Initial commit

1 files changed, 96 insertions, 0 deletions

diff --git a/mastodon/apps.go b/mastodon/apps.go
new file mode 100644
index 0000000..5d925c3
--- /dev/null
+++ b/mastodon/apps.go
@@ -0,0 +1,96 @@
+package mastodon
+
+import (
+	"context"
+	"encoding/json"
+	"net/http"
+	"net/url"
+	"path"
+	"strings"
+)
+
+// AppConfig is a setting for registering applications.
+type AppConfig struct {
+	http.Client
+	Server     string
+	ClientName string
+
+	// Where the user should be redirected after authorization (for no redirect, use urn:ietf:wg:oauth:2.0:oob)
+	RedirectURIs string
+
+	// This can be a space-separated list of items listed on the /settings/applications/new page of any Mastodon
+	// instance. "read", "write", and "follow" are top-level scopes that include all the permissions of the more
+	// specific scopes like "read:favourites", "write:statuses", and "write:follows".
+	Scopes string
+
+	// Optional.
+	Website string
+}
+
+// Application is mastodon application.
+type Application struct {
+	ID           string `json:"id"`
+	RedirectURI  string `json:"redirect_uri"`
+	ClientID     string `json:"client_id"`
+	ClientSecret string `json:"client_secret"`
+
+	// AuthURI is not part of the Mastodon API; it is generated by go-mastodon.
+	AuthURI string `json:"auth_uri,omitempty"`
+}
+
+// RegisterApp returns the mastodon application.
+func RegisterApp(ctx context.Context, appConfig *AppConfig) (*Application, error) {
+	params := url.Values{}
+	params.Set("client_name", appConfig.ClientName)
+	if appConfig.RedirectURIs == "" {
+		params.Set("redirect_uris", "urn:ietf:wg:oauth:2.0:oob")
+	} else {
+		params.Set("redirect_uris", appConfig.RedirectURIs)
+	}
+	params.Set("scopes", appConfig.Scopes)
+	params.Set("website", appConfig.Website)
+
+	u, err := url.Parse(appConfig.Server)
+	if err != nil {
+		return nil, err
+	}
+	u.Path = path.Join(u.Path, "/api/v1/apps")
+
+	req, err := http.NewRequest(http.MethodPost, u.String(), strings.NewReader(params.Encode()))
+	if err != nil {
+		return nil, err
+	}
+	req = req.WithContext(ctx)
+	req.Header.Set("Content-Type", "application/x-www-form-urlencoded")
+	resp, err := appConfig.Do(req)
+	if err != nil {
+		return nil, err
+	}
+	defer resp.Body.Close()
+
+	if resp.StatusCode != http.StatusOK {
+		return nil, parseAPIError("bad request", resp)
+	}
+
+	var app Application
+	err = json.NewDecoder(resp.Body).Decode(&app)
+	if err != nil {
+		return nil, err
+	}
+
+	u, err = url.Parse(appConfig.Server)
+	if err != nil {
+		return nil, err
+	}
+	u.Path = path.Join(u.Path, "/oauth/authorize")
+	u.RawQuery = url.Values{
+		"scope":         {appConfig.Scopes},
+		"response_type": {"code"},
+		"redirect_uri":  {app.RedirectURI},
+		"client_id":     {app.ClientID},
+	}.Encode()
+
+	app.AuthURI = u.String()
+
+	return &app, nil
+}