package com.ruoyi.config;

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.JSONObject;
import com.ruoyi.device.simulator.BtsSimulatorStateStore;

/** 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
        {
            String json = stored.toString();
            JSONObject root = JSON.parseObject(json);
            Integer version = root.getInteger("version");
            if (version == null || version != CURRENT_VERSION)
                throw new IllegalStateException("Unsupported BTS simulator state version: " + version);
            return JSON.parseObject(json, SimulatorState.class);
        }
        catch (IllegalStateException exception)
        {
            throw exception;
        }
        catch (Exception exception)
        {
            throw new IllegalStateException("Invalid BTS simulator state in Redis", exception);
        }
    }
}