import type {
  ExplainBusinessUnit,
  ExplainGuideStop,
  ExplainGuideStopPage,
  ExplainTrack,
  MuseumExhibit,
  MuseumHall,
  SearchIndexItem
} from '@/domain/museum'
import {
  mediaRepository,
  type MediaRepository
} from '@/repositories/MediaRepository'
import {
  museumContentRepository,
  type MuseumContentRepository
} from '@/repositories/MuseumContentRepository'
import {
  explainContentProvider,
  type ExplainContentProvider
} from '@/data/providers/staticMuseumContentProvider'

export interface ExplainRepository {
  listExplainExhibits(): Promise<MuseumExhibit[]>
  listExplainExhibitsByHall(hallId: string): Promise<MuseumExhibit[]>
  listExhibits(): Promise<MuseumExhibit[]>
  getExhibitById(id: string): Promise<MuseumExhibit | null>
  listHalls(): Promise<MuseumHall[]>
  getHallById(id: string): Promise<MuseumHall | null>
  listGuideStopsByHall(hallId: string): Promise<ExplainGuideStop[]>
  listGuideStopsPageByHall(hallId: string, pageNo: number, pageSize: number): Promise<ExplainGuideStopPage>
  listGuideStopsByBusinessUnit(hallId: string, unitId: string): Promise<ExplainGuideStop[]>
  listTemporaryBusinessUnitsByHall(hallId: string): Promise<ExplainBusinessUnit[]>
  listTracks(): Promise<ExplainTrack[]>
  getTrackByExhibitId(exhibitId: string): Promise<ExplainTrack | null>
  searchExplain(keyword?: string): Promise<SearchIndexItem[]>
}

const trackTitleFor = (exhibit: MuseumExhibit) => `${exhibit.name}讲解`

export class DefaultExplainRepository implements ExplainRepository {
  constructor(
    private readonly content: MuseumContentRepository = museumContentRepository,
    private readonly media: MediaRepository = mediaRepository,
    private readonly explainContent: ExplainContentProvider = explainContentProvider
  ) {}

  listExplainExhibits() {
    return this.explainContent.listExplainExhibits()
  }

  async listExplainExhibitsByHall(hallId: string) {
    if (this.explainContent.listExplainExhibitsByHall) {
      return this.explainContent.listExplainExhibitsByHall(hallId)
    }
    const exhibits = await this.listExplainExhibits()
    return exhibits.filter((exhibit) => exhibit.hallId === hallId)
  }

  listExhibits() {
    return this.content.listExhibits()
  }

  getExhibitById(id: string) {
    return this.explainContent.getExhibitById?.(id) || this.content.getExhibitById(id)
  }

  listHalls() {
    return this.explainContent.listHalls()
  }

  async getHallById(id: string) {
    const halls = await this.explainContent.listHalls()
    return halls.find((hall) => hall.id === id || hall.poiId === id) || null
  }

  async listGuideStopsByHall(hallId: string) {
    const pageSize = 100
    const items: ExplainGuideStop[] = []
    const seen = new Set<string>()
    for (let pageNo = 1; ; pageNo += 1) {
      const page = await this.listGuideStopsPageByHall(hallId, pageNo, pageSize)
      page.items.forEach((item) => {
        if (!seen.has(item.id)) {
          seen.add(item.id)
          items.push(item)
        }
      })
      if (!page.hasMore || items.length >= page.total) return items
    }
  }

  async listGuideStopsPageByHall(hallId: string, pageNo: number, pageSize: number) {
    if (this.explainContent.listGuideStopsPageByHall) {
      return this.explainContent.listGuideStopsPageByHall(hallId, pageNo, pageSize)
    }
    const items = await this.explainContent.listGuideStopsByHall?.(hallId) || []
    const normalizedPageNo = Math.max(1, Math.floor(pageNo) || 1)
    const normalizedPageSize = Math.max(1, Math.floor(pageSize) || 20)
    const offset = (normalizedPageNo - 1) * normalizedPageSize
    return {
      items: items.slice(offset, offset + normalizedPageSize),
      total: items.length,
      pageNo: normalizedPageNo,
      pageSize: normalizedPageSize,
      hasMore: offset + normalizedPageSize < items.length
    }
  }

  async listGuideStopsByBusinessUnit(hallId: string, unitId: string) {
    if (this.explainContent.listGuideStopsByBusinessUnit) {
      return this.explainContent.listGuideStopsByBusinessUnit(hallId, unitId)
    }
    const units = await this.listTemporaryBusinessUnitsByHall(hallId)
    return units.find((unit) => unit.id === unitId)?.stops || []
  }

  async listTemporaryBusinessUnitsByHall(hallId: string) {
    if (this.explainContent.listTemporaryBusinessUnitsByHall) {
      return this.explainContent.listTemporaryBusinessUnitsByHall(hallId)
    }

    return []
  }

  async listTracks() {
    const tracks = await this.explainContent.listTracks()
    if (tracks.length) return tracks

    const exhibits = await this.content.listExhibits()

    return Promise.all(exhibits.map(async (exhibit): Promise<ExplainTrack> => {
      const media = await this.media.getMediaForExplainTrack(exhibit.id)
      return {
        id: `track-${exhibit.id}`,
        exhibitId: exhibit.id,
        hallId: exhibit.hallId,
        title: trackTitleFor(exhibit),
        summary: exhibit.description,
        mediaId: media?.id,
        coverImage: exhibit.image,
        poiId: exhibit.poiId,
        floorId: exhibit.floorId,
        available: media?.available === true
      }
    }))
  }

  async getTrackByExhibitId(exhibitId: string) {
    const detail = await this.getExhibitById(exhibitId).catch(() => null)
    if (detail) {
      return {
        id: `track-${detail.guideContentId || detail.id}`,
        exhibitId: detail.id,
        hallId: detail.hallId,
        title: detail.guideTitle || trackTitleFor(detail),
        summary: detail.guideText || detail.description,
        mediaId: detail.audioUrl ? `media-${detail.guideContentId || detail.id}` : undefined,
        coverImage: detail.image,
        poiId: detail.poiId,
        floorId: detail.floorId,
        available: Boolean(detail.audioUrl) || detail.audioAvailable === true,
        playTargetType: detail.playTargetType,
        playTargetId: detail.playTargetId
      }
    }

    const tracks = await this.listTracks()
    return tracks.find((track) => track.exhibitId === exhibitId) || null
  }

  async searchExplain(keyword = '') {
    if (this.explainContent.searchExplainExhibits) {
      const exhibits = await this.explainContent.searchExplainExhibits(keyword)
      return exhibits.map<SearchIndexItem>((exhibit) => ({
        id: exhibit.id,
        name: exhibit.name,
        desc: `${exhibit.hallName || '展品讲解'} · ${exhibit.floorLabel || ''}`.trim(),
        type: 'exhibit',
        exhibitId: exhibit.id,
        hallId: exhibit.hallId,
        poiId: exhibit.poiId,
        floorId: exhibit.floorId
      }))
    }

    const normalizedKeyword = keyword.trim().toLowerCase()
    const [exhibits, halls] = await Promise.all([
      this.explainContent.listExplainExhibits(),
      this.explainContent.listHalls()
    ])

    const exhibitItems = exhibits
      .filter((exhibit) => !normalizedKeyword || [
        exhibit.name,
        exhibit.hallName,
        exhibit.floorLabel,
        ...(exhibit.tags || [])
      ].filter(Boolean).join(' ').toLowerCase().includes(normalizedKeyword))
      .map<SearchIndexItem>((exhibit) => ({
        id: exhibit.id,
        name: exhibit.name,
        desc: `${exhibit.hallName || '展品讲解'} · ${exhibit.floorLabel || ''}`.trim(),
        type: 'exhibit',
        exhibitId: exhibit.id,
        hallId: exhibit.hallId,
        poiId: exhibit.poiId,
        floorId: exhibit.floorId
      }))

    const hallItems = halls
      .filter((hall) => !normalizedKeyword || [
        hall.name,
        hall.floorLabel,
        hall.description
      ].filter(Boolean).join(' ').toLowerCase().includes(normalizedKeyword))
      .map<SearchIndexItem>((hall) => ({
        id: hall.id,
        name: hall.name,
        desc: `${hall.floorLabel || ''} · ${hall.exhibitCount || 0}个讲解内容`.trim(),
        type: 'hall',
        hallId: hall.id,
        poiId: hall.poiId,
        floorId: hall.floorId
      }))

    return [...exhibitItems, ...hallItems]
  }
}

export const explainRepository = new DefaultExplainRepository()