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/wiki.go

@@ -0,0 +1,39 @@
+// Copyright 2015 The Gogs Authors. All rights reserved.
+// 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 repo
+
+import (
+	"path/filepath"
+	"strings"
+
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/util"
+)
+
+// WikiCloneLink returns clone URLs of repository wiki.
+func (repo *Repository) WikiCloneLink() *CloneLink {
+	return repo.cloneLink(true)
+}
+
+// WikiPath returns wiki data path by given user and repository name.
+func WikiPath(userName, repoName string) string {
+	return filepath.Join(user_model.UserPath(userName), strings.ToLower(repoName)+".wiki.git")
+}
+
+// WikiPath returns wiki data path for given repository.
+func (repo *Repository) WikiPath() string {
+	return WikiPath(repo.OwnerName, repo.Name)
+}
+
+// HasWiki returns true if repository has wiki.
+func (repo *Repository) HasWiki() bool {
+	isDir, err := util.IsDir(repo.WikiPath())
+	if err != nil {
+		log.Error("Unable to check if %s is a directory: %v", repo.WikiPath(), err)
+	}
+	return isDir
+}