/**
 * Constants for OpenAI Codex (ChatGPT OAuth) backend
 */

export const CODEX_BASE_URL = "https://chatgpt.com/backend-api";

export const OPENAI_HEADERS = {
  BETA: "OpenAI-Beta",
  ACCOUNT_ID: "chatgpt-account-id",
  ORIGINATOR: "originator",
  SESSION_ID: "session_id",
  CONVERSATION_ID: "conversation_id",
} as const;

export const OPENAI_HEADER_VALUES = {
  BETA_RESPONSES: "responses=experimental",
  BETA_RESPONSES_WEBSOCKETS_V2: "responses_websockets=2026-02-06",
  ORIGINATOR_CODEX: "pi",
} as const;

export const URL_PATHS = {
  RESPONSES: "/responses",
  CODEX_RESPONSES: "/codex/responses",
} as const;

export const JWT_CLAIM_PATH = "https://api.openai.com/auth" as const;

/**
 * Extract account ID from a Codex JWT access token.
 * Returns undefined if the token is not a valid Codex JWT.
 */
export function getCodexAccountId(accessToken: string): string | undefined {
  try {
    const parts = accessToken.split(".");
    if (parts.length !== 3) return undefined;
    const decoded = Buffer.from(parts[1] ?? "", "base64").toString("utf-8");
    const payload = JSON.parse(decoded) as Record<string, unknown>;
    const auth = payload[JWT_CLAIM_PATH] as
      | { chatgpt_account_id?: string }
      | undefined;
    return auth?.chatgpt_account_id ?? undefined;
  } catch {
    return undefined;
  }
}