import type {
  Bar,
  BarConfig,
  CreateTransactionRequest,
  CreateTransactionResponse,
} from '@wutzcalc/shared';

async function json<T>(res: Response): Promise<T> {
  if (!res.ok) throw new Error(`${res.status} ${await res.text()}`);
  return res.json() as Promise<T>;
}

export const api = {
  bars: () => fetch('/api/bars').then(json<Bar[]>),
  config: (barId: number) => fetch(`/api/config?bar=${barId}`).then(json<BarConfig>),
  createTransaction: (body: CreateTransactionRequest) =>
    fetch('/api/transactions', {
      method: 'POST',
      headers: { 'Content-Type': 'application/json' },
      body: JSON.stringify(body),
    }).then(json<CreateTransactionResponse>),
};

export function formatCents(cents: number): string {
  const sign = cents < 0 ? '-' : '';
  const abs = Math.abs(cents);
  return `${sign}${(abs / 100).toFixed(2)} €`;
}

export type Theme = 'dark' | 'light';
const THEME_KEY = 'wutz.theme';

export function getTheme(): Theme {
  return localStorage.getItem(THEME_KEY) === 'light' ? 'light' : 'dark';
}

export function applyTheme(t: Theme = getTheme()): void {
  document.documentElement.setAttribute('data-theme', t);
}

export function setTheme(t: Theme): void {
  localStorage.setItem(THEME_KEY, t);
  applyTheme(t);
}

export function uuid(): string {
  if (typeof crypto !== 'undefined' && 'randomUUID' in crypto) {
    return (crypto as any).randomUUID();
  }
  return 'xxxxxxxx-xxxx-4xxx-yxxx-xxxxxxxxxxxx'.replace(/[xy]/g, c => {
    const r = (Math.random() * 16) | 0;
    const v = c === 'x' ? r : (r & 0x3) | 0x8;
    return v.toString(16);
  });
}