package main

import (
	"errors"
	"fmt"
	"io/ioutil"
	"log"
	"math/rand"
	"net/http"
	"os"
	"strconv"
	"strings"
	"student_bot/commands"
	"student_bot/date"
	"student_bot/messages"
	"student_bot/new_year_service"
	"student_bot/parser"
	"time"

	weather "github.com/3crabs/go-yandex-weather-api"
	tgbot "github.com/go-telegram-bot-api/telegram-bot-api"
	"github.com/umputun/go-flags"
)

type Opts struct {
	Token  string `short:"t" long:"token" description:"Telegram api token"`
	Name   string `short:"n" long:"name" description:"Telegram bot name" default:"@student_verochka_bot"`
	Key    string `short:"k" long:"key" description:"Yandex weather API key"`
	ChatID int64  `short:"c" long:"chat_id" description:"Telegram chat id"`
}

var sendMessage = false

var opts Opts

func readToken() (string, error) {
	b, err := ioutil.ReadFile("token.txt")
	if err != nil {
		return "", err
	}
	str := string(b)
	str = strings.ReplaceAll(str, "\n", "")
	return str, nil
}

func readWeatherToken() (string, error) {
	b, err := ioutil.ReadFile("token_weather.txt")
	if err != nil {
		return "", err
	}
	str := string(b)
	str = strings.ReplaceAll(str, "\n", "")
	return str, nil
}

func readChatID() (int64, error) {
	b, err := ioutil.ReadFile("chat_id.txt")
	if err != nil {
		return 0, err
	}
	str := string(b)
	str = strings.ReplaceAll(str, "\n", "")
	return strconv.ParseInt(str, 10, 64)
}

func main() {
	run()
}

func run() {
	p := flags.NewParser(&opts, flags.PrintErrors|flags.PassDoubleDash|flags.HelpFlag)
	p.SubcommandsOptional = true
	if _, err := p.Parse(); err != nil {
		if err.(*flags.Error).Type != flags.ErrHelp {
			log.Println(errors.New("[ERROR] cli error: " + err.Error()))
		}
		os.Exit(2)
	}

	if opts.Token == "" {
		token, err := readToken()
		if err != nil {
			panic(err)
		}
		opts.Token = token
	}
	fmt.Println(opts.Token)

	if opts.Key == "" {
		token, err := readWeatherToken()
		if err != nil {
			panic(err)
		}
		opts.Key = token
	}
	fmt.Println(opts.Key)

	if opts.ChatID == 0 {
		chatID, err := readChatID()
		if err != nil {
			panic(err)
		}
		opts.ChatID = chatID
	}
	fmt.Println(opts.ChatID)

	rand.Seed(time.Now().UnixNano())

	imageService, err := new_year_service.NewNewYearService()
	if err != nil {
		log.Panicln(err)
	}
	imageService = new_year_service.NewNewYearServiceLogWrapper(imageService)

	bot, err := tgbot.NewBotAPI(opts.Token)
	if err != nil {
		log.Panicln(err)
	}

	u := tgbot.NewUpdate(0)
	u.Timeout = 60

	updates, err := bot.GetUpdatesChan(u)
	if err != nil {
		log.Panicln(err)
	}

	go func() {
		http.HandleFunc("/send_today_lessons_to_chat", func(w http.ResponseWriter, r *http.Request) {
			sendTodayLessonsToChat(bot, opts.ChatID, "Сегодня эти пары:")
			w.Header().Add("Content-Type", "application/json")
			w.WriteHeader(http.StatusOK)
			_, _ = fmt.Fprintf(w, `{"result":"ok"}`)
		})
		http.HandleFunc("/send_tomorrow_lessons_to_chat", func(w http.ResponseWriter, r *http.Request) {
			sendTomorrowLessonsToChat(bot, opts.ChatID, "Завтра эти пары:")
			w.Header().Add("Content-Type", "application/json")
			w.WriteHeader(http.StatusOK)
			_, _ = fmt.Fprintf(w, `{"result":"ok"}`)
		})
		http.HandleFunc("/send_new_year_to_chat", func(w http.ResponseWriter, r *http.Request) {
			sendNewYearToChat(bot, opts.ChatID, imageService)
			w.Header().Add("Content-Type", "application/json")
			w.WriteHeader(http.StatusOK)
			_, _ = fmt.Fprintf(w, `{"result":"ok"}`)
		})

		port := ":10001"
		log.Println("Server is start up! port", port)
		log.Fatal(http.ListenAndServe(port, nil))
	}()

	log.Println("Bot is start up!")

	for update := range updates {

		// empty message
		if update.Message == nil {
			continue
		}

		text := update.Message.Text
		chatID := update.Message.Chat.ID

		if strings.Contains(strings.ToLower(text), "спасибо") {
			if sendMessage {
				_, _ = bot.Send(tgbot.NewMessage(chatID, messages.ThanksMessage()))
				sendMessage = false
			}
			continue
		}
		sendMessage = false

		command := commands.Command(strings.Replace(text, opts.Name, "", 1))
		switch command {

		case commands.Start:
			send(bot, tgbot.NewMessage(chatID, messages.StartMessage()))

		case commands.Help:
			send(bot, tgbot.NewMessage(chatID, messages.HelpMessage(chatID)))

		case commands.Ping:
			send(bot, tgbot.NewMessage(chatID, messages.PongMessage()))

		case commands.TodayLessons:
			sendTodayLessonsToChat(bot, chatID, "Сегодня, "+update.Message.From.FirstName+", эти пары:")

		case commands.TomorrowLessons:
			sendTomorrowLessonsToChat(bot, chatID, "Завтра, "+update.Message.From.FirstName+", эти пары:")

		case commands.Weather:
			w, err := weather.GetWeatherWithCache(opts.Key, 53.346853, 83.777012, time.Hour)
			if err != nil {
				continue
			}
			send(bot, tgbot.NewMessage(chatID, messages.WeatherMessage(w)))

		case commands.NewYear:
			sendNewYearToChat(bot, chatID, imageService)

		default:
		}
	}
}

func send(bot *tgbot.BotAPI, msg tgbot.Chattable) {
	_, _ = bot.Send(msg)
	sendMessage = true
}

func sendTodayLessonsToChat(bot *tgbot.BotAPI, chatID int64, prefix string) {
	send(
		bot,
		tgbot.NewMessage(
			chatID,
			messages.LessonsMessage(
				parser.ParseByDay(date.Today()),
				prefix,
				"Сегодня пар нет",
			),
		),
	)
}

func sendTomorrowLessonsToChat(bot *tgbot.BotAPI, chatID int64, prefix string) {
	send(
		bot,
		tgbot.NewMessage(
			chatID,
			messages.LessonsMessage(
				parser.ParseByDay(date.Today()+1),
				prefix,
				"Завтра пар нет",
			),
		),
	)
}

func sendNewYearToChat(bot *tgbot.BotAPI, chatID int64, imageService new_year_service.NewYearService) {
	url := imageService.GetRandomImageURL()
	message := imageService.GetRandomMessage()
	msg := tgbot.NewPhotoShare(chatID, url)
	msg.Caption = messages.NewYearMessage(message)
	send(bot, msg)
}