go-twitch/auth/auth.go

119 lines
3.0 KiB
Go

package auth
import (
"context"
"encoding/json"
"fmt"
"net/http"
"strings"
"time"
"github.com/google/go-querystring/query"
)
type Auth struct {
client *http.Client
clientId string
clientSecret string
redirectUri string
stateStorage StateStorage
}
func New(clientId string, clientSecret string, redirectUri string) *Auth {
return NewWithClient(clientId, clientSecret, redirectUri, http.DefaultClient)
}
func NewWithClient(clientId string, clientSecret string, redirectUri string, client *http.Client) *Auth {
return &Auth{
client: client,
clientId: clientId,
clientSecret: clientSecret,
redirectUri: redirectUri,
stateStorage: NewHttpCookieStateStorage(StateStorageCookie),
}
}
const TokenUrl = "https://id.twitch.tv/oauth2/token"
type GetTokenParams struct {
ClientId string `url:"client_id"`
ClientSecret string `url:"client_secret"`
Code string `url:"code"`
GrantType string `url:"grant_type"`
RedirectUri string `url:"redirect_uri"`
}
// GetToken exchanges an authorization code or refresh token for an access token.
func (a *Auth) GetToken(ctx context.Context, params *GetTokenParams) (*Token, error) {
v, err := query.Values(params)
if err != nil {
return nil, err
}
req, err := http.NewRequestWithContext(ctx, http.MethodPost, TokenUrl, strings.NewReader(v.Encode()))
if err != nil {
return nil, err
}
req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
res, err := a.client.Do(req)
if err != nil {
return nil, err
}
defer res.Body.Close()
statusOK := res.StatusCode >= 200 && res.StatusCode < 300
if !statusOK {
return nil, fmt.Errorf("failed to get token (%d)", res.StatusCode)
}
var token Token
if err := json.NewDecoder(res.Body).Decode(&token); err != nil {
return nil, err
}
token.Expiry = time.Now().Add(time.Duration(token.ExpiresIn) * time.Second)
return &token, nil
}
// GetTokenFromCode exchanges an authorization code for an access token.
//
// https://dev.twitch.tv/docs/authentication/getting-tokens-oidc/#oidc-authorization-code-grant-flow
func (a *Auth) GetTokenFromCode(ctx context.Context, code string) (*Token, error) {
return a.GetToken(ctx, &GetTokenParams{
ClientId: a.clientId,
ClientSecret: a.clientSecret,
Code: code,
GrantType: "authorization_code",
RedirectUri: a.redirectUri,
})
}
// RefreshToken exchanges a refresh token for an access token.
//
// https://dev.twitch.tv/docs/authentication/refresh-tokens/
func (a *Auth) RefreshToken(ctx context.Context, token *Token) (*Token, error) {
return a.GetToken(ctx, &GetTokenParams{
ClientId: a.clientId,
ClientSecret: a.clientSecret,
Code: token.RefreshToken,
GrantType: "refresh_token",
RedirectUri: a.redirectUri,
})
}
// WithStateStorage sets the instance's state storage,
// which is used to store the state parameter between requests.
//
// By default, the http cookie state storage is used.
func (a *Auth) WithStateStorage(storage StateStorage) *Auth {
a.stateStorage = storage
return a
}