frontend/src/services/mappers/PostMapper.ts

/**
 * 帖子数据映射器
 * 负责 Post 模型与 API 响应之间的转换
 */

import { PostModel, UserModel } from '../models';
import type { PostDTO } from '../../types/dto';

export class PostMapper {
  static fromApiResponse(response: PostDTO): PostModel {
    return {
      id: String(response.id || ''),
      authorId: String(response.user_id || ''),
      author: response.author ? this.mapAuthorFromApi(response.author) : undefined,
      title: response.title || '',
      content: response.content || '',
      images: response.images?.map(img => img.url) || [],
      likeCount: response.likes_count || 0,
      commentCount: response.comments_count || 0,
      shareCount: response.shares_count || 0,
      viewCount: response.views_count || 0,
      favoriteCount: response.favorites_count || 0,
      isLiked: response.is_liked || false,
      isFavorited: response.is_favorited || false,
      isTop: response.is_pinned || false,
      status: (response.status || 'published') as 'published' | 'draft' | 'deleted',
      channelId: response.channel_id,
      channel:
        response.channel && response.channel.id
          ? { id: String(response.channel.id), name: String(response.channel.name || '') }
          : undefined,
      tags: [],
      createdAt: new Date(response.created_at || Date.now()),
      // 空字符串/缺省时用 created_at，避免误用 Date.now() 导致全部显示「刚修改」
      updatedAt: new Date(
        response.updated_at ||
          response.created_at ||
          Date.now()
      ),
    };
  }

  /**
   * 将 API 响应数组转换为应用模型数组
   */
  static fromApiResponseList(responses: PostDTO[]): PostModel[] {
    return responses.map(r => this.fromApiResponse(r));
  }

  /**
   * 将应用模型转换为 API 请求数据
   */
  static toApiRequest(model: Partial<PostModel>): Record<string, any> {
    const request: Record<string, any> = {};

    if (model.title !== undefined) {
      request.title = model.title;
    }
    if (model.content !== undefined) {
      request.content = model.content;
    }
    if (model.images !== undefined) {
      request.images = model.images;
    }
    if (model.channelId !== undefined) {
      request.channel_id = model.channelId;
    }
    if (model.tags !== undefined) {
      request.tags = model.tags;
    }

    return request;
  }

  /**
   * 创建帖子请求
   */
  static createPostRequest(
    title: string,
    content: string,
    images?: string[],
    channelId?: string
  ): Record<string, any> {
    const request: Record<string, any> = {
      title,
      content,
    };
    if (images && images.length > 0) {
      request.images = images;
    }
    if (channelId) {
      request.channel_id = channelId;
    }
    return request;
  }

  /**
   * 更新帖子请求
   */
  static updatePostRequest(
    title?: string,
    content?: string,
    images?: string[]
  ): Record<string, any> {
    const request: Record<string, any> = {};
    if (title !== undefined) {
      request.title = title;
    }
    if (content !== undefined) {
      request.content = content;
    }
    if (images !== undefined) {
      request.images = images;
    }
    return request;
  }

  /**
   * 映射作者信息
   */
  private static mapAuthorFromApi(author: any): UserModel {
    return {
      id: String(author.id || ''),
      username: author.username || '',
      nickname: author.nickname,
      avatar: author.avatar,
    };
  }
}