import { onMounted, onUnmounted } from 'vue'
import { useContributionPolling } from './useContributionPolling.js'
import { getActivitySocket } from '@/utils/socket/ActivitySocket.js'

/**
 * 贡献实时推送 composable（WS 优先，断线降级为轮询）
 * @param {import('vue').Ref<string|number>} activityId
 * @param {import('vue').Ref<boolean>} isPageActive
 */
export function useContributionRealtime(activityId, isPageActive) {
    const MAX_RECORDS = 5

    const {
        records,
        visible,
        loading,
        error,
        start: startPolling,
        stop: stopPolling,
        reset: resetPolling,
        highestIdRef,
    } = useContributionPolling(activityId, isPageActive)

    const socket = getActivitySocket()
    let usingWS = false

    function onWsMessage(payload) {
        if (!payload || Number(payload.activity_id) !== Number(activityId.value)) return
        if (!payload.record) return
        const record = payload.record
        if (record.id > highestIdRef()) {
            // 追加到列表末尾（与轮询的方向不同），保留最近 MAX_RECORDS 条
            records.value = [...records.value, record].slice(-MAX_RECORDS)
        }
    }

    function onWsConnect() {
        if (usingWS) return
        usingWS = true
        stopPolling() // 停掉可能的轮询
        socket.subscribe(activityId.value, ['contributions'])
    }

    function onWsDisconnect() {
        if (!usingWS) return
        usingWS = false
        startPolling() // 降级为轮询
    }

    socket.onContributionsResponse(onWsMessage)
    socket.on('connect', onWsConnect)
    socket.on('disconnect', onWsDisconnect)

    onMounted(() => {
        // 总是调用 connect():SocketManager.connect() 内部会判断 token 是否变化
        // (详见 useMessageRealtime.js 注释)。这样能确保用户切换登录后,
        // contribution channel 也能用新 token 重新订阅,而不是复用上一个用户的 WS。
        const token = uni.getStorageSync('access_token')
        if (token) {
            socket.connect(token).catch(err => console.warn('[useContributionRealtime] connect error:', err))
        }
        // 同步分支:如果 WS 已连接(单例复用导致 'connect' 事件不会再次触发),
        // 必须直接调 onWsConnect 停轮询,否则 polling 会一直跑。
        // 异步分支:WS 还没连上时,先起 polling 兜底;
        // 等 'connect' 事件触发 onWsConnect 后会停掉轮询。
        if (socket.isConnected) {
            onWsConnect()
        } else {
            startPolling()
        }
    })

    onUnmounted(() => {
        if (usingWS) socket.unsubscribe(activityId.value, ['contributions'])
        socket.off('connect', onWsConnect)
        socket.off('disconnect', onWsDisconnect)
        socket.offContributionsResponse(onWsMessage)
        stopPolling()
        resetPolling()
    })

    return {
        records,
        visible,
        loading,
        error,
        isUsingWS: () => usingWS,
    }
}