package main

import (
	"encoding/json"
	"errors"
	"fmt"
	"github.com/hajimehoshi/go-mp3"
	"github.com/hajimehoshi/oto/v2"
	"io/ioutil"
	"net/http"
	"net/url"
	"time"
)

const (
	api_url   = "https://translate.googleapis.com/translate_a/single?client=gtx&sl=%s&tl=%s&dt=t&q=%s"
	sound_url = "https://translate.google.com.vn/translate_tts?ie=UTF-8&q=%s&tl=%s&client=tw-ob"
)

type Translator struct {
	src_lang string
	dst_lang string
}

func (t Translator) Translate(message string) (string, error) {
	var data []interface{}
	var translated string

	url_str := fmt.Sprintf(
		api_url,
		LangCode[t.src_lang],
		LangCode[t.dst_lang],
		url.QueryEscape(message),
	)
	res, err := http.Get(url_str)
	if err != nil {
		return "", err
	}
	body, err := ioutil.ReadAll(res.Body)
	if err != nil {
		return "", err
	}

	err = json.Unmarshal(body, &data)
	if err != nil {
		return "", err
	}

	if len(data) > 0 {
		result := data[0]
		for _, lines := range result.([]interface{}) {
			translated_line := lines.([]interface{})[0]
			translated += fmt.Sprintf("%v", translated_line)
		}
		return translated, nil
	}
	return "", errors.New("Translation not found")
}

func (t Translator) PlaySound(lang string, message string) {
	url_str := fmt.Sprintf(
		sound_url,
		url.QueryEscape(message),
		LangCode[lang],
	)
	res, err := http.Get(url_str)
	if err != nil {
		panic(err)
	}
	decoder, err := mp3.NewDecoder(res.Body)
	if err != nil {
		panic(err)
	}
	otoCtx, readyChan, err := oto.NewContext(decoder.SampleRate(), 2, 2)
	if err != nil {
		panic(err)
	}
	<-readyChan
	player := otoCtx.NewPlayer(decoder)
	player.Play()
	for player.IsPlaying() {
		time.Sleep(time.Second)
	}
	err = player.Close()
	if err != nil {
		panic(err)
	}
}