Implement `CheckIBDUsername` for `UserService`

1 files changed, 59 insertions, 0 deletions

diff --git a/backend/internal/ibd/check_ibd_username.go b/backend/internal/ibd/check_ibd_username.go
new file mode 100644
index 0000000..03d2640
--- /dev/null
+++ b/backend/internal/ibd/check_ibd_username.go
@@ -0,0 +1,59 @@
+package ibd
+
+import (
+	"bytes"
+	"context"
+	"encoding/json"
+	"fmt"
+	"net/http"
+)
+
+const (
+	checkUsernameUrl = "https://sso.accounts.dowjones.com/getuser"
+)
+
+func (c *Client) CheckIBDUsername(ctx context.Context, username string) (bool, error) {
+	cfg, err := c.getLoginPage(ctx)
+	if err != nil {
+		return false, err
+	}
+
+	return c.checkIBDUsername(ctx, cfg, username)
+}
+
+func (c *Client) checkIBDUsername(ctx context.Context, cfg *authConfig, username string) (bool, error) {
+	body := map[string]string{
+		"username": username,
+		"csrf":     cfg.ExtraParams.Csrf,
+	}
+	bodyJson, err := json.Marshal(body)
+	if err != nil {
+		return false, err
+	}
+
+	req, err := http.NewRequestWithContext(ctx, http.MethodPost, checkUsernameUrl, bytes.NewReader(bodyJson))
+	if err != nil {
+		return false, err
+	}
+
+	req.Header.Set("Content-Type", "application/json")
+	req.Header.Set("X-REMOTE-USER", username)
+	req.Header.Set("X-REQUEST-EDITIONID", "IBD-EN_US")
+	req.Header.Set("X-REQUEST-SCHEME", "https")
+
+	resp, err := c.Do(req)
+	if err != nil {
+		return false, err
+	}
+
+	if resp.Result.StatusCode == http.StatusUnauthorized {
+		return false, nil
+	} else if resp.Result.StatusCode != http.StatusOK {
+		return false, fmt.Errorf(
+			"unexpected status code %d: %s",
+			resp.Result.StatusCode,
+			resp.Result.Content,
+		)
+	}
+	return true, nil
+}