feat: process notification and send emails (#803)

app/services/notification/branch_updated.go

@@ -0,0 +1,96 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package notification
+
+import (
+	"context"
+	"fmt"
+
+	pullreqevents "github.com/harness/gitness/app/events/pullreq"
+	"github.com/harness/gitness/events"
+	"github.com/harness/gitness/types"
+)
+
+type PullReqBranchUpdatedPayload struct {
+	Base      *BasePullReqPayload
+	Committer *types.PrincipalInfo
+	NewSHA    string
+}
+
+func (s *Service) notifyPullReqBranchUpdated(
+	ctx context.Context,
+	event *events.Event[*pullreqevents.BranchUpdatedPayload],
+) error {
+	payload, reviewers, err := s.processPullReqBranchUpdatedEvent(ctx, event)
+	if err != nil {
+		return fmt.Errorf(
+			"failed to process %s event for pullReqID %d: %w",
+			pullreqevents.BranchUpdatedEvent,
+			event.Payload.PullReqID,
+			err,
+		)
+	}
+
+	if len(reviewers) == 0 {
+		return nil
+	}
+
+	err = s.notificationClient.SendPullReqBranchUpdated(ctx, reviewers, payload)
+	if err != nil {
+		return fmt.Errorf(
+			"failed to send notification for event %s for pullReqID %d: %w",
+			pullreqevents.BranchUpdatedEvent,
+			event.Payload.PullReqID,
+			err,
+		)
+	}
+
+	return nil
+}
+
+func (s *Service) processPullReqBranchUpdatedEvent(
+	ctx context.Context,
+	event *events.Event[*pullreqevents.BranchUpdatedPayload],
+) (*PullReqBranchUpdatedPayload, []*types.PrincipalInfo, error) {
+	base, err := s.getBasePayload(ctx, event.Payload.Base)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to get base payload: %w", err)
+	}
+
+	committer, err := s.principalInfoCache.Get(ctx, event.Payload.PrincipalID)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to get principal info for %d: %w", event.Payload.PrincipalID, err)
+	}
+
+	reviewers, err := s.pullReqReviewersStore.List(ctx, event.Payload.PullReqID)
+	if err != nil {
+		return nil, nil,
+			fmt.Errorf("failed to get reviewers for pull request %d: %w", event.Payload.PullReqID, err)
+	}
+
+	reviewerPrincipals := make([]*types.PrincipalInfo, len(reviewers))
+	for i, reviewer := range reviewers {
+		reviewerPrincipals[i], err = s.principalInfoCache.Get(ctx, reviewer.PrincipalID)
+		if err != nil {
+			return nil, nil, fmt.Errorf("failed to get principal info for %d: %w", reviewer.PrincipalID, err)
+		}
+	}
+
+	return &PullReqBranchUpdatedPayload{
+		Base:      base,
+		NewSHA:    event.Payload.NewSHA,
+		Committer: committer,
+	}, reviewerPrincipals, nil
+}

app/services/notification/client_interface.go

@@ -0,0 +1,33 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package notification
+
+import (
+	"context"
+
+	"github.com/harness/gitness/types"
+)
+
+// Client is an interface for sending notifications, such as emails, Slack messages etc.
+// It is implemented by MailClient and in future we can have other implementations for other channels like Slack etc.
+type Client interface {
+	SendCommentCreated(ctx context.Context, recipients []*types.PrincipalInfo, payload *CommentCreatedPayload) error
+	SendReviewerAdded(ctx context.Context, recipients []*types.PrincipalInfo, payload *ReviewerAddedPayload) error
+	SendPullReqBranchUpdated(
+		ctx context.Context,
+		recipients []*types.PrincipalInfo,
+		payload *PullReqBranchUpdatedPayload,
+	) error
+}

app/services/notification/comment_created.go

@@ -0,0 +1,85 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package notification
+
+import (
+	"context"
+	"fmt"
+
+	pullreqevents "github.com/harness/gitness/app/events/pullreq"
+	"github.com/harness/gitness/events"
+	"github.com/harness/gitness/types"
+)
+
+type CommentCreatedPayload struct {
+	Base      *BasePullReqPayload
+	Commenter *types.PrincipalInfo
+	Text      string
+}
+
+func (s *Service) notifyCommentCreated(
+	ctx context.Context,
+	event *events.Event[*pullreqevents.CommentCreatedPayload],
+) error {
+	payload, recipients, err := s.processCommentCreatedEvent(ctx, event)
+	if err != nil {
+		return fmt.Errorf(
+			"failed to process %s event for pullReqID %d: %w",
+			pullreqevents.CommentCreatedEvent,
+			event.Payload.PullReqID,
+			err,
+		)
+	}
+
+	err = s.notificationClient.SendCommentCreated(ctx, recipients, payload)
+	if err != nil {
+		return fmt.Errorf(
+			"failed to send notification for event %s for pullReqID %d: %w",
+			pullreqevents.CommentCreatedEvent,
+			event.Payload.PullReqID,
+			err,
+		)
+	}
+	return nil
+}
+
+func (s *Service) processCommentCreatedEvent(
+	ctx context.Context,
+	event *events.Event[*pullreqevents.CommentCreatedPayload],
+) (*CommentCreatedPayload, []*types.PrincipalInfo, error) {
+	base, err := s.getBasePayload(ctx, event.Payload.Base)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to get base payload: %w", err)
+	}
+
+	activity, err := s.pullReqActivityStore.Find(ctx, event.Payload.ActivityID)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to fetch activity from pullReqActivityStore: %w", err)
+	}
+
+	commenter, err := s.principalInfoView.Find(ctx, activity.CreatedBy)
+	if err != nil {
+		return nil, nil, fmt.Errorf("failed to fetch commenter from principalInfoView: %w", err)
+	}
+	recipients := []*types.PrincipalInfo{
+		base.Author,
+	}
+
+	return &CommentCreatedPayload{
+		Base:      base,
+		Commenter: commenter,
+		Text:      activity.Text,
+	}, recipients, nil
+}

app/services/notification/mail_client.go

@@ -0,0 +1,149 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package notification
+
+import (
+	"bytes"
+	"context"
+	"fmt"
+
+	pullreqevents "github.com/harness/gitness/app/events/pullreq"
+	"github.com/harness/gitness/app/services/notification/mailer"
+	"github.com/harness/gitness/types"
+)
+
+const (
+	TemplateReviewerAdded        = "reviewer_added.html"
+	TemplateCommentCreated       = "comment_created.html"
+	TemplatePullReqBranchUpdated = "pullreq_branch_updated.html"
+)
+
+type MailClient struct {
+	mailer.Mailer
+}
+
+func NewMailClient(mailer mailer.Mailer) MailClient {
+	return MailClient{
+		Mailer: mailer,
+	}
+}
+
+func (m MailClient) SendCommentCreated(
+	ctx context.Context,
+	recipients []*types.PrincipalInfo,
+	payload *CommentCreatedPayload,
+) error {
+	mailPayload, err := GenerateEmailFromPayload(
+		TemplateCommentCreated,
+		recipients,
+		payload.Base,
+		payload,
+	)
+	if err != nil {
+		return fmt.Errorf("failed to generate mail requests after processing %s event: %w",
+			pullreqevents.CommentCreatedEvent, err)
+	}
+
+	return m.Mailer.Send(ctx, *mailPayload)
+}
+
+func (m MailClient) SendReviewerAdded(
+	ctx context.Context,
+	recipients []*types.PrincipalInfo,
+	payload *ReviewerAddedPayload,
+) error {
+	reviewerAddedMail, err := GenerateEmailFromPayload(
+		TemplateReviewerAdded,
+		recipients,
+		payload.Base,
+		payload,
+	)
+	if err != nil {
+		return fmt.Errorf("failed to generate mail requests after processing %s event: %w",
+			pullreqevents.ReviewerAddedEvent, err)
+	}
+
+	return m.Mailer.Send(ctx, *reviewerAddedMail)
+}
+
+func (m MailClient) SendPullReqBranchUpdated(
+	ctx context.Context,
+	recipients []*types.PrincipalInfo,
+	payload *PullReqBranchUpdatedPayload,
+) error {
+	mailPayload, err := GenerateEmailFromPayload(
+		TemplatePullReqBranchUpdated,
+		recipients,
+		payload.Base,
+		payload,
+	)
+	if err != nil {
+		return fmt.Errorf("failed to generate mail requests after processing %s event: %w",
+			pullreqevents.BranchUpdatedEvent, err)
+	}
+
+	return m.Mailer.Send(ctx, *mailPayload)
+}
+
+func GetSubjectPullRequest(
+	repoUID string,
+	prNum int64,
+	prTitle string,
+) string {
+	return fmt.Sprintf(subjectPullReqEvent, repoUID, prTitle, prNum)
+}
+
+func GetHTMLBody(templateName string, data interface{}) ([]byte, error) {
+	tmpl := htmlTemplates[templateName]
+	tmplOutput := bytes.Buffer{}
+	err := tmpl.Execute(&tmplOutput, data)
+	if err != nil {
+		return nil, fmt.Errorf("failed to execute template %s", templateName)
+	}
+
+	return tmplOutput.Bytes(), nil
+}
+
+func GenerateEmailFromPayload(
+	templateName string,
+	recipients []*types.PrincipalInfo,
+	base *BasePullReqPayload,
+	payload interface{},
+) (*mailer.Payload, error) {
+	subject := GetSubjectPullRequest(base.Repo.UID, base.PullReq.Number,
+		base.PullReq.Title)
+
+	body, err := GetHTMLBody(templateName, payload)
+	if err != nil {
+		return nil, err
+	}
+
+	var mail mailer.Payload
+	mail.Body = string(body)
+	mail.Subject = subject
+	mail.RepoRef = base.Repo.Path
+
+	recipientEmails := RetrieveEmailsFromPrincipals(recipients)
+	mail.ToRecipients = recipientEmails
+	return &mail, nil
+}
+
+func RetrieveEmailsFromPrincipals(principals []*types.PrincipalInfo) []string {
+	emails := make([]string, len(principals))
+	for i, principal := range principals {
+		emails[i] = principal.Email
+	}
+	return emails
+}

app/services/notification/mailer/mail.go

@@ -15,12 +15,13 @@
 package mailer
 
 import (
+	"context"
 	"crypto/tls"
 
 	gomail "gopkg.in/mail.v2"
 )
 
-type Service struct {
+type GoMailClient struct {
 	dialer   *gomail.Dialer
 	fromMail string
 }
@@ -32,18 +33,18 @@ func NewMailClient(
 	fromMail string,
 	password string,
 	insecure bool,
-) *Service {
+) GoMailClient {
 	d := gomail.NewDialer(host, port, username, password)
 	d.TLSConfig = &tls.Config{InsecureSkipVerify: insecure} // #nosec G402 (insecure TLS configuration)
 
-	return &Service{
+	return GoMailClient{
 		dialer:   d,
 		fromMail: fromMail,
 	}
 }
 
-func (c *Service) SendMail(mailRequest *MailRequest) error {
-	mail := mailRequest.ToGoMail()
+func (c GoMailClient) Send(_ context.Context, mailPayload Payload) error {
+	mail := ToGoMail(mailPayload)
 	mail.SetHeader("From", c.fromMail)
 	return c.dialer.DialAndSend(mail)
 }

app/services/notification/mailer/mail_interface.go

@@ -14,21 +14,34 @@
 
 package mailer
 
-import gomail "gopkg.in/mail.v2"
+import (
+	"context"
 
-type MailRequest struct {
-	CCRecipients []string `json:"cc_recipients"`
-	ToRecipients []string `json:"to_recipients"`
-	Subject      string   `json:"subject"`
-	Body         string   `json:"body"`
-	ContentType  string   `json:"content_type"`
+	gomail "gopkg.in/mail.v2"
+)
+
+const (
+	mailContentType = "text/html"
+)
+
+type Mailer interface {
+	Send(ctx context.Context, mailPayload Payload) error
 }
 
-func (dto *MailRequest) ToGoMail() *gomail.Message {
+type Payload struct {
+	CCRecipients []string
+	ToRecipients []string
+	Subject      string
+	Body         string
+	ContentType  string
+	RepoRef      string
+}
+
+func ToGoMail(dto Payload) *gomail.Message {
 	mail := gomail.NewMessage()
 	mail.SetHeader("To", dto.ToRecipients...)
 	mail.SetHeader("Cc", dto.CCRecipients...)
 	mail.SetHeader("Subject", dto.Subject)
-	mail.SetBody(dto.ContentType, dto.Body)
+	mail.SetBody(mailContentType, dto.Body)
 	return mail
 }

app/services/notification/mailer/wire.go

@@ -21,11 +21,11 @@ import (
 )
 
 var WireSet = wire.NewSet(
-	ProvideMailService,
+	ProvideMailClient,
 )
 
-func ProvideMailService(config *types.Config) *Service {
-	mailSvc := NewMailClient(
+func ProvideMailClient(config *types.Config) Mailer {
+	return NewMailClient(
 		config.SMTP.Host,
 		config.SMTP.Port,
 		config.SMTP.Username,
@@ -33,5 +33,4 @@ func ProvideMailService(config *types.Config) *Service {
 		config.SMTP.Password,
 		config.SMTP.Insecure, // #nosec G402 (insecure skipVerify configuration)
 	)
-	return mailSvc
 }

app/services/notification/reviewer_added.go

@@ -0,0 +1,81 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package notification
+
+import (
+	"context"
+	"fmt"
+
+	pullreqevents "github.com/harness/gitness/app/events/pullreq"
+	"github.com/harness/gitness/events"
+	"github.com/harness/gitness/types"
+)
+
+type ReviewerAddedPayload struct {
+	Base     *BasePullReqPayload
+	Reviewer *types.PrincipalInfo
+}
+
+func (s *Service) notifyReviewerAdded(
+	ctx context.Context,
+	event *events.Event[*pullreqevents.ReviewerAddedPayload],
+) error {
+	payload, err := s.processReviewerAddedEvent(ctx, event)
+	if err != nil {
+		return fmt.Errorf(
+			"failed to process %s event for pullReqID %d: %w",
+			pullreqevents.ReviewerAddedEvent,
+			event.Payload.PullReqID,
+			err,
+		)
+	}
+
+	// Send notification to author and reviewer
+	recipients := []*types.PrincipalInfo{
+		payload.Base.Author,
+		payload.Reviewer,
+	}
+	err = s.notificationClient.SendReviewerAdded(ctx, recipients, payload)
+	if err != nil {
+		return fmt.Errorf(
+			"failed to send notification for event %s for pullReqID %d: %w",
+			pullreqevents.ReviewerAddedEvent,
+			event.Payload.PullReqID,
+			err,
+		)
+	}
+
+	return nil
+}
+
+func (s *Service) processReviewerAddedEvent(
+	ctx context.Context,
+	event *events.Event[*pullreqevents.ReviewerAddedPayload],
+) (*ReviewerAddedPayload, error) {
+	base, err := s.getBasePayload(ctx, event.Payload.Base)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get base payload: %w", err)
+	}
+
+	reviewerPrincipal, err := s.principalInfoCache.Get(ctx, event.Payload.ReviewerID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to get reviewer from principalInfoCache: %w", err)
+	}
+
+	return &ReviewerAddedPayload{
+		Base:     base,
+		Reviewer: reviewerPrincipal,
+	}, nil
+}

app/services/notification/service.go

@@ -0,0 +1,179 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package notification
+
+import (
+	"context"
+	"embed"
+	"fmt"
+	"html/template"
+	"io/fs"
+	"path"
+
+	pullreqevents "github.com/harness/gitness/app/events/pullreq"
+	"github.com/harness/gitness/app/store"
+	"github.com/harness/gitness/app/url"
+	"github.com/harness/gitness/events"
+	"github.com/harness/gitness/stream"
+	"github.com/harness/gitness/types"
+)
+
+const (
+	eventReaderGroupName = "gitness:notification"
+	templatesDir         = "templates"
+	subjectPullReqEvent  = "[%s] %s (PR #%d)"
+)
+
+var (
+	//go:embed  templates/*
+	files         embed.FS
+	htmlTemplates map[string]*template.Template
+)
+
+func init() {
+	err := LoadTemplates()
+	if err != nil {
+		panic(err)
+	}
+}
+
+func LoadTemplates() error {
+	htmlTemplates = make(map[string]*template.Template)
+	tmplFiles, err := fs.ReadDir(files, templatesDir)
+	if err != nil {
+		return err
+	}
+
+	for _, tmpl := range tmplFiles {
+		if tmpl.IsDir() {
+			continue
+		}
+
+		pt, err := template.ParseFS(files, path.Join(templatesDir, tmpl.Name()))
+		if err != nil {
+			return err
+		}
+
+		htmlTemplates[tmpl.Name()] = pt
+	}
+	return nil
+}
+
+type BasePullReqPayload struct {
+	Repo       *types.Repository
+	PullReq    *types.PullReq
+	Author     *types.PrincipalInfo
+	PullReqURL string
+}
+
+type Config struct {
+	EventReaderName string
+	Concurrency     int
+	MaxRetries      int
+}
+
+type Service struct {
+	config                Config
+	notificationClient    Client
+	prReaderFactory       *events.ReaderFactory[*pullreqevents.Reader]
+	pullReqStore          store.PullReqStore
+	repoStore             store.RepoStore
+	principalInfoView     store.PrincipalInfoView
+	principalInfoCache    store.PrincipalInfoCache
+	pullReqReviewersStore store.PullReqReviewerStore
+	pullReqActivityStore  store.PullReqActivityStore
+	spacePathStore        store.SpacePathStore
+	urlProvider           url.Provider
+}
+
+func NewService(
+	ctx context.Context,
+	config Config,
+	notificationClient Client,
+	prReaderFactory *events.ReaderFactory[*pullreqevents.Reader],
+	pullReqStore store.PullReqStore,
+	repoStore store.RepoStore,
+	principalInfoView store.PrincipalInfoView,
+	principalInfoCache store.PrincipalInfoCache,
+	pullReqReviewersStore store.PullReqReviewerStore,
+	pullReqActivityStore store.PullReqActivityStore,
+	spacePathStore store.SpacePathStore,
+	urlProvider url.Provider,
+) (*Service, error) {
+	service := &Service{
+		config:                config,
+		notificationClient:    notificationClient,
+		prReaderFactory:       prReaderFactory,
+		pullReqStore:          pullReqStore,
+		repoStore:             repoStore,
+		principalInfoView:     principalInfoView,
+		principalInfoCache:    principalInfoCache,
+		pullReqReviewersStore: pullReqReviewersStore,
+		pullReqActivityStore:  pullReqActivityStore,
+		spacePathStore:        spacePathStore,
+		urlProvider:           urlProvider,
+	}
+
+	_, err := service.prReaderFactory.Launch(
+		ctx,
+		eventReaderGroupName,
+		config.EventReaderName,
+		func(r *pullreqevents.Reader,
+		) error {
+			r.Configure(
+				stream.WithConcurrency(config.Concurrency),
+				stream.WithHandlerOptions(
+					stream.WithMaxRetries(config.MaxRetries),
+				))
+
+			_ = r.RegisterReviewerAdded(service.notifyReviewerAdded)
+			_ = r.RegisterCommentCreated(service.notifyCommentCreated)
+			_ = r.RegisterBranchUpdated(service.notifyPullReqBranchUpdated)
+			return nil
+		})
+	if err != nil {
+		return nil, fmt.Errorf("failed to launch event reader for %s: %w", eventReaderGroupName, err)
+	}
+
+	return service, nil
+}
+
+func (s *Service) getBasePayload(
+	ctx context.Context,
+	base pullreqevents.Base,
+) (*BasePullReqPayload, error) {
+	repo, err := s.repoStore.Find(ctx, base.TargetRepoID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch repo from repoStore: %w", err)
+	}
+	pullReq, err := s.pullReqStore.Find(ctx, base.PullReqID)
+	if err != nil {
+		return nil, fmt.Errorf("failed to fetch pullreq from pullReqStore: %w", err)
+	}
+
+	author, err := s.principalInfoCache.Get(ctx, pullReq.CreatedBy)
+	if err != nil {
+		return nil,
+			fmt.Errorf("failed to fetch author %d from principalInfoCache while building base notification: %w",
+				pullReq.CreatedBy, err)
+	}
+
+	return &BasePullReqPayload{
+		Repo:       repo,
+		PullReq:    pullReq,
+		Author:     author,
+		PullReqURL: s.urlProvider.GenerateUIPRURL(repo.Path, pullReq.Number),
+	}, nil
+}

app/services/notification/templates/comment_created.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+</head>
+<body>
+<p>
+    <b>@{{.Commenter.DisplayName}}</b> commented on pull request <b>#{{.Base.PullReq.Number}}:{{.Base.PullReq.Title}}</b>
+</p>
+<p>
+    {{.Text}}
+</p>
+<p>
+    <a href="{{.Base.PullReqURL}}">View pull request #{{.Base.PullReq.Number}}</a>
+</p>
+</body>
+</html>

app/services/notification/templates/pullreq_branch_updated.html

@@ -0,0 +1,17 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+    <meta charset="UTF-8">
+</head>
+<body>
+<p>
+    <b>@{{.Committer.DisplayName}}</b> pushed new commits to pull request <b>#{{.Base.PullReq.Number}}:{{.Base.PullReq.Title}}</b>
+</p>
+<p>
+    Latest commit is {{.NewSHA}}
+</p>
+<p>
+    <a href="{{.Base.PullReqURL}}">View pull request #{{.Base.PullReq.Number}}</a>
+</p>
+</body>
+</html>

app/services/notification/templates/reviewer_added.html

@@ -0,0 +1,14 @@
+<!DOCTYPE html>
+<html lang="en">
+<head>
+  <meta charset="UTF-8">
+</head>
+<body>
+<p>
+  <b>@{{.Reviewer.DisplayName}}</b> was added as a reviewer for the Pull request: <b>#{{.Base.PullReq.Number}}:{{.Base.PullReq.Title}}</b>
+</p>
+<p>
+  <a href="{{.Base.PullReqURL}}">View pull request #{{.Base.PullReq.Number}}</a>
+</p>
+</body>
+</html>

app/services/notification/wire.go

@@ -0,0 +1,66 @@
+// Copyright 2023 Harness, Inc.
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package notification
+
+import (
+	"context"
+
+	pullreqevents "github.com/harness/gitness/app/events/pullreq"
+	"github.com/harness/gitness/app/services/notification/mailer"
+	"github.com/harness/gitness/app/store"
+	"github.com/harness/gitness/app/url"
+	"github.com/harness/gitness/events"
+
+	"github.com/google/wire"
+)
+
+var WireSet = wire.NewSet(
+	ProvideMailClient,
+	ProvideNotificationService,
+)
+
+func ProvideNotificationService(
+	ctx context.Context,
+	notificationClient Client,
+	pullReqConfig Config,
+	prReaderFactory *events.ReaderFactory[*pullreqevents.Reader],
+	pullReqStore store.PullReqStore,
+	repoStore store.RepoStore,
+	principalInfoView store.PrincipalInfoView,
+	principalInfoCache store.PrincipalInfoCache,
+	pullReqReviewersStore store.PullReqReviewerStore,
+	pullReqActivityStore store.PullReqActivityStore,
+	spacePathStore store.SpacePathStore,
+	urlProvider url.Provider,
+) (*Service, error) {
+	return NewService(
+		ctx,
+		pullReqConfig,
+		notificationClient,
+		prReaderFactory,
+		pullReqStore,
+		repoStore,
+		principalInfoView,
+		principalInfoCache,
+		pullReqReviewersStore,
+		pullReqActivityStore,
+		spacePathStore,
+		urlProvider,
+	)
+}
+
+func ProvideMailClient(mailer mailer.Mailer) Client {
+	return NewMailClient(mailer)
+}

app/services/wire.go

@@ -19,6 +19,7 @@ import (
 	"github.com/harness/gitness/app/services/job"
 	"github.com/harness/gitness/app/services/keywordsearch"
 	"github.com/harness/gitness/app/services/metric"
+	"github.com/harness/gitness/app/services/notification"
 	"github.com/harness/gitness/app/services/pullreq"
 	"github.com/harness/gitness/app/services/trigger"
 	"github.com/harness/gitness/app/services/webhook"
@@ -37,6 +38,7 @@ type Services struct {
 	JobScheduler    *job.Scheduler
 	MetricCollector *metric.Collector
 	Cleanup         *cleanup.Service
+	Notification    *notification.Service
 	Keywordsearch   *keywordsearch.Service
 }
 
@@ -47,6 +49,7 @@ func ProvideServices(
 	jobScheduler *job.Scheduler,
 	metricCollector *metric.Collector,
 	cleanupSvc *cleanup.Service,
+	notificationSvc *notification.Service,
 	keywordsearchSvc *keywordsearch.Service,
 ) Services {
 	return Services{
@@ -56,6 +59,7 @@ func ProvideServices(
 		JobScheduler:    jobScheduler,
 		MetricCollector: metricCollector,
 		Cleanup:         cleanupSvc,
+		Notification:    notificationSvc,
 		Keywordsearch:   keywordsearchSvc,
 	}
 }

cli/server/config.go

@@ -25,6 +25,7 @@ import (
 	"github.com/harness/gitness/app/services/cleanup"
 	"github.com/harness/gitness/app/services/codeowners"
 	"github.com/harness/gitness/app/services/keywordsearch"
+	"github.com/harness/gitness/app/services/notification"
 	"github.com/harness/gitness/app/services/trigger"
 	"github.com/harness/gitness/app/services/webhook"
 	"github.com/harness/gitness/blob"
@@ -279,6 +280,14 @@ func ProvideWebhookConfig(config *types.Config) webhook.Config {
 	}
 }
 
+func ProvideNotificationConfig(config *types.Config) notification.Config {
+	return notification.Config{
+		EventReaderName: config.InstanceID,
+		Concurrency:     config.Notification.Concurrency,
+		MaxRetries:      config.Notification.MaxRetries,
+	}
+}
+
 // ProvideTriggerConfig loads the trigger service config from the main config.
 func ProvideTriggerConfig(config *types.Config) trigger.Config {
 	return trigger.Config{

cmd/gitness/wire.go

@@ -9,7 +9,6 @@ package main
 
 import (
 	"context"
-
 	checkcontroller "github.com/harness/gitness/app/api/controller/check"
 	"github.com/harness/gitness/app/api/controller/connector"
 	"github.com/harness/gitness/app/api/controller/execution"
@@ -56,6 +55,8 @@ import (
 	"github.com/harness/gitness/app/services/job"
 	"github.com/harness/gitness/app/services/keywordsearch"
 	"github.com/harness/gitness/app/services/metric"
+	"github.com/harness/gitness/app/services/notification"
+	"github.com/harness/gitness/app/services/notification/mailer"
 	"github.com/harness/gitness/app/services/protection"
 	pullreqservice "github.com/harness/gitness/app/services/pullreq"
 	"github.com/harness/gitness/app/services/trigger"
@@ -92,6 +93,8 @@ func initSystem(ctx context.Context, config *types.Config) (*cliserver.System, e
 		cliserver.ProvideDatabaseConfig,
 		database.WireSet,
 		cliserver.ProvideBlobStoreConfig,
+		mailer.WireSet,
+		notification.WireSet,
 		blob.WireSet,
 		dbtx.WireSet,
 		cache.WireSet,
@@ -124,6 +127,7 @@ func initSystem(ctx context.Context, config *types.Config) (*cliserver.System, e
 		cliserver.ProvideEventsConfig,
 		events.WireSet,
 		cliserver.ProvideWebhookConfig,
+		cliserver.ProvideNotificationConfig,
 		webhook.WireSet,
 		cliserver.ProvideTriggerConfig,
 		trigger.WireSet,

cmd/gitness/wire_gen.go

@@ -55,6 +55,8 @@ import (
 	"github.com/harness/gitness/app/services/job"
 	"github.com/harness/gitness/app/services/keywordsearch"
 	"github.com/harness/gitness/app/services/metric"
+	"github.com/harness/gitness/app/services/notification"
+	"github.com/harness/gitness/app/services/notification/mailer"
 	"github.com/harness/gitness/app/services/protection"
 	"github.com/harness/gitness/app/services/pullreq"
 	trigger2 "github.com/harness/gitness/app/services/trigger"
@@ -286,12 +288,19 @@ func initSystem(ctx context.Context, config *types.Config) (*server.System, erro
 	if err != nil {
 		return nil, err
 	}
+	mailerMailer := mailer.ProvideMailClient(config)
+	notificationClient := notification.ProvideMailClient(mailerMailer)
+	notificationConfig := server.ProvideNotificationConfig(config)
+	notificationService, err := notification.ProvideNotificationService(ctx, notificationClient, notificationConfig, eventsReaderFactory, pullReqStore, repoStore, principalInfoView, principalInfoCache, pullReqReviewerStore, pullReqActivityStore, spacePathStore, provider)
+	if err != nil {
+		return nil, err
+	}
 	keywordsearchConfig := server.ProvideKeywordSearchConfig(config)
 	keywordsearchService, err := keywordsearch.ProvideService(ctx, keywordsearchConfig, readerFactory, repoStore, indexer)
 	if err != nil {
 		return nil, err
 	}
-	servicesServices := services.ProvideServices(webhookService, pullreqService, triggerService, jobScheduler, collector, cleanupService, keywordsearchService)
+	servicesServices := services.ProvideServices(webhookService, pullreqService, triggerService, jobScheduler, collector, cleanupService, notificationService, keywordsearchService)
 	serverSystem := server.NewSystem(bootstrapBootstrap, serverServer, poller, pluginManager, servicesServices)
 	return serverSystem, nil
 }

types/config.go

@@ -324,6 +324,11 @@ type Config struct {
 		Insecure bool   `envconfig:"GITNESS_SMTP_INSECURE"`
 	}
 
+	Notification struct {
+		MaxRetries  int `envconfig:"GITNESS_NOTIFICATION_MAX_RETRIES" default:"3"`
+		Concurrency int `envconfig:"GITNESS_NOTIFICATION_CONCURRENCY" default:"4"`
+	}
+
 	KeywordSearch struct {
 		Concurrency int `envconfig:"GITNESS_KEYWORD_SEARCH_CONCURRENCY" default:"4"`
 		MaxRetries  int `envconfig:"GITNESS_KEYWORD_SEARCH_MAX_RETRIES" default:"3"`