import type { CodexAuth, CodexUsageResponse } from "@/types/codex";

const USAGE_URL = "https://chatgpt.com/backend-api/wham/usage";

export async function fetchCodexUsage(auth: CodexAuth): Promise<CodexUsageResponse> {
  const headers: Record<string, string> = {
    Authorization: `Bearer ${auth.accessToken}`,
    "Content-Type": "application/json",
  };

  if (auth.accountId) {
    headers["ChatGPT-Account-Id"] = auth.accountId;
  }

  const response = await fetch(USAGE_URL, { headers });

  if (response.status === 401 || response.status === 403) {
    throw new Error("TOKEN_EXPIRED");
  }
  if (!response.ok) {
    await response.text().catch(() => null);
    throw new Error(`HTTP_ERROR_${response.status}`);
  }

  return response.json() as Promise<CodexUsageResponse>;
}