package discord

import (
	"bytes"
	"encoding/json"
	"errors"
	"fmt"
	"net/http"

	"github.com/gorilla/websocket"
)

const DISCORD_URl = "https://discord.com/api/v9/"
const USER_AGENT = "DiscordBot (https://jinx.rnrd.eu/, v0.0.0) Jinx"

type Discord struct {
	Token string
}

func NewClient(token string) *Discord {
	return &Discord{
		Token: token,
	}
}

func (d *Discord) Connect() error {
	gatewayURL, err := d.gateway()
	if err != nil {
		return err
	}

	fmt.Printf("Gateway: %s\n", gatewayURL)

	connectHeader := http.Header{}
	conn, _, err := websocket.DefaultDialer.Dial(gatewayURL, connectHeader)
	if err != nil {
		return err
	}

	defer conn.Close()

	messageType, message, err := conn.ReadMessage()
	if err != nil {
		return err
	}

	fmt.Printf("Type: %d, Message: %s\n", messageType, message)

	return nil
}

func (d *Discord) gateway() (string, error) {
	url := DISCORD_URl + "gateway"

	req, err := http.NewRequest("GET", url, nil)
	if err != nil {
		return "", err
	}

	req.Header.Set("Authorization", d.Token)
	req.Header.Set("Content-Type", "application/json")
	req.Header.Set("User-Agent", USER_AGENT)

	resp, err := http.DefaultClient.Do(req)
	if err != nil {
		return "", err
	}

	defer resp.Body.Close()

	var buf bytes.Buffer
	_, err = buf.ReadFrom(resp.Body)
	if err != nil {
		return "", err
	}

	switch resp.StatusCode {
	case 200:
	default:
		return "", errors.New("Gateway response status code: " + resp.Status)
	}

	body := struct {
		URL string `json:"url"`
	}{}

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

	url = body.URL + "?v=9&encoding=json"
	return url, nil
}