/*
 *  Copyright (c) 2021 Neil Alexander
 *
 *  This Source Code Form is subject to the terms of the Mozilla Public
 *  License, v. 2.0. If a copy of the MPL was not distributed with this
 *  file, You can obtain one at http://mozilla.org/MPL/2.0/.
 */

package smtpserver

import (
	"bytes"
	"encoding/hex"
	"fmt"
	"io"
	"time"

	"github.com/emersion/go-message"
	"github.com/emersion/go-smtp"
	"github.com/neilalexander/yggmail/internal/utils"
)

type SessionLocal struct {
	backend *Backend
	state   *smtp.ConnectionState
	from    string
	rcpt    []string
}

func (s *SessionLocal) Mail(from string, opts smtp.MailOptions) error {
	s.rcpt = s.rcpt[:0]

	pk, err := utils.ParseAddress(from)
	if err != nil {
		return fmt.Errorf("parseAddress: %w", err)
	}

	if !pk.Equal(s.backend.Config.PublicKey) {
		return fmt.Errorf("not allowed to send outgoing mail as %s", from)
	}

	s.from = from
	return nil
}

func (s *SessionLocal) Rcpt(to string) error {
	s.rcpt = append(s.rcpt, to)
	return nil
}

func (s *SessionLocal) Data(r io.Reader) error {
	m, err := message.Read(r)
	if err != nil {
		return fmt.Errorf("message.Read: %w", err)
	}

	m.Header.Add(
		"Received", fmt.Sprintf("from %s by Yggmail %s; %s",
			s.state.RemoteAddr.String(),
			hex.EncodeToString(s.backend.Config.PublicKey),
			time.Now().String(),
		),
	)

	var b bytes.Buffer
	if err := m.WriteTo(&b); err != nil {
		return fmt.Errorf("m.WriteTo: %w", err)
	}

	if err := s.backend.Queues.QueueFor(s.from, s.rcpt, b.Bytes()); err != nil {
		return fmt.Errorf("s.backend.Queues.QueueFor: %w", err)
	}

	s.backend.Log.Println("Queued mail for", s.rcpt)

	return nil
}

func (s *SessionLocal) Reset() {
	s.rcpt = s.rcpt[:0]
	s.from = ""
}

func (s *SessionLocal) Logout() error {
	return nil
}