import { DialogHelper } from '@pura/harmony-dialog';
import { Playlist } from '../viewmodel/Playlist';
import { ToastUtil, LogUtil, StrUtil, FileUtil, PreferencesUtil } from '@pura/harmony-utils';
import { VideoItem } from '../viewmodel/VideoItem';
import MediaTable from '../common/util/MediaTable';
import PlaylistTable from '../common/util/PlaylistTable';
import { LazyDataSource } from '../common/util/LazyDataSource';
import { ConfigurationConstant, common } from '@kit.AbilityKit';
import { CommonConstants } from '../common/constants/CommonConstants';
import { SegmentButton } from '@kit.ArkUI';
import { SegmentButtonOptions, SegmentButtonItemTuple } from '@kit.ArkUI';
import { Utility } from '../common/util/Utility';
import fs from '@ohos.file.fs';

// 工具函数：将 #RRGGBB 字符串和透明度转为 'rgba(r,g,b,a)' 字符串，深色模式下可返回深色变体
function themeColorWithAlpha(themeColor: string, alpha: number, isDarkMode: boolean = false): string {
  if (isDarkMode) {
    // 深色模式下返回更深的灰色或半透明黑色
    return `rgba(34,34,34,${alpha + 0.2 > 1 ? 1 : alpha + 0.2})`;
  }
  const color = themeColor.replace('#', '');
  const r = parseInt(color.substring(0, 2), 16);
  const g = parseInt(color.substring(2, 4), 16);
  const b = parseInt(color.substring(4, 6), 16);
  return `rgba(${r},${g},${b},${alpha})`;
}

// 定义SegmentButton按钮元组类型
const viewModeButtons: SegmentButtonItemTuple = [{ text: '全部' }, { text: '目录' }];

/**
 * 添加歌曲到歌单对话框内容组件
 */
@Component
struct AddSongsToPlaylistDialogContent {
  context = this.getUIContext().getHostContext() as common.UIAbilityContext
  @State opacityItem: number = 1; // 控制透明度的状态变量
  @StorageProp('themeColor') themeColor: string = CommonConstants.DEFAULT_THEME_COLOR;
  @State isDarkMode: boolean = false
  @StorageProp('currentColorMode') @Watch('onColorModeChange') currentMode: number =
    ConfigurationConstant.ColorMode.COLOR_MODE_DARK;

  onColorModeChange() {
    this.isDarkMode = this.currentMode === ConfigurationConstant.ColorMode.COLOR_MODE_DARK
  }
  @State selectedSongs: VideoItem[] = []
  @State isLoading: boolean = false
  @State searchText: string = ''
  @State filteredSongs: VideoItem[] = []
  private listScroller: ListScroller = new ListScroller()
  @State isSearchMode: boolean = false
  @Prop playlist: Playlist
  @StorageProp('mediaKuList') mediaKuList: Array<VideoItem> = []; //媒体库文件
  private mediaTable: MediaTable = new MediaTable(getContext(this))
  private playlistTable: PlaylistTable = new PlaylistTable(getContext(this))
  @State dataSource: LazyDataSource<VideoItem> = new LazyDataSource([])
  // 分页相关状态
  @State currentPage: number = 0
  @State hasMoreData: boolean = true
  private readonly PAGE_SIZE: number = 50
  // 用于存储完整数据的引用
  private allSongs: VideoItem[] = []
  private baseDownloadPath: string = ''
  // 回调函数
  onConfirm?: (songs: VideoItem[]) => void
  onCancel?: () => void
  
  // 添加目录浏览相关状态
  @State @Watch('onViewModeChange') viewMode: number[] = [0]; // 0: 全部歌曲, 1: 目录模式
  @State currentPath: string = '';
  @State folderItems: VideoItem[] = [];
  @State selectedFolders: Set<string> = new Set();
  @State isFolderLoading: boolean = false;
  private table: MediaTable = new MediaTable(getContext(this))
  // 用于高效判断歌曲选中状态（避免在大列表中频繁遍历）
  @State totalSelectedCount: number = 0;
  private selectedSongIds: Set<string> = new Set();
  private updateTimer: number = -1;
  // SegmentButton选项配置
  @State viewModeOptions: SegmentButtonOptions = SegmentButtonOptions.capsule({
    buttons: viewModeButtons,
    backgroundColor: $r('app.color.index_background'),
    selectedBackgroundColor: $r('app.color.start_window_background'),
    selectedFontColor: $r('app.color.text_color'),
    buttonPadding: { top: 10, bottom: 10 },
    multiply: false
  });

  async aboutToAppear() {
    // 初始化深色模式状态
    this.isDarkMode = this.currentMode === ConfigurationConstant.ColorMode.COLOR_MODE_DARK
    LogUtil.info('heanup  AddSongsToPlaylistDialogContent aboutToAppear 开始')
    LogUtil.info('heanup  初始化深色模式状态: ' + this.isDarkMode + ', currentMode: ' + this.currentMode)
    LogUtil.info('heanup  playlist: ' +
      (this.playlist ? JSON.stringify({ id: this.playlist.id, name: this.playlist.name }) : 'null'))
    console.info('onecold  mediaKuList 对话框 aboutToAppear=' + this.mediaKuList.length)
    this.allSongs = [...this.mediaKuList]
    this.filteredSongs = [...this.mediaKuList]
    this.loadInitialData()
    this.clearSelection()
    this.baseDownloadPath = this.normalizeFsPath(PreferencesUtil.getStringSync('download_path', '/storage/Users/currentUser'))
    this.currentPath = this.baseDownloadPath
    // 异步加载目录数据
    await this.loadFile(this.currentPath)
  }

  aboutToDisappear() {
    // 清理定时器，防止内存泄漏
    if (this.updateTimer !== -1) {
      clearTimeout(this.updateTimer)
      this.updateTimer = -1
    }
  }

  /**
   * 加载初始数据
   */
  private loadInitialData() {
    this.currentPage = 0
    this.hasMoreData = true
    this.updateListData(false)
  }
  @State fileList: Array<string> = []

  async loadFile(curPath: string) {
    const fsPath = this.normalizeFsPath(curPath)
    this.isFolderLoading = true
    this.currentPath = fsPath
    let directories: Array<VideoItem> = []
    let files: Array<VideoItem> = []
    const normalizedCurrent = this.normalizeLocalPath(fsPath)

    try {
      const entries: Array<string> = fs.listFileSync(fsPath) as Array<string>
      this.fileList = entries

      for (let i = 0; i < entries.length; i++) {
        const name = entries[i]
        if (name.startsWith('.')) {
          continue
        }
        const fullPath = `${fsPath}/${name}`
        try {
          const stat: fs.Stat = fs.statSync(fullPath) as fs.Stat
          if (stat.isDirectory()) {
            directories.push(new VideoItem(name, name, fullPath, CommonConstants.TYPE_IS_DIR, 0, ''))
          } else {
            // 仅显示音频文件
            if (!Utility.isMeidaByExtension(fullPath)) {
              continue
            }
            const normalized = this.normalizeLocalPath(fullPath)
            const matched = this.allSongs.find((item: VideoItem) =>
              this.normalizeLocalPath(item.filePath) === normalized)
            if (matched) {
              files.push(matched)
            } else {
              // 构造最小信息的 VideoItem 兜底显示
              const fallback = new VideoItem(name, normalized, fullPath, CommonConstants.TYPE_LOCAL, stat.size, '')
              fallback.fileName = name
              fallback.parentPath = fsPath
              files.push(fallback)
            }
          }
        } catch (error) {
          LogUtil.warn('heanup AddSongsToPlaylistDialog', `无法访问: ${fullPath}`)
        }
      }

      // 目录优先，其次按名称排序
      this.folderItems = directories.concat(files).sort((a: VideoItem, b: VideoItem) => {
        if (a.type === CommonConstants.TYPE_IS_DIR && b.type !== CommonConstants.TYPE_IS_DIR) {
          return -1
        }
        if (a.type !== CommonConstants.TYPE_IS_DIR && b.type === CommonConstants.TYPE_IS_DIR) {
          return 1
        }
        return a.name.localeCompare(b.name)
      })
    } catch (error) {
      LogUtil.error('heanup AddSongsToPlaylistDialog', `加载文件列表失败: ${(error as Error).message}`)
      this.fileList = []
      this.folderItems = directories
    } finally {
      this.isFolderLoading = false
    }
  }

  /**
   * 用于文件系统访问的路径清洗：去掉多余 //，保留单个前导 /
   */
  private normalizeFsPath(path: string): string {
    if (!path) {
      return ''
    }
    let cleaned = path.replace('file://', '').replace('file://docs', '').replace('docs://', '')
    cleaned = cleaned.replace(/\/{2,}/g, '/')
    if (!cleaned.startsWith('/')) {
      cleaned = '/' + cleaned
    }
    if (cleaned.endsWith('/') && cleaned.length > 1) {
      cleaned = cleaned.slice(0, -1)
    }
    return cleaned
  }

  /**
   * 安全获取 parentPath，避免因异常抛出导致目录加载中断
   */
  private safeGetParentPath(item: VideoItem): string {
    if (item.parentPath) {
      return item.parentPath
    }
    try {
      return FileUtil.getParentPath(item.filePath)
    } catch (error) {
      const idx = item.filePath?.lastIndexOf('/') ?? -1
      if (idx > 0) {
        return item.filePath.substring(0, idx)
      }
      LogUtil.warn('heanup AddSongsToPlaylistDialog', `fallback parentPath for ${item.filePath}: ${(error as Error).message}`)
      return ''
    }
  }

  private querySongsByParentPath(path: string): Promise<VideoItem[]> {
    return new Promise((resolve) => {
      try {
        this.table.queryByParentPath(path, (result: VideoItem[]) => resolve(result))
      } catch (error) {
        LogUtil.error('heanup AddSongsToPlaylistDialog', `queryByParentPath 异常: ${(error as Error).message}`)
        resolve([])
      }
    })
  }

  onViewModeChange() {
    if (this.viewMode && this.viewMode[0] === 1) {
      this.loadFile(this.currentPath)
    } else {
      this.updateSelectedCount()
    }
  }

  private enterFolder(path: string) {
    this.loadFile(path)
  }

  private normalizeLocalPath(path: string): string {
    if (!path) {
      return ''
    }
    let normalized = path.replace('file://docs', '').replace('file://', '')
    if (normalized.startsWith('/docs/')) {
      normalized = normalized.replace('/docs', '')
    } else if (normalized.startsWith('docs/')) {
      normalized = normalized.substring(4)
      if (!normalized.startsWith('/')) {
        normalized = '/' + normalized
      }
    }
    if (!normalized.startsWith('/')) {
      normalized = '/' + normalized
    }
    if (normalized.endsWith('/') && normalized.length > 1) {
      normalized = normalized.slice(0, -1)
    }
    return normalized
  }

  private navigateToParent() {
    if (!this.currentPath) {
      return
    }
    // 限制在下载目录之下
    if (this.baseDownloadPath && this.normalizeFsPath(this.currentPath) === this.baseDownloadPath) {
      LogUtil.info('heanup AddSongsToPlaylistDialog', 'navigateToParent blocked at baseDownloadPath')
      return
    }
    const idx = this.currentPath.lastIndexOf('/')
    if (idx <= 0) {
      return
    }
    const parent = this.currentPath.substring(0, idx)
    if (!parent || parent === this.currentPath) {
      return
    }
    this.loadFile(parent)
  }

  private canNavigateUp(): boolean {
    if (!this.currentPath) {
      return false
    }
    const current = this.normalizeFsPath(this.currentPath)
    if (!this.baseDownloadPath) {
      return current.lastIndexOf('/') > 0
    }
    return current.startsWith(this.baseDownloadPath) && current !== this.baseDownloadPath
  }

  private toggleSongSelection(song: VideoItem) {
    if (song.type === CommonConstants.TYPE_IS_DIR) {
      this.toggleFolderSelection(song.filePath)
      return
    }
    
    const exists = this.selectedSongIds.has(song.id)
    if (exists) {
      this.selectedSongs = this.selectedSongs.filter((s: VideoItem) => s.id !== song.id)
      this.selectedSongIds.delete(song.id)
    } else {
      this.selectedSongs = [...this.selectedSongs, song]
      this.selectedSongIds.add(song.id)
    }
    this.updateSelectedCount()
  }

  private toggleFolderSelection(folderPath: string) {
    const normalized = this.normalizeLocalPath(folderPath)
    const next = new Set(this.selectedFolders)
    if (next.has(normalized)) {
      next.delete(normalized)
    } else {
      next.add(normalized)
    }
    LogUtil.info('heanup AddSongsToPlaylistDialog', `toggleFolderSelection folder=${normalized}, now=${Array.from(next).join(',')}`)
    this.selectedFolders = next
    this.updateSelectedCount()
  }

  private clearSelection() {
    this.selectedSongs = []
    this.selectedFolders = new Set()
    this.selectedSongIds.clear()
    this.totalSelectedCount = 0
  }

  private mergeSongs(primary: VideoItem[], extra: VideoItem[]): VideoItem[] {
    const map = new Map<string, VideoItem>()
    primary.forEach((item: VideoItem) => {
      map.set(this.normalizeLocalPath(item.filePath), item)
    })
    extra.forEach((item: VideoItem) => {
      const key = this.normalizeLocalPath(item.filePath)
      if (!map.has(key)) {
        map.set(key, item)
      }
    })
    return Array.from(map.values())
  }

  private safeParentFromPath(path: string): string {
    if (!path) {
      return ''
    }
    try {
      return FileUtil.getParentPath(path)
    } catch (error) {
      const idx = path.lastIndexOf('/')
      return idx > 0 ? path.substring(0, idx) : ''
    }
  }

  private getSongsFromFolders(folderPaths: string[]): VideoItem[] {
    if (!folderPaths || folderPaths.length === 0) {
      LogUtil.info('heanup AddSongsToPlaylistDialog', 'getSongsFromFolders empty folderPaths')
      return []
    }

    try {
      // 使用 Set 优化查找性能，并统一路径格式
      const normalizedSet = new Set(folderPaths.map((path: string) => this.normalizeLocalPath(path)))
      const result: VideoItem[] = []
      
      // 单次遍历，避免嵌套循环
      for (let i = 0; i < this.allSongs.length; i++) {
        const item = this.allSongs[i]
        if (!item || item.type === CommonConstants.TYPE_IS_DIR || !item.filePath) {
          continue
        }

        const parentPath = this.normalizeLocalPath(item.parentPath || this.safeParentFromPath(item.filePath))
        const filePath = this.normalizeLocalPath(item.filePath)
        
        // 直接使用 Set 查找，O(1) 时间复杂度
        if (normalizedSet.has(parentPath)) {
          result.push(item)
          continue
        }
        
        // 检查是否在子目录中（这部分仍需遍历，但通常文件夹数量不多）
        for (const folder of normalizedSet) {
          if (filePath.startsWith(folder + '/')) {
            result.push(item)
            break
          }
        }
      }

      // 额外兜底：将当前目录列表中展示的文件也纳入（防止媒体表尚未入库时无法计数）
      this.folderItems.forEach((item: VideoItem) => {
        if (!item || item.type === CommonConstants.TYPE_IS_DIR) {
          return
        }
        const parentPath = this.normalizeLocalPath(item.parentPath || this.safeParentFromPath(item.filePath))
        const filePath = this.normalizeLocalPath(item.filePath)
        if (normalizedSet.has(parentPath) || Array.from(normalizedSet).some(folder => filePath.startsWith(folder + '/'))) {
          result.push(item)
        }
      })
      LogUtil.info('heanup AddSongsToPlaylistDialog', `getSongsFromFolders folders=${Array.from(normalizedSet).join(',')}, result=${result.length}`)
      
      return result
    } catch (error) {
      LogUtil.error('heanup AddSongsToPlaylistDialog', `getSongsFromFolders error: ${(error as Error).message}`)
      return []
    }
  }

  private updateSelectedCount() {
    // 清除之前的定时器，实现防抖
    if (this.updateTimer !== -1) {
      clearTimeout(this.updateTimer)
    }
    
    // 延迟执行计算，避免阻塞主线程
    this.updateTimer = setTimeout(() => {
      try {
        const folderSongs = this.getSongsFromFolders(Array.from(this.selectedFolders))
        const merged = this.mergeSongs(
          this.selectedSongs.filter((item: VideoItem) => item.type !== CommonConstants.TYPE_IS_DIR), 
          folderSongs
        )
        this.totalSelectedCount = merged.length
        LogUtil.info('heanup AddSongsToPlaylistDialog', `updateSelectedCount folders=${Array.from(this.selectedFolders).join(',')}, folderSongs=${folderSongs.length}, directSongs=${this.selectedSongs.length}, total=${this.totalSelectedCount}`)
      } catch (error) {
        LogUtil.error('heanup AddSongsToPlaylistDialog', `更新选中数量失败: ${(error as Error).message}`)
        // 发生错误时至少显示已选歌曲数量
        this.totalSelectedCount = this.selectedSongs.filter(
          (item: VideoItem) => item.type !== CommonConstants.TYPE_IS_DIR
        ).length
      }
      this.updateTimer = -1
    }, 50)
  }

  /**
   * 异步全选歌曲，分批处理避免阻塞主线程
   */
  private selectAllSongsAsync() {
    const allSongs = this.filteredSongs && this.filteredSongs.length > 0 ? this.filteredSongs : this.allSongs
    LogUtil.info('heanup AddSongsToPlaylistDialog', `selectAllSongsAsync start, total=${allSongs.length}`)
    const BATCH_SIZE = 500 // 单批进一步增大，减少全选等待时间
    let currentIndex = 0
    const tempSelected: VideoItem[] = [...this.selectedSongs] // 保留已选歌曲
    const tempIds = new Set(this.selectedSongIds)
    
    const processBatch = () => {
      const endIndex = Math.min(currentIndex + BATCH_SIZE, allSongs.length)
      const batch = allSongs.slice(currentIndex, endIndex)
      
      // 批量添加到临时列表和 Set
      batch.forEach((song: VideoItem) => {
        if (!tempIds.has(song.id)) {
          tempSelected.push(song)
          tempIds.add(song.id)
        }
      })
      
      // 重新赋值触发响应式更新
      this.selectedSongs = [...tempSelected]
      this.selectedSongIds = new Set(tempIds)
      
      currentIndex = endIndex
      
      if (currentIndex < allSongs.length) {
        // 还有更多数据，继续处理下一批
        setTimeout(processBatch, 0) // 使用 setTimeout 让出主线程
      } else {
        // 全部处理完成，更新计数
        this.updateSelectedCount()
        LogUtil.info('AddSongsToPlaylistDialog', `全选完成，共选中 ${this.selectedSongs.length} 首歌曲`)
      }
    }
    
    // 开始第一批处理
    processBatch()
  }

  /**
   * 搜索过滤歌曲
   */
  filterSongs() {
    this.isSearchMode = true
    if (!this.searchText.trim()) {
      this.filteredSongs = [...this.allSongs]
    } else {
      // 添加空值检查以防止TypeError
      if (!this.allSongs || !Array.isArray(this.allSongs)) {
        this.filteredSongs = []
      } else {
        this.filteredSongs = this.allSongs.filter(item => {
          //支持模糊匹配和艺术家 专辑匹配
          const regex = new RegExp(this.searchText.replace(/\s+/g, '.*'), 'i');
          return regex.test(item.name.toLowerCase()) ||
          regex.test(item.fileName?.toLowerCase() ?? "") ||
          regex.test(item.artist?.toLowerCase() ?? "") ||
          regex.test(item.album?.toLowerCase() ?? "")
        })
      }
    }
    // 重置分页状态并重新加载数据
    this.loadInitialData()
  }

  // 修改 updateListData 方法，使其更清晰
  updateListData(append: boolean = false) {
    this.getUIContext().animateTo({ duration: 666 }, () => {
      this.opacityItem = 0;
    })

    setTimeout(() => {
      const sourceData = this.filteredSongs
      let dataToShow: VideoItem[] = []

      if (append) {
        // 追加数据模式
        const currentData = this.dataSource.dataArray
        const startIndex = this.currentPage * this.PAGE_SIZE
        const endIndex = Math.min(startIndex + this.PAGE_SIZE, sourceData.length)
        const newData = sourceData.slice(startIndex, endIndex)

        if (newData.length > 0) {
          dataToShow = [...currentData, ...newData]
          this.currentPage++
        }
      } else {
        // 初始加载模式
        this.currentPage = 1
        const endIndex = Math.min(this.PAGE_SIZE, sourceData.length)
        dataToShow = sourceData.slice(0, endIndex)
      }

      // 更新数据源
      this.dataSource.pushArrayData(dataToShow)

      // 检查是否还有更多数据
      const totalLoaded = dataToShow.length
      this.hasMoreData = totalLoaded < sourceData.length

      this.getUIContext().animateTo({ duration: 666 }, () => {
        this.opacityItem = 1
      })
    }, 200)
  }

  loadMoreData() {
    console.info('loadMoreData  called, hasMoreData:', this.hasMoreData, 'isLoading:', this.isLoading)

    if (!this.hasMoreData || this.isLoading) {
      console.info('loadMoreData  skipped - no more data or already loading')
      return
    }

    console.info('loadMoreData  executing')
    this.isLoading = true

    // 使用 setTimeout 模拟异步加载
    setTimeout(() => {
      this.updateListData(true) // append mode
      this.isLoading = false
      console.info('loadMoreData  completed, current data length:', this.dataSource.dataArray.length)
    }, 50)
  }

  build() {
    Column({ space: 16 }) {
      // 搜索框
      Row({ space: 8 }) {
        Image($r('app.media.ic_action_search'))
          .width(20)
          .height(20)
          .fillColor(this.isDarkMode ? '#8E8E93' : $r('app.color.text_color'))
          .opacity(0.6)

        TextInput({ placeholder: '搜索歌曲、歌手或专辑', text: this.searchText })
          .layoutWeight(1)
          .height(35)
          .backgroundColor(this.isDarkMode ? '#2C2C2E' : $r('app.color.input_background'))
          .borderRadius(8)
          .padding({ left: 8, right: 8 })
          .fontSize(14)
          .fontColor(this.isDarkMode ? '#FFFFFF' : $r('app.color.text_color'))
          .placeholderColor(this.isDarkMode ? '#8E8E93' : '#999999')
          .onChange((value: string) => {
            this.searchText = value
            this.filterSongs()
          })
      }
      .width('100%')
      .padding(12)
      .backgroundColor(this.isDarkMode ? '#2C2C2E' : $r('app.color.input_background'))
      .borderRadius(20)

      // 视图模式切换 SegmentButton
      SegmentButton({
        options: this.viewModeOptions,
        selectedIndexes: $viewMode
      })
        .width('100%')
        .margin({ top: 8 })

      // 已选择歌曲数量（包含目录展开后的歌曲）
      if (this.totalSelectedCount > 0) {
        Row() {
          Text(`已选择 ${this.totalSelectedCount} 首歌曲`)
            .fontSize(14)
            .fontColor(this.isDarkMode ? '#FFFFFF' : this.themeColor)
            .fontWeight(FontWeight.Medium)

          Blank()

          if (this.viewMode[0] === 0) {
            Button((this.selectedSongs.length === this.dataSource.dataArray.length
              && this.dataSource.dataArray.length > 0) ? '全不选' : '全选')
              .fontSize(12)
              .fontColor(this.isDarkMode ? '#FFFFFF' : $r('app.color.text_color'))
              .backgroundColor(Color.Transparent)
              .height(30)
              .padding({ left: 8, right: 8 })
              .onClick(() => {
                if (this.selectedSongs.length === this.dataSource.dataArray.length
                  && this.dataSource.dataArray.length > 0) {
                  // 全不选：清空所有选择
                  this.selectedSongs = []
                  this.selectedSongIds.clear()
                  this.updateSelectedCount()
                } else {
                  // 全选：异步分批处理，避免阻塞主线程
                  this.selectAllSongsAsync()
                }
              })
          }

          Button('清空')
            .fontSize(12)
            .fontColor(this.isDarkMode ? '#FFFFFF' : $r('app.color.text_color'))
            .backgroundColor(Color.Transparent)
            .height(30)
            .padding({ left: 8, right: 8 })
            .onClick(() => {
              this.clearSelection()
            })
        }
        .width('100%')
        .padding({ left: 4, right: 4 })
      }

      // 歌曲列表或目录列表
      if (this.viewMode[0] === 0) {
        // 全部歌曲模式
        if (this.dataSource.dataArray.length === 0 && this.isSearchMode) {
          Column({ space: 12 }) {
            Image($r('app.media.music_red'))
              .width(64)
              .height(64)
              .opacity(0.3)

            Text(this.searchText ? '没有找到匹配的歌曲' : '没有可添加的歌曲')
              .fontSize(14)
              .fontColor(this.isDarkMode ? '#8E8E93' : '#999999')
          }
          .width('100%')
          .height(300)
          .justifyContent(FlexAlign.Center)
        } else {
          this.getListView()
        }
      } else {
        // 目录模式
        this.getFolderView()
      }

      // 按钮区域
      Row({ space: 12 }) {
        Button('取消')
          .width('45%')
          .height(40)
          .borderRadius(8)
          .fontSize(14)
          .backgroundColor(this.isDarkMode ? themeColorWithAlpha(this.themeColor, 0.8, this.isDarkMode)
            :$r('app.color.cancel_button_background') )
          .fontColor($r('app.color.cancel_button_text'))
          .onClick(() => {
            this.onCancel?.()
            DialogHelper.closeDialog('addSongsToPlaylistDialog')
          })

        Button(`添加${this.totalSelectedCount > 0 ? `(${this.totalSelectedCount})` : ''}`)
          .width('45%')
          .height(40)
          .backgroundColor(this.isDarkMode ? $r('app.color.silvery'):this.themeColor)
          .borderRadius(8)
          .fontSize(14)
          .fontColor(Color.White)
          .enabled(this.totalSelectedCount > 0)
          .opacity(this.totalSelectedCount > 0 ? 1 : 0.5)
          .onClick(() => {
            this.handleConfirm()
          })
      }
      .width('100%')
      .justifyContent(FlexAlign.SpaceBetween)
      .margin({ top: 10, bottom: 10 })
    }
    .width('100%')
    .constraintSize({ maxWidth: 400 })
    .backgroundColor(this.isDarkMode ? '#2C2C2E' : $r('app.color.dialog_background'))
    .borderRadius(12)
    .padding({ left: 20, right: 20 })
  }

  /**
   * 处理确认操作
   */
  private handleConfirm() {
    const folderSongs = this.getSongsFromFolders(Array.from(this.selectedFolders))
    const submitSongs = this.mergeSongs(
      this.selectedSongs.filter((item: VideoItem) => item.type !== CommonConstants.TYPE_IS_DIR),
      folderSongs
    )
    LogUtil.info('heanup AddSongsToPlaylistDialog', `handleConfirm selectedFolders=${Array.from(this.selectedFolders).join(',')}, folderSongs=${folderSongs.length}, directSongs=${this.selectedSongs.length}, submit=${submitSongs.length}`)
    if (submitSongs.length === 0) {
      ToastUtil.showToast(' 请选择至少一首歌曲')
      return
    }

    this.onConfirm?.(submitSongs)
    DialogHelper.closeDialog('addSongsToPlaylistDialog')
  }

  @Builder
  getListView() {
    Scroll() {
      Column({ space: 0 }) {
        List({ scroller: this.listScroller }) {
          LazyForEach(this.dataSource, (song: VideoItem, index: number) => {
            ListItem() {
              Row({ space: 12 }) {

                Image(StrUtil.isEmpty(song.pixelMapPath) ? $r('app.media.music_red') : song.pixelMapPath)
                  .fillColor(StrUtil.isEmpty(song.pixelMapPath) ? (this.isDarkMode ? Color.White : this.themeColor) : undefined)
                  .height(40)
                  .width(40)
                  .alt($r('app.media.music_red'))
                  .borderRadius('100%')
                  .clip(true)
                  .draggable(false)
                  .interpolation(ImageInterpolation.High)// 用于重采样后的抗锯齿
                  .autoResize(true) // 重采样，可减少内存占用
                  .opacity(this.opacityItem) //  绑定透明度
                // 歌曲信息
                Column({ space: 4 }) {
                  Text(song.name || '未知歌曲')
                    .fontSize(14)
                    .fontColor(this.isDarkMode ? '#FFFFFF' : $r('app.color.text_color'))
                    .maxLines(1)
                    .textOverflow({ overflow: TextOverflow.Ellipsis })
                    .width('100%')

                  Row() {
                    if (song.artist) {
                      Text(song.artist+'  '+song.duration)
                        .fontSize(12)
                        .fontColor(this.isDarkMode ? '#8E8E93' : '#999999')
                        .maxLines(1)
                        .textOverflow({ overflow: TextOverflow.Ellipsis })
                        .layoutWeight(1)
                    }

                  }
                  .width('100%')
                }
                .alignItems(HorizontalAlign.Start)
                .layoutWeight(1)

                // 选择框
                Checkbox({ name: 'song_' + song.id })
                  .select(this.selectedSongIds.has(song.id))
                  .selectedColor($r('app.color.theme_color'))
                  .shape(CheckBoxShape.ROUNDED_SQUARE)
                  .onChange(() => {
                    this.toggleSongSelection(song)
                  })
              }
              .width('100%')
              .padding(12)
              .borderRadius(10)
              .onClick(() => {
                this.toggleSongSelection(song)
              })
            }
            .transition(TransitionEffect.asymmetric(TransitionEffect.scale({ x: 1.2, y: 1.2 })
              .animation({ duration: 500 }),
              TransitionEffect.scale({ x: 0, y: 0 })))
            .clickEffect({ level: ClickEffectLevel.LIGHT })

          }, (song: VideoItem) => song.id)

          // 添加 footer 来显示加载状态
          ListItem() {
            this.footer()
          }
          .visibility(this.hasMoreData ? Visibility.Visible : Visibility.None)
        }
        .cachedCount(6)
        .height('100%')
        .scrollBar(BarState.Off)
        .edgeEffect(EdgeEffect.Spring, { alwaysEnabled: true })
        .onReachEnd(() => {
          // 滚动到底部时加载更多数据
          console.info('List  onReachEnd triggered')
          this.loadMoreData()
        })
      }

    }
    .scrollBar(BarState.Auto)
    .scrollable(ScrollDirection.Vertical)
    .height(300)
  }

  @Builder
  getFolderView() {
    Column({ space: 12 }) {
      Row({ space: 8 }) {
        Text('目录视图')
          .fontSize(16)
          .fontColor(this.isDarkMode ? '#FFFFFF' : $r('app.color.text_color'))
        Blank()
        Button('上一级')
          .fontSize(12)
          .fontColor(this.isDarkMode ? '#FFFFFF' : $r('app.color.text_color'))
          .height(28)
          .padding({ left: 10, right: 10 })
          .backgroundColor(Color.Transparent)
          .border({ width: 1, color: this.isDarkMode ? '#444444' : '#dddddd' })
          .borderRadius(14)
          .enabled(this.canNavigateUp())
          .opacity(this.canNavigateUp() ? 1 : 0.4)
          .onClick(() => {
            this.navigateToParent()
          })
        Button('刷新')
          .fontSize(12)
          .fontColor(this.isDarkMode ? '#FFFFFF' : $r('app.color.text_color'))
          .height(28)
          .padding({ left: 10, right: 10 })
          .backgroundColor(Color.Transparent)
          .border({ width: 1, color: this.isDarkMode ? '#444444' : '#dddddd' })
          .borderRadius(14)
          .onClick(() => {
            this.loadFile(this.currentPath)
          })
      }
      .width('100%')

      Text(this.normalizeLocalPath(this.currentPath) || '未选择路径')
        .fontSize(12)
        .fontColor(this.isDarkMode ? '#8E8E93' : '#666666')
        .maxLines(1)
        .textOverflow({ overflow: TextOverflow.Ellipsis })
        .padding({ left: 4, right: 4 })

      if (this.isFolderLoading) {
        Row() {
          LoadingProgress()
            .width(20)
            .height(20)
          Text('正在加载目录...')
            .fontSize(12)
            .fontColor(this.isDarkMode ? '#8E8E93' : '#666666')
            .margin({ left: 8 })
        }
        .width('100%')
        .height(80)
        .justifyContent(FlexAlign.Center)
      } else {
        Scroll() {
          Column() {
            ForEach(this.folderItems, (item: VideoItem, index: number) => {
              Row() {
                Text(item.type === CommonConstants.TYPE_IS_DIR ? '📁' : '🎵')
                  .fontSize(20)
                  .margin({ right: 6 })

                Column({ space: 2 }) {
                  Text(item.name || '未知歌曲')
                    .fontSize(14)
                    .fontColor(this.isDarkMode ? '#FFFFFF' : $r('app.color.text_color'))
                    .maxLines(1)
                    .textOverflow({ overflow: TextOverflow.Ellipsis })

                  if (item.artist && item.type !== CommonConstants.TYPE_IS_DIR) {
                    Text(item.artist + '  ' + (item.duration || ''))
                      .fontSize(12)
                      .fontColor(this.isDarkMode ? '#8E8E93' : '#999999')
                      .maxLines(1)
                      .textOverflow({ overflow: TextOverflow.Ellipsis })
                  } else if (item.type === CommonConstants.TYPE_IS_DIR) {
                    Text('包含子目录内的所有音乐将一起添加')
                      .fontSize(12)
                      .fontColor(this.isDarkMode ? '#8E8E93' : '#999999')
                      .maxLines(1)
                  }
                }
                .layoutWeight(1)
                .margin({ left: 8 })

                if (item.type === CommonConstants.TYPE_IS_DIR) {
                  Button() {
                    Text('进入')
                      .fontSize(12)
                      .fontColor(this.isDarkMode ? '#FFFFFF' : this.themeColor)
                  }
                    .height(30)
                    .padding({ left: 10, right: 10 })
                    .backgroundColor(this.isDarkMode ? '#3a3a3c' : '#f1f1f1')
                    .borderRadius(8)
                    .margin({ right: 8 })
                    .onClick(() => {
                      this.enterFolder(item.filePath)
                    })
                }

                Checkbox({ name: 'folder_item_' + item.id })
                  .select((item.type === CommonConstants.TYPE_IS_DIR)
                    ? this.selectedFolders.has(this.normalizeLocalPath(item.filePath))
                    : this.selectedSongIds.has(item.id))
                  .selectedColor($r('app.color.theme_color'))
                  .onChange(() => {
                    if (item.type === CommonConstants.TYPE_IS_DIR) {
                      this.toggleFolderSelection(item.filePath)
                    } else {
                      this.toggleSongSelection(item)
                    }
                  })
              }
              .width('100%')
              .padding(12)
              .backgroundColor(this.isDarkMode ? '#2C2C2E' : '#F8F8F8')
              .borderRadius(8)
              .margin({ bottom: 4 })
              .onClick(() => {
                if (item.type === CommonConstants.TYPE_IS_DIR) {
                  this.toggleFolderSelection(item.filePath)
                } else {
                  this.toggleSongSelection(item)
                }
              })
            }, (item: VideoItem) => item.id)
          }
        }
        .height(300)
      }
    }
    .width('100%')
  }

  // 改进的 footer Builder
  @Builder
  footer() {
    Column() {
      if (this.isLoading) {
        Row() {
          LoadingProgress()
            .height(20)
            .width(20)
          Text('加载中...')
            .fontSize(12)
            .fontColor(this.isDarkMode ? '#8E8E93' : '#999999')
            .margin({ left: 8 })
        }
        .width('100%')
        .height(40)
        .justifyContent(FlexAlign.Center)
      } else if (this.hasMoreData) {
        Row() {
          Text('上拉加载更多')
            .fontSize(12)
            .fontColor(this.isDarkMode ? '#8E8E93' : '#999999')
        }
        .width('100%')
        .height(40)
        .justifyContent(FlexAlign.Center)
      }
    }
    .width('100%')
  }
}

/**
 * 添加歌曲到歌单对话框管理器
 */
@Component
export struct AddSongsToPlaylistDialogManager {
  /**
   * 添加歌曲到歌单对话框构建器
   */
  @Builder
  buildAddSongsToPlaylistDialog(
    playlist: Playlist,
    onConfirm: (songs: VideoItem[]) => void,
    onCancel?: () => void,
  ) {
    AddSongsToPlaylistDialogContent({
      playlist: playlist,
      onConfirm: onConfirm,
      onCancel: onCancel
    })
  }

  /**
   * 显示添加歌曲到歌单对话框
   */
  showAddSongsToPlaylistDialog(
    playlist: Playlist,
    onConfirm: (songs: VideoItem[]) => void,
    onCancel?: () => void,
  ) {
    DialogHelper.showCustomContentDialog({
      dialogId: 'addSongsToPlaylistDialog',
      title: '添加歌曲到歌单',
      autoCancel: true,
      contentBuilder: () => {
        this.buildAddSongsToPlaylistDialog(playlist, onConfirm,onCancel)
      },
      buttons: []
    })
  }

  build() {
  }
}

// 创建全局实例
const dialogManager = new AddSongsToPlaylistDialogManager()

/**
 * 显示添加歌曲到歌单对话框
 */
export function showAddSongsToPlaylistDialog(
  playlist: Playlist,
  onConfirm: (songs: VideoItem[]) => void,
  onCancel?: () => void,
) {
  dialogManager.showAddSongsToPlaylistDialog(playlist, onConfirm, onCancel)
}