/*
 *  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 (
	"crypto/ed25519"
	"fmt"
	"io"

	"github.com/emersion/go-smtp"
	"github.com/neilalexander/yggmail/internal/account"
	"github.com/neilalexander/yggmail/internal/remote"
	"github.com/neilalexander/yggmail/internal/storage"
	"github.com/neilalexander/yggmail/internal/utils"
	"github.com/neilalexander/yggmail/internal/utils/e2ee"
)

type SessionLocal struct {
	backend *Backend
	storage storage.Storage
	state   *smtp.ConnectionState
	session *account.Session
	from    string
	rcpt    []string
}

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

	_, aPk, err := utils.ParseAddress(from)
	if err != nil {
		return fmt.Errorf("parseAddress: %w", err)
	}
	if !aPk.Equal(s.session.Publickey()) {
		return fmt.Errorf("not allowed to send outgoing mail as account: %s", utils.EncodeString(aPk))
	}

	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 {
	payload, size, err := remote.ReadRawData(io.NopCloser(r))
	if err != nil {
		return err
	}

	var rcpt []ed25519.PublicKey
	for _, r := range s.rcpt {
		_, aPk, err := utils.ParseAddress(r)
		if err != nil {
			s.backend.Log.Println("Data: Parse address: cant parse: ", r)
			continue
		}
		rcpt = append(rcpt, aPk)
	}
	payload, err = e2ee.EncryptFilter(payload.(io.ReadSeekCloser), s.from, rcpt, s.session.Sign, s.session.Encrypt)
	if err != nil {
		s.backend.Log.Printf("\nSMTP DATA: error encrypt: %w", err)
		return err
	}

	payload, size, err = remote.ReadRawData(payload)
	if err != nil {
		return err
	}

	if err := s.backend.Queues.QueueFor(s.storage, s.session.Username(), s.from, s.rcpt, payload, size); err != nil {
		return fmt.Errorf("s.backend.Queues.QueueFor: %w", err)
	}

	s.backend.Log.Println("SMTP L: 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
}