package writefreely import ( "context" "errors" "net/http" "net/url" "strings" ) type writeAsOauthClient struct { ClientID string ClientSecret string AuthLocation string ExchangeLocation string InspectLocation string CallbackLocation string HttpClient HttpClient } var _ oauthClient = writeAsOauthClient{} const ( writeAsAuthLocation = "https://write.as/oauth/login" writeAsExchangeLocation = "https://write.as/oauth/token" writeAsIdentityLocation = "https://write.as/oauth/inspect" ) func (c writeAsOauthClient) GetProvider() string { return "write.as" } func (c writeAsOauthClient) GetClientID() string { return c.ClientID } func (c writeAsOauthClient) GetCallbackLocation() string { return c.CallbackLocation } func (c writeAsOauthClient) buildLoginURL(state string) (string, error) { u, err := url.Parse(c.AuthLocation) if err != nil { return "", err } q := u.Query() q.Set("client_id", c.ClientID) q.Set("redirect_uri", c.CallbackLocation) q.Set("response_type", "code") q.Set("state", state) u.RawQuery = q.Encode() return u.String(), nil } func (c writeAsOauthClient) exchangeOauthCode(ctx context.Context, code string) (*TokenResponse, error) { form := url.Values{} form.Add("grant_type", "authorization_code") form.Add("redirect_uri", c.CallbackLocation) form.Add("code", code) req, err := http.NewRequest("POST", c.ExchangeLocation, strings.NewReader(form.Encode())) if err != nil { return nil, err } req.WithContext(ctx) req.Header.Set("User-Agent", ServerUserAgent("")) req.Header.Set("Accept", "application/json") req.Header.Set("Content-Type", "application/x-www-form-urlencoded") req.SetBasicAuth(c.ClientID, c.ClientSecret) resp, err := c.HttpClient.Do(req) if err != nil { return nil, err } if resp.StatusCode != http.StatusOK { return nil, errors.New("unable to exchange code for access token") } var tokenResponse TokenResponse if err := limitedJsonUnmarshal(resp.Body, tokenRequestMaxLen, &tokenResponse); err != nil { return nil, err } if tokenResponse.Error != "" { return nil, errors.New(tokenResponse.Error) } return &tokenResponse, nil } func (c writeAsOauthClient) inspectOauthAccessToken(ctx context.Context, accessToken string) (*InspectResponse, error) { req, err := http.NewRequest("GET", c.InspectLocation, nil) if err != nil { return nil, err } req.WithContext(ctx) req.Header.Set("User-Agent", ServerUserAgent("")) req.Header.Set("Accept", "application/json") req.Header.Set("Authorization", "Bearer "+accessToken) resp, err := c.HttpClient.Do(req) if err != nil { return nil, err } if resp.StatusCode != http.StatusOK { return nil, errors.New("unable to inspect access token") } var inspectResponse InspectResponse if err := limitedJsonUnmarshal(resp.Body, infoRequestMaxLen, &inspectResponse); err != nil { return nil, err } if inspectResponse.Error != "" { return nil, errors.New(inspectResponse.Error) } return &inspectResponse, nil }