package util

import (
	"fmt"
	"github.com/davidebianchi/go-jsonclient"
	"net/http"
	"net/url"
)

type oAuthAccessTokenReq struct {
	ClientID     string `json:"client_id"`
	ClientSecret string `json:"client_secret"`
	Code         string `json:"code"`
	GrantType    string `json:"grant_type"`
	RedirectURI  string `json:"redirect_uri"`
}
type oAuthAccessTokenResp struct {
	AccessToken  string `json:"access_token"`
	TokenType    string `json:"token_type"`
	ExpiresIn    int    `json:"expires_in"`
	RefreshToken string `json:"refresh_token"`
}

func GetOAuthToken(oAuthAccessTokenURL, clientID, clientSecret, code, redirectURI string) (string, error) {
	u, err := url.Parse(oAuthAccessTokenURL)
	if err != nil {
		logger.Errorf(`failed to parse oAuthAccessTokenURL. error: %s`, err.Error())
		return ``, err
	}

	client, err := jsonclient.New(jsonclient.Options{
		BaseURL: fmt.Sprintf(`%s://%s/`, u.Scheme, u.Host),
	})
	if err != nil {
		logger.Errorf(`failed to create access_token client. error: %s`, err.Error())
		return ``, err
	}

	req, err := client.NewRequest(http.MethodPost, u.Path, &oAuthAccessTokenReq{
		ClientID:     clientID,
		ClientSecret: clientSecret,
		Code:         code,
		GrantType:    `authorization_code`,
		RedirectURI:  redirectURI,
	})
	if err != nil {
		logger.Errorf(`failed to create access_token request. error: %s`, err.Error())
		return ``, err
	}

	atResp := new(oAuthAccessTokenResp)

	resp, err := client.Do(req, atResp)
	if err != nil {
		logger.Errorf(`failed to request access_token. error: %s`, err.Error())
		return ``, err
	}

	if resp.StatusCode >= 300 {
		logger.Errorf(`access_token request return wrong code. code: %d, err_msg: %s`, resp.StatusCode, resp.Status)
		return ``, err
	}

	return atResp.AccessToken, nil
}