import { parseT } from '$lib/time';
import type { Shifts } from '$lib/shifts';

export type { Shifts };

const IPV4 = /^((25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)\.){3}(25[0-5]|2[0-4]\d|1\d\d|[1-9]?\d)$/;

// A DNS label: alphanumeric, hyphens allowed in the middle, 1-63 chars.
const LABEL = '[A-Za-z0-9](?:[A-Za-z0-9-]{0,61}[A-Za-z0-9])?';
const HOSTNAME = new RegExp(`^${LABEL}(?:\\.${LABEL})*$`);

/** Whether `v` is a usable time clock address: an IPv4 address, a bare
 * hostname (e.g. "timbratore") or a FQDN (e.g. "timbratore.lan"). */
export const isValidHost = (v: string): boolean => IPV4.test(v) || HOSTNAME.test(v);

/** The 4 time fields of `Shifts` — everything but `round_step_min`, which isn't a time. */
export type ShiftTimeKey = 'in1' | 'out1' | 'in2' | 'out2';

export const SHIFT_ROWS: { titleKey: string; a: ShiftTimeKey; b: ShiftTimeKey }[] = [
  { titleKey: 'settings.shift_1', a: 'in1', b: 'out1' },
  { titleKey: 'settings.shift_2', a: 'in2', b: 'out2' }
];

export interface ShiftCheck {
  minutes: Record<ShiftTimeKey, number> | null;
  bad: Partial<Record<ShiftTimeKey, true>>;
  errorKey: string | null;
}

export function checkShifts(shifts: Shifts): ShiftCheck {
  const t: Record<ShiftTimeKey, number | null> = {
    in1: parseT(shifts.in1),
    out1: parseT(shifts.out1),
    in2: parseT(shifts.in2),
    out2: parseT(shifts.out2)
  };
  const bad: Partial<Record<ShiftTimeKey, true>> = {};
  for (const key of Object.keys(t) as ShiftTimeKey[]) {
    if (t[key] === null) bad[key] = true;
  }
  if (Object.keys(bad).length) return { minutes: null, bad, errorKey: 'settings.shift_error_format' };

  const n = t as Record<ShiftTimeKey, number>;
  if (n.out1 <= n.in1) return { minutes: null, bad: { out1: true }, errorKey: 'settings.shift_error_out1' };
  if (n.in2 < n.out1) return { minutes: null, bad: { in2: true }, errorKey: 'settings.shift_error_in2' };
  if (n.out2 <= n.in2) return { minutes: null, bad: { out2: true }, errorKey: 'settings.shift_error_out2' };
  return { minutes: n, bad: {}, errorKey: null };
}

export const roundValid = (v: string): boolean => /^\d{1,2}$/.test(v) && Number(v) >= 1 && Number(v) <= 60;