后台站点设计UIUX优化

2026-09-19 04:14:13 +08:00
parent a8efb9ecef
commit 2b3d122e56
24 changed files with 2952 additions and 306 deletions
--- a/backend/service/brand_store.go
+++ b/backend/service/brand_store.go
@@ -0,0 +1,187 @@
+package service
+
+import (
+	"bytes"
+	"crypto/rand"
+	"encoding/hex"
+	"errors"
+	"io"
+	"log"
+	"os"
+	"path/filepath"
+	"strings"
+
+	"github.com/freefire/jiang13-bbs/model"
+)
+
+const (
+	BrandLogoMaxBytes    = 2 << 20   // 2 MiB
+	BrandFaviconMaxBytes = 512 << 10 // 512 KiB
+	brandMaxDim          = 2048
+)
+
+// ErrBrandFileMissing 设置了合法 URL 但磁盘上没有对应文件
+var ErrBrandFileMissing = errors.New("品牌图文件不存在")
+
+type brandFormat struct {
+	ext  string
+	mime string
+	svg  bool
+	ico  bool
+}
+
+func brandMaxBytes(slot string) int64 {
+	if slot == BrandSlotFavicon {
+		return BrandFaviconMaxBytes
+	}
+	return BrandLogoMaxBytes
+}
+
+func detectBrandFormat(data []byte, slot string) (brandFormat, error) {
+	logo := slot != BrandSlotFavicon
+	too := "仅支持 PNG / WebP / SVG"
+	if !logo {
+		too = "仅支持 PNG / WebP / SVG / ICO"
+	}
+	fail := errors.New(too)
+	if len(data) >= 8 && string(data[0:8]) == "\x89PNG\r\n\x1a\n" {
+		return brandFormat{ext: ".png", mime: "image/png"}, nil
+	}
+	if len(data) >= 12 && string(data[0:4]) == "RIFF" && string(data[8:12]) == "WEBP" {
+		return brandFormat{ext: ".webp", mime: "image/webp"}, nil
+	}
+	if !logo && len(data) >= 4 && data[0] == 0 && data[1] == 0 && data[2] == 1 && data[3] == 0 {
+		return brandFormat{ext: ".ico", mime: "image/x-icon", ico: true}, nil
+	}
+	if looksLikeSVG(data) {
+		return brandFormat{ext: ".svg", mime: "image/svg+xml", svg: true}, nil
+	}
+	return brandFormat{}, fail
+}
+
+func looksLikeSVG(data []byte) bool {
+	s := strings.ToLower(string(data))
+	if !strings.Contains(s, "<svg") {
+		return false
+	}
+	if strings.Contains(s, "<script") || strings.Contains(s, "javascript:") {
+		return false
+	}
+	if strings.Contains(s, "onload=") || strings.Contains(s, "onerror=") {
+		return false
+	}
+	return true
+}
+
+// SaveBrand 把品牌图落到 uploads/brand，不写站点设置
+func (s *UploadService) SaveBrand(slot string, src io.Reader) (string, error) {
+	slot, ok := NormalizeBrandSlot(slot)
+	if !ok {
+		return "", errors.New("无效的品牌图位置")
+	}
+	if src == nil {
+		return "", errors.New("文件为空")
+	}
+	maxB := brandMaxBytes(slot)
+	data, err := io.ReadAll(io.LimitReader(src, maxB+1))
+	if err != nil {
+		return "", errors.New("读取图片失败")
+	}
+	if len(data) == 0 {
+		return "", errors.New("文件为空")
+	}
+	if int64(len(data)) > maxB {
+		if slot == BrandSlotFavicon {
+			return "", errors.New("Favicon 不能超过 512KB")
+		}
+		return "", errors.New("Logo 不能超过 2MB")
+	}
+	format, err := detectBrandFormat(data, slot)
+	if err != nil {
+		return "", err
+	}
+	if !format.svg && !format.ico {
+		w, h, derr := decodeImageSizeReader(bytes.NewReader(data), format.mime)
+		if derr != nil {
+			return "", derr
+		}
+		if w < 1 || h < 1 || w > brandMaxDim || h > brandMaxDim {
+			return "", errors.New("图片尺寸超出限制")
+		}
+	}
+
+	if err := os.MkdirAll(filepath.Join(s.dir, "brand"), 0o755); err != nil {
+		return "", err
+	}
+	nameBytes := make([]byte, 16)
+	if _, err := rand.Read(nameBytes); err != nil {
+		return "", err
+	}
+	filename := hex.EncodeToString(nameBytes) + format.ext
+	fullPath := filepath.Join(s.dir, "brand", filename)
+	if err := os.WriteFile(fullPath, data, 0o644); err != nil {
+		return "", err
+	}
+	return "/uploads/brand/" + filename, nil
+}
+
+// CopyBrandFromMedia 把当前用户媒体库里的一张图复制进品牌目录，不写站点设置
+func (s *UploadService) CopyBrandFromMedia(userID, attachmentID uint, slot string) (string, error) {
+	if _, ok := NormalizeBrandSlot(slot); !ok {
+		return "", errors.New("无效的品牌图位置")
+	}
+	var att model.Attachment
+	if err := s.db.Where("id = ? AND user_id = ?", attachmentID, userID).First(&att).Error; err != nil {
+		return "", errors.New("图片不存在或不属于你")
+	}
+	abs, ok := s.safeUploadPath(att.URL)
+	if !ok {
+		return "", errors.New("无效的图片地址")
+	}
+	f, err := os.Open(abs)
+	if err != nil {
+		return "", errors.New("读取图片失败")
+	}
+	defer f.Close()
+	return s.SaveBrand(slot, f)
+}
+
+func (s *UploadService) safeUploadPath(url string) (string, bool) {
+	rel := strings.TrimPrefix(strings.TrimSpace(url), "/uploads/")
+	if rel == "" || rel == url || strings.Contains(rel, "..") {
+		return "", false
+	}
+	abs := filepath.Join(s.dir, filepath.FromSlash(rel))
+	root := filepath.Clean(s.dir)
+	clean := filepath.Clean(abs)
+	if clean != root && !strings.HasPrefix(clean, root+string(os.PathSeparator)) {
+		return "", false
+	}
+	return clean, true
+}
+
+// BrandFileExists 确认 URL 对应文件在 brand 目录内
+func (s *UploadService) BrandFileExists(url string) bool {
+	rel := BrandRelPath(url)
+	if rel == "" {
+		return false
+	}
+	abs := filepath.Join(s.dir, filepath.FromSlash(rel))
+	info, err := os.Stat(abs)
+	return err == nil && !info.IsDir()
+}
+
+// RemoveBrandIfUnused 旧品牌图不再被任一槽位引用时删除
+func (s *UploadService) RemoveBrandIfUnused(oldURL, light, dark, favicon string) {
+	if oldURL == "" || oldURL == light || oldURL == dark || oldURL == favicon {
+		return
+	}
+	rel := BrandRelPath(oldURL)
+	if rel == "" {
+		return
+	}
+	abs := filepath.Join(s.dir, filepath.FromSlash(rel))
+	if err := os.Remove(abs); err != nil && !os.IsNotExist(err) {
+		log.Printf("[upload] 删除品牌图失败 path=%s: %v", abs, err)
+	}
+}