Convert User expose ID each time (#12855)

* git blame tells me a lot of gitea things happen here around 2018, add header

* move user code int its own file

* expose user id

* adopt things from APIFormat

* fix test

* CI.restart()

modules/convert/user.go

@@ -0,0 +1,35 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// Use of this source code is governed by a MIT-style
+// license that can be found in the LICENSE file.
+
+package convert
+
+import (
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/markup"
+	api "code.gitea.io/gitea/modules/structs"
+)
+
+// ToUser convert models.User to api.User
+// signed shall only be set if requester is logged in. authed shall only be set if user is site admin or user himself
+func ToUser(user *models.User, signed, authed bool) *api.User {
+	result := &api.User{
+		ID:        user.ID,
+		UserName:  user.Name,
+		FullName:  markup.Sanitize(user.FullName),
+		Email:     user.GetEmail(),
+		AvatarURL: user.AvatarLink(),
+		Created:   user.CreatedUnix.AsTime(),
+	}
+	// hide primary email if API caller is anonymous or user keep email private
+	if signed && (!user.KeepEmailPrivate || authed) {
+		result.Email = user.Email
+	}
+	// only site admin will get these information and possibly user himself
+	if authed {
+		result.IsAdmin = user.IsAdmin
+		result.LastLogin = user.LastLoginUnix.AsTime()
+		result.Language = user.Language
+	}
+	return result
+}