import { computed, ref } from 'vue'
import { usePolling } from '../../composables/usePolling'
import { useProjectContext } from '../projects/context'
import { mergeDesignedShots } from '../storyboard/model'
import { storyboardApi } from '../storyboard/api'
import { breakdownSnapshot } from '../workflows/selectors'
import { getOperation, runOperation } from '../workflows/operations'
import { productionApi } from './api'
import { getProductionSession } from './model'

/** 项目级生产动作；每次请求都由统一项目锁防止重复提交。 */
export type ProductionCommand = 'prompts' | 'keyframes' | 'videos' | 'retry-videos'

/** 镜头生产页的查询、筛选、就绪状态与批量操作。 */
export function useProduction() {
    const context = useProjectContext()
    const id = computed(() => context.project.value?.id ?? '')
    const selectedEpisode = ref<number>()
    const selectedShot = ref('')
    const concurrency = ref(2)
    const force = ref(false)
    const snapshot = computed(() => breakdownSnapshot(context.checkpoints.value))
    const sourceEpisodes = computed(
        () => snapshot.value?.storyboardEpisodeShots ?? snapshot.value?.breakdownResult?.storyboardEpisodeShots ?? []
    )
    const episodeOptions = computed(() => {
        const entries = new Map(context.project.value?.episodes.map(episode => [episode.episode, episode.title]) ?? [])
        for (const episode of sourceEpisodes.value) {
            if (!entries.has(episode.episodeNo)) entries.set(episode.episodeNo, episode.episodePlan.episodeTitle)
        }
        return [...entries]
            .map(([episodeNo, title]) => ({ episodeNo, title }))
            .toSorted((a, b) => a.episodeNo - b.episodeNo)
    })
    const episodeNo = computed(
        () =>
            episodeOptions.value.find(item => item.episodeNo === selectedEpisode.value)?.episodeNo ??
            episodeOptions.value[0]?.episodeNo ??
            0
    )
    const queryKey = computed(() => JSON.stringify([id.value, episodeNo.value, force.value]))
    const query = usePolling(queryKey, async (key, signal) => {
        const [projectId, number, overwrite] = JSON.parse(key) as [string, number, boolean]
        if (!projectId || !number) return null
        const [directions, prompts, keyframes, videos, videoStatus] = await Promise.all([
            storyboardApi.directions(projectId, number, signal),
            productionApi.promptReadiness(projectId, overwrite, signal),
            productionApi.keyframeReadiness(projectId, overwrite, signal),
            productionApi.videoReadiness(projectId, overwrite, signal),
            productionApi.projectVideoStatus(projectId, signal)
        ])
        if (directions.projectId !== projectId || directions.episodeNo !== number)
            throw new Error('镜头生产查询返回了不匹配的项目或剧集，请刷新后重试。')
        return { directions, prompts, keyframes, videos, videoStatus }
    })
    const source = computed(() => sourceEpisodes.value.find(item => item.episodeNo === episodeNo.value))
    const shots = computed(() => mergeDesignedShots(query.data.value?.directions ?? null, null, source.value))
    const shot = computed(() => shots.value.find(item => item.shotId === selectedShot.value) ?? shots.value[0])
    const promptItem = computed(() => query.data.value?.prompts.items.find(item => item.shotId === shot.value?.shotId))
    const keyframeItem = computed(() =>
        query.data.value?.keyframes.items.find(item => item.shotId === shot.value?.shotId)
    )
    const videoItem = computed(() => query.data.value?.videos.items.find(item => item.shotId === shot.value?.shotId))
    const videoStatusItem = computed(() =>
        query.data.value?.videoStatus.items.find(item => item.shotId === shot.value?.shotId)
    )
    const operation = computed(() => getOperation(id.value))
    const session = computed(() => getProductionSession(id.value))
    const batchValid = computed(() => Number.isSafeInteger(concurrency.value) && concurrency.value > 0)
    const blocked = computed(
        () =>
            operation.value.pending ||
            !!context.error.value ||
            !!query.error.value ||
            !query.data.value ||
            context.project.value?.status === 'generating'
    )

    /** 批量操作只向就绪镜头提交；最终资产状态由轮询查询确认。 */
    async function run(command: ProductionCommand) {
        if (blocked.value || !batchValid.value) return
        const projectId = id.value
        const input = { concurrency: concurrency.value, force: force.value }
        const target = getProductionSession(projectId)
        target.receipt = null
        const labels: Record<ProductionCommand, string> = {
            prompts: force.value ? '重生成项目视频提示词' : '补齐项目视频提示词',
            keyframes: force.value ? '新增项目首帧候选' : '补齐或更新项目主首帧',
            videos: force.value ? '新增项目视频候选' : '提交就绪视频任务',
            'retry-videos': '重试失败视频任务'
        }
        await runOperation(projectId, labels[command], async () => {
            if (command === 'prompts') {
                target.receipt = {
                    kind: 'prompts',
                    title: labels[command],
                    result: await productionApi.generatePrompts(projectId, input)
                }
            } else if (command === 'keyframes') {
                target.receipt = {
                    kind: 'keyframes',
                    title: labels[command],
                    result: await productionApi.generateKeyframes(projectId, { provider: 'seedream', ...input })
                }
            } else if (command === 'videos') {
                target.receipt = {
                    kind: 'videos',
                    title: labels[command],
                    result: await productionApi.generateVideos(projectId, { provider: 'seedance', ...input })
                }
            } else {
                target.receipt = {
                    kind: 'retry',
                    title: labels[command],
                    result: await productionApi.retryVideos(projectId, concurrency.value)
                }
            }
        })
        await query.refresh()
    }

    return {
        id,
        selectedEpisode,
        selectedShot,
        episodeNo,
        episodeOptions,
        shots,
        shot,
        promptItem,
        keyframeItem,
        videoItem,
        videoStatusItem,
        query,
        operation,
        session,
        concurrency,
        force,
        batchValid,
        blocked,
        run
    }
}