package parser

import (
	"bufio"
	"fmt"
	"html"
	"log"
	"os"
	"regexp"
	"strings"

	"google.golang.org/api/gmail/v1"
)

// Message .
type Message struct {
	gmailID string
	date    string // retrieved from message header
	snippet string
}

// GetMessages .
func GetMessages(srv *gmail.Service) []Message {
	msgs := []Message{}
	pageToken := ""
	for {
		req := srv.Users.Messages.List("me").Q("is:unread").Q("from:messaging@iamresponding.com")
		// req := srv.Users.Messages.List("me").Q("is:unread")
		if pageToken != "" {
			req.PageToken(pageToken)
		}
		r, err := req.Do()
		if err != nil {
			log.Fatalf("Unable to retrieve messages: %v", err)
		}

		log.Printf("Processing %v messages...\n", len(r.Messages))
		for _, m := range r.Messages {
			msg, err := srv.Users.Messages.Get("me", m.Id).Format("full").Do()
			if err != nil {
				log.Fatalf("Unable to retrieve message %v: %v", m.Id, err)
			}
			date := ""
			for _, h := range msg.Payload.Headers {
				if h.Name == "Date" {
					date = h.Value
				}
				// break
			}

			msgs = append(msgs, Message{
				gmailID: msg.Id,
				date:    date,
				snippet: html.UnescapeString(msg.Snippet),
			})
		}

		if r.NextPageToken == "" {
			break
		}
		pageToken = r.NextPageToken
	}

	reader := bufio.NewReader(os.Stdin)
	count, deleted := 0, 0
	for _, m := range msgs {
		count++

		re := regexp.MustCompile(`^(?P<address>[^\s\[\[].*)\s\[\[(?P<city>[^\]\]].*)\]\]\s\((?P<type>[^\)].*)\)\s\-\s(?P<description>.*?)(?P<phone>\(\d{3}\)\s\d{3}\-\d{4})?\s?(?:F\d{9})?\s?(?:\d{7})?\s?(?P<time>\d{2}\:\d{2})?$`)
		if re.Match([]byte(m.snippet)) {

			groups := re.SubexpNames()
			result := re.FindAllStringSubmatch(m.snippet, -1)

			rt := map[string]string{}
			for i, n := range result[0] {
				rt[groups[i]] = n
			}

			fmt.Printf("=============================================================\n")
			fmt.Printf("Message URL: https://mail.google.com/mail/u/0/#all/%v\n", m.gmailID)
			fmt.Printf("Snippet: %q\n", m.snippet)
			if value, ok := rt["address"]; ok {
				fmt.Printf("Address: %s\n", value)
			} else {
				fmt.Print("There is no address value\n")
			}
			if value, ok := rt["city"]; ok {
				fmt.Printf("City: %s\n", value)
			} else {
				fmt.Print("There is no city value\n")
			}
			if value, ok := rt["type"]; ok {
				fmt.Printf("Type: %s\n", value)
			} else {
				fmt.Print("There is no type value\n")
			}
			if value, ok := rt["description"]; ok {
				fmt.Printf("Description: %s\n", value)
			} else {
				fmt.Print("There is no description value\n")
			}
			if value, ok := rt["phone"]; ok {
				fmt.Printf("Phone: %s\n", value)
			} else {
				fmt.Print("There is no phone value\n")
			}
			if value, ok := rt["time"]; ok {
				fmt.Printf("Time: %s\n", value)
			} else {
				fmt.Print("There is no time value\n")
			}
			fmt.Printf("Date: %v\n", m.date)
			fmt.Printf("=============================================================\n")
			fmt.Printf("Options: (d)elete, (r)ead, (p)rint, (s)kip, (q)uit: [s] ")
			val := ""
			if _, err := reader.ReadString('\n'); err != nil {
				log.Fatalf("unable to scan input: %v", err)
			}
			val = strings.TrimSpace(val)
			switch val {
			case "d": // delete message
				if err := srv.Users.Messages.Delete("me", m.gmailID).Do(); err != nil {
					log.Fatalf("unable to delete message %v: %v", m.gmailID, err)
				}
				log.Printf("Deleted message %v.\n", m.gmailID)
				deleted++
			case "r": // mark as read
				msg, err := srv.Users.Messages.Modify("me", m.gmailID, &gmail.ModifyMessageRequest{RemoveLabelIds: []string{"UNREAD"}}).Do()
				if err != nil {
					log.Fatalf("unable to modify message %v: %v", m.gmailID, err)
				}
				log.Printf("Modified message %v.\n", msg)
			case "q": // quit
				log.Printf("Done.  %v messages processed, %v deleted\n", count, deleted)
				os.Exit(0)
			default:
			}

		}
	}

	return msgs
}