package ffiii

import (
	"context"
	"fmt"
	"io"
	"log"
	"net/http"
	"os"
	"time"

	"golang.org/x/oauth2"
)

type Client struct {
	url        string
	client     *http.Client
	apiToken   string
	apiID      string
	oauthToken *oauth2.Token
	oauthCode  string
	reader     io.Reader
}

func New(apiID, apiToken, url string) (*Client, error) {
	c := &Client{
		apiID:    apiID,
		apiToken: apiToken,
		url:      url,
		reader:   os.Stdin,
	}
	if err := c.Authorize(); err != nil {
		return nil, err
	}
	return c, nil
}

func (c *Client) Authorize() error {
	conf := &oauth2.Config{
		ClientID:     c.apiID,
		ClientSecret: c.apiToken,
		RedirectURL:  c.url,
		Scopes:       []string{},
		Endpoint: oauth2.Endpoint{
			AuthURL:  fmt.Sprintf("%s/oauth/authorize", c.url),
			TokenURL: fmt.Sprintf("%s/oauth/token", c.url),
		},
	}

	authURL := conf.AuthCodeURL("state", oauth2.AccessTypeOffline)
	fmt.Printf("Go to the following link in your browser then type the "+
		"authorization code: \n%v\n", authURL)
	var authCode string
	if _, err := fmt.Fscan(c.reader, &authCode); err != nil {
		log.Fatalf("Unable to read authorization code: %v", err)
	}
	c.oauthCode = authCode

	ctx, can := context.WithTimeout(context.Background(), time.Second*30)
	defer can()

	tok, err := conf.Exchange(ctx, c.oauthCode)
	if err != nil {
		return err
	}
	c.client = conf.Client(context.Background(), tok)

	return nil
}