/*
 *  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 imapserver

import (
	"fmt"
	"log"

	"github.com/emersion/go-imap"
	"github.com/emersion/go-imap/backend"
	"github.com/neilalexander/yggmail/internal/account"
	"github.com/neilalexander/yggmail/internal/config"
	"github.com/neilalexander/yggmail/internal/notify"
	nfremote "github.com/neilalexander/yggmail/internal/notify/remote"
	"github.com/neilalexander/yggmail/internal/storage"
	"github.com/neilalexander/yggmail/internal/storage/remote"
	"github.com/neilalexander/yggmail/internal/transport"
	"github.com/neilalexander/yggmail/internal/utils"
)

type Backend struct {
	Config    *config.Config
	Log       *log.Logger
	Storage   storage.Storage
	Server    *IMAPServer
	Account   *account.Manager
	Transport transport.Transport
	Notify    *notify.Notify
	updates   chan backend.Update
}

func NewBackend(
	config *config.Config,
	log *log.Logger,
	storage storage.Storage,
	// server *IMAPServer,
	account *account.Manager,
	transport transport.Transport,
	notify *notify.Notify,
) *Backend {
	b := &Backend{
		Config:  config,
		Log:     log,
		Storage: storage,
		//Server:    server,
		Account:   account,
		Transport: transport,
		Notify:    notify,
		updates:   make(chan backend.Update, 100),
	}
	b.listenUpdates()
	return b
}
func (b *Backend) Updates() <-chan backend.Update {
	b.Log.Println("Updates is loaded!")
	return b.updates
}

func (b *Backend) Login(conn *imap.ConnInfo, username, password string) (backend.User, error) {
	// If our username is email-like, then take just the localpart
	dPk, _, err := utils.ParseAddress(username)
	if err != nil {
		return nil, fmt.Errorf("Failed ")
	}

	remoteDomain := !dPk.Equal(b.Config.PublicKey)

	session, err := b.Account.Login(username, password)
	if err != nil {
		return nil, fmt.Errorf("IMAP: Error to authenticate: %w", err)
	}

	defer b.Log.Printf("IMAP: Authenticated user from %s as %q\n", conn.RemoteAddr.String(), username)

	var storage storage.Storage
	if remoteDomain {
		storage = remote.NewRemoteStorage(dPk, session, b.Transport)
		notifer := nfremote.NewRemoteNotifer(dPk, session.Publickey(), session.Sign, b.Transport)
		notifer.StartRemoteNotifer(b.Notify, session.Publickey(), "INBOX")
	} else {
		storage = b.Storage
	}
	user := &User{
		storage:  storage,
		username: session.Username(),
		session:  session,
		conn:     conn,
		log:      b.Log,
	}
	return user, nil
}

/*
func (b *Backend) NotifyNew(id int) error {
	b.Server.server.ForEachConn(func(conn server.Conn) {
		notify := false
		for _, cap := range conn.Capabilities() {
			if cap == "NOTIFY" {
				notify = true
			}
		}
		if !notify {
			return
		}
		conn.WaitReady()
		conn.WriteResp()
	})
	return nil
}
*/