1 files changed, 187 insertions, 0 deletions
diff --git a/services/mailer/incoming/incoming_handler.go b/services/mailer/incoming/incoming_handler.go
new file mode 100644
index 0000000..dc3c4ec
--- /dev/null
+++ b/services/mailer/incoming/incoming_handler.go
@@ -0,0 +1,187 @@
+// Copyright 2023 The Gitea Authors. All rights reserved.
+// SPDX-License-Identifier: MIT
+
+package incoming
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+
+	issues_model "code.gitea.io/gitea/models/issues"
+	access_model "code.gitea.io/gitea/models/perm/access"
+	repo_model "code.gitea.io/gitea/models/repo"
+	user_model "code.gitea.io/gitea/models/user"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	"code.gitea.io/gitea/modules/util"
+	attachment_service "code.gitea.io/gitea/services/attachment"
+	"code.gitea.io/gitea/services/context/upload"
+	issue_service "code.gitea.io/gitea/services/issue"
+	incoming_payload "code.gitea.io/gitea/services/mailer/incoming/payload"
+	"code.gitea.io/gitea/services/mailer/token"
+	pull_service "code.gitea.io/gitea/services/pull"
+)
+
+type MailHandler interface {
+	Handle(ctx context.Context, content *MailContent, doer *user_model.User, payload []byte) error
+}
+
+var handlers = map[token.HandlerType]MailHandler{
+	token.ReplyHandlerType:       &ReplyHandler{},
+	token.UnsubscribeHandlerType: &UnsubscribeHandler{},
+}
+
+// ReplyHandler handles incoming emails to create a reply from them
+type ReplyHandler struct{}
+
+func (h *ReplyHandler) Handle(ctx context.Context, content *MailContent, doer *user_model.User, payload []byte) error {
+	if doer == nil {
+		return util.NewInvalidArgumentErrorf("doer can't be nil")
+	}
+
+	ref, err := incoming_payload.GetReferenceFromPayload(ctx, payload)
+	if err != nil {
+		return err
+	}
+
+	var issue *issues_model.Issue
+
+	switch r := ref.(type) {
+	case *issues_model.Issue:
+		issue = r
+	case *issues_model.Comment:
+		comment := r
+
+		if err := comment.LoadIssue(ctx); err != nil {
+			return err
+		}
+
+		issue = comment.Issue
+	default:
+		return util.NewInvalidArgumentErrorf("unsupported reply reference: %v", ref)
+	}
+
+	if err := issue.LoadRepo(ctx); err != nil {
+		return err
+	}
+
+	perm, err := access_model.GetUserRepoPermission(ctx, issue.Repo, doer)
+	if err != nil {
+		return err
+	}
+
+	// Locked issues require write permissions
+	if issue.IsLocked && !perm.CanWriteIssuesOrPulls(issue.IsPull) && !doer.IsAdmin {
+		log.Debug("can't write issue or pull")
+		return nil
+	}
+
+	if !perm.CanReadIssuesOrPulls(issue.IsPull) {
+		log.Debug("can't read issue or pull")
+		return nil
+	}
+
+	log.Trace("incoming mail related to %T", ref)
+
+	attachmentIDs := make([]string, 0, len(content.Attachments))
+	if setting.Attachment.Enabled {
+		for _, attachment := range content.Attachments {
+			a, err := attachment_service.UploadAttachment(ctx, bytes.NewReader(attachment.Content), setting.Attachment.AllowedTypes, int64(len(attachment.Content)), &repo_model.Attachment{
+				Name:       attachment.Name,
+				UploaderID: doer.ID,
+				RepoID:     issue.Repo.ID,
+			})
+			if err != nil {
+				if upload.IsErrFileTypeForbidden(err) {
+					log.Info("Skipping disallowed attachment type: %s", attachment.Name)
+					continue
+				}
+				return err
+			}
+			attachmentIDs = append(attachmentIDs, a.UUID)
+		}
+	}
+
+	if content.Content == "" && len(attachmentIDs) == 0 {
+		log.Trace("incoming mail has no content and no attachment", ref)
+		return nil
+	}
+
+	switch r := ref.(type) {
+	case *issues_model.Issue:
+		_, err = issue_service.CreateIssueComment(ctx, doer, issue.Repo, issue, content.Content, attachmentIDs)
+		if err != nil {
+			return fmt.Errorf("CreateIssueComment failed: %w", err)
+		}
+	case *issues_model.Comment:
+		comment := r
+
+		switch comment.Type {
+		case issues_model.CommentTypeComment, issues_model.CommentTypeReview:
+			_, err = issue_service.CreateIssueComment(ctx, doer, issue.Repo, issue, content.Content, attachmentIDs)
+			if err != nil {
+				return fmt.Errorf("CreateIssueComment failed: %w", err)
+			}
+		case issues_model.CommentTypeCode:
+			_, err := pull_service.CreateCodeComment(
+				ctx,
+				doer,
+				nil,
+				issue,
+				comment.Line,
+				content.Content,
+				comment.TreePath,
+				false, // not pending review but a single review
+				comment.ReviewID,
+				"",
+				attachmentIDs,
+			)
+			if err != nil {
+				return fmt.Errorf("CreateCodeComment failed: %w", err)
+			}
+		default:
+			log.Trace("incoming mail related to comment of type %v is ignored", comment.Type)
+		}
+	default:
+		log.Trace("incoming mail related to %T is ignored", ref)
+	}
+	return nil
+}
+
+// UnsubscribeHandler handles unwatching issues/pulls
+type UnsubscribeHandler struct{}
+
+func (h *UnsubscribeHandler) Handle(ctx context.Context, _ *MailContent, doer *user_model.User, payload []byte) error {
+	if doer == nil {
+		return util.NewInvalidArgumentErrorf("doer can't be nil")
+	}
+
+	ref, err := incoming_payload.GetReferenceFromPayload(ctx, payload)
+	if err != nil {
+		return err
+	}
+
+	switch r := ref.(type) {
+	case *issues_model.Issue:
+		issue := r
+
+		if err := issue.LoadRepo(ctx); err != nil {
+			return err
+		}
+
+		perm, err := access_model.GetUserRepoPermission(ctx, issue.Repo, doer)
+		if err != nil {
+			return err
+		}
+
+		if !perm.CanReadIssuesOrPulls(issue.IsPull) {
+			log.Debug("can't read issue or pull")
+			return nil
+		}
+
+		return issues_model.CreateOrUpdateIssueWatch(ctx, doer.ID, issue.ID, false)
+	default:
+		return fmt.Errorf("unsupported unsubscribe reference: %v", ref)
+	}
+}