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/issue_comment.go

@@ -0,0 +1,175 @@
+// Copyright 2020 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package convert
+
+import (
+	"context"
+
+	issues_model "code.gitea.io/gitea/models/issues"
+	repo_model "code.gitea.io/gitea/models/repo"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/log"
+	api "code.gitea.io/gitea/modules/structs"
+)
+
+// ToComment converts a issues_model.Comment to the api.Comment format
+func ToComment(c *issues_model.Comment) *api.Comment {
+	return &api.Comment{
+		ID:          c.ID,
+		Poster:      ToUser(c.Poster, nil),
+		HTMLURL:     c.HTMLURL(),
+		IssueURL:    c.IssueURL(),
+		PRURL:       c.PRURL(),
+		Body:        c.Content,
+		Attachments: ToAttachments(c.Attachments),
+		Created:     c.CreatedUnix.AsTime(),
+		Updated:     c.UpdatedUnix.AsTime(),
+	}
+}
+
+// ToTimelineComment converts a issues_model.Comment to the api.TimelineComment format
+func ToTimelineComment(ctx context.Context, c *issues_model.Comment, doer *user_model.User) *api.TimelineComment {
+	err := c.LoadMilestone(ctx)
+	if err != nil {
+		log.Error("LoadMilestone: %v", err)
+		return nil
+	}
+
+	err = c.LoadAssigneeUserAndTeam()
+	if err != nil {
+		log.Error("LoadAssigneeUserAndTeam: %v", err)
+		return nil
+	}
+
+	err = c.LoadResolveDoer()
+	if err != nil {
+		log.Error("LoadResolveDoer: %v", err)
+		return nil
+	}
+
+	err = c.LoadDepIssueDetails()
+	if err != nil {
+		log.Error("LoadDepIssueDetails: %v", err)
+		return nil
+	}
+
+	err = c.LoadTime()
+	if err != nil {
+		log.Error("LoadTime: %v", err)
+		return nil
+	}
+
+	err = c.LoadLabel()
+	if err != nil {
+		log.Error("LoadLabel: %v", err)
+		return nil
+	}
+
+	comment := &api.TimelineComment{
+		ID:       c.ID,
+		Type:     c.Type.String(),
+		Poster:   ToUser(c.Poster, nil),
+		HTMLURL:  c.HTMLURL(),
+		IssueURL: c.IssueURL(),
+		PRURL:    c.PRURL(),
+		Body:     c.Content,
+		Created:  c.CreatedUnix.AsTime(),
+		Updated:  c.UpdatedUnix.AsTime(),
+
+		OldProjectID: c.OldProjectID,
+		ProjectID:    c.ProjectID,
+
+		OldTitle: c.OldTitle,
+		NewTitle: c.NewTitle,
+
+		OldRef: c.OldRef,
+		NewRef: c.NewRef,
+
+		RefAction:    c.RefAction.String(),
+		RefCommitSHA: c.CommitSHA,
+
+		ReviewID: c.ReviewID,
+
+		RemovedAssignee: c.RemovedAssignee,
+	}
+
+	if c.OldMilestone != nil {
+		comment.OldMilestone = ToAPIMilestone(c.OldMilestone)
+	}
+	if c.Milestone != nil {
+		comment.Milestone = ToAPIMilestone(c.Milestone)
+	}
+
+	if c.Time != nil {
+		err = c.Time.LoadAttributes()
+		if err != nil {
+			log.Error("Time.LoadAttributes: %v", err)
+			return nil
+		}
+
+		comment.TrackedTime = ToTrackedTime(ctx, c.Time)
+	}
+
+	if c.RefIssueID != 0 {
+		issue, err := issues_model.GetIssueByID(ctx, c.RefIssueID)
+		if err != nil {
+			log.Error("GetIssueByID(%d): %v", c.RefIssueID, err)
+			return nil
+		}
+		comment.RefIssue = ToAPIIssue(ctx, issue)
+	}
+
+	if c.RefCommentID != 0 {
+		com, err := issues_model.GetCommentByID(ctx, c.RefCommentID)
+		if err != nil {
+			log.Error("GetCommentByID(%d): %v", c.RefCommentID, err)
+			return nil
+		}
+		err = com.LoadPoster(ctx)
+		if err != nil {
+			log.Error("LoadPoster: %v", err)
+			return nil
+		}
+		comment.RefComment = ToComment(com)
+	}
+
+	if c.Label != nil {
+		var org *user_model.User
+		var repo *repo_model.Repository
+		if c.Label.BelongsToOrg() {
+			var err error
+			org, err = user_model.GetUserByID(ctx, c.Label.OrgID)
+			if err != nil {
+				log.Error("GetUserByID(%d): %v", c.Label.OrgID, err)
+				return nil
+			}
+		}
+		if c.Label.BelongsToRepo() {
+			var err error
+			repo, err = repo_model.GetRepositoryByID(ctx, c.Label.RepoID)
+			if err != nil {
+				log.Error("GetRepositoryByID(%d): %v", c.Label.RepoID, err)
+				return nil
+			}
+		}
+		comment.Label = ToLabel(c.Label, repo, org)
+	}
+
+	if c.Assignee != nil {
+		comment.Assignee = ToUser(c.Assignee, nil)
+	}
+	if c.AssigneeTeam != nil {
+		comment.AssigneeTeam, _ = ToTeam(c.AssigneeTeam)
+	}
+
+	if c.ResolveDoer != nil {
+		comment.ResolveDoer = ToUser(c.ResolveDoer, nil)
+	}
+
+	if c.DependentIssue != nil {
+		comment.DependentIssue = ToAPIIssue(ctx, c.DependentIssue)
+	}
+
+	return comment
+}