[feature] Email notifications for new / closed moderation reports (#1628)

* start fiddling about with email sending to allow multiple recipients

* do some fiddling

* notifs working

* notify on closed report

* finishing up

* envparsing

* use strings.ContainsAny

internal/email/report.go

@@ -0,0 +1,64 @@
+// GoToSocial
+// Copyright (C) GoToSocial Authors admin@gotosocial.org
+// SPDX-License-Identifier: AGPL-3.0-or-later
+//
+// This program is free software: you can redistribute it and/or modify
+// it under the terms of the GNU Affero General Public License as published by
+// the Free Software Foundation, either version 3 of the License, or
+// (at your option) any later version.
+//
+// This program is distributed in the hope that it will be useful,
+// but WITHOUT ANY WARRANTY; without even the implied warranty of
+// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+// GNU Affero General Public License for more details.
+//
+// You should have received a copy of the GNU Affero General Public License
+// along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+package email
+
+const (
+	newReportTemplate    = "email_new_report.tmpl"
+	newReportSubject     = "GoToSocial New Report"
+	reportClosedTemplate = "email_report_closed.tmpl"
+	reportClosedSubject  = "GoToSocial Report Closed"
+)
+
+type NewReportData struct {
+	// URL of the instance to present to the receiver.
+	InstanceURL string
+	// Name of the instance to present to the receiver.
+	InstanceName string
+	// URL to open the report in the settings panel.
+	ReportURL string
+	// Domain from which the report originated.
+	// Can be empty string for local reports.
+	ReportDomain string
+	// Domain targeted by the report.
+	// Can be empty string for local reports targeting local users.
+	ReportTargetDomain string
+}
+
+func (s *sender) SendNewReportEmail(toAddresses []string, data NewReportData) error {
+	return s.sendTemplate(newReportTemplate, newReportSubject, data, toAddresses...)
+}
+
+type ReportClosedData struct {
+	// Username to be addressed.
+	Username string
+	// URL of the instance to present to the receiver.
+	InstanceURL string
+	// Name of the instance to present to the receiver.
+	InstanceName string
+	// Username of the report target.
+	ReportTargetUsername string
+	// Domain of the report target.
+	// Can be empty string for local reports targeting local users.
+	ReportTargetDomain string
+	// Comment left by the admin who closed the report.
+	ActionTakenComment string
+}
+
+func (s *sender) SendReportClosedEmail(toAddress string, data ReportClosedData) error {
+	return s.sendTemplate(reportClosedTemplate, reportClosedSubject, data, toAddress)
+}