"use client";

import type { ApiError } from "@spinza/shared";

export class ApiClientError extends Error {
  constructor(
    public status: number,
    public code: string,
    message: string,
    public details?: unknown,
  ) {
    super(message);
  }
}

/** Browser fetch wrapper: same-origin `/api/*`, JSON in/out, typed errors. */
export async function api<T>(path: string, init: RequestInit & { json?: unknown } = {}): Promise<T> {
  const { json, headers, ...rest } = init;
  const res = await fetch(path, {
    ...rest,
    method: rest.method ?? (json !== undefined ? "POST" : "GET"),
    credentials: "same-origin",
    headers: { ...(json !== undefined ? { "Content-Type": "application/json" } : {}), ...(headers ?? {}) },
    body: json !== undefined ? JSON.stringify(json) : rest.body,
  }).catch(() => {
    throw new ApiClientError(0, "NETWORK", "Connection lost. Check your network and try again.");
  });
  const text = await res.text();
  let data: unknown = null;
  try {
    data = text ? JSON.parse(text) : null;
  } catch {
    data = null;
  }
  if (!res.ok) {
    const e = (data ?? {}) as Partial<ApiError>;
    throw new ApiClientError(res.status, e.error ?? "HTTP_" + res.status, e.message ?? (res.status >= 500 ? "Server unavailable. Please try again shortly." : "Request failed."), e.details);
  }
  return data as T;
}

export const isUnauthorized = (e: unknown) => e instanceof ApiClientError && e.status === 401;