import { DateType } from "react-native-ui-datepicker";

/**
 * Transforms "YYYY-MM-DD" to "DD/MM/YYYY"
 * @param dateStr string in ISO date format "YYYY-MM-DD"
 * @returns formatted string "DD/MM/YYYY"
 */
export const formatDate = (dateStr: string | null | undefined): string => {
    if (!dateStr) return '';
    const [year, month, day] = dateStr.split('-');
    return `${day}/${month}/${year}`;
};

/**
 * Transforms time from "HH:MM:SS" to "HH:MM"
 * @param timeStr string in time format "HH:MM:SS"
 * @returns formatted string "HH:MM"
 */
export const formatTime = (timeStr: string | null | undefined): string => {
    if (!timeStr) return '';
    const [hours, minutes] = timeStr.split(':');
    return `${hours}:${minutes}`;
};

/**
 * Formats a date for use with a date picker, normalizing it to midnight
 * @param d Date in DateType format
 * @returns string in "YYYY-MM-DD" format or null if input is null/undefined
 */
export const formatPickerDate = (d: DateType | null | undefined) => {
    if (!d) return null;

    const date = new Date(d as string | number | Date);
    const normalized = new Date(date.getFullYear(), date.getMonth(), date.getDate());

    const yyyy = normalized.getFullYear();
    const mm = String(normalized.getMonth() + 1).padStart(2, "0");
    const dd = String(normalized.getDate()).padStart(2, "0");

    return `${yyyy}-${mm}-${dd}`;
}

/**
 * Transforms a timestamp into a string "DD/MM/YYYY HH:mm:ss"
 * @param timestamp string or Date object
 * @returns formatted string or empty string if input is invalid
 */
export const formatTimestamp = (timestamp: string | Date | null | undefined): string => {
    if (!timestamp) return '';

    const date = timestamp instanceof Date ? timestamp : new Date(timestamp);
    if (isNaN(date.getTime())) return '';

    const dd = String(date.getDate()).padStart(2, '0');
    const mm = String(date.getMonth() + 1).padStart(2, '0'); // months from 0 to 11
    const yyyy = date.getFullYear();

    const hh = String(date.getHours()).padStart(2, '0');
    const min = String(date.getMinutes()).padStart(2, '0');
    const ss = String(date.getSeconds()).padStart(2, '0');

    return `${dd}/${mm}/${yyyy} ${hh}:${min}:${ss}`;
};

/**
 * Converts an ISO timestamp to a Date object
 * @param dateStr string in ISO date format
 * @returns corresponding Date object
 */
export const parseTimestamp = (dateStr: string | undefined | null): Date => {
    if (!dateStr) return new Date();
    const date = new Date(dateStr);
    if (isNaN(date.getTime())) return new Date();
    return date;
};

export const parseSecondsToTime = (totalSeconds: number | null | undefined): string => {
    if (totalSeconds == null || isNaN(totalSeconds)) return '';

    const hours = Math.floor(totalSeconds / 3600);
    const minutes = Math.floor((totalSeconds % 3600) / 60);
    const seconds = totalSeconds % 60;

    const hh = String(hours);
    const mm = String(minutes).padStart(2, '0');
    const ss = String(seconds).padStart(2, '0');

    return `${hh}h`;
}