RECENT_REQUESTS_KEY);
        save(defaultState);
    }

    private SimulatorState parseState(Object stored)
    {
        try
        {
            // 通用 RedisTemplate 在可执行包中可能将泛型数组恢复为 JSONObject，必须在存储边界逐层重建。
            JSONObject root = jsonObject(stored);
            Integer version = root.getInteger("version");
            if (version == null || version != CURRENT_VERSION)
                throw new IllegalStateException("Unsupported BTS simulator state version: " + version);
            List<DeviceState> devices = new ArrayList<>();
            requiredArray(root, "devices").forEach(item -> devices.add(deviceState(item)));
            List<CollectorState> collectors = new ArrayList<>();
            requiredArray(root, "collectors").forEach(item -> collectors.add(collectorState(item)));
            List<ChannelTombstone> tombstones = new ArrayList<>();
            requiredArray(root, "tombstones").forEach(item -> tombstones.add(channelTombstone(item)));
            return new SimulatorState(version, devices, collectors,
                    requiredInteger(root, "nextDeviceId"), requiredInteger(root, "nextCollectorId"), tombstones);
        }
        catch (IllegalStateException exception)
        {
            throw exception;
        }
        catch (Exception exception)
        {
            throw new IllegalStateException("Invalid BTS simulator state in Redis", exception);
        }
    }

    private JSONObject jsonObject(Object value)
    {
        if (value instanceof JSONObject object) return object;
        if (value instanceof String text)
        {
            Object parsed = JSON.parse(text);
            if (parsed instanceof String nested) parsed = JSON.parse(nested);
            if (parsed instanceof JSONObject object) return object;
            return JSON.parseObject(JSON.toJSONString(parsed));
        }
        return JSON.parseObject(JSON.toJSONString(value));
    }

    private JSONArray requiredArray(JSONObject object, String field)
    {
        JSONArray array = object.getJSONArray(field);
        if (array == null) throw new IllegalStateException("Missing BTS simulator state field: " + field);
        return array;
    }

    private int requiredInteger(JSONObject object, String field)
    {
        Integer value = object.getInteger(field);
        if (value == null) throw new IllegalStateException("Missing BTS simulator state field: " + field);
        return value;
    }

    private DeviceState deviceState(Object value)
    {
        JSONObject object = jsonObject(value);
        List<ChannelState> channels = new ArrayList<>();
        requiredArray(object, "channels").forEach(item -> channels.add(channelState(item)));
        return new DeviceState(requiredInteger(object, "deviceId"), object.getString("ip"),
                object.getBooleanValue("online"), channels);
    }

    private CollectorState collectorState(Object value)
    {
        JSONObject object = jsonObject(value);
        int collectorId = requiredInteger(object, "collectorId");
        String deviceCode = object.getString("deviceCode");
        String ip = object.getString("ip");
        String mac = object.getString("mac");
        String name = object.getString("name");
        String manufacturer = object.getString("manufacturer");
        String model = object.getString("model");
        int channelCount = requiredInteger(object, "channelCount");
        boolean online = object.getBooleanValue("online");
        // Ticket04 状态只包含发现配置；首次恢复时以演示默认值补齐采样状态。
        if (!object.containsKey("sampleIntervalMs"))
            return new CollectorState(collectorId, deviceCode, ip, mac, name, manufacturer, model,
                    channelCount, online);

        List<CollectorChannelState> channels = new ArrayList<>();
        requiredArray(object, "channels").forEach(item -> channels.add(collectorChannelState(item)));
        List<CollectorMeasurementRecord> history = new ArrayList<>();
        requiredArray(object, "history").forEach(item -> history.add(collectorMeasurementRecord(item)));
        return new CollectorState(collectorId, deviceCode, ip, mac, name, manufacturer, model,
                channelCount, online, requiredInteger(object, "sampleIntervalMs"),
                requiredLong(object, "nextSequence"), optionalInstant(object, "lastSampledAt"),
                channels, history, collectorHistoryFaults(object.get("historyFaults")));
    }

    private CollectorChannelState collectorChannelState(Object value)
    {
        JSONObject object = jsonObject(value);
        List<CollectorMetricState> metrics = new ArrayList<>();
        requiredArray(object, "metrics").forEach(item -> metrics.add(collectorMetricState(item)));
        return new CollectorChannelState(object.getString("channelCode"), metrics);
    }

    private CollectorMetricState collectorMetricState(Object value)
    {
        JSONObject object = jsonObject(value);
        BigDecimal measurement = object.getBigDecimal("value");
        if (measurement == null) throw new IllegalStateException("Missing BTS simulator state field: value");
        return new CollectorMetricState(object.getString("metricCode"), measurement, object.getString("unit"));
    }

    private CollectorMeasurementRecord collectorMeasurementRecord(Object value)
    {
        JSONObject object = jsonObject(value);
        BigDecimal measurement = object.getBigDecimal("value");
        if (measurement == null) throw new IllegalStateException("Missing BTS simulator state field: value");
        return new CollectorMeasurementRecord(object.getString("adapterCode"), object.getString("collectorCode"),
                object.getString("channelCode"), requiredLong(object, "sequenceId"),
                requiredInstant(object, "deviceTime"), object.getString("deviceTimeRaw"),
                requiredInstant(object, "serverReceivedAt"), object.getString("metricCode"),
                measurement, object.getString("unit"));
    }

    private CollectorHistoryFaults collectorHistoryFaults(Object value)
    {
        if (value == null) return CollectorHistoryFaults.none();
        JSONObject object = jsonObject(value);
        List<Long> missing = new ArrayList<>();
        JSONArray values = object.getJSONArray("missingSequences");
        if (values != null) values.forEach(item -> missing.add(Long.valueOf(item.toString())));
        return new CollectorHistoryFaults(missing, object.getLong("duplicateSequence"),
                object.getLong("conflictingSequence"), object.getBooleanValue("outOfOrder"));
    }

    private ChannelState channelState(Object value)
    {
        JSONObject object = jsonObject(value);
        String workStatus = object.getString("workStatus");
        if (workStatus == null) throw new IllegalStateException("Missing BTS simulator state field: workStatus");
        return new ChannelState(requiredInteger(object, "channelId"), object.getBooleanValue("online"),
                DeviceWorkStatus.valueOf(workStatus));
    }

    private ChannelTombstone channelTombstone(Object value)
    {
        JSONObject object = jsonObject(value);
        return new ChannelTombstone(requiredInteger(object, "deviceId"), object.getString("ip"),
                requiredInteger(object, "channelId"), requiredInteger(object, "remainingDiscoveries"));
    }

    private long requiredLong(JSONObject object, String field)
    {
        Long value = object.getLong(field);
        if (value == null) throw new IllegalStateException("Missing BTS simulator state field: " + field);
        return value;
    }

    private Instant requiredInstant(JSONObject object, String field)
    {
        Instant value = optionalInstant(object, field);
        if (value == null) throw new IllegalStateException("Missing BTS simulator state field: " + field);
        return value;
    }

    private Instant optionalInstant(JSONObject object, String field)
    {
        String value = object.getString(field);
        return value == null ? null : Instant.parse(value);
    }
}