Utility APIs for app version management.

* GETing individual app versions.
* DELETEing individual app versions.

Fix #3

server/constants.go

@@ -6,6 +6,7 @@ const (
 	URIHardFail          = "/hard-fail"
 	URISoftFail          = "/soft-fail"
 	URIAppVersions       = "/app-versions"
+	URIAppVersion        = "/app-versions/:version"
 	URIReinit            = "/reinit"
 	URIMapPack           = "/mappack"
 	URIHandshake         = "/handshake"

server/handling.go

@@ -115,6 +115,8 @@ func (s *Server) setupRouter() *gin.Engine {
 	})
 	router.GET(URIAppVersions, s.handleGETAppVersions)
 	router.POST(URIAppVersions, s.handlePOSTAppVersions)
+	router.GET(URIAppVersion, s.handleGETAppVersion)
+	router.DELETE(URIAppVersion, s.handleDELETEAppVersion)
 	router.POST(URIReinit, s.handlePOSTReset)
 
 	return router
@@ -179,6 +181,44 @@ func (s *Server) handlePOSTAppVersions(gc *gin.Context) {
 	gc.Status(http.StatusNoContent)
 }
 
+func (s *Server) handleGETAppVersion(gc *gin.Context) {
+	version := gc.Param("version")
+	if version == "" {
+		badRequest(gc, fmt.Errorf("version not provided"))
+		return
+	}
+
+	ver, err := s.getAppVersion(version)
+	if err != nil {
+		internalError(gc, err)
+		return
+	}
+	if ver == nil {
+		gc.Status(http.StatusNotFound)
+		return
+	}
+	gc.JSON(http.StatusOK, ver)
+}
+
+func (s *Server) handleDELETEAppVersion(gc *gin.Context) {
+	version := gc.Param("version")
+	if version == "" {
+		badRequest(gc, fmt.Errorf("version not provided"))
+		return
+	}
+
+	deleted, err := s.deleteAppVersion(version)
+	if err != nil {
+		internalError(gc, err)
+		return
+	}
+	if !deleted {
+		gc.Status(http.StatusNotFound)
+		return
+	}
+	gc.Status(http.StatusNoContent)
+}
+
 func (s *Server) handlePOSTReset(gc *gin.Context) {
 	err := s.initDB(true)
 	if err != nil {

server/server.go

@@ -434,6 +434,44 @@ func (s *Server) putAppVersion(versionInfo *models.AppVersionInfo) error {
 	return nil
 }
 
+func (s *Server) getAppVersion(version string) (*models.AppVersionInfo, error) {
+	conn := s.getDbConn()
+	defer s.dbpool.Put(conn)
+
+	var v *models.AppVersionInfo
+	err := sqlitex.Exec(conn, "select version, address from app_versions where version = ?", func(stmt *sqlite.Stmt) error {
+		verStr := stmt.ColumnText(0)
+		ver, err := semver.NewVersion(verStr)
+		if err != nil {
+			return fmt.Errorf("failed to parse version string %s from db: %w", verStr, err)
+		}
+		addr := stmt.ColumnText(1)
+		v = &models.AppVersionInfo{
+			Version: *ver,
+			Address: addr,
+		}
+		return nil
+	}, version)
+	if err != nil {
+		return nil, fmt.Errorf("failed to retrieve app version %s from db: %w", version, err)
+	}
+
+	return v, nil
+}
+
+func (s *Server) deleteAppVersion(version string) (bool, error) {
+	conn := s.getDbConn()
+	defer s.dbpool.Put(conn)
+
+	err := sqlitex.Exec(conn, "delete from app_versions where version = ?", nil, version)
+	if err != nil {
+		return false, fmt.Errorf("failed to delete app version %s from db: %w", version, err)
+	}
+	n := conn.Changes()
+
+	return n > 0, nil
+}
+
 func (s *Server) handshake(hc models.HandshakeChallenge) (models.UserID, error) {
 	conn := s.getDbConn()
 	defer s.dbpool.Put(conn)