'use client';

import useSWR from 'swr';
import { createApiClient, type MeDTO } from '@musicshare/shared';

export const API_URL = process.env.NEXT_PUBLIC_API_URL ?? 'http://localhost:4000';

export class ApiError extends Error {
  constructor(
    public status: number,
    message: string,
  ) {
    super(message);
  }
}

export async function api<T = unknown>(path: string, init: { method?: string; body?: unknown } = {}): Promise<T> {
  const res = await fetch(API_URL + path, {
    method: init.method ?? (init.body ? 'POST' : 'GET'),
    credentials: 'include',
    headers: init.body !== undefined ? { 'content-type': 'application/json' } : undefined,
    body: init.body !== undefined ? JSON.stringify(init.body) : undefined,
  });
  const data = await res.json().catch(() => ({}));
  if (!res.ok) throw new ApiError(res.status, (data as { error?: string }).error ?? res.statusText);
  return data as T;
}

/** Uploads one file as multipart form data (e.g. the profile picture). */
export async function uploadFile<T = unknown>(path: string, file: File): Promise<T> {
  const form = new FormData();
  form.append('file', file);
  const res = await fetch(API_URL + path, { method: 'POST', credentials: 'include', body: form });
  const data = await res.json().catch(() => ({}));
  if (!res.ok) throw new ApiError(res.status, (data as { error?: string }).error ?? res.statusText);
  return data as T;
}

export const fetcher = <T,>(path: string) => api<T>(path);

export function useMe() {
  const { data, error, isLoading, mutate } = useSWR<MeDTO, ApiError>('/me', fetcher, {
    shouldRetryOnError: false,
    revalidateOnFocus: false,
  });
  return { me: data, isLoading, loggedOut: error?.status === 401, mutate };
}

/** The shared typed client, for calls not covered by `api` above. */
export const client = createApiClient({ baseUrl: API_URL, credentials: 'include' });