import { shallowRef } from 'vue'
import { defineStore } from 'pinia'
import { createVideoApi, VideoRequestError } from '../services/videoApi.js'
import { createVideoLiveSession } from '../services/videoLiveSession.js'
import { createVideoPlaybackSession, defaultHistoryWindow } from '../services/videoPlaybackSession.js'
import { useDetailStore } from './detailStore.js'
import { useEnhancementDevicesStore } from './enhancementDevicesStore.js'

export const useVideoStore = defineStore('cockpitVideo', () => {
    const state = shallowRef({ open: false, device: null, ownerSource: 'detail', phase: 'idle', media: null, error: '', cleanupError: '',
        playbackMedia: null, historyPhase: '', historyError: '', records: [], empty: false })
    const playerOptions = shallowRef({})
    let options = {}, controller, history
    const publish = (patch) => { state.value = { ...state.value, ...patch } }
    // History is a separate viewer: its media/error/phase live under their own fields so the
    // live player never consumes a playback stream or vice versa.
    const publishHistory = ({ media, error, phase, controls, ...rest }) => {
        const next = { ...rest }
        if (media !== undefined) next.playbackMedia = media
        if (error !== undefined) next.historyError = error
        if (phase !== undefined) next.historyPhase = phase
        if (controls !== undefined) next.playbackControls = controls
        publish(next)
    }
    function configure(next = {}) {
        if (controller) throw new Error('请在建立视频会话前配置传输')
        options = next
        playerOptions.value = next.playerOptions || {}
    }
    const session = () => controller || (controller = createVideoLiveSession(createVideoApi(options), publish, options.timers))
    async function loadDevice(deviceCode) {
        const data = await createVideoApi(options).device(deviceCode)
        if (data.deviceCode !== deviceCode || typeof data.typeCode !== 'string' || typeof data.capabilities?.live !== 'boolean') {
            throw new VideoRequestError('INVALID_RESPONSE', '视频能力载荷与当前设备不匹配')
        }
        return data
    }
    async function open(device, ownerSource = 'detail') {
        if (!['detail', 'enhancement'].includes(ownerSource)) throw new Error('监控入口来源不合法')
        const selection = useDetailStore().selection
        const selectedCode = ownerSource === 'enhancement' ? useEnhancementDevicesStore().selected?.code
            : selection.level === 'equipment' ? selection.deviceCode : ''
        // A detached/late entry cannot take ownership from a still-valid viewer.
        if (!selectedCode || selectedCode !== device?.deviceCode) return
        if (state.value.open && state.value.device?.deviceCode === device?.deviceCode) { publish({ ownerSource }); return }
        publish({ open: true, device, ownerSource, error: '' })
        if (device?.typeCode !== '20' || device.bound !== true || device.capabilities?.live !== true) {
            publish({ phase: 'failed', error: '当前设备未确认实时视频能力' }); return
        }
        await session().start(device.deviceCode)
    }
    async function close() { publish({ open: false, playbackMedia: null, playbackControls: {} }); if (history) await history.dispose(); history = undefined; if (controller) await controller.stop() }
    /** Ends the live stream but keeps the monitor open; tab switches use this instead of close(). */
    async function stopLive() { if (controller) await controller.stop() }
    async function startLive() {
        const device = state.value.device
        if (!device?.deviceCode) return
        if (device.typeCode !== '20' || device.bound !== true || device.capabilities?.live !== true) {
            publish({ phase: 'failed', error: '当前设备未确认实时视频能力' }); return
        }
        await session().start(device.deviceCode)
    }
    const playback = () => history || (history = createVideoPlaybackSession(createVideoApi(options), publishHistory, options.timers))
    /** History only lists what the device/NVR returns; it never starts a stream by itself. */
    async function queryHistory(startTime, endTime) {
        const device = state.value.device
        if (!device?.deviceCode) return []
        const records = await playback().query(device.deviceCode, startTime, endTime)
        return records
    }
    async function play(startTime, endTime) {
        const device = state.value.device
        if (!device?.deviceCode) return false
        return playback().play(device.deviceCode, startTime, endTime)
    }
    async function stopPlayback() { if (history) await history.stop(); publish({ playbackMedia: null, playbackControls: {} }) }
    /** Only a confirmed control may be sent; the panel greys the rest out. */
    async function controlPlayback(key) { return history ? history.control(key) : false }
    const historyWindow = (now) => defaultHistoryWindow(now)
    async function retry() { if (state.value.device) await session().start(state.value.device.deviceCode) }
    async function retryCleanup() { if (controller) await controller.stop() }
    const ready = () => controller?.ready()
    // Keep the player's own failure code: without it a permanent browser/media error looks retryable.
    const fail = (error, code) => {
        if (code) controller?.fail(Object.assign(new Error(typeof error === 'string' ? error : error?.message || '视频播放失败'), { code }))
        else controller?.fail(error instanceof Error ? error : error?.message || '视频播放失败')
    }
    return { state, playerOptions, configure, loadDevice, open, close, retry, retryCleanup, ready, fail,
        stopLive, startLive, queryHistory, play, stopPlayback, controlPlayback, historyWindow }
})