Move repository model into models/repo (#17933)

* Some refactors related repository model

* Move more methods out of repository

* Move repository into models/repo

* Fix test

* Fix test

* some improvements

* Remove unnecessary function

models/repo/avatar.go

@@ -0,0 +1,94 @@
+// Copyright 2021 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 repo
+
+import (
+	"fmt"
+	"image/png"
+	"io"
+	"net/url"
+	"strings"
+
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/modules/avatar"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/storage"
+)
+
+// CustomAvatarRelativePath returns repository custom avatar file path.
+func (repo *Repository) CustomAvatarRelativePath() string {
+	return repo.Avatar
+}
+
+// RelAvatarLink returns a relative link to the repository's avatar.
+func (repo *Repository) RelAvatarLink() string {
+	return repo.relAvatarLink(db.GetEngine(db.DefaultContext))
+}
+
+// generateRandomAvatar generates a random avatar for repository.
+func generateRandomAvatar(e db.Engine, repo *Repository) error {
+	idToString := fmt.Sprintf("%d", repo.ID)
+
+	seed := idToString
+	img, err := avatar.RandomImage([]byte(seed))
+	if err != nil {
+		return fmt.Errorf("RandomImage: %v", err)
+	}
+
+	repo.Avatar = idToString
+
+	if err := storage.SaveFrom(storage.RepoAvatars, repo.CustomAvatarRelativePath(), func(w io.Writer) error {
+		if err := png.Encode(w, img); err != nil {
+			log.Error("Encode: %v", err)
+		}
+		return err
+	}); err != nil {
+		return fmt.Errorf("Failed to create dir %s: %v", repo.CustomAvatarRelativePath(), err)
+	}
+
+	log.Info("New random avatar created for repository: %d", repo.ID)
+
+	if _, err := e.ID(repo.ID).Cols("avatar").NoAutoTime().Update(repo); err != nil {
+		return err
+	}
+
+	return nil
+}
+
+func (repo *Repository) relAvatarLink(e db.Engine) string {
+	// If no avatar - path is empty
+	avatarPath := repo.CustomAvatarRelativePath()
+	if len(avatarPath) == 0 {
+		switch mode := setting.RepoAvatar.Fallback; mode {
+		case "image":
+			return setting.RepoAvatar.FallbackImage
+		case "random":
+			if err := generateRandomAvatar(e, repo); err != nil {
+				log.Error("generateRandomAvatar: %v", err)
+			}
+		default:
+			// default behaviour: do not display avatar
+			return ""
+		}
+	}
+	return setting.AppSubURL + "/repo-avatars/" + url.PathEscape(repo.Avatar)
+}
+
+// AvatarLink returns a link to the repository's avatar.
+func (repo *Repository) AvatarLink() string {
+	return repo.avatarLink(db.GetEngine(db.DefaultContext))
+}
+
+// avatarLink returns user avatar absolute link.
+func (repo *Repository) avatarLink(e db.Engine) string {
+	link := repo.relAvatarLink(e)
+	// we only prepend our AppURL to our known (relative, internal) avatar link to get an absolute URL
+	if strings.HasPrefix(link, "/") && !strings.HasPrefix(link, "//") {
+		return setting.AppURL + strings.TrimPrefix(link, setting.AppSubURL)[1:]
+	}
+	// otherwise, return the link as it is
+	return link
+}