import type { ApiErrorBody, ApiErrorCode } from '@akrababul/shared';

export class ApiError extends Error {
  constructor(public readonly code: ApiErrorCode, message: string, public readonly status: number, public readonly details?: Record<string, unknown>) {
    super(message); this.name = 'ApiError';
  }
}

async function call<T>(method: string, path: string, body?: unknown, headers: Record<string, string> = {}): Promise<T> {
  let res: Response;
  try {
    const isForm = body instanceof FormData;
    // FormData'da content-type elle verilmez; tarayıcı multipart sınırını kendisi ekler.
    const init: RequestInit = { method, credentials: 'same-origin', headers: { ...(body !== undefined && !isForm ? { 'content-type': 'application/json' } : {}), ...headers } };
    if (body !== undefined) init.body = isForm ? body : JSON.stringify(body);
    res = await fetch(path, init);
  } catch {
    throw new ApiError('INTERNAL', 'Sunucuya ulaşılamadı. İnternet bağlantınızı kontrol edip tekrar deneyin.', 0);
  }
  if (res.status === 204) return undefined as T;
  const text = await res.text();
  let data: unknown = null;
  try { data = text ? JSON.parse(text) : null; } catch { /* json değil */ }
  if (!res.ok) {
    const e = (data ?? {}) as Partial<ApiErrorBody>;
    // Emniyet ağı: sayfa denetimi atlanmış olsa bile rızasız kullanıcı onay ekranına gider.
    if (e.code === 'CONSENT_REQUIRED' && !location.pathname.startsWith('/onay')) {
      location.href = '/onay.html?next=' + encodeURIComponent(location.pathname);
    }
    throw new ApiError(e.code ?? 'INTERNAL', e.message ?? `Sunucu hatası (${res.status})`, res.status, e.details);
  }
  return data as T;
}
export const apiGet = <T>(path: string) => call<T>('GET', path);
export const apiPost = <T>(path: string, body: unknown, headers?: Record<string, string>) => call<T>('POST', path, body, headers);
export const apiPatch = <T>(path: string, body: unknown) => call<T>('PATCH', path, body);
export const apiDelete = <T>(path: string, body?: unknown) => call<T>('DELETE', path, body);
export const apiUpload = <T>(path: string, fd: FormData) => call<T>('POST', path, fd);