Move clearlabels from models to issue service (#8326)

* move clearlabels from models to issue service

* improve code

* Apply suggestions from code review

Co-Authored-By: zeripath <art27@cantab.net>

modules/notification/webhook/webhook.go

@@ -0,0 +1,67 @@
+// Copyright 2019 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 webhook
+
+import (
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/notification/base"
+	api "code.gitea.io/gitea/modules/structs"
+)
+
+type webhookNotifier struct {
+	base.NullNotifier
+}
+
+var (
+	_ base.Notifier = &webhookNotifier{}
+)
+
+// NewNotifier create a new webhookNotifier notifier
+func NewNotifier() base.Notifier {
+	return &webhookNotifier{}
+}
+
+func (m *webhookNotifier) NotifyIssueClearLabels(doer *models.User, issue *models.Issue) {
+	if err := issue.LoadPoster(); err != nil {
+		log.Error("loadPoster: %v", err)
+		return
+	}
+
+	if err := issue.LoadRepo(); err != nil {
+		log.Error("LoadRepo: %v", err)
+		return
+	}
+
+	mode, _ := models.AccessLevel(issue.Poster, issue.Repo)
+	var err error
+	if issue.IsPull {
+		if err = issue.LoadPullRequest(); err != nil {
+			log.Error("LoadPullRequest: %v", err)
+			return
+		}
+
+		err = models.PrepareWebhooks(issue.Repo, models.HookEventPullRequest, &api.PullRequestPayload{
+			Action:      api.HookIssueLabelCleared,
+			Index:       issue.Index,
+			PullRequest: issue.PullRequest.APIFormat(),
+			Repository:  issue.Repo.APIFormat(mode),
+			Sender:      doer.APIFormat(),
+		})
+	} else {
+		err = models.PrepareWebhooks(issue.Repo, models.HookEventIssues, &api.IssuePayload{
+			Action:     api.HookIssueLabelCleared,
+			Index:      issue.Index,
+			Issue:      issue.APIFormat(),
+			Repository: issue.Repo.APIFormat(mode),
+			Sender:     doer.APIFormat(),
+		})
+	}
+	if err != nil {
+		log.Error("PrepareWebhooks [is_pull: %v]: %v", issue.IsPull, err)
+	} else {
+		go models.HookQueue.Add(issue.RepoID)
+	}
+}