// This is Free Software under GNU Affero General Public License v >= 3.0
// without warranty, see README.md and license for details.
//
// SPDX-License-Identifier: AGPL-3.0-or-later
// License-Filename: LICENSES/AGPL-3.0.txt
//
// Copyright (C) 2018 by via donau
//   – Österreichische Wasserstraßen-Gesellschaft mbH
// Software engineering by Intevation GmbH
//
// Author(s):
//  * Sascha L. Teichmann <sascha.teichmann@intevation.de>

package imports

import (
	"context"
	"database/sql"
	"strings"
	"text/template"

	"gemma.intevation.de/gemma/pkg/auth"
	"gemma.intevation.de/gemma/pkg/config"
	"gemma.intevation.de/gemma/pkg/log"
	"gemma.intevation.de/gemma/pkg/misc"
)

const (
	selectEmailSQL = `SELECT email_address FROM users.list_users WHERE username = $1`

	importNotificationMailSubject = `Gemma: import notification mail`
)

var (
	importNotificationMailTmpl = template.Must(
		template.New("notification").Parse(`Dear {{ .User }},

a {{ .Description }} import on server {{ .Server }} triggered
this email notification.

{{ if eq .State "accepted" }}The imported data were successfully integrated into the database. {{ end -}}
{{ if eq .State "unchanged" }}The import has not changed any data in the database. {{ end -}}
{{ if eq .State "failed" }}The import failed for some reasons. {{ end -}}
{{ if eq .State "pending" }}The imported data could be integrated into the database
but your final decision is needed. {{ end -}}

Please follow this link to have a closer look at the details:

{{ .Server }}/#/imports/overview/{{ .ID }}

Best regards
    Your service team`))
)

func sendNotificationMail(user, description, state string, id int64) {
	config.WaitReady()

	ctx := context.Background()
	var email string
	if err := auth.RunAs(ctx, user,
		func(conn *sql.Conn) error {
			return conn.QueryRowContext(ctx, selectEmailSQL, user).Scan(&email)
		},
	); err != nil {
		log.Errorf("%v\n", err)
		return
	}

	data := struct {
		User        string
		Description string
		Server      string
		State       string
		ID          int64
	}{
		User:        user,
		Description: description,
		Server:      config.ExternalURL(),
		State:       state,
		ID:          id,
	}

	var body strings.Builder
	if err := importNotificationMailTmpl.Execute(&body, &data); err != nil {
		log.Errorf("%v\n", err)
		return
	}

	if err := misc.SendMail(email, importNotificationMailSubject, body.String()); err != nil {
		log.Errorf("%v\n", err)
	}
}