feat(album): add cover picture functionality to albums and enhance album management API

Services/Media/AlbumService.cs

@@ -3,60 +3,66 @@ using Foxel.Models;
 using Foxel.Models.DataBase;
 using Foxel.Models.Response.Album;
 using Microsoft.EntityFrameworkCore;
+using Foxel.Services.Mapping; // 添加 using
 
 namespace Foxel.Services.Media;
 
 public class AlbumService(
     IDbContextFactory<MyDbContext> contextFactory,
-    IHttpContextAccessor httpContextAccessor)
+    IHttpContextAccessor httpContextAccessor,
+    IMappingService mappingService) // 注入新的映射服务
     : IAlbumService
 {
     public async Task<PaginatedResult<AlbumResponse>> GetAlbumsAsync(int page = 1, int pageSize = 10, int? userId = null)
     {
         if (page < 1) page = 1;
         if (pageSize < 1) pageSize = 10;
-        
+
         await using var dbContext = await contextFactory.CreateDbContextAsync();
-        
+
         // 构建查询
         IQueryable<Album> query = dbContext.Albums
             .Include(a => a.User)
+            .Include(a => a.CoverPicture) // 确保包含封面图片
+            .Include(a => a.Pictures) // 确保包含图片集合以计算 PictureCount
             .OrderByDescending(a => a.CreatedAt);
-        
+
         // 如果指定了用户ID，则只获取该用户的相册
         if (userId.HasValue)
         {
             query = query.Where(a => a.UserId == userId.Value);
         }
-        
+
         // 获取总数和分页数据
         var totalCount = await query.CountAsync();
         var albums = await query
+            // .Include(a => a.CoverPicture) // 已在上面包含
             .Skip((page - 1) * pageSize)
             .Take(pageSize)
             .ToListAsync();
-        
-        // 获取每个相册中的图片数量
-        var albumIds = albums.Select(a => a.Id).ToList();
-        var albumPictureCounts = await dbContext.Pictures
-            .Where(p => p.AlbumId != null && albumIds.Contains(p.AlbumId.Value))
-            .GroupBy(p => p.AlbumId)
-            .Select(g => new { AlbumId = g.Key, Count = g.Count() })
-            .ToDictionaryAsync(x => x.AlbumId!.Value, x => x.Count);
-        
+
+        // 获取每个相册中的图片数量 - 不再需要，MapAlbumToResponse 会处理
+        // var albumIds = albums.Select(a => a.Id).ToList();
+        // var albumPictureCounts = await dbContext.Pictures
+        //     .Where(p => p.AlbumId != null && albumIds.Contains(p.AlbumId.Value))
+        //     .GroupBy(p => p.AlbumId)
+        //     .Select(g => new { AlbumId = g.Key, Count = g.Count() })
+        //     .ToDictionaryAsync(x => x.AlbumId!.Value, x => x.Count);
+
         // 转换为响应模型
-        var albumResponses = albums.Select(a => new AlbumResponse
-        {
-            Id = a.Id,
-            Name = a.Name,
-            Description = a.Description,
-            PictureCount = albumPictureCounts.GetValueOrDefault(a.Id, 0),
-            UserId = a.UserId,
-            Username = a.User.UserName,
-            CreatedAt = a.CreatedAt,
-            UpdatedAt = a.UpdatedAt
-        }).ToList();
-        
+        var albumResponses = albums.Select(mappingService.MapAlbumToResponse).ToList();
+        // var albumResponses = albums.Select(a => new AlbumResponse
+        // {
+        //     Id = a.Id,
+        //     Name = a.Name,
+        //     Description = a.Description,
+        //     PictureCount = albumPictureCounts.GetValueOrDefault(a.Id, 0), // 使用 MapAlbumToResponse 后不再需要
+        //     UserId = a.UserId,
+        //     Username = a.User.UserName,
+        //     CreatedAt = a.CreatedAt,
+        //     UpdatedAt = a.UpdatedAt
+        // }).ToList();
+
         return new PaginatedResult<AlbumResponse>
         {
             Data = albumResponses,
@@ -65,206 +71,222 @@ public class AlbumService(
             TotalCount = totalCount
         };
     }
-    
+
     public async Task<AlbumResponse> GetAlbumByIdAsync(int id)
     {
         await using var dbContext = await contextFactory.CreateDbContextAsync();
-        
+
         var album = await dbContext.Albums
             .Include(a => a.User)
+            .Include(a => a.CoverPicture) // 确保包含封面图片
+            .Include(a => a.Pictures) // 确保包含图片集合以计算 PictureCount
             .FirstOrDefaultAsync(a => a.Id == id);
-        
+
         if (album == null)
             throw new KeyNotFoundException($"找不到ID为{id}的相册");
-        
-        // 获取相册中图片的数量
-        var pictureCount = await dbContext.Pictures
-            .Where(p => p.AlbumId == id)
-            .CountAsync();
-            
+
+        // 获取相册中图片的数量 - 不再需要
+        // var pictureCount = await dbContext.Pictures
+        //     .Where(p => p.AlbumId == id)
+        //     .CountAsync();
+
         // 转换为响应模型
-        var response = new AlbumResponse
-        {
-            Id = album.Id,
-            Name = album.Name,
-            Description = album.Description,
-            PictureCount = pictureCount,
-            UserId = album.UserId,
-            Username = album.User.UserName,
-            CreatedAt = album.CreatedAt,
-            UpdatedAt = album.UpdatedAt
-        };
-        
-        return response;
+        return mappingService.MapAlbumToResponse(album);
+        // var response = new AlbumResponse
+        // {
+        //     Id = album.Id,
+        //     Name = album.Name,
+        //     Description = album.Description,
+        //     PictureCount = pictureCount, // 使用 MapAlbumToResponse 后不再需要
+        //     UserId = album.UserId,
+        //     Username = album.User.UserName,
+        //     CreatedAt = album.CreatedAt,
+        //     UpdatedAt = album.UpdatedAt
+        // };
+        //
+        // return response;
     }
-    
-    public async Task<AlbumResponse> CreateAlbumAsync(string name, string? description, int userId)
+
+    public async Task<AlbumResponse> CreateAlbumAsync(string name, string? description, int userId, int? coverPictureId)
     {
         if (string.IsNullOrWhiteSpace(name))
             throw new ArgumentException("相册名称不能为空", nameof(name));
-            
+
         await using var dbContext = await contextFactory.CreateDbContextAsync();
-        
+
         // 检查用户是否存在
         var user = await dbContext.Users.FindAsync(userId);
         if (user == null)
             throw new KeyNotFoundException($"找不到ID为{userId}的用户");
-            
+
         // 创建新相册
         var album = new Album
         {
             Name = name.Trim(),
             Description = description?.Trim() ?? string.Empty,
             UserId = userId,
-            User = user,
+            // User = user, // EF Core 会自动关联
             CreatedAt = DateTime.UtcNow,
-            UpdatedAt = DateTime.UtcNow
+            UpdatedAt = DateTime.UtcNow,
+            CoverPictureId = coverPictureId
         };
-        
+
         dbContext.Albums.Add(album);
         await dbContext.SaveChangesAsync();
-        
+
+        // 重新加载创建的相册以包含导航属性，用于 MapAlbumToResponse
+        var createdAlbum = await dbContext.Albums
+            .Include(a => a.User)
+            .Include(a => a.CoverPicture)
+            .Include(a => a.Pictures)
+            .FirstAsync(a => a.Id == album.Id);
+
         // 转换为响应模型
-        return new AlbumResponse
-        {
-            Id = album.Id,
-            Name = album.Name,
-            Description = album.Description,
-            PictureCount = 0,
-            UserId = album.UserId,
-            Username = user.UserName,
-            CreatedAt = album.CreatedAt,
-            UpdatedAt = album.UpdatedAt
-        };
+        return mappingService.MapAlbumToResponse(createdAlbum);
+        // return new AlbumResponse
+        // {
+        //     Id = album.Id,
+        //     Name = album.Name,
+        //     Description = album.Description,
+        //     PictureCount = 0, // MapAlbumToResponse 会处理
+        //     UserId = album.UserId,
+        //     Username = user.UserName, // MapAlbumToResponse 会处理
+        //     CreatedAt = album.CreatedAt,
+        //     UpdatedAt = album.UpdatedAt
+        // };
     }
-    
-    public async Task<AlbumResponse> UpdateAlbumAsync(int id, string name, string? description, int? userId = null)
+
+    public async Task<AlbumResponse> UpdateAlbumAsync(int id, string name, string? description, int? userId = null, int? coverPictureId = null)
     {
         if (string.IsNullOrWhiteSpace(name))
             throw new ArgumentException("相册名称不能为空", nameof(name));
-            
+
         await using var dbContext = await contextFactory.CreateDbContextAsync();
-        
+
         // 获取相册
         var album = await dbContext.Albums
-            .Include(a => a.User)
-            .Include(a => a.Pictures)
+            // .Include(a => a.User) // 将在更新后重新加载
+            // .Include(a => a.Pictures) // 将在更新后重新加载
             .FirstOrDefaultAsync(a => a.Id == id);
-            
+
         if (album == null)
             throw new KeyNotFoundException($"找不到ID为{id}的相册");
-            
-        // 权限检查 - 只有相册的创建者或系统管理员可以更新
-        if (userId.HasValue && album.UserId != userId.Value)
+        if (!userId.HasValue) // userId 仍然需要用于权限检查
+            throw new ArgumentException("无效的用户ID", nameof(userId));
+        if (album.UserId != userId.Value)
         {
-            // 检查用户是否是管理员
-            var user = await dbContext.Users.FindAsync(userId.Value);
-            if (user == null)
-            {
-                throw new UnauthorizedAccessException("您没有权限更新此相册");
-            }
+            throw new UnauthorizedAccessException("您没有权限更新此相册");
         }
-        
+
         // 更新相册信息
         album.Name = name.Trim();
         album.Description = description?.Trim() ?? album.Description;
         album.UpdatedAt = DateTime.UtcNow;
-        
+        album.CoverPictureId = coverPictureId;
+
         await dbContext.SaveChangesAsync();
-        
+
+        // 重新加载更新后的相册以包含导航属性
+        var updatedAlbum = await dbContext.Albums
+            .Include(a => a.User)
+            .Include(a => a.CoverPicture)
+            .Include(a => a.Pictures)
+            .FirstAsync(a => a.Id == album.Id);
+            
         // 转换为响应模型
-        return new AlbumResponse
-        {
-            Id = album.Id,
-            Name = album.Name,
-            Description = album.Description,
-            PictureCount = album.Pictures?.Count ?? 0,
-            UserId = album.UserId,
-            Username = album.User.UserName,
-            CreatedAt = album.CreatedAt,
-            UpdatedAt = album.UpdatedAt
-        };
+        return mappingService.MapAlbumToResponse(updatedAlbum);
+        // return new AlbumResponse
+        // {
+        //     Id = album.Id,
+        //     Name = album.Name,
+        //     Description = album.Description,
+        //     PictureCount = album.Pictures?.Count ?? 0, // MapAlbumToResponse 会处理
+        //     UserId = album.UserId,
+        //     Username = album.User.UserName, // MapAlbumToResponse 会处理
+        //     CreatedAt = album.CreatedAt,
+        //     UpdatedAt = album.UpdatedAt
+        // };
     }
-    
+
     public async Task<bool> DeleteAlbumAsync(int id)
     {
         await using var dbContext = await contextFactory.CreateDbContextAsync();
-        
+
         var album = await dbContext.Albums.FindAsync(id);
         if (album == null)
             return false;
-            
+
         // 先找出所有属于这个相册的图片
         var pictures = await dbContext.Pictures
             .Where(p => p.AlbumId == id)
             .ToListAsync();
-            
+
         // 将这些图片的AlbumId设置为null
         foreach (var picture in pictures)
         {
             picture.AlbumId = null;
             picture.Album = null;
         }
-        
+
         // 保存图片更改
         await dbContext.SaveChangesAsync();
-        
+
         // 然后删除相册
         dbContext.Albums.Remove(album);
         await dbContext.SaveChangesAsync();
-        
+
         return true;
     }
-    
+
     public async Task<bool> AddPictureToAlbumAsync(int albumId, int pictureId)
     {
         await using var dbContext = await contextFactory.CreateDbContextAsync();
-        
+
         // 获取相册和图片
         var album = await dbContext.Albums.FindAsync(albumId);
         if (album == null)
             throw new KeyNotFoundException($"找不到ID为{albumId}的相册");
-            
+
         var picture = await dbContext.Pictures.FindAsync(pictureId);
         if (picture == null)
             throw new KeyNotFoundException($"找不到ID为{pictureId}的图片");
-            
+
         // 将图片添加到相册
         picture.AlbumId = albumId;
         picture.Album = album;
-        
+
         await dbContext.SaveChangesAsync();
-        
+
         return true;
     }
-    
+
     public async Task<bool> RemovePictureFromAlbumAsync(int albumId, int pictureId)
     {
         await using var dbContext = await contextFactory.CreateDbContextAsync();
-        
+
         // 获取图片
         var picture = await dbContext.Pictures
             .FirstOrDefaultAsync(p => p.Id == pictureId && p.AlbumId == albumId);
-            
+
         if (picture == null)
             throw new KeyNotFoundException($"在相册中找不到ID为{pictureId}的图片");
-            
+
         // 从相册中移除图片
         picture.AlbumId = null;
         picture.Album = null;
-        
+
         await dbContext.SaveChangesAsync();
-        
+
         return true;
     }
 
     public async Task<bool> AddPicturesToAlbumAsync(int albumId, List<int> pictureIds)
     {
         await using var dbContext = await contextFactory.CreateDbContextAsync();
-        
-        var album = await dbContext.Albums.FindAsync(albumId) 
+
+        var album = await dbContext.Albums.FindAsync(albumId)
             ?? throw new KeyNotFoundException("相册不存在");
-        
+
         // 检查是否有权限修改此相册
         var currentUser = httpContextAccessor.HttpContext?.User;
         if (currentUser != null)
@@ -275,14 +297,14 @@ public class AlbumService(
                 throw new UnauthorizedAccessException("您没有权限修改此相册");
             }
         }
-        
+
         var successCount = 0;
-        
+
         foreach (var pictureId in pictureIds)
         {
             var picture = await dbContext.Pictures.FindAsync(pictureId);
             if (picture == null) continue; // 跳过不存在的图片
-            
+
             // 直接更新 Picture 的 AlbumId
             if (picture.AlbumId != albumId)
             {
@@ -290,13 +312,40 @@ public class AlbumService(
                 successCount++;
             }
         }
-        
+
         if (successCount > 0)
         {
             await dbContext.SaveChangesAsync();
             return true;
         }
-        
+
         return false;
     }
+
+    public async Task<bool> SetAlbumCoverAsync(int albumId, int pictureId, int userId)
+    {
+        await using var dbContext = await contextFactory.CreateDbContextAsync();
+
+        var album = await dbContext.Albums.FirstOrDefaultAsync(a => a.Id == albumId);
+        if (album == null)
+            throw new KeyNotFoundException($"找不到ID为 {albumId} 的相册");
+
+        // 权限检查：只有相册所有者可以设置封面
+        if (album.UserId != userId)
+            throw new UnauthorizedAccessException("您没有权限修改此相册的封面");
+
+        var picture = await dbContext.Pictures.FirstOrDefaultAsync(p => p.Id == pictureId);
+        if (picture == null)
+            throw new KeyNotFoundException($"找不到ID为 {pictureId} 的图片");
+
+        // 确保图片属于该相册
+        if (picture.AlbumId != albumId)
+            throw new InvalidOperationException($"图片 {pictureId} 不属于相册 {albumId}");
+
+        album.CoverPictureId = pictureId;
+        album.UpdatedAt = DateTime.UtcNow;
+
+        await dbContext.SaveChangesAsync();
+        return true;
+    }
 }