import { useState, useCallback, useMemo } from 'react';
import { VideoSegmentEntity } from '../domain/Entities';
import { RoleEditUseCase } from '../usecase/RoleEditUseCase';
import { getRoleShots, applyRoleToShots } from '@/api/video_flow';

/**
 * 扩展的视频片段实体，包含选择状态
 */
interface ExtendedVideoSegmentEntity extends VideoSegmentEntity {
  /** 是否已选中 */
  selected?: boolean;
  /** 是否已应用角色 */
  applied?: boolean;
}

/**
 * 角色视频片段服务Hook返回值接口
 */
interface UseRoleShotService {
  // 响应式数据
  /** 分镜选择列表 */
  shotSelectionList: ExtendedVideoSegmentEntity[];
  /** 是否全选分镜 */
  isAllVideoSegmentSelected: boolean;
  /** 已选中的分镜数量 */
  selectedVideoSegmentCount: number;
  /** 当前选中的角色ID */
  selectedRoleId: string | null;
  // 操作方法
  /** 获取角色出现的分镜列表 */
  fetchRoleShots: (roleId: string) => Promise<void>;
  /** 切换全选与全不选 */
  toggleSelectAllShots: () => void;
  /** 选择/取消选择单个分镜 */
  toggleShotSelection: (shotId: string) => void;
  /** 应用角色到选中的分镜 */
  applyRoleToSelectedShots: (roleId: string) => Promise<void>;
  /** 清空选择列表 */
  clearShotSelection: () => void;
}

/**
 * 角色视频片段服务Hook
 * 提供角色与视频片段交互的所有响应式功能和业务逻辑
 */
export const useRoleShotServiceHook = (): UseRoleShotService => {
  // 响应式状态
  const [shotSelectionList, setShotSelectionList] = useState<ExtendedVideoSegmentEntity[]>([]);
  const [selectedRoleId, setSelectedRoleId] = useState<string | null>(null);

  // UseCase实例
  const [roleEditUseCase, setRoleEditUseCase] = useState<RoleEditUseCase | null>(null);

  // 计算属性
  /**
   * 是否全选分镜
   * @description 判断是否所有分镜都被选中
   */
  const isAllVideoSegmentSelected = useMemo(() => {
    return shotSelectionList.length > 0 && shotSelectionList.every(shot => shot.selected);
  }, [shotSelectionList]);

  /**
   * 已选中的分镜数量
   * @description 获取当前选中的分镜数量
   */
  const selectedVideoSegmentCount = useMemo(() => {
    return shotSelectionList.filter(shot => shot.selected).length;
  }, [shotSelectionList]);

  /**
   * 获取角色出现的分镜列表
   * @description 获取当前角色应用到的分镜列表，包括已应用状态
   * @param roleId 角色ID
   * @throws {Error} 当API调用失败时抛出错误
   * @returns {Promise<void>} 获取完成后的Promise
   */
  const fetchRoleShots = useCallback(async (roleId: string) => {
    try {
      const response = await getRoleShots({ roleId });
      if (response.successful) {
        const { shots, appliedShotIds } = response.data;

        const extendedShots: ExtendedVideoSegmentEntity[] = shots.map(shot => ({
          ...shot,
          selected: false,
          applied: appliedShotIds.includes(shot.id)
        }));

        setShotSelectionList(extendedShots);
        setSelectedRoleId(roleId);

        // 初始化角色编辑UseCase实例
        const newRoleEditUseCase = new RoleEditUseCase();
        setRoleEditUseCase(newRoleEditUseCase);
      } else {
        throw new Error(`获取角色分镜列表失败: ${response.message}`);
      }
    } catch (error) {
      console.error('获取角色分镜列表失败:', error);
      throw error;
    }
  }, []);

  /**
   * 切换全选与全不选
   * @description 如果当前是全选状态则全不选，否则全选
   */
  const toggleSelectAllShots = useCallback(() => {
    setShotSelectionList(prev => {
      const isAllSelected = prev.length > 0 && prev.every(shot => shot.selected);
      return prev.map(shot => ({ ...shot, selected: !isAllSelected }));
    });
  }, []);

  /**
   * 选择/取消选择单个分镜
   * @description 切换指定分镜的选择状态
   * @param shotId 分镜ID
   */
  const toggleShotSelection = useCallback((shotId: string) => {
    setShotSelectionList(prev =>
      prev.map(shot =>
        shot.id === shotId
          ? { ...shot, selected: !shot.selected }
          : shot
      )
    );
  }, []);

  /**
   * 应用角色到选中的分镜
   * @description 将当前角色应用到选中的分镜，并更新应用状态
   * @param roleId 角色ID
   * @throws {Error} 当未选择分镜或UseCase未初始化时抛出错误
   * @returns {Promise<void>} 应用完成后的Promise
   */
  const applyRoleToSelectedShots = useCallback(async (roleId: string) => {
    if (!roleEditUseCase) {
      throw new Error('角色编辑UseCase未初始化');
    }

    const selectedShotIds = shotSelectionList
      .filter(shot => shot.selected)
      .map(shot => shot.id);

    if (selectedShotIds.length === 0) {
      throw new Error('请先选择要应用的分镜');
    }

    try {
      await roleEditUseCase.applyRole(selectedShotIds, roleId);

      // 更新应用状态
      setShotSelectionList(prev =>
        prev.map(shot =>
          selectedShotIds.includes(shot.id)
            ? { ...shot, applied: true, selected: false }
            : shot
        )
      );
    } catch (error) {
      console.error('应用角色到分镜失败:', error);
      throw error;
    }
  }, [roleEditUseCase, shotSelectionList]);

  /**
   * 清空选择列表
   * @description 清空所有分镜的选择状态
   */
  const clearShotSelection = useCallback(() => {
    setShotSelectionList(prev =>
      prev.map(shot => ({ ...shot, selected: false }))
    );
  }, []);

  return {
    // 响应式数据
    shotSelectionList,
    isAllVideoSegmentSelected,
    selectedVideoSegmentCount,
    selectedRoleId,

    // 操作方法
    fetchRoleShots,
    toggleSelectAllShots,
    toggleShotSelection,
    applyRoleToSelectedShots,
    clearShotSelection,
  };
};