feat: 门户网站初始提交

- Go + Gin + html/template 服务端渲染 - 主页：Google 风格搜索框 + 导航卡片 - 后台：卡片 CRUD、搜索引擎配置、主页背景/标题配置 - 图片上传：支持 jpg/jpeg/png/gif，自动压缩，缩略图参数 ?thumb=1 - 安全：登录日志、修改密码、IP 自动封禁、IP 白名单 - 访问统计：主页访问/卡片点击/搜索追踪、实时流量、IP 统计 - SQLite 存储（modernc.org/sqlite，纯 Go） - 内存 Session + bcrypt 密码哈希
2026-05-28 13:54:07 +08:00
commit c16a8dfbc4
42 changed files with 5295 additions and 0 deletions
@@ -0,0 +1,269 @@
+package handlers
+
+import (
+	"fmt"
+	"image"
+	"image/jpeg"
+	"io"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/disintegration/imaging"
+	"github.com/gin-gonic/gin"
+	"github.com/google/uuid"
+)
+
+// allowedMIMETypes defines the permitted upload file MIME types.
+var allowedMIMETypes = map[string]string{
+	"image/jpeg": ".jpg",
+	"image/png":  ".png",
+	"image/gif":  ".gif",
+}
+
+// maxUploadSize is the maximum allowed file size in bytes (5 MB).
+const maxUploadSize = 5 << 20
+
+// uploadDir is the directory where uploaded files are stored.
+const uploadDir = "./data/uploads"
+
+// thumbSuffix is the suffix appended to compressed image filenames.
+const thumbSuffix = "_thumb"
+
+// UploadResponse is the JSON response returned after a successful upload.
+type UploadResponse struct {
+	URL string `json:"url"`
+}
+
+// UploadHandler handles image upload requests.
+// POST /admin/upload
+// Accepts multipart form with "file" field and optional "type" parameter ("icon" or "background").
+// Returns JSON: {"url": "/uploads/{uuid}.{ext}"}
+func UploadHandler(c *gin.Context) {
+	// Parse multipart form with size limit
+	if err := c.Request.ParseMultipartForm(maxUploadSize); err != nil {
+		c.JSON(400, gin.H{"error": "文件太大，最大允许 5MB"})
+		return
+	}
+
+	file, header, err := c.Request.FormFile("file")
+	if err != nil {
+		c.JSON(400, gin.H{"error": "请选择要上传的文件"})
+		return
+	}
+	defer file.Close()
+
+	// Validate file size
+	if header.Size > maxUploadSize {
+		c.JSON(400, gin.H{"error": "文件太大，最大允许 5MB"})
+		return
+	}
+
+	// Validate MIME type by reading first 512 bytes
+	buf := make([]byte, 512)
+	n, err := file.Read(buf)
+	if err != nil && err != io.EOF {
+		c.JSON(500, gin.H{"error": "读取文件失败"})
+		return
+	}
+	// Seek back to start
+	if _, err := file.Seek(0, 0); err != nil {
+		c.JSON(500, gin.H{"error": "处理文件失败"})
+		return
+	}
+
+	mimeType := strings.Split(c.Request.Header.Get("Content-Type"), ";")[0]
+	// Also detect from file content
+	detectedType := detectMIMEType(buf[:n])
+	if detectedType == "" {
+		detectedType = mimeType
+	}
+
+	ext, ok := allowedMIMETypes[detectedType]
+	if !ok {
+		// Try the header's content type as fallback
+		ext, ok = allowedMIMETypes[mimeType]
+		if !ok {
+			c.JSON(400, gin.H{"error": "不支持的文件格式，仅支持 jpg, png, gif"})
+			return
+		}
+	}
+
+	// Generate UUID filename
+	fileUUID := uuid.New().String()
+	filename := fileUUID + ext
+
+	// Ensure upload directory exists
+	if err := os.MkdirAll(uploadDir, 0755); err != nil {
+		c.JSON(500, gin.H{"error": "创建上传目录失败"})
+		return
+	}
+
+	// Save original file
+	originalPath := filepath.Join(uploadDir, filename)
+	dst, err := os.Create(originalPath)
+	if err != nil {
+		c.JSON(500, gin.H{"error": "保存文件失败"})
+		return
+	}
+	defer dst.Close()
+
+	if _, err := io.Copy(dst, file); err != nil {
+		os.Remove(originalPath)
+		c.JSON(500, gin.H{"error": "保存文件失败"})
+		return
+	}
+	dst.Close()
+
+	// Generate compressed thumbnail
+	uploadType := c.PostForm("type")
+	if err := generateThumbnail(originalPath, fileUUID, uploadType); err != nil {
+		// Log the error but don't fail the upload — thumbnail is optional
+		fmt.Printf("Warning: failed to generate thumbnail for %s: %v\n", filename, err)
+	}
+
+	url := "/uploads/" + filename
+	c.JSON(200, UploadResponse{URL: url})
+}
+
+// ServeUploadHandler serves uploaded files.
+// GET /uploads/:filename
+// If query param thumb=1, returns the compressed version.
+func ServeUploadHandler(c *gin.Context) {
+	filename := c.Param("filename")
+	if filename == "" {
+		c.Status(404)
+		return
+	}
+
+	// Prevent directory traversal
+	if strings.Contains(filename, "..") || strings.Contains(filename, "/") || strings.Contains(filename, "\\") {
+		c.Status(404)
+		return
+	}
+
+	filePath := filepath.Join(uploadDir, filename)
+
+	// Check if thumb=1 query parameter is requested
+	if c.Query("thumb") == "1" {
+		// Try to serve the thumbnail version
+		ext := filepath.Ext(filename)
+		baseName := filename[:len(filename)-len(ext)]
+		thumbPath := filepath.Join(uploadDir, baseName+thumbSuffix+".jpg")
+
+		if _, err := os.Stat(thumbPath); err == nil {
+			c.File(thumbPath)
+			return
+		}
+		// If thumbnail doesn't exist, fall through to serve original
+	}
+
+	// Serve original file
+	if _, err := os.Stat(filePath); os.IsNotExist(err) {
+		c.Status(404)
+		return
+	}
+	c.File(filePath)
+}
+
+// detectMIMEType detects the MIME type from file content bytes.
+func detectMIMEType(data []byte) string {
+	if len(data) < 3 {
+		return ""
+	}
+
+	// JPEG: starts with FF D8 FF
+	if data[0] == 0xFF && data[1] == 0xD8 && data[2] == 0xFF {
+		return "image/jpeg"
+	}
+	// PNG: starts with 89 50 4E 47
+	if len(data) >= 4 && data[0] == 0x89 && data[1] == 0x50 && data[2] == 0x4E && data[3] == 0x47 {
+		return "image/png"
+	}
+	// GIF: starts with "GIF"
+	if len(data) >= 3 && data[0] == 'G' && data[1] == 'I' && data[2] == 'F' {
+		return "image/gif"
+	}
+	return ""
+}
+
+// generateThumbnail creates a compressed version of the uploaded image.
+// Icon type: max 200x200, quality 80
+// Background type: max 1920x1080, quality 85
+// Default: max 800x600, quality 85
+// Thumbnails are saved as JPG format.
+func generateThumbnail(originalPath, fileUUID, uploadType string) error {
+	// Open the original image
+	img, err := imaging.Open(originalPath)
+	if err != nil {
+		return fmt.Errorf("failed to open image for thumbnail: %w", err)
+	}
+
+	var maxWidth, maxHeight int
+	var quality int
+
+	switch uploadType {
+	case "icon":
+		maxWidth = 200
+		maxHeight = 200
+		quality = 80
+	case "background":
+		maxWidth = 1920
+		maxHeight = 1080
+		quality = 85
+	default:
+		maxWidth = 800
+		maxHeight = 600
+		quality = 85
+	}
+
+	// Resize if needed, maintaining aspect ratio
+	thumb := fitImage(img, maxWidth, maxHeight)
+
+	// Save thumbnail as JPEG
+	thumbPath := filepath.Join(uploadDir, fileUUID+thumbSuffix+".jpg")
+	thumbFile, err := os.Create(thumbPath)
+	if err != nil {
+		return fmt.Errorf("failed to create thumbnail file: %w", err)
+	}
+	defer thumbFile.Close()
+
+	if err := jpeg.Encode(thumbFile, thumb, &jpeg.Options{Quality: quality}); err != nil {
+		os.Remove(thumbPath)
+		return fmt.Errorf("failed to encode thumbnail: %w", err)
+	}
+
+	return nil
+}
+
+// fitImage resizes the image to fit within maxWidth x maxHeight while
+// maintaining aspect ratio. If the image is already smaller, it is returned as-is.
+func fitImage(img image.Image, maxWidth, maxHeight int) image.Image {
+	bounds := img.Bounds()
+	w := bounds.Dx()
+	h := bounds.Dy()
+
+	if w <= maxWidth && h <= maxHeight {
+		return img
+	}
+
+	// Calculate the scaling factor to fit within bounds
+	scaleW := float64(maxWidth) / float64(w)
+	scaleH := float64(maxHeight) / float64(h)
+	scale := scaleW
+	if scaleH < scaleW {
+		scale = scaleH
+	}
+
+	newW := int(float64(w) * scale)
+	newH := int(float64(h) * scale)
+
+	if newW < 1 {
+		newW = 1
+	}
+	if newH < 1 {
+		newH = 1
+	}
+
+	return imaging.Resize(img, newW, newH, imaging.Lanczos)
+}