package mail

import (
	"errors"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"strconv"
	"time"

	"github.com/emersion/go-imap"
	"github.com/emersion/go-imap/client"
	"golang.org/x/net/proxy"
)

type Mail struct {
	Client *client.Client
}

type Message struct {
	SeqNum  uint32
	Subject string
	To      []*imap.Address
	From    []*imap.Address
	Date    time.Time
	Body    imap.Literal
}

type Messages struct {
	Message []Message
}

type Conn struct {
	Addr     string
	Username string
	Password string
}

func login(conn Conn, client *client.Client) (mail *Mail, err error) {
	fmt.Fprintf(os.Stdout, "\x1b[32mConnecting to %s\n\x1b[0m", conn.Addr)
	if err = client.Login(conn.Username, conn.Password); err != nil {
		return nil, err
	}
	log.Println("Logged in as", conn.Username)
	return &Mail{
		Client: client,
	}, nil
}

func LoginWithProxy(conn Conn, network string, proxyAddress string, auth *proxy.Auth) (mail *Mail, err error) {
	proxy, err := proxy.SOCKS5("tcp", proxyAddress, auth, proxy.Direct)
	if err != nil {
		return nil, err
	}
	client, err := client.DialWithDialerTLS(proxy, conn.Addr, nil)
	if err != nil {
		return nil, err
	}
	mail, err = login(conn, client)
	if err != nil {
		return nil, err
	}
	return mail, nil
}

func Login(conn Conn) (mail *Mail, err error) {
	client, err := client.DialTLS(conn.Addr, nil)
	if err != nil {
		return nil, err
	}
	mail, err = login(conn, client)
	if err != nil {
		return nil, err
	}
	return mail, nil
}

func (mail *Mail) GetMessages(mailbox string, msgs int32) (*Messages, error) {
	var messages Messages
	mbox, err := mail.Client.Select(mailbox, true)
	if err != nil {
		return nil, err
	}
	if mbox.Messages == 0 {
		return nil, errors.New("no messages in mailbox")
	}
	seqSet := new(imap.SeqSet)
	seqSet.AddRange(1, mbox.Messages)
	var section imap.BodySectionName

	imapMessages := make(chan *imap.Message, msgs)
	done := make(chan error, 1)
	go func() {
		done <- mail.Client.Fetch(seqSet, []imap.FetchItem{imap.FetchEnvelope, section.FetchItem()}, imapMessages)
	}()

	for msg := range imapMessages {
		body := msg.GetBody(&section)
		if body == nil {
			return nil, errors.New("server didn't returned message body")
		}
		message := Message{
			SeqNum:  msg.SeqNum,
			Subject: msg.Envelope.Subject,
			To:      msg.Envelope.To,
			From:    msg.Envelope.From,
			Date:    msg.Envelope.Date,
			Body:    body,
		}
		messages.Message = append(messages.Message, message)
	}
	if err := <-done; err != nil {
		return nil, err
	}
	return &messages, nil
}

func WriteMessages(path string, messages *Messages) error {
	for _, msg := range messages.Message {
		body, err := ioutil.ReadAll(msg.Body)
		if err != nil {
			return err
		}
		if err := ioutil.WriteFile(path+"/"+strconv.Itoa(int(msg.SeqNum))+"_"+msg.Date.String()+".eml", body, 0644); err != nil {
			return err
		}
	}
	return nil
}