package main

import (
	"fmt"
	"io"
	"io/ioutil"
	"log"
	"strings"
	"time"

	imap "github.com/emersion/go-imap"
	"github.com/emersion/go-imap/client"
	"github.com/emersion/go-message/mail"
	"github.com/jaytaylor/html2text"
)

func Poll() {
	//r := rand.New(rand.NewSource(99))
	c := time.Tick(10 * time.Second)
	for _ = range c {
		//Download the current contents of the URL and do something with it
		fmt.Printf("Grab at %s\n", time.Now())
		// add a bit of jitter
		//jitter := time.Duration(r.Int31n(5000)) * time.Millisecond
		//time.Sleep(jitter)
		doAll()
	}
}

func doAll() {
	var c *client.Client

	// Connect to server
	c, err := client.DialTLS("imap.yandex.ru:993", nil)
	//c.SetDebug(os.Stdout)

	if err != nil {
		log.Fatal(err)
	}
	log.Println("Connected")

	// Don't forget to logout
	defer c.Logout()

	// Login
	if err := c.Login("vadim", "!"); err != nil {
		log.Fatal(err)
	}
	log.Println("Logged in")

	// Select INBOX
	mbox, err := c.Select("INBOX", false)
	if err != nil {
		log.Fatal(err)
	}

	// Get the last message
	if mbox.Messages == 0 {
		log.Fatal("No message in mailbox")
	}

	readMsg(c, mbox.Messages)
}

func readMsg(c *client.Client, msgID uint32) {
	log.Println("read msg:", msgID)
	seqSet := new(imap.SeqSet)
	seqSet.AddNum(msgID)

	// Get the whole message body
	section := &imap.BodySectionName{}
	items := []imap.FetchItem{section.FetchItem()}

	messages := make(chan *imap.Message, 1)
	//go func() {
	if err := c.Fetch(seqSet, items, messages); err != nil {
		log.Fatal(err)
	}
	//}()

	msg := <-messages
	if msg == nil {
		log.Fatal("Server didn't returned message")
	}

	r := msg.GetBody(section)
	if r == nil {
		log.Fatal("Server didn't returned message body")
	}

	// Create a new mail reader
	mr, err := mail.CreateReader(r)
	if err != nil {
		log.Fatal(err)
	}

	// Print some info about the message
	header := mr.Header
	if date, err := header.Date(); err == nil {
		log.Println("Date:", date)
	}
	if from, err := header.AddressList("From"); err == nil {
		log.Println("From:", from)
	}
	if to, err := header.AddressList("To"); err == nil {
		log.Println("To:", to)
	}
	if subject, err := header.Subject(); err == nil {
		log.Println("Subject:", subject)
	}

	text := ""
	bodyText := ""
	bodyHtml := ""
	// Process each message's part
	for {
		p, err := mr.NextPart()
		if err == io.EOF {
			break
		} else if err != nil {
			log.Fatal(err)
		}

		switch h := p.Header.(type) {
		case mail.TextHeader:
			b, _ := ioutil.ReadAll(p.Body)
			text += string(b)
			if strings.HasPrefix(p.Header.Get("Content-Type"), "text/plain") {
				bodyText += string(b)
			}
			if strings.HasPrefix(p.Header.Get("Content-Type"), "text/html") {
				bodyHtml += string(b)
			}
		case mail.AttachmentHeader:
			// This is an attachment
			filename, _ := h.Filename()
			log.Println("Got attachment: %v", filename)
		}
	}
	if bodyText != "" {
		text = bodyText
	}
	if bodyText == "" && bodyHtml != "" {
		t, err := html2text.FromString(bodyHtml, html2text.Options{PrettyTables: false})
		if err != nil {
			panic(err)
		}
		text = t
	}
	log.Println("Text:\n", text)
}

func main() {
	Poll()
  }