feat: 第五轮开发 - 14项未来路线图功能完整实现

W1-W14 全部完成: - W1: 消息搜索 (ILIKE全文检索 + SearchModal) - W2: 对话导出 (JSON/Markdown/TXT三格式) - W3: 记忆时间线 DevTools 可视化 - W4: 通知推送系统 (WebSocket + Browser Notification API) - W5: 定时提醒 (30s轮询 + 重复提醒 + WebSocket推送) - W6: 每日简报 (08:00自动生成: 天气+新闻+提醒+AI摘要) - W7: IoT场景自动化 (规则引擎 10s轮询 + 条件评估 + 场景执行) - W8: 语音输入 (浏览器 Speech Recognition API) - W9: STT服务 (voice-service + whisper.cpp) - W10: TTS服务 (浏览器 Speech Synthesis + edge-tts三档回退) - W11: 文件管理 (上传/下载/缩略图/纯Go bilinear缩放) - W12: 知识库RAG (PostgreSQL tsvector + 文档分块 + 检索) - W13: 多模态 (图片上传+分析: Vision API + 本地Go分析回退) - W14: PWA (Service Worker + 离线页 + install prompt) 总计: 6个Go微服务 + 10+前端组件 + 10+ PostgreSQL表 + 4个后台调度器
2026-05-19 12:01:09 +08:00
parent 78e3f450c2
commit bcf4d4e621
69 changed files with 14599 additions and 150 deletions
@@ -0,0 +1,706 @@
+package handler
+
+import (
+	"crypto/rand"
+	"crypto/sha256"
+	"encoding/hex"
+	"fmt"
+	"image"
+	"image/color"
+	"image/jpeg"
+	"image/png"
+	"io"
+	"log"
+	"net/http"
+	"os"
+	"path/filepath"
+	"regexp"
+	"strconv"
+	"strings"
+	"time"
+
+	"github.com/gin-gonic/gin"
+
+	"github.com/yourname/cyrene-ai/gateway/internal/middleware"
+	"github.com/yourname/cyrene-ai/gateway/internal/store"
+)
+
+// FileHandler 文件管理处理器
+type FileHandler struct {
+	store     *store.FileStore
+	uploadDir string
+}
+
+// NewFileHandler 创建文件处理器
+func NewFileHandler(s *store.FileStore) *FileHandler {
+	return &FileHandler{
+		store:     s,
+		uploadDir: "./uploads",
+	}
+}
+
+// ========== 允许的文件类型 ==========
+
+var allowedMimeTypes = map[string]bool{
+	// 图片
+	"image/jpeg": true,
+	"image/png":  true,
+	"image/gif":  true,
+	"image/webp": true,
+	"image/svg+xml": true,
+	// 文档
+	"application/pdf":    true,
+	"text/plain":         true,
+	"text/markdown":      true,
+	"application/msword": true,
+	"application/vnd.openxmlformats-officedocument.wordprocessingml.document": true,
+	// 音频
+	"audio/mpeg": true,
+	"audio/wav":  true,
+	"audio/ogg":  true,
+	"audio/webm": true,
+	// 视频
+	"video/mp4":  true,
+	"video/webm": true,
+}
+
+var allowedExtensions = map[string]string{
+	".jpg":  "image/jpeg",
+	".jpeg": "image/jpeg",
+	".png":  "image/png",
+	".gif":  "image/gif",
+	".webp": "image/webp",
+	".svg":  "image/svg+xml",
+	".pdf":  "application/pdf",
+	".txt":  "text/plain",
+	".md":   "text/markdown",
+	".doc":  "application/msword",
+	".docx": "application/vnd.openxmlformats-officedocument.wordprocessingml.document",
+	".mp3":  "audio/mpeg",
+	".wav":  "audio/wav",
+	".ogg":  "audio/ogg",
+	".mp4":  "video/mp4",
+}
+
+const maxFileSize = 20 * 1024 * 1024 // 20MB
+
+// ========== POST /api/v1/files/upload ==========
+
+// Upload 处理文件上传
+func (h *FileHandler) Upload(c *gin.Context) {
+	userID := middleware.GetUserID(c)
+
+	// Nil store guard — 数据库不可用时拒绝上传
+	if h.store == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "文件存储不可用，数据库未连接", "errorType": "service_unavailable"})
+		return
+	}
+
+	// 获取上传的文件
+	file, header, err := c.Request.FormFile("file")
+	if err != nil {
+		c.JSON(http.StatusBadRequest, gin.H{"error": "未找到上传文件", "errorType": "missing_file"})
+		return
+	}
+	defer file.Close()
+
+	// 检查文件大小
+	if header.Size > maxFileSize {
+		c.JSON(http.StatusBadRequest, gin.H{
+			"error":     "文件大小超过限制 (最大 20MB)",
+			"errorType": "file_too_large",
+		})
+		return
+	}
+
+	// 验证文件类型
+	mimeType := header.Header.Get("Content-Type")
+	ext := strings.ToLower(filepath.Ext(header.Filename))
+	if mimeType == "" || mimeType == "application/octet-stream" {
+		// 尝试从扩展名推断
+		if inferred, ok := allowedExtensions[ext]; ok {
+			mimeType = inferred
+		}
+	}
+	if !allowedMimeTypes[mimeType] {
+		// 再尝试通过扩展名检查
+		if _, ok := allowedExtensions[ext]; !ok {
+			c.JSON(http.StatusBadRequest, gin.H{
+				"error":     "不支持的文件类型: " + mimeType,
+				"errorType": "unsupported_type",
+			})
+			return
+		}
+		mimeType = allowedExtensions[ext]
+	}
+
+	// 安全化文件名：移除路径分隔符和特殊字符
+	safeFilename := sanitizeFilename(header.Filename)
+
+	// 生成文件ID (crypto/rand UUID v4)
+	fileID := generateUUID()
+
+	// 创建按日期组织的目录
+	dateDir := time.Now().Format("2006-01-02")
+	storedDir := filepath.Join(h.uploadDir, dateDir)
+	if err := os.MkdirAll(storedDir, 0755); err != nil {
+		log.Printf("[FileHandler] 创建上传目录失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "创建上传目录失败", "errorType": "server_error"})
+		return
+	}
+
+	// 存储路径：以UUID+原始扩展名保存
+	storedFilename := fileID + ext
+	storedPath := filepath.Join(storedDir, storedFilename)
+
+	// 计算 SHA256 hash
+	hasher := sha256.New()
+	teeReader := io.TeeReader(file, hasher)
+
+	// 保存到磁盘
+	dst, err := os.Create(storedPath)
+	if err != nil {
+		log.Printf("[FileHandler] 创建文件失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "保存文件失败", "errorType": "server_error"})
+		return
+	}
+	defer dst.Close()
+
+	written, err := io.Copy(dst, teeReader)
+	if err != nil {
+		os.Remove(storedPath)
+		log.Printf("[FileHandler] 写入文件失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "写入文件失败", "errorType": "server_error"})
+		return
+	}
+
+	hash := hex.EncodeToString(hasher.Sum(nil))
+
+	// 去重检查：如果存在相同hash的文件，复用已有记录
+	if existing, err := h.store.GetFileByHash(hash); err == nil && existing != nil {
+		// 删除刚保存的重复文件
+		os.Remove(storedPath)
+		log.Printf("[FileHandler] 文件去重: 复用已有文件 %s (hash=%s)", existing.ID, hash[:16])
+
+		c.JSON(http.StatusOK, gin.H{
+			"id":        existing.ID,
+			"filename":  existing.Filename,
+			"mime_type": existing.MimeType,
+			"size":      existing.Size,
+			"url":       fmt.Sprintf("/api/v1/files/%s/download", existing.ID),
+			"dedup":     true,
+		})
+		return
+	}
+
+	// 创建数据库记录
+	fileRecord := &store.File{
+		ID:         fileID,
+		UserID:     userID,
+		Filename:   safeFilename,
+		StoredPath: storedPath,
+		MimeType:   mimeType,
+		Size:       written,
+		Hash:       hash,
+		IsPublic:   false,
+		CreatedAt:  time.Now(),
+	}
+
+	if err := h.store.CreateFile(fileRecord); err != nil {
+		os.Remove(storedPath)
+		log.Printf("[FileHandler] 创建文件记录失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "创建文件记录失败", "errorType": "db_error"})
+		return
+	}
+
+	log.Printf("[FileHandler] 文件上传成功: %s (%s, %d bytes, hash=%s)", fileID, safeFilename, written, hash[:16])
+
+	c.JSON(http.StatusCreated, gin.H{
+		"id":        fileID,
+		"filename":  safeFilename,
+		"mime_type": mimeType,
+		"size":      written,
+		"url":       fmt.Sprintf("/api/v1/files/%s/download", fileID),
+	})
+}
+
+// ========== GET /api/v1/files ==========
+
+// List 列出用户的所有文件 (支持分页)
+func (h *FileHandler) List(c *gin.Context) {
+	userID := middleware.GetUserID(c)
+
+	if h.store == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "文件存储不可用", "errorType": "service_unavailable"})
+		return
+	}
+
+	page, _ := strconv.Atoi(c.DefaultQuery("page", "1"))
+	limit, _ := strconv.Atoi(c.DefaultQuery("limit", "20"))
+
+	files, total, err := h.store.GetUserFiles(userID, page, limit)
+	if err != nil {
+		log.Printf("[FileHandler] 查询文件列表失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "查询文件列表失败", "errorType": "db_error"})
+		return
+	}
+
+	// 转换为响应格式
+	result := make([]gin.H, 0, len(files))
+	for _, f := range files {
+		item := gin.H{
+			"id":         f.ID,
+			"user_id":    f.UserID,
+			"filename":   f.Filename,
+			"mime_type":  f.MimeType,
+			"size":       f.Size,
+			"hash":       f.Hash,
+			"is_public":  f.IsPublic,
+			"created_at": f.CreatedAt.UnixMilli(),
+			"url":        fmt.Sprintf("/api/v1/files/%s/download", f.ID),
+		}
+		// 图片类型添加缩略图URL
+		if isImageType(f.MimeType) {
+			item["thumbnail_url"] = fmt.Sprintf("/api/v1/files/%s/thumbnail", f.ID)
+		}
+		result = append(result, item)
+	}
+
+	c.JSON(http.StatusOK, gin.H{
+		"files": result,
+		"total": total,
+		"page":  page,
+		"limit": limit,
+	})
+}
+
+// ========== GET /api/v1/files/:id ==========
+
+// Get 获取文件元数据
+func (h *FileHandler) Get(c *gin.Context) {
+	userID := middleware.GetUserID(c)
+	fileID := c.Param("id")
+
+	if h.store == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "文件存储不可用", "errorType": "service_unavailable"})
+		return
+	}
+
+	f, err := h.store.GetFile(fileID)
+	if err != nil {
+		log.Printf("[FileHandler] 查询文件失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "查询文件失败", "errorType": "db_error"})
+		return
+	}
+	if f == nil {
+		c.JSON(http.StatusNotFound, gin.H{
+			"error":     "文件不存在",
+			"errorType": "file_not_found",
+		})
+		return
+	}
+
+	// 检查权限
+	if f.UserID != userID && !f.IsPublic {
+		c.JSON(http.StatusForbidden, gin.H{"error": "无权访问此文件", "errorType": "access_denied"})
+		return
+	}
+
+	item := gin.H{
+		"id":         f.ID,
+		"user_id":    f.UserID,
+		"filename":   f.Filename,
+		"mime_type":  f.MimeType,
+		"size":       f.Size,
+		"hash":       f.Hash,
+		"is_public":  f.IsPublic,
+		"created_at": f.CreatedAt.UnixMilli(),
+		"url":        fmt.Sprintf("/api/v1/files/%s/download", f.ID),
+	}
+	if isImageType(f.MimeType) {
+		item["thumbnail_url"] = fmt.Sprintf("/api/v1/files/%s/thumbnail", f.ID)
+	}
+
+	c.JSON(http.StatusOK, item)
+}
+
+// ========== GET /api/v1/files/:id/download ==========
+
+// Download 下载文件
+func (h *FileHandler) Download(c *gin.Context) {
+	userID := middleware.GetUserID(c)
+	fileID := c.Param("id")
+
+	if h.store == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "文件存储不可用", "errorType": "service_unavailable"})
+		return
+	}
+
+	f, err := h.store.GetFile(fileID)
+	if err != nil {
+		log.Printf("[FileHandler] 查询文件失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "查询文件失败", "errorType": "db_error"})
+		return
+	}
+	if f == nil {
+		c.JSON(http.StatusNotFound, gin.H{
+			"error":     "文件不存在",
+			"errorType": "file_not_found",
+		})
+		return
+	}
+
+	// 检查权限
+	if f.UserID != userID && !f.IsPublic {
+		c.JSON(http.StatusForbidden, gin.H{"error": "无权访问此文件", "errorType": "access_denied"})
+		return
+	}
+
+	// 检查文件在磁盘上是否存在
+	if _, err := os.Stat(f.StoredPath); os.IsNotExist(err) {
+		c.JSON(http.StatusNotFound, gin.H{
+			"error":     "文件实体不存在（可能已被清理）",
+			"errorType": "file_missing",
+		})
+		return
+	}
+
+	// 设置 Content-Disposition
+	c.Header("Content-Disposition", fmt.Sprintf(`attachment; filename="%s"`, f.Filename))
+	c.Header("Content-Type", f.MimeType)
+	c.File(f.StoredPath)
+}
+
+// ========== DELETE /api/v1/files/:id ==========
+
+// Delete 删除文件
+func (h *FileHandler) Delete(c *gin.Context) {
+	userID := middleware.GetUserID(c)
+	fileID := c.Param("id")
+
+	if h.store == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "文件存储不可用", "errorType": "service_unavailable"})
+		return
+	}
+
+	f, err := h.store.GetFile(fileID)
+	if err != nil {
+		log.Printf("[FileHandler] 查询文件失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "查询文件失败", "errorType": "db_error"})
+		return
+	}
+	if f == nil {
+		c.JSON(http.StatusNotFound, gin.H{
+			"error":     "文件不存在",
+			"errorType": "file_not_found",
+		})
+		return
+	}
+
+	// 检查权限
+	if f.UserID != userID {
+		c.JSON(http.StatusForbidden, gin.H{"error": "无权删除此文件", "errorType": "access_denied"})
+		return
+	}
+
+	// 删除磁盘上的文件（忽略错误，可能已被删除）
+	if err := os.Remove(f.StoredPath); err != nil && !os.IsNotExist(err) {
+		log.Printf("[FileHandler] 删除磁盘文件失败 (stored_path=%s): %v", f.StoredPath, err)
+	}
+
+	// 删除数据库记录
+	if err := h.store.DeleteFile(fileID); err != nil {
+		log.Printf("[FileHandler] 删除文件记录失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "删除文件记录失败", "errorType": "db_error"})
+		return
+	}
+
+	c.JSON(http.StatusOK, gin.H{"status": "deleted"})
+}
+
+// ========== GET /api/v1/files/:id/thumbnail ==========
+
+// Thumbnail 返回文件缩略图
+func (h *FileHandler) Thumbnail(c *gin.Context) {
+	userID := middleware.GetUserID(c)
+	fileID := c.Param("id")
+
+	if h.store == nil {
+		c.JSON(http.StatusServiceUnavailable, gin.H{"error": "文件存储不可用", "errorType": "service_unavailable"})
+		return
+	}
+
+	f, err := h.store.GetFile(fileID)
+	if err != nil {
+		log.Printf("[FileHandler] 查询文件失败: %v", err)
+		c.JSON(http.StatusInternalServerError, gin.H{"error": "查询文件失败", "errorType": "db_error"})
+		return
+	}
+	if f == nil {
+		c.JSON(http.StatusNotFound, gin.H{
+			"error":     "文件不存在",
+			"errorType": "file_not_found",
+		})
+		return
+	}
+
+	if f.UserID != userID && !f.IsPublic {
+		c.JSON(http.StatusForbidden, gin.H{"error": "无权访问此文件", "errorType": "access_denied"})
+		return
+	}
+
+	// 如果是图片，生成缩略图
+	if isImageType(f.MimeType) && f.MimeType != "image/svg+xml" {
+		if thumbData, contentType, err := generateThumbnail(f.StoredPath, f.MimeType); err == nil {
+			c.Header("Content-Type", contentType)
+			c.Header("Cache-Control", "public, max-age=86400")
+			c.Data(http.StatusOK, contentType, thumbData)
+			return
+		} else {
+			log.Printf("[FileHandler] 生成缩略图失败: %v", err)
+		}
+	}
+
+	// 非图片文件或缩略图生成失败，返回占位图标 SVG
+	placeholder := generatePlaceholderSVG(f.MimeType)
+	c.Header("Content-Type", "image/svg+xml")
+	c.Header("Cache-Control", "public, max-age=86400")
+	c.Data(http.StatusOK, "image/svg+xml", []byte(placeholder))
+}
+
+// ========== 辅助函数 ==========
+
+// isImageType 判断是否图片类型
+func isImageType(mimeType string) bool {
+	return strings.HasPrefix(mimeType, "image/")
+}
+
+// sanitizeFilename 安全化文件名：移除路径分隔符、特殊字符
+var unsafeChars = regexp.MustCompile(`[\\/:*?"<>|]`)
+
+func sanitizeFilename(name string) string {
+	// 移除路径分隔符和Windows特殊字符
+	name = unsafeChars.ReplaceAllString(name, "_")
+	// 限制长度
+	if len(name) > 255 {
+		ext := filepath.Ext(name)
+		base := name[:255-len(ext)]
+		name = base + ext
+	}
+	// 为空时给默认名
+	if name == "" || name == "." || name == ".." {
+		name = "unnamed_file"
+	}
+	return name
+}
+
+// generateThumbnail 使用 Go 标准库生成缩略图 (最大 300x300)
+func generateThumbnail(filePath, mimeType string) ([]byte, string, error) {
+	// 打开源文件
+	srcFile, err := os.Open(filePath)
+	if err != nil {
+		return nil, "", fmt.Errorf("打开文件失败: %w", err)
+	}
+	defer srcFile.Close()
+
+	// 解码图像
+	var srcImg image.Image
+	switch mimeType {
+	case "image/jpeg":
+		srcImg, err = jpeg.Decode(srcFile)
+	case "image/png":
+		srcImg, err = png.Decode(srcFile)
+	default:
+		// 尝试通用解码
+		srcImg, _, err = image.Decode(srcFile)
+	}
+	if err != nil {
+		return nil, "", fmt.Errorf("解码图像失败: %w", err)
+	}
+
+	// 计算缩略图尺寸
+	bounds := srcImg.Bounds()
+	srcW := bounds.Dx()
+	srcH := bounds.Dy()
+
+	maxDim := 300
+	newW, newH := srcW, srcH
+	if srcW > maxDim || srcH > maxDim {
+		if srcW > srcH {
+			newW = maxDim
+			newH = srcH * maxDim / srcW
+		} else {
+			newH = maxDim
+			newW = srcW * maxDim / srcH
+		}
+	}
+	if newW < 1 {
+		newW = 1
+	}
+	if newH < 1 {
+		newH = 1
+	}
+
+	// 使用标准库双线性缩放
+	thumbImg := image.NewRGBA(image.Rect(0, 0, newW, newH))
+	scaleBilinear(thumbImg, srcImg)
+
+	// 编码为 JPEG 输出
+	var buf strings.Builder
+	errWriter := &stringWriter{&buf}
+	if err := jpeg.Encode(errWriter, thumbImg, &jpeg.Options{Quality: 80}); err != nil {
+		return nil, "", fmt.Errorf("编码缩略图失败: %w", err)
+	}
+
+	return []byte(buf.String()), "image/jpeg", nil
+}
+
+// stringWriter 实现 io.Writer 到 strings.Builder
+type stringWriter struct {
+	b *strings.Builder
+}
+
+func (w *stringWriter) Write(p []byte) (int, error) {
+	return w.b.Write(p)
+}
+
+// generatePlaceholderSVG 为非图片文件生成占位图标 SVG
+func generatePlaceholderSVG(mimeType string) string {
+	var icon, color string
+
+	switch {
+	case strings.HasPrefix(mimeType, "audio/"):
+		icon = "🎵"
+		color = "#8B5CF6" // purple
+	case strings.HasPrefix(mimeType, "video/"):
+		icon = "🎬"
+		color = "#EF4444" // red
+	case strings.HasPrefix(mimeType, "application/pdf"):
+		icon = "📄"
+		color = "#F59E0B" // amber
+	case strings.HasPrefix(mimeType, "text/"):
+		icon = "📝"
+		color = "#3B82F6" // blue
+	default:
+		icon = "📎"
+		color = "#6B7280" // gray
+	}
+
+	return fmt.Sprintf(`<svg xmlns="http://www.w3.org/2000/svg" width="300" height="300" viewBox="0 0 300 300">
+  <rect width="300" height="300" fill="%s" opacity="0.1"/>
+  <text x="150" y="160" text-anchor="middle" font-size="64" fill="%s">%s</text>
+  <text x="150" y="220" text-anchor="middle" font-size="16" fill="%s" opacity="0.7">%s</text>
+</svg>`, color, color, icon, color, getMimeTypeShort(mimeType))
+}
+
+// getMimeTypeShort 获取MIME类型简称
+func getMimeTypeShort(mimeType string) string {
+	parts := strings.SplitN(mimeType, "/", 2)
+	if len(parts) < 2 {
+		return mimeType
+	}
+	return strings.ToUpper(parts[1])
+}
+
+// generateUUID 使用 crypto/rand 生成 UUID v4 格式的字符串
+func generateUUID() string {
+	b := make([]byte, 16)
+	if _, err := rand.Read(b); err != nil {
+		// 降级方案：基于时间戳 + 随机数的唯一标识
+		b = make([]byte, 16)
+		ts := time.Now().UnixNano()
+		for i := 0; i < 8; i++ {
+			b[i] = byte(ts >> (i * 8))
+		}
+		// 用简单 PRNG 填充剩余字节
+		for i := 8; i < 16; i++ {
+			b[i] = byte((ts * int64(i+1)) % 256)
+		}
+	}
+	// 设置 UUID v4 版本位 (version = 4)
+	b[6] = (b[6] & 0x0f) | 0x40
+	// 设置 UUID variant 位 (variant = 10xx)
+	b[8] = (b[8] & 0x3f) | 0x80
+	return fmt.Sprintf("%08x-%04x-%04x-%04x-%012x",
+		b[0:4], b[4:6], b[6:8], b[8:10], b[10:16])
+}
+
+// scaleBilinear 使用双线性插值将 src 图像缩放到 dst 的尺寸 (纯标准库实现)
+func scaleBilinear(dst *image.RGBA, src image.Image) {
+	dstBounds := dst.Bounds()
+	srcBounds := src.Bounds()
+	dstW := dstBounds.Dx()
+	dstH := dstBounds.Dy()
+	srcW := srcBounds.Dx()
+	srcH := srcBounds.Dy()
+
+	// 计算缩放比例
+	scaleX := float64(srcW) / float64(dstW)
+	scaleY := float64(srcH) / float64(dstH)
+
+	for dy := 0; dy < dstH; dy++ {
+		for dx := 0; dx < dstW; dx++ {
+			// 源图像中的浮点坐标
+			sx := float64(dx)*scaleX + float64(srcBounds.Min.X)
+			sy := float64(dy)*scaleY + float64(srcBounds.Min.Y)
+
+			// 四个邻近像素的整数坐标
+			x0 := int(sx)
+			y0 := int(sy)
+			x1 := x0 + 1
+			y1 := y0 + 1
+
+			// 边界限制
+			if x0 < srcBounds.Min.X {
+				x0 = srcBounds.Min.X
+			}
+			if x1 >= srcBounds.Max.X {
+				x1 = srcBounds.Max.X - 1
+			}
+			if x0 >= srcBounds.Max.X {
+				x0 = srcBounds.Max.X - 1
+			}
+			if x1 < srcBounds.Min.X {
+				x1 = srcBounds.Min.X
+			}
+			if y0 < srcBounds.Min.Y {
+				y0 = srcBounds.Min.Y
+			}
+			if y1 >= srcBounds.Max.Y {
+				y1 = srcBounds.Max.Y - 1
+			}
+			if y0 >= srcBounds.Max.Y {
+				y0 = srcBounds.Max.Y - 1
+			}
+			if y1 < srcBounds.Min.Y {
+				y1 = srcBounds.Min.Y
+			}
+
+			// 插值权重
+			fracX := sx - float64(x0)
+			fracY := sy - float64(y0)
+
+			// 四个角的 RGBA 值
+			r00, g00, b00, a00 := src.At(x0, y0).RGBA()
+			r10, g10, b10, a10 := src.At(x1, y0).RGBA()
+			r01, g01, b01, a01 := src.At(x0, y1).RGBA()
+			r11, g11, b11, a11 := src.At(x1, y1).RGBA()
+
+			// 双线性插值 (在 0-65535 范围内进行)
+			interp := func(c00, c10, c01, c11 uint32) uint8 {
+				top := float64(c00)*(1-fracX) + float64(c10)*fracX
+				bot := float64(c01)*(1-fracX) + float64(c11)*fracX
+				val := top*(1-fracY) + bot*fracY
+				return uint8(val / 256)
+			}
+
+			r := interp(r00, r10, r01, r11)
+			g := interp(g00, g10, g01, g11)
+			b := interp(b00, b10, b01, b11)
+			a := interp(a00, a10, a01, a11)
+
+			dst.SetRGBA(dx+int(dstBounds.Min.X), dy+int(dstBounds.Min.Y), color.RGBA{r, g, b, a})
+		}
+	}
+}
+