Add Ability for User to Customize Email Notification Frequency (#7813)

* Add Backend Logic for Toggling Email Notification

This commit adds the backend logic for
allowing users to enable or disable email
notifications. The implementation ensures
that only issue notification emails get disabled
and important emails are still sent regardless
of the setting.

The UI to toggle this setting has not yet been
implemented.

* Add UI and complete user email notification enable

This commit completes the functionality to allow
users to disable their own email notifications.

Signed-off-by: Gary Kim <gary@garykim.dev>

* Add Third Option for Only Email on Mention

Signed-off-by: Gary Kim <gary@garykim.dev>

* Readd NOT NULL to new preference string

Signed-off-by: Gary Kim <gary@garykim.dev>

* Add Tests and Rewrite Comment

Signed-off-by: Gary Kim <gary@garykim.dev>

* Allow admin to set default email frequency

Signed-off-by: Gary Kim <gary@garykim.dev>

* Add new config option to docs

Signed-off-by: Gary Kim <gary@garykim.dev>

* Fix a few mistakes

Signed-off-by: Gary Kim <gary@garykim.dev>

* Only update required columns

Signed-off-by: Gary Kim <gary@garykim.dev>

* Simplify an error check

Signed-off-by: Gary Kim <gary@garykim.dev>

* Make email_notification_preference column in DB be VARCHAR(20)

Signed-off-by: Gary Kim <gary@garykim.dev>

* Handle errors

Signed-off-by: Gary Kim <gary@garykim.dev>

* Update models/migrations/v93.go

Co-Authored-By: Lauris BH <lauris@nix.lv>

14 files changed, 162 insertions, 14 deletions

diff --git a/custom/conf/app.ini.sample b/custom/conf/app.ini.sample
index 82ffd2d785..a2ac7248e7 100644
--- a/custom/conf/app.ini.sample
+++ b/custom/conf/app.ini.sample
@@ -306,6 +306,8 @@ MAX_FILE_SIZE = 1048576
 [admin]
 ; Disallow regular (non-admin) users from creating organizations.
 DISABLE_REGULAR_ORG_CREATION = false
+; Default configuration for email notifications for users (user configurable). Options: enabled, onmention, disabled
+DEFAULT_EMAIL_NOTIFICATIONS = enabled
 
 [security]
 ; Whether the installer is disabled
diff --git a/docs/content/doc/advanced/config-cheat-sheet.en-us.md b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
index 252ceee733..10c6110f37 100644
--- a/docs/content/doc/advanced/config-cheat-sheet.en-us.md
+++ b/docs/content/doc/advanced/config-cheat-sheet.en-us.md
@@ -184,6 +184,9 @@ Values containing `#` or `;` must be quoted using `` ` `` or `"""`.
 - `UPDATE_BUFFER_LEN`: **20**: Buffer length of index request.
 - `MAX_FILE_SIZE`: **1048576**: Maximum size in bytes of files to be indexed.
 
+## Admin (`admin`)
+- `DEFAULT_EMAIL_NOTIFICATIONS`: **enabled**: Default configuration for email notifications for users (user configurable). Options: enabled, onmention, disabled
+
 ## Security (`security`)
 
 - `INSTALL_LOCK`: **false**: Disallow access to the install page.
diff --git a/models/fixtures/user.yml b/models/fixtures/user.yml
index d89dc3c126..37225f1449 100644
--- a/models/fixtures/user.yml
+++ b/models/fixtures/user.yml
@@ -6,6 +6,7 @@
   name: user1
   full_name: User One
   email: user1@example.com
+  email_notifications_preference: enabled
   passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
   type: 0 # individual
   salt: ZogKvWdyEx
@@ -22,6 +23,7 @@
   full_name: "   < U<se>r Tw<o > ><  "
   email: user2@example.com
   keep_email_private: true
+  email_notifications_preference: enabled
   passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
   type: 0 # individual
   salt: ZogKvWdyEx
@@ -40,6 +42,7 @@
   name: user3
   full_name: " <<<< >> >> > >> > >>> >> "
   email: user3@example.com
+  email_notifications_preference: onmention
   passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
   type: 1 # organization
   salt: ZogKvWdyEx
@@ -56,6 +59,7 @@
   name: user4
   full_name: "          "
   email: user4@example.com
+  email_notifications_preference: onmention
   passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
   type: 0 # individual
   salt: ZogKvWdyEx
@@ -72,6 +76,7 @@
   name: user5
   full_name: User Five
   email: user5@example.com
+  email_notifications_preference: enabled
   passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
   type: 0 # individual
   salt: ZogKvWdyEx
@@ -89,6 +94,7 @@
   name: user6
   full_name: User Six
   email: user6@example.com
+  email_notifications_preference: enabled
   passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
   type: 1 # organization
   salt: ZogKvWdyEx
@@ -105,6 +111,7 @@
   name: user7
   full_name: User Seven
   email: user7@example.com
+  email_notifications_preference: disabled
   passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
   type: 1 # organization
   salt: ZogKvWdyEx
@@ -121,6 +128,7 @@
   name: user8
   full_name: User Eight
   email: user8@example.com
+  email_notifications_preference: enabled
   passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
   type: 0 # individual
   salt: ZogKvWdyEx
@@ -138,6 +146,7 @@
   name: user9
   full_name: User Nine
   email: user9@example.com
+  email_notifications_preference: onmention
   passwd: 7d93daa0d1e6f2305cc8fa496847d61dc7320bb16262f9c55dd753480207234cdd96a93194e408341971742f4701772a025a # password
   type: 0 # individual
   salt: ZogKvWdyEx
diff --git a/models/issue_mail.go b/models/issue_mail.go
index 829c4cea78..87d991e500 100644
--- a/models/issue_mail.go
+++ b/models/issue_mail.go
@@ -70,7 +70,7 @@ func mailIssueCommentToParticipants(e Engine, issue *Issue, doer *User, content
 		if err != nil {
 			return fmt.Errorf("GetUserByID [%d]: %v", watchers[i].UserID, err)
 		}
-		if to.IsOrganization() {
+		if to.IsOrganization() || to.EmailNotifications() != EmailNotificationsEnabled {
 			continue
 		}
 
@@ -78,9 +78,9 @@ func mailIssueCommentToParticipants(e Engine, issue *Issue, doer *User, content
 		names = append(names, to.Name)
 	}
 	for i := range participants {
-		if participants[i].ID == doer.ID {
-			continue
-		} else if com.IsSliceContainsStr(names, participants[i].Name) {
+		if participants[i].ID == doer.ID ||
+			com.IsSliceContainsStr(names, participants[i].Name) ||
+			participants[i].EmailNotifications() != EmailNotificationsEnabled {
 			continue
 		}
 
diff --git a/models/migrations/migrations.go b/models/migrations/migrations.go
index 7d97741a20..15e021c05a 100644
--- a/models/migrations/migrations.go
+++ b/models/migrations/migrations.go
@@ -240,6 +240,8 @@ var migrations = []Migration{
 	NewMigration("add index on owner_id of repository and type, review_id of comment", addIndexOnRepositoryAndComment),
 	// v92 -> v93
 	NewMigration("remove orphaned repository index statuses", removeLingeringIndexStatus),
+	// v93 -> v94
+	NewMigration("add email notification enabled preference to user", addEmailNotificationEnabledToUser),
 }
 
 // Migrate database to current version
diff --git a/models/migrations/v93.go b/models/migrations/v93.go
new file mode 100644
index 0000000000..0b0441cd5d
--- /dev/null
+++ b/models/migrations/v93.go
@@ -0,0 +1,16 @@
+// Copyright 2019 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 migrations
+
+import "github.com/go-xorm/xorm"
+
+func addEmailNotificationEnabledToUser(x *xorm.Engine) error {
+	// User see models/user.go
+	type User struct {
+		EmailNotificationsPreference string `xorm:"VARCHAR(20) NOT NULL DEFAULT 'enabled'"`
+	}
+
+	return x.Sync2(new(User))
+}
diff --git a/models/user.go b/models/user.go
index ed0fe524e4..af4ccacf6f 100644
--- a/models/user.go
+++ b/models/user.go
@@ -58,6 +58,13 @@ const (
 	algoScrypt = "scrypt"
 	algoArgon2 = "argon2"
 	algoPbkdf2 = "pbkdf2"
+
+	// EmailNotificationsEnabled indicates that the user would like to receive all email notifications
+	EmailNotificationsEnabled = "enabled"
+	// EmailNotificationsOnMention indicates that the user would like to be notified via email when mentioned.
+	EmailNotificationsOnMention = "onmention"
+	// EmailNotificationsDisabled indicates that the user would not like to be notified via email.
+	EmailNotificationsDisabled = "disabled"
 )
 
 var (
@@ -87,10 +94,11 @@ type User struct {
 	Name      string `xorm:"UNIQUE NOT NULL"`
 	FullName  string
 	// Email is the primary email address (to be used for communication)
-	Email            string `xorm:"NOT NULL"`
-	KeepEmailPrivate bool
-	Passwd           string `xorm:"NOT NULL"`
-	PasswdHashAlgo   string `xorm:"NOT NULL DEFAULT 'pbkdf2'"`
+	Email                        string `xorm:"NOT NULL"`
+	KeepEmailPrivate             bool
+	EmailNotificationsPreference string `xorm:"VARCHAR(20) NOT NULL DEFAULT 'enabled'"`
+	Passwd                       string `xorm:"NOT NULL"`
+	PasswdHashAlgo               string `xorm:"NOT NULL DEFAULT 'pbkdf2'"`
 
 	// MustChangePassword is an attribute that determines if a user
 	// is to change his/her password after registration.
@@ -719,6 +727,21 @@ func (u *User) IsMailable() bool {
 	return u.IsActive
 }
 
+// EmailNotifications returns the User's email notification preference
+func (u *User) EmailNotifications() string {
+	return u.EmailNotificationsPreference
+}
+
+// SetEmailNotifications sets the user's email notification preference
+func (u *User) SetEmailNotifications(set string) error {
+	u.EmailNotificationsPreference = set
+	if err := UpdateUserCols(u, "email_notifications_preference"); err != nil {
+		log.Error("SetEmailNotifications: %v", err)
+		return err
+	}
+	return nil
+}
+
 func isUserExist(e Engine, uid int64, name string) (bool, error) {
 	if len(name) == 0 {
 		return false, nil
@@ -868,6 +891,7 @@ func CreateUser(u *User) (err error) {
 	}
 	u.HashPassword(u.Passwd)
 	u.AllowCreateOrganization = setting.Service.DefaultAllowCreateOrganization && !setting.Admin.DisableRegularOrgCreation
+	u.EmailNotificationsPreference = setting.Admin.DefaultEmailNotification
 	u.MaxRepoCreation = -1
 	u.Theme = setting.UI.DefaultTheme
 
@@ -1253,7 +1277,8 @@ func getUserByName(e Engine, name string) (*User, error) {
 	return u, nil
 }
 
-// GetUserEmailsByNames returns a list of e-mails corresponds to names.
+// GetUserEmailsByNames returns a list of e-mails corresponds to names of users
+// that have their email notifications set to enabled or onmention.
 func GetUserEmailsByNames(names []string) []string {
 	return getUserEmailsByNames(x, names)
 }
@@ -1265,7 +1290,7 @@ func getUserEmailsByNames(e Engine, names []string) []string {
 		if err != nil {
 			continue
 		}
-		if u.IsMailable() {
+		if u.IsMailable() && u.EmailNotifications() != EmailNotificationsDisabled {
 			mails = append(mails, u.Email)
 		}
 	}
diff --git a/models/user_test.go b/models/user_test.go
index 290253c4b1..d01b482ae8 100644
--- a/models/user_test.go
+++ b/models/user_test.go
@@ -74,6 +74,8 @@ func TestGetUserEmailsByNames(t *testing.T) {
 	// ignore none active user email
 	assert.Equal(t, []string{"user8@example.com"}, GetUserEmailsByNames([]string{"user8", "user9"}))
 	assert.Equal(t, []string{"user8@example.com", "user5@example.com"}, GetUserEmailsByNames([]string{"user8", "user5"}))
+
+	assert.Equal(t, []string{"user8@example.com"}, GetUserEmailsByNames([]string{"user8", "user7"}))
 }
 
 func TestUser_APIFormat(t *testing.T) {
@@ -196,6 +198,37 @@ func TestDeleteUser(t *testing.T) {
 	test(11)
 }
 
+func TestEmailNotificationPreferences(t *testing.T) {
+	assert.NoError(t, PrepareTestDatabase())
+	for _, test := range []struct {
+		expected string
+		userID   int64
+	}{
+		{EmailNotificationsEnabled, 1},
+		{EmailNotificationsEnabled, 2},
+		{EmailNotificationsOnMention, 3},
+		{EmailNotificationsOnMention, 4},
+		{EmailNotificationsEnabled, 5},
+		{EmailNotificationsEnabled, 6},
+		{EmailNotificationsDisabled, 7},
+		{EmailNotificationsEnabled, 8},
+		{EmailNotificationsOnMention, 9},
+	} {
+		user := AssertExistsAndLoadBean(t, &User{ID: test.userID}).(*User)
+		assert.Equal(t, test.expected, user.EmailNotifications())
+
+		// Try all possible settings
+		assert.NoError(t, user.SetEmailNotifications(EmailNotificationsEnabled))
+		assert.Equal(t, EmailNotificationsEnabled, user.EmailNotifications())
+
+		assert.NoError(t, user.SetEmailNotifications(EmailNotificationsOnMention))
+		assert.Equal(t, EmailNotificationsOnMention, user.EmailNotifications())
+
+		assert.NoError(t, user.SetEmailNotifications(EmailNotificationsDisabled))
+		assert.Equal(t, EmailNotificationsDisabled, user.EmailNotifications())
+	}
+}
+
 func TestHashPasswordDeterministic(t *testing.T) {
 	b := make([]byte, 16)
 	rand.Read(b)
diff --git a/modules/setting/setting.go b/modules/setting/setting.go
index 3ff9f89ad5..5e476854b2 100644
--- a/modules/setting/setting.go
+++ b/modules/setting/setting.go
@@ -231,6 +231,7 @@ var (
 	// Admin settings
 	Admin struct {
 		DisableRegularOrgCreation bool
+		DefaultEmailNotification  string
 	}
 
 	// Picture settings
@@ -754,6 +755,9 @@ func NewContext() {
 		}
 	}
 
+	sec = Cfg.Section("admin")
+	Admin.DefaultEmailNotification = sec.Key("DEFAULT_EMAIL_NOTIFICATIONS").MustString("enabled")
+
 	sec = Cfg.Section("security")
 	InstallLock = sec.Key("INSTALL_LOCK").MustBool(false)
 	SecretKey = sec.Key("SECRET_KEY").MustString("!#@FDEWREWR&*(")
diff --git a/options/locale/locale_en-US.ini b/options/locale/locale_en-US.ini
index d6d54a2249..90ee32a25c 100644
--- a/options/locale/locale_en-US.ini
+++ b/options/locale/locale_en-US.ini
@@ -557,6 +557,11 @@ confirm_delete_account = Confirm Deletion
 delete_account_title = Delete User Account
 delete_account_desc = Are you sure you want to permanently delete this user account?
 
+email_notifications.enable = Enable Email Notifications
+email_notifications.onmention = Only Email on Mention
+email_notifications.disable = Disable Email Notifications
+email_notifications.submit = Set Email Preference
+
 [repo]
 owner = Owner
 repo_name = Repository Name
@@ -1126,6 +1131,10 @@ settings.basic_settings = Basic Settings
 settings.mirror_settings = Mirror Settings
 settings.sync_mirror = Synchronize Now
 settings.mirror_sync_in_progress = Mirror synchronization is in progress. Check back in a minute.
+settings.email_notifications.enable = Enable Email Notifications
+settings.email_notifications.onmention = Only Email on Mention
+settings.email_notifications.disable = Disable Email Notifications
+settings.email_notifications.submit = Set Email Preference
 settings.site = Website
 settings.update_settings = Update Settings
 settings.advanced_settings = Advanced Settings
diff --git a/public/css/index.css b/public/css/index.css
index ad1d0313f7..a609637581 100644
--- a/public/css/index.css
+++ b/public/css/index.css
@@ -786,7 +786,7 @@ footer .ui.left,footer .ui.right{line-height:40px}
 .ui.form .dropzone .dz-error-message{top:140px}
 .settings .content{margin-top:2px}
 .settings .content .segment,.settings .content>.header{box-shadow:0 1px 2px 0 rgba(34,36,38,.15)}
-.settings .list>.item .green{color:#21ba45}
+.settings .list>.item .green:not(.ui.button){color:#21ba45}
 .settings .list>.item:not(:first-child){border-top:1px solid #eaeaea;padding:1rem;margin:15px -1rem -1rem -1rem}
 .settings .list>.item>.mega-octicon{display:table-cell}
 .settings .list>.item>.mega-octicon+.content{display:table-cell;padding:0 0 0 .5em;vertical-align:top}
diff --git a/public/less/_repository.less b/public/less/_repository.less
index ef05beb6fa..a66d13891b 100644
--- a/public/less/_repository.less
+++ b/public/less/_repository.less
@@ -2013,7 +2013,7 @@
 
     .list {
         > .item {
-            .green {
+            .green:not(.ui.button) {
                 color: #21ba45;
             }
 
diff --git a/routers/user/setting/account.go b/routers/user/setting/account.go
index c6b5c0c2dc..674606cce8 100644
--- a/routers/user/setting/account.go
+++ b/routers/user/setting/account.go
@@ -6,6 +6,8 @@
 package setting
 
 import (
+	"errors"
+
 	"code.gitea.io/gitea/models"
 	"code.gitea.io/gitea/modules/auth"
 	"code.gitea.io/gitea/modules/base"
@@ -24,6 +26,7 @@ func Account(ctx *context.Context) {
 	ctx.Data["Title"] = ctx.Tr("settings")
 	ctx.Data["PageIsSettingsAccount"] = true
 	ctx.Data["Email"] = ctx.User.Email
+	ctx.Data["EmailNotificationsPreference"] = ctx.User.EmailNotifications()
 
 	loadAccountData(ctx)
 
@@ -82,6 +85,25 @@ func EmailPost(ctx *context.Context, form auth.AddEmailForm) {
 		ctx.Redirect(setting.AppSubURL + "/user/settings/account")
 		return
 	}
+	// Set Email Notification Preference
+	if ctx.Query("_method") == "NOTIFICATION" {
+		preference := ctx.Query("preference")
+		if !(preference == models.EmailNotificationsEnabled ||
+			preference == models.EmailNotificationsOnMention ||
+			preference == models.EmailNotificationsDisabled) {
+			log.Error("Email notifications preference change returned unrecognized option %s: %s", preference, ctx.User.Name)
+			ctx.ServerError("SetEmailPreference", errors.New("option unrecognized"))
+			return
+		}
+		if err := ctx.User.SetEmailNotifications(preference); err != nil {
+			log.Error("Set Email Notifications failed: %v", err)
+			ctx.ServerError("SetEmailNotifications", err)
+			return
+		}
+		log.Trace("Email notifications preference made %s: %s", preference, ctx.User.Name)
+		ctx.Redirect(setting.AppSubURL + "/user/settings/account")
+		return
+	}
 
 	if ctx.HasError() {
 		loadAccountData(ctx)
diff --git a/templates/user/settings/account.tmpl b/templates/user/settings/account.tmpl
index 778103e44d..dcb5770acc 100644
--- a/templates/user/settings/account.tmpl
+++ b/templates/user/settings/account.tmpl
@@ -43,7 +43,30 @@
 		<div class="ui attached segment">
 			<div class="ui email list">
 				<div class="item">
-					{{.i18n.Tr "settings.email_desc"}}
+					<form action="{{AppSubUrl}}/user/settings/account/email" class="ui form" method="post">
+						{{.i18n.Tr "settings.email_desc"}}
+						<div class="right floated content">
+							<div class="field">
+								<button class="ui green button">{{$.i18n.Tr "settings.email_notifications.submit"}}</button>
+							</div>
+						</div>
+						<div class="right floated content">
+							{{$.CsrfTokenHtml}}
+							<input name="_method" type="hidden" value="NOTIFICATION">
+							<div class="field">
+								<div class="ui selection dropdown" tabindex="0">
+									<input name="preference" type="hidden" value="{{.EmailNotificationsPreference}}">
+									<i class="dropdown icon"></i>
+									<div class="text">{{$.i18n.Tr "settings.email_notifications"}}</div>
+									<div class="menu">
+										<div data-value="enabled" class="{{if eq .EmailNotificationsPreference "enabled"}}active selected {{end}}item">{{$.i18n.Tr "settings.email_notifications.enable"}}</div>
+										<div data-value="onmention" class="{{if eq .EmailNotificationsPreference "onmention"}}active selected {{end}}item">{{$.i18n.Tr "settings.email_notifications.onmention"}}</div>
+										<div data-value="disabled" class="{{if eq .EmailNotificationsPreference "disabled"}}active selected {{end}}item">{{$.i18n.Tr "settings.email_notifications.disable"}}</div>
+									</div>
+								</div>
+							</div>
+						</div>
+					</form>
 				</div>
 				{{range .Emails}}
 					<div class="item">
@@ -103,7 +126,7 @@
 							<i class="dropdown icon"></i>
 							<div class="text">
 								{{range $i,$a := .AllThemes}}
-								    {{if eq $.SignedUser.Theme $a}}{{$a}}{{end}}
+									{{if eq $.SignedUser.Theme $a}}{{$a}}{{end}}
 								{{end}}
 							</div>