import { MS_PER_DAY, DayKey, DAY_KEYS } from "../types/timesheet.types";


export function toUTCDateOnly(date: Date | string): Date {
  const d = new Date(date);
  return new Date(Date.UTC(d.getUTCFullYear(), d.getUTCMonth(), d.getUTCDate()));
}

export function addDays(date:Date, days: number): Date {
    return new Date(date.getTime() + days * MS_PER_DAY);
}

export function endOfDayUTC(date: Date | string): Date {
  const d = toUTCDateOnly(date);
  return new Date(d.getTime() + MS_PER_DAY - 1); 
}

export function isBetweenUTC(date: Date, start: Date, end_inclusive: Date): boolean {
    const time   = date.getTime();
    return time >= start.getTime() && time <= end_inclusive.getTime();
}

export function toTimeString(date: Date): string {
    const hours   = String(date.getUTCHours()).padStart(2,'0');
    const minutes = String(date.getUTCMinutes()).padStart(2,'0');
    return `${hours}:${minutes}`;
}

export function round2(num: number) { 
    return Math.round(num * 100) / 100; 
}

export function shortDate(date:Date): string {
    const mm = String(date.getUTCMonth()+1).padStart(2,'0');
    const dd = String(date.getUTCDate()).padStart(2,'0');
    return `${mm}/${dd}`;
}

export function dayKeyFromDate(date: Date, useUTC = true): DayKey {
  const index = useUTC ? date.getUTCDay() : date.getDay(); // 0=Sunday..6=Saturday
  return DAY_KEYS[index];
}

export const toHHmm = (date: Date) => date.toISOString().slice(11, 16);

//create shifts within timesheet's week - employee overview functions
export function parseISODate(iso: string): Date {
    const [ y, m, d ] = iso.split('-').map(Number);
    return new Date(y, (m ?? 1) - 1, d ?? 1);
}

export function parseHHmm(t: string): Date {
    const [ hh, mm ] = t.split(':').map(Number);
    return new Date(1970, 0, 1, hh || 0, mm || 0, 0, 0);
}