type CommandCodeCredits = {
  credits?: { monthlyCredits?: number; purchasedCredits?: number; freeCredits?: number };
  windowLimits?: {
    fiveHour?: { used?: number; cap?: number; resetAt?: number };
    weekly?: { used?: number; cap?: number; resetAt?: number };
  };
};

type WindowData = { usedPercent: number | null; resetAt: number | null; windowSeconds: number | null; valueLabel: string };

const toWindow = (data: WindowData) => ({
  usedPercent: data.usedPercent,
  remainingPercent: data.usedPercent === null ? null : Math.max(0, 100 - data.usedPercent),
  windowSeconds: data.windowSeconds,
  resetAfterSeconds: data.resetAt === null ? null : Math.max(0, Math.floor((data.resetAt - Date.now()) / 1000)),
  resetAt: data.resetAt,
  resetAtFormatted: null,
  resetAfterFormatted: null,
  valueLabel: data.valueLabel,
});

const isFiniteNumber = (value: unknown): value is number => typeof value === 'number' && Number.isFinite(value);
const formatCredits = (value: number): string => String(Math.round((value + Number.EPSILON) * 100) / 100);

const parseCredits = (value: unknown): CommandCodeCredits | null => {
  if (!value || typeof value !== 'object') return null;
  const payload = value as CommandCodeCredits;
  return payload;
};

const parseOrgId = (value: unknown): string | null | undefined => {
  if (!value || typeof value !== 'object') return undefined;
  const org = (value as { org?: { id?: unknown } }).org;
  return typeof org?.id === 'string' && org.id.trim() ? org.id.trim() : null;
};

const parseCommandCodeCredits = (payload: CommandCodeCredits) => {
  const windows: Record<string, ReturnType<typeof toWindow>> = {};
  for (const [label, value] of [['monthly_credits', payload.credits?.monthlyCredits], ['purchased_credits', payload.credits?.purchasedCredits], ['free_credits', payload.credits?.freeCredits]] as const) {
    if (isFiniteNumber(value)) windows[label] = toWindow({ usedPercent: null, resetAt: null, windowSeconds: null, valueLabel: formatCredits(value) });
  }
  for (const [label, limit, seconds] of [['5h', payload.windowLimits?.fiveHour, 5 * 60 * 60], ['weekly', payload.windowLimits?.weekly, 7 * 24 * 60 * 60]] as const) {
    if (!isFiniteNumber(limit?.used) || !isFiniteNumber(limit.cap) || limit.cap <= 0) continue;
    const resetAt = isFiniteNumber(limit.resetAt) ? (limit.resetAt < 1_000_000_000_000 ? limit.resetAt * 1000 : limit.resetAt) : null;
    windows[label] = toWindow({ usedPercent: Math.min(100, Math.max(0, limit.used / limit.cap * 100)), resetAt, windowSeconds: seconds, valueLabel: `${formatCredits(limit.used)} / ${formatCredits(limit.cap)}` });
  }
  return windows;
};

const requestJson = async (path: string, apiKey: string): Promise<unknown> => {
  const response = await fetch(`https://api.commandcode.ai${path}`, { headers: { Accept: 'application/json', Authorization: `Bearer ${apiKey}` }, signal: AbortSignal.timeout(15_000) });
  if (response.status === 401 || response.status === 403) throw new Error('Command Code authentication failed');
  if (!response.ok) throw new Error(`Command Code usage API returned HTTP ${response.status}`);
  return response.json().catch(() => null);
};

export const fetchCommandCodeUsage = async (apiKey: string) => {
  const orgId = parseOrgId(await requestJson('/alpha/whoami', apiKey));
  if (orgId === undefined) throw new Error('Command Code account could not be determined');
  const creditsPath = orgId ? `/alpha/billing/credits?orgId=${encodeURIComponent(orgId)}` : '/alpha/billing/credits';
  const payload = parseCredits(await requestJson(creditsPath, apiKey));
  if (!payload) throw new Error('Command Code usage data could not be parsed');
  const windows = parseCommandCodeCredits(payload);
  if (!Object.keys(windows).length) throw new Error('Command Code usage data could not be parsed');
  return windows;
};