feat(apk): 增加公开APK管理接口和CI/CD工作流

- 新增获取最新APK版本信息和下载APK的公开接口
- 更新README文档，添加APK管理接口的使用说明
- 实现CI/CD工作流，支持自动构建和部署
- 优化APK存储逻辑，确保只保留最新APK文件

internal/app/server.go

@@ -32,6 +32,8 @@ func (s *Server) Routes() http.Handler {
 	mux := http.NewServeMux()
 	mux.HandleFunc("/api/manifest", s.handlers.Manifest)
 	mux.HandleFunc("/api/assets", s.handlers.Asset)
+	mux.HandleFunc("/api/apk/latest", s.handlers.PublicLatestAPK)
+	mux.HandleFunc("/api/apk/download", s.handlers.PublicDownloadAPK)
 	mux.HandleFunc("/admin/publish", s.handlers.AdminPublish)
 	mux.HandleFunc("/admin/rollback", s.handlers.AdminRollback)
 	mux.HandleFunc("/admin/releases", s.handlers.AdminReleases)

internal/handlers/handlers.go

@@ -10,7 +10,9 @@ import (
 	"path/filepath"
 	"strconv"
 	"strings"
+	"time"
 
+	"expo-updates-server-go/internal/model"
 	"expo-updates-server-go/internal/service"
 	"expo-updates-server-go/internal/storage"
 )
@@ -284,6 +286,50 @@ func (h *Handler) AdminListAPKs(w http.ResponseWriter, r *http.Request) {
 	writeJSON(w, http.StatusOK, map[string]any{"apks": apks})
 }
 
+func (h *Handler) PublicLatestAPK(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		writeJSON(w, http.StatusMethodNotAllowed, map[string]any{"error": "Expected GET."})
+		return
+	}
+	apk, err := h.svc.GetLatestAPK()
+	if err != nil {
+		writeJSON(w, http.StatusInternalServerError, map[string]any{"error": err.Error()})
+		return
+	}
+	if apk == nil {
+		writeJSON(w, http.StatusNotFound, map[string]any{"error": "No APK available"})
+		return
+	}
+	resp := model.LatestAPKResponse{
+		RuntimeVersion: apk.RuntimeVersion,
+		VersionName:    apk.RuntimeVersion,
+		Size:           apk.Size,
+		DownloadURL:    fmt.Sprintf("%s/api/apk/download?runtimeVersion=%s", h.svc.Hostname(), apk.RuntimeVersion),
+		CreatedAt:      apk.CreatedAt.Format(time.RFC3339),
+	}
+	writeJSON(w, http.StatusOK, resp)
+}
+
+func (h *Handler) PublicDownloadAPK(w http.ResponseWriter, r *http.Request) {
+	if r.Method != http.MethodGet {
+		writeJSON(w, http.StatusMethodNotAllowed, map[string]any{"error": "Expected GET."})
+		return
+	}
+	runtimeVersion := r.URL.Query().Get("runtimeVersion")
+	if runtimeVersion == "" {
+		writeJSON(w, http.StatusBadRequest, map[string]any{"error": "runtimeVersion is required"})
+		return
+	}
+	apkPath, err := h.svc.GetAPKPath(runtimeVersion)
+	if err != nil {
+		writeJSON(w, http.StatusNotFound, map[string]any{"error": fmt.Sprintf("APK for runtimeVersion %s not found", runtimeVersion)})
+		return
+	}
+	w.Header().Set("Content-Type", "application/vnd.android.package-archive")
+	w.Header().Set("Content-Disposition", fmt.Sprintf("attachment; filename=carrot-bbs-%s.apk", runtimeVersion))
+	http.ServeFile(w, r, apkPath)
+}
+
 func (h *Handler) authorizeAdmin(w http.ResponseWriter, r *http.Request) bool {
 	if h.adminToken == "" {
 		writeJSON(w, http.StatusForbidden, map[string]any{"error": "ADMIN_TOKEN is not configured"})
@@ -328,7 +374,7 @@ func firstNonEmpty(values ...string) string {
 	return ""
 }
 
-func writeJSON(w http.ResponseWriter, code int, data map[string]any) {
+func writeJSON(w http.ResponseWriter, code int, data any) {
 	w.Header().Set("content-type", "application/json")
 	w.WriteHeader(code)
 	_ = json.NewEncoder(w).Encode(data)

internal/model/types.go

@@ -52,3 +52,11 @@ type APKInfo struct {
 	CreatedAt      time.Time `json:"createdAt"`
 }
 
+type LatestAPKResponse struct {
+	RuntimeVersion string `json:"runtimeVersion"`
+	VersionName    string `json:"versionName"`
+	Size           int64  `json:"size"`
+	DownloadURL    string `json:"downloadUrl"`
+	CreatedAt      string `json:"createdAt"`
+}
+

internal/service/update_service.go

@@ -56,6 +56,10 @@ func NewUpdateService(store *storage.LocalStore, hostname string, privateKeyPath
 	return &UpdateService{store: store, hostname: hostname, privateKeyPath: privateKeyPath}
 }
 
+func (s *UpdateService) Hostname() string {
+	return s.hostname
+}
+
 func (s *UpdateService) PublishZip(runtimeVersion string, platform string, zipReader *bytes.Reader, size int64) (string, error) {
 	return s.store.PublishZip(runtimeVersion, platform, zipReader, size)
 }
@@ -80,6 +84,10 @@ func (s *UpdateService) ListAPKs() ([]model.APKInfo, error) {
 	return s.store.ListAPKs()
 }
 
+func (s *UpdateService) GetLatestAPK() (*model.APKInfo, error) {
+	return s.store.GetLatestAPK()
+}
+
 func (s *UpdateService) BuildManifestResponse(req ManifestRequest) (ManifestResponse, error) {
 	releasePath, err := s.store.LatestReleasePath(req.RuntimeVersion, req.Platform)
 	if err != nil {

internal/storage/local.go

@@ -172,6 +172,22 @@ func (s *LocalStore) SaveAPK(runtimeVersion string, reader io.Reader) (string, e
 	if err := os.MkdirAll(apkDir, 0o755); err != nil {
 		return "", err
 	}
+ 
+	// 删除所有旧的 APK 文件，只保留最新的一个
+	entries, err := os.ReadDir(apkDir)
+	if err != nil && !os.IsNotExist(err) {
+		return "", err
+	}
+	for _, e := range entries {
+		if !e.IsDir() && strings.HasSuffix(e.Name(), ".apk") {
+			oldPath := filepath.Join(apkDir, e.Name())
+			if err := os.Remove(oldPath); err != nil {
+				// 记录错误但不中断，继续保存新文件
+				fmt.Printf("Warning: failed to remove old APK %s: %v\n", oldPath, err)
+			}
+		}
+	}
+
 	filename := fmt.Sprintf("%s.apk", runtimeVersion)
 	apkPath := filepath.Join(apkDir, filename)
 	tmpPath := apkPath + ".tmp"
@@ -243,6 +259,20 @@ func (s *LocalStore) ListAPKs() ([]model.APKInfo, error) {
 			CreatedAt:      fi.ModTime(),
 		})
 	}
+	// 按版本号降序排列，确保最新的在前
 	sort.Slice(out, func(i, j int) bool { return out[i].RuntimeVersion > out[j].RuntimeVersion })
 	return out, nil
 }
+
+func (s *LocalStore) GetLatestAPK() (*model.APKInfo, error) {
+	apks, err := s.ListAPKs()
+	if err != nil {
+		return nil, err
+	}
+	if len(apks) == 0 {
+		return nil, nil
+	}
+	// 由于 SaveAPK 会删除旧文件，理论上只会有一个 APK
+	// 但为了安全起见，返回版本号最大的那个
+	return &apks[0], nil
+}