Add Matrix webhook (#10831)

* Add Matrix webhook

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Add template and related translations for Matrix hook

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Add actual webhook routes and form

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Add missing file

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Update modules/webhook/matrix_test.go

* Use stricter regex to replace URLs

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Escape url and text

Signed-off-by: Till Faelligen <tfaelligen@gmail.com>

* Remove unnecessary whitespace

* Fix copy and paste mistake

Co-Authored-By: Tulir Asokan <tulir@maunium.net>

* Fix indention inconsistency

* Use Authorization header instead of url parameter

* Add raw commit information to webhook

Co-authored-by: Lauris BH <lauris@nix.lv>
Co-authored-by: Tulir Asokan <tulir@maunium.net>

1 files changed, 299 insertions, 0 deletions

diff --git a/modules/webhook/matrix.go b/modules/webhook/matrix.go
new file mode 100644
index 0000000000..bf72e6e340
--- /dev/null
+++ b/modules/webhook/matrix.go
@@ -0,0 +1,299 @@
+// 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 webhook
+
+import (
+	"encoding/json"
+	"errors"
+	"fmt"
+	"html"
+	"net/http"
+	"regexp"
+	"strings"
+
+	"code.gitea.io/gitea/models"
+	"code.gitea.io/gitea/modules/git"
+	"code.gitea.io/gitea/modules/log"
+	"code.gitea.io/gitea/modules/setting"
+	api "code.gitea.io/gitea/modules/structs"
+)
+
+const matrixPayloadSizeLimit = 1024 * 64
+
+// MatrixMeta contains the Matrix metadata
+type MatrixMeta struct {
+	HomeserverURL string `json:"homeserver_url"`
+	Room          string `json:"room_id"`
+	AccessToken   string `json:"access_token"`
+	MessageType   int    `json:"message_type"`
+}
+
+var messageTypeText = map[int]string{
+	1: "m.notice",
+	2: "m.text",
+}
+
+// GetMatrixHook returns Matrix metadata
+func GetMatrixHook(w *models.Webhook) *MatrixMeta {
+	s := &MatrixMeta{}
+	if err := json.Unmarshal([]byte(w.Meta), s); err != nil {
+		log.Error("webhook.GetMatrixHook(%d): %v", w.ID, err)
+	}
+	return s
+}
+
+// MatrixPayloadUnsafe contains the (unsafe) payload for a Matrix room
+type MatrixPayloadUnsafe struct {
+	MatrixPayloadSafe
+	AccessToken string `json:"access_token"`
+}
+
+// safePayload "converts" a unsafe payload to a safe payload
+func (p *MatrixPayloadUnsafe) safePayload() *MatrixPayloadSafe {
+	return &MatrixPayloadSafe{
+		Body:          p.Body,
+		MsgType:       p.MsgType,
+		Format:        p.Format,
+		FormattedBody: p.FormattedBody,
+		Commits:       p.Commits,
+	}
+}
+
+// MatrixPayloadSafe contains (safe) payload for a Matrix room
+type MatrixPayloadSafe struct {
+	Body          string               `json:"body"`
+	MsgType       string               `json:"msgtype"`
+	Format        string               `json:"format"`
+	FormattedBody string               `json:"formatted_body"`
+	Commits       []*api.PayloadCommit `json:"io.gitea.commits,omitempty"`
+}
+
+// SetSecret sets the Matrix secret
+func (p *MatrixPayloadUnsafe) SetSecret(_ string) {}
+
+// JSONPayload Marshals the MatrixPayloadUnsafe to json
+func (p *MatrixPayloadUnsafe) JSONPayload() ([]byte, error) {
+	data, err := json.MarshalIndent(p, "", "  ")
+	if err != nil {
+		return []byte{}, err
+	}
+	return data, nil
+}
+
+// MatrixLinkFormatter creates a link compatible with Matrix
+func MatrixLinkFormatter(url string, text string) string {
+	return fmt.Sprintf(`<a href="%s">%s</a>`, html.EscapeString(url), html.EscapeString(text))
+}
+
+// MatrixLinkToRef Matrix-formatter link to a repo ref
+func MatrixLinkToRef(repoURL, ref string) string {
+	refName := git.RefEndName(ref)
+	switch {
+	case strings.HasPrefix(ref, git.BranchPrefix):
+		return MatrixLinkFormatter(repoURL+"/src/branch/"+refName, refName)
+	case strings.HasPrefix(ref, git.TagPrefix):
+		return MatrixLinkFormatter(repoURL+"/src/tag/"+refName, refName)
+	default:
+		return MatrixLinkFormatter(repoURL+"/src/commit/"+refName, refName)
+	}
+}
+
+func getMatrixCreatePayload(p *api.CreatePayload, matrix *MatrixMeta) (*MatrixPayloadUnsafe, error) {
+	repoLink := MatrixLinkFormatter(p.Repo.HTMLURL, p.Repo.FullName)
+	refLink := MatrixLinkToRef(p.Repo.HTMLURL, p.Ref)
+	text := fmt.Sprintf("[%s:%s] %s created by %s", repoLink, refLink, p.RefType, p.Sender.UserName)
+
+	return getMatrixPayloadUnsafe(text, nil, matrix), nil
+}
+
+// getMatrixDeletePayload composes Matrix payload for delete a branch or tag.
+func getMatrixDeletePayload(p *api.DeletePayload, matrix *MatrixMeta) (*MatrixPayloadUnsafe, error) {
+	refName := git.RefEndName(p.Ref)
+	repoLink := MatrixLinkFormatter(p.Repo.HTMLURL, p.Repo.FullName)
+	text := fmt.Sprintf("[%s:%s] %s deleted by %s", repoLink, refName, p.RefType, p.Sender.UserName)
+
+	return getMatrixPayloadUnsafe(text, nil, matrix), nil
+}
+
+// getMatrixForkPayload composes Matrix payload for forked by a repository.
+func getMatrixForkPayload(p *api.ForkPayload, matrix *MatrixMeta) (*MatrixPayloadUnsafe, error) {
+	baseLink := MatrixLinkFormatter(p.Forkee.HTMLURL, p.Forkee.FullName)
+	forkLink := MatrixLinkFormatter(p.Repo.HTMLURL, p.Repo.FullName)
+	text := fmt.Sprintf("%s is forked to %s", baseLink, forkLink)
+
+	return getMatrixPayloadUnsafe(text, nil, matrix), nil
+}
+
+func getMatrixIssuesPayload(p *api.IssuePayload, matrix *MatrixMeta) (*MatrixPayloadUnsafe, error) {
+	text, _, _, _ := getIssuesPayloadInfo(p, MatrixLinkFormatter, true)
+
+	return getMatrixPayloadUnsafe(text, nil, matrix), nil
+}
+
+func getMatrixIssueCommentPayload(p *api.IssueCommentPayload, matrix *MatrixMeta) (*MatrixPayloadUnsafe, error) {
+	text, _, _ := getIssueCommentPayloadInfo(p, MatrixLinkFormatter, true)
+
+	return getMatrixPayloadUnsafe(text, nil, matrix), nil
+}
+
+func getMatrixReleasePayload(p *api.ReleasePayload, matrix *MatrixMeta) (*MatrixPayloadUnsafe, error) {
+	text, _ := getReleasePayloadInfo(p, MatrixLinkFormatter, true)
+
+	return getMatrixPayloadUnsafe(text, nil, matrix), nil
+}
+
+func getMatrixPushPayload(p *api.PushPayload, matrix *MatrixMeta) (*MatrixPayloadUnsafe, error) {
+	var commitDesc string
+
+	if len(p.Commits) == 1 {
+		commitDesc = "1 commit"
+	} else {
+		commitDesc = fmt.Sprintf("%d commits", len(p.Commits))
+	}
+
+	repoLink := MatrixLinkFormatter(p.Repo.HTMLURL, p.Repo.FullName)
+	branchLink := MatrixLinkToRef(p.Repo.HTMLURL, p.Ref)
+	text := fmt.Sprintf("[%s] %s pushed %s to %s:<br>", repoLink, p.Pusher.UserName, commitDesc, branchLink)
+
+	// for each commit, generate a new line text
+	for i, commit := range p.Commits {
+		text += fmt.Sprintf("%s: %s - %s", MatrixLinkFormatter(commit.URL, commit.ID[:7]), commit.Message, commit.Author.Name)
+		// add linebreak to each commit but the last
+		if i < len(p.Commits)-1 {
+			text += "<br>"
+		}
+
+	}
+
+	return getMatrixPayloadUnsafe(text, p.Commits, matrix), nil
+}
+
+func getMatrixPullRequestPayload(p *api.PullRequestPayload, matrix *MatrixMeta) (*MatrixPayloadUnsafe, error) {
+	text, _, _, _ := getPullRequestPayloadInfo(p, MatrixLinkFormatter, true)
+
+	return getMatrixPayloadUnsafe(text, nil, matrix), nil
+}
+
+func getMatrixPullRequestApprovalPayload(p *api.PullRequestPayload, matrix *MatrixMeta, event models.HookEventType) (*MatrixPayloadUnsafe, error) {
+	senderLink := MatrixLinkFormatter(setting.AppURL+p.Sender.UserName, p.Sender.UserName)
+	title := fmt.Sprintf("#%d %s", p.Index, p.PullRequest.Title)
+	titleLink := fmt.Sprintf("%s/pulls/%d", p.Repository.HTMLURL, p.Index)
+	repoLink := MatrixLinkFormatter(p.Repository.HTMLURL, p.Repository.FullName)
+	var text string
+
+	switch p.Action {
+	case api.HookIssueReviewed:
+		action, err := parseHookPullRequestEventType(event)
+		if err != nil {
+			return nil, err
+		}
+
+		text = fmt.Sprintf("[%s] Pull request review %s: [%s](%s) by %s", repoLink, action, title, titleLink, senderLink)
+	}
+
+	return getMatrixPayloadUnsafe(text, nil, matrix), nil
+}
+
+func getMatrixRepositoryPayload(p *api.RepositoryPayload, matrix *MatrixMeta) (*MatrixPayloadUnsafe, error) {
+	senderLink := MatrixLinkFormatter(setting.AppURL+p.Sender.UserName, p.Sender.UserName)
+	repoLink := MatrixLinkFormatter(p.Repository.HTMLURL, p.Repository.FullName)
+	var text string
+
+	switch p.Action {
+	case api.HookRepoCreated:
+		text = fmt.Sprintf("[%s] Repository created by %s", repoLink, senderLink)
+	case api.HookRepoDeleted:
+		text = fmt.Sprintf("[%s] Repository deleted by %s", repoLink, senderLink)
+	}
+
+	return getMatrixPayloadUnsafe(text, nil, matrix), nil
+}
+
+// GetMatrixPayload converts a Matrix webhook into a MatrixPayloadUnsafe
+func GetMatrixPayload(p api.Payloader, event models.HookEventType, meta string) (*MatrixPayloadUnsafe, error) {
+	s := new(MatrixPayloadUnsafe)
+
+	matrix := &MatrixMeta{}
+	if err := json.Unmarshal([]byte(meta), &matrix); err != nil {
+		return s, errors.New("GetMatrixPayload meta json:" + err.Error())
+	}
+
+	switch event {
+	case models.HookEventCreate:
+		return getMatrixCreatePayload(p.(*api.CreatePayload), matrix)
+	case models.HookEventDelete:
+		return getMatrixDeletePayload(p.(*api.DeletePayload), matrix)
+	case models.HookEventFork:
+		return getMatrixForkPayload(p.(*api.ForkPayload), matrix)
+	case models.HookEventIssues, models.HookEventIssueAssign, models.HookEventIssueLabel, models.HookEventIssueMilestone:
+		return getMatrixIssuesPayload(p.(*api.IssuePayload), matrix)
+	case models.HookEventIssueComment, models.HookEventPullRequestComment:
+		return getMatrixIssueCommentPayload(p.(*api.IssueCommentPayload), matrix)
+	case models.HookEventPush:
+		return getMatrixPushPayload(p.(*api.PushPayload), matrix)
+	case models.HookEventPullRequest, models.HookEventPullRequestAssign, models.HookEventPullRequestLabel,
+		models.HookEventPullRequestMilestone, models.HookEventPullRequestSync:
+		return getMatrixPullRequestPayload(p.(*api.PullRequestPayload), matrix)
+	case models.HookEventPullRequestReviewRejected, models.HookEventPullRequestReviewApproved, models.HookEventPullRequestReviewComment:
+		return getMatrixPullRequestApprovalPayload(p.(*api.PullRequestPayload), matrix, event)
+	case models.HookEventRepository:
+		return getMatrixRepositoryPayload(p.(*api.RepositoryPayload), matrix)
+	case models.HookEventRelease:
+		return getMatrixReleasePayload(p.(*api.ReleasePayload), matrix)
+	}
+
+	return s, nil
+}
+
+func getMatrixPayloadUnsafe(text string, commits []*api.PayloadCommit, matrix *MatrixMeta) *MatrixPayloadUnsafe {
+	p := MatrixPayloadUnsafe{}
+	p.AccessToken = matrix.AccessToken
+	p.FormattedBody = text
+	p.Body = getMessageBody(text)
+	p.Format = "org.matrix.custom.html"
+	p.MsgType = messageTypeText[matrix.MessageType]
+	p.Commits = commits
+	return &p
+}
+
+var urlRegex = regexp.MustCompile(`<a [^>]*?href="([^">]*?)">(.*?)</a>`)
+
+func getMessageBody(htmlText string) string {
+	htmlText = urlRegex.ReplaceAllString(htmlText, "[$2]($1)")
+	htmlText = strings.ReplaceAll(htmlText, "<br>", "\n")
+	return htmlText
+}
+
+// getMatrixHookRequest creates a new request which contains an Authorization header.
+// The access_token is removed from t.PayloadContent
+func getMatrixHookRequest(t *models.HookTask) (*http.Request, error) {
+	payloadunsafe := MatrixPayloadUnsafe{}
+	if err := json.Unmarshal([]byte(t.PayloadContent), &payloadunsafe); err != nil {
+		log.Error("Matrix Hook delivery failed: %v", err)
+		return nil, err
+	}
+
+	payloadsafe := payloadunsafe.safePayload()
+
+	var payload []byte
+	var err error
+	if payload, err = json.MarshalIndent(payloadsafe, "", "  "); err != nil {
+		return nil, err
+	}
+	if len(payload) >= matrixPayloadSizeLimit {
+		return nil, fmt.Errorf("getMatrixHookRequest: payload size %d > %d", len(payload), matrixPayloadSizeLimit)
+	}
+	t.PayloadContent = string(payload)
+
+	req, err := http.NewRequest("POST", t.URL, strings.NewReader(string(payload)))
+	if err != nil {
+		return nil, err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Add("Authorization", "Bearer "+payloadunsafe.AccessToken)
+
+	return req, nil
+}