Refactor blog post logic to standardize field names and improve error handling; implement pagination for post listing and add tag retrieval functionality.

app/internal/logic/listpostslogic.go

@@ -2,10 +2,13 @@ package logic
 
 import (
 	"context"
+	"database/sql"
+	"time"
 
 	"git.cialloo.com/CiallooWeb/Blog/app/internal/svc"
 	"git.cialloo.com/CiallooWeb/Blog/app/internal/types"
 
+	"github.com/aws/aws-sdk-go-v2/service/s3"
 	"github.com/zeromicro/go-zero/core/logx"
 )
 
@@ -25,7 +28,82 @@ func NewListPostsLogic(ctx context.Context, svcCtx *svc.ServiceContext) *ListPos
 }
 
 func (l *ListPostsLogic) ListPosts(req *types.ListPostsReq) (resp *types.ListPostsResp, err error) {
-	// todo: add your logic here and delete this line
+	// Set default values
+	page := req.Page
+	if page < 1 {
+		page = 1
+	}
+	pageSize := req.PageSize
+	if pageSize < 1 || pageSize > 100 {
+		pageSize = 10 // Default page size
+	}
+	offset := (page - 1) * pageSize
 
-	return
+	// Get total count
+	var totalCount int
+	countQuery := `SELECT COUNT(*) FROM posts`
+	err = l.svcCtx.DB.QueryRowContext(l.ctx, countQuery).Scan(&totalCount)
+	if err != nil {
+		l.Errorf("Failed to get total count: %v", err)
+		return nil, err
+	}
+
+	// Get posts with pagination
+	postsQuery := `
+		SELECT p.id, p.title, p.created_at, p.updated_at, p.cover_id
+		FROM posts p
+		ORDER BY p.created_at DESC
+		LIMIT $1 OFFSET $2
+	`
+	rows, err := l.svcCtx.DB.QueryContext(l.ctx, postsQuery, pageSize, offset)
+	if err != nil {
+		l.Errorf("Failed to get posts: %v", err)
+		return nil, err
+	}
+	defer rows.Close()
+
+	var posts []types.ListPostsRespPosts
+	for rows.Next() {
+		var post types.ListPostsRespPosts
+		var coverID sql.NullInt64
+
+		err := rows.Scan(&post.PostId, &post.Title, &post.CreatedAt, &post.UpdatedAt, &coverID)
+		if err != nil {
+			l.Errorf("Failed to scan post: %v", err)
+			continue
+		}
+
+		// If cover image exists, get its URL
+		if coverID.Valid {
+			coverQuery := `SELECT file_key FROM files WHERE id = $1`
+			var fileKey string
+			err = l.svcCtx.DB.QueryRowContext(l.ctx, coverQuery, coverID.Int64).Scan(&fileKey)
+			if err == nil {
+				// Generate presigned URL for cover image
+				expiration := time.Duration(l.svcCtx.Config.S3.PresignedURLExpiration) * time.Second
+				presignClient := s3.NewPresignClient(l.svcCtx.S3Client)
+				getObjectInput := &s3.GetObjectInput{
+					Bucket: &l.svcCtx.Config.S3.Bucket,
+					Key:    &fileKey,
+				}
+				presignedReq, err := presignClient.PresignGetObject(l.ctx, getObjectInput, func(opts *s3.PresignOptions) {
+					opts.Expires = expiration
+				})
+				if err == nil {
+					post.CoverImageUrl = presignedReq.URL
+				}
+			}
+		}
+
+		// Convert timestamps to Unix milliseconds
+		post.CreatedAt = post.CreatedAt * 1000
+		post.UpdatedAt = post.UpdatedAt * 1000
+
+		posts = append(posts, post)
+	}
+
+	return &types.ListPostsResp{
+		Posts:      posts,
+		TotalCount: totalCount,
+	}, nil
 }