Move convert package to services (#22264)

Addition to #22256

The `convert` package relies heavily on different models which is
[disallowed by our definition of
modules](https://github.com/go-gitea/gitea/blob/main/CONTRIBUTING.md#design-guideline).
This helps to prevent possible import cycles.

Co-authored-by: Lunny Xiao <xiaolunwen@gmail.com>

services/convert/notification.go

@@ -0,0 +1,96 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package convert
+
+import (
+	"net/url"
+
+	activities_model "code.gitea.io/gitea/models/activities"
+	"code.gitea.io/gitea/models/db"
+	"code.gitea.io/gitea/models/perm"
+	api "code.gitea.io/gitea/modules/structs"
+)
+
+// ToNotificationThread convert a Notification to api.NotificationThread
+func ToNotificationThread(n *activities_model.Notification) *api.NotificationThread {
+	result := &api.NotificationThread{
+		ID:        n.ID,
+		Unread:    !(n.Status == activities_model.NotificationStatusRead || n.Status == activities_model.NotificationStatusPinned),
+		Pinned:    n.Status == activities_model.NotificationStatusPinned,
+		UpdatedAt: n.UpdatedUnix.AsTime(),
+		URL:       n.APIURL(),
+	}
+
+	// since user only get notifications when he has access to use minimal access mode
+	if n.Repository != nil {
+		result.Repository = ToRepo(db.DefaultContext, n.Repository, perm.AccessModeRead)
+
+		// This permission is not correct and we should not be reporting it
+		for repository := result.Repository; repository != nil; repository = repository.Parent {
+			repository.Permissions = nil
+		}
+	}
+
+	// handle Subject
+	switch n.Source {
+	case activities_model.NotificationSourceIssue:
+		result.Subject = &api.NotificationSubject{Type: api.NotifySubjectIssue}
+		if n.Issue != nil {
+			result.Subject.Title = n.Issue.Title
+			result.Subject.URL = n.Issue.APIURL()
+			result.Subject.HTMLURL = n.Issue.HTMLURL()
+			result.Subject.State = n.Issue.State()
+			comment, err := n.Issue.GetLastComment()
+			if err == nil && comment != nil {
+				result.Subject.LatestCommentURL = comment.APIURL()
+				result.Subject.LatestCommentHTMLURL = comment.HTMLURL()
+			}
+		}
+	case activities_model.NotificationSourcePullRequest:
+		result.Subject = &api.NotificationSubject{Type: api.NotifySubjectPull}
+		if n.Issue != nil {
+			result.Subject.Title = n.Issue.Title
+			result.Subject.URL = n.Issue.APIURL()
+			result.Subject.HTMLURL = n.Issue.HTMLURL()
+			result.Subject.State = n.Issue.State()
+			comment, err := n.Issue.GetLastComment()
+			if err == nil && comment != nil {
+				result.Subject.LatestCommentURL = comment.APIURL()
+				result.Subject.LatestCommentHTMLURL = comment.HTMLURL()
+			}
+
+			pr, _ := n.Issue.GetPullRequest()
+			if pr != nil && pr.HasMerged {
+				result.Subject.State = "merged"
+			}
+		}
+	case activities_model.NotificationSourceCommit:
+		url := n.Repository.HTMLURL() + "/commit/" + url.PathEscape(n.CommitID)
+		result.Subject = &api.NotificationSubject{
+			Type:    api.NotifySubjectCommit,
+			Title:   n.CommitID,
+			URL:     url,
+			HTMLURL: url,
+		}
+	case activities_model.NotificationSourceRepository:
+		result.Subject = &api.NotificationSubject{
+			Type:  api.NotifySubjectRepository,
+			Title: n.Repository.FullName(),
+			// FIXME: this is a relative URL, rather useless and inconsistent, but keeping for backwards compat
+			URL:     n.Repository.Link(),
+			HTMLURL: n.Repository.HTMLURL(),
+		}
+	}
+
+	return result
+}
+
+// ToNotifications convert list of Notification to api.NotificationThread list
+func ToNotifications(nl activities_model.NotificationList) []*api.NotificationThread {
+	result := make([]*api.NotificationThread, 0, len(nl))
+	for _, n := range nl {
+		result = append(result, ToNotificationThread(n))
+	}
+	return result
+}