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/getpostlogic.go

@@ -2,10 +2,14 @@ package logic
 
 import (
 	"context"
+	"database/sql"
+	"fmt"
+	"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 +29,52 @@ func NewGetPostLogic(ctx context.Context, svcCtx *svc.ServiceContext) *GetPostLo
 }
 
 func (l *GetPostLogic) GetPost(req *types.GetPostReq) (resp *types.GetPostResp, err error) {
-	// todo: add your logic here and delete this line
+	var post types.GetPostResp
+	var coverID sql.NullInt64
 
-	return
+	// Query post with cover image
+	query := `
+		SELECT p.id, p.title, p.content, p.created_at, p.updated_at, p.cover_id
+		FROM posts p
+		WHERE p.id = $1
+	`
+	err = l.svcCtx.DB.QueryRowContext(l.ctx, query, req.PostId).Scan(
+		&post.PostId, &post.Title, &post.Content, &post.CreatedAt, &post.UpdatedAt, &coverID,
+	)
+	if err != nil {
+		if err == sql.ErrNoRows {
+			l.Errorf("Post not found with id: %s", req.PostId)
+			return nil, fmt.Errorf("post not found")
+		}
+		l.Errorf("Failed to get post: %v", err)
+		return nil, err
+	}
+
+	// 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
+	post.CreatedAt = post.CreatedAt * 1000 // Convert to milliseconds if needed
+	post.UpdatedAt = post.UpdatedAt * 1000
+
+	return &post, nil
 }