import { weekDays } from "./weekDays";
import { DateFormat, DateOptions } from "./DateType";
import { setZhCnTimeStr, addZero } from './utils'

/**
 * DateKit class
 * 
 * @author qiuny
 */
const SEPARATE_TIME: string = ':';

let C_Date: Date = new Date();
let C_Year: number = C_Date.getFullYear();
let C_Month: number = C_Date.getMonth() + 1;
let C_Day: number = C_Date.getDate();
let C_Hour: number = C_Date.getHours();
let C_Minute: number = C_Date.getMinutes();
let C_Second: number = C_Date.getSeconds();

class DateKit {
    date!: Date;
    year!: number;
    month!: number;
    day!: number;
    hour!: number;
    minute!: number;
    second!: number;
    isTrue!: boolean;

    private constructor(_date?: string) {
        // this.isTrue = _date ? true : false;
        // this.initDate(_date)
    }

    /**
     *  Set date by developer
     * @param _date YYYY-MM-DD HH:MM:SS or 2023-09-01T03:17:45.944Z
     * @returns date
     */
    static setDate(_date?: string) {
        // this.isTrue = _date ? true : false;
        // this.initDate(_date)
        C_Date = _date ? new Date(_date) : null as any;
        C_Year = C_Date.getFullYear();
        C_Month = C_Date.getMonth() + 1;
        C_Day = C_Date.getDate();
        C_Hour = C_Date.getHours();
        C_Minute = C_Date.getMinutes();
        C_Second = C_Date.getSeconds();
        return this;
    }

    // Get timestamp
    static getTimeStamp() {
        return C_Date.getTime()
    }

    // Get the total number of days and list of the current month.
    static getTotalDays() {
        const lastDay = new Date(C_Year, C_Month, 0).getDate()
        let totalDay: Array<number> = []
        for (let i = 0; i < lastDay; i++) {
            totalDay = totalDay.concat([i + 1])
        }
        return totalDay;
    }

    /**
     * Get what day of the week today is
     * @param _date pattern: YYYY-MM-DD HH:MM:SS
     * @returns week
     */
    static getWeekOfDate(_date?: string) {
        const dates = _date ? new Date(_date) : C_Date;
        return weekDays[dates.getDay()]
    }

    // Get date or coversion date by format
    static format(format?: DateFormat) {
        let currentDate: string = "";
        switch (format) {
            case "YYYY":
                currentDate = `${C_Year}`;
                break;
            case "YYYY-MM":
                currentDate = `${C_Year}-${addZero(C_Month)}`;
                break;
            case "YYYY-MM-DD":
                currentDate = `${C_Year}-${addZero(C_Month)}-${addZero(C_Day)}`;
                break;
            case "YYYY/MM/DD":
                currentDate = `${C_Year}/${addZero(C_Month)}/${addZero(C_Day)}`;
                break;
            case "YYYY-MM-DD HH":
                currentDate = `${C_Year}-${addZero(C_Month)}-${addZero(C_Day)} ${addZero(C_Hour)}`;
                break;
            case "YYYY/MM/DD HH":
                currentDate = `${C_Year}/${addZero(C_Month)}/${addZero(C_Day)} ${addZero(C_Hour)}`;
                break;
            case "YYYY-MM-DD HH:MM":
                currentDate = `${C_Year}-${addZero(C_Month)}-${addZero(C_Day)} ${addZero(C_Hour)}${SEPARATE_TIME}${addZero(C_Minute)}`;
                break;
            case "YYYY/MM/DD HH:MM":
                currentDate = `${C_Year}/${addZero(C_Month)}/${addZero(C_Day)} ${addZero(C_Hour)}${SEPARATE_TIME}${addZero(C_Minute)}`;
                break;
            case "YYYY-MM-DD HH:MM:SS":
                currentDate = `${C_Year}-${addZero(C_Month)}-${addZero(C_Day)} ${addZero(C_Hour)}${SEPARATE_TIME}${addZero(C_Minute)}${SEPARATE_TIME}${addZero(C_Second)}`;
                break;
            case "YYYY/MM/DD HH:MM:SS":
                currentDate = `${C_Year}/${addZero(C_Month)}/${addZero(C_Day)} ${addZero(C_Hour)}${SEPARATE_TIME}${addZero(C_Minute)}${SEPARATE_TIME}${addZero(C_Second)}`;
                break;
            case "HH:MM:SS":
                currentDate = `${addZero(C_Hour)}${SEPARATE_TIME}${addZero(C_Minute)}${SEPARATE_TIME}${addZero(C_Second)}`;
                break;
            default:
                currentDate = `${C_Year}-${addZero(C_Month)}-${addZero(C_Day)} ${addZero(C_Hour)}${SEPARATE_TIME}${addZero(C_Minute)}${SEPARATE_TIME}${addZero(C_Second)}`;
                break;
        }
        return currentDate;
    }

    /**
     *  Calculate the difference between time intervals and return the difference in days, hours and minutes
     * 
     * @param {*} startTime Starting time
     * @param {*} endTime End Time
     * @returns 
     * {
     *    day: days,
     *    hours: hour,
     *    timeStr: time,
     *    minutes
     *  }
     */
    static calcDateDifference = (startTime: string, endTime: string) => {
        const _s = new Date(startTime).toString();
        const _e = new Date(endTime).toString();

        if (_s === 'Invalid Date' || _e === 'Invalid Date') {
            throw new Error('Invalid Date')
        }

        const _start_time_stamp = new Date(startTime).getTime();
        const _end_time_stamp = new Date(endTime).getTime();

        // Number of milliseconds difference between two timestamps.
        const _used_time = _end_time_stamp - _start_time_stamp;

        // Days difference.
        const _days_value = Math.floor(_used_time / (24 * 3600 * 1000));

        // Calculate hours.
        const _hour_value = _used_time % (24 * 3600 * 1000);

        // Keep all decimals and round off when returning to ensure the accuracy of the data.
        const _hours = _hour_value / (3600 * 1000);

        // Calculate difference in minutes.
        const _hour_value_minute = _hour_value % (3600 * 1000);

        // Calculate the number of milliseconds remaining after hours.
        const minutes = Math.floor(_hour_value_minute / (60 * 1000));

        const hour = +_hours.toFixed(2);
        const time = `${_days_value}天${hour}时${minutes}分钟`;

        return {
            day: _days_value,
            hours: hour,
            timeStr: time,
            minutes
        };
    }

    /**
     * Get historical time
     * format: YYYY-MM-DD HH:MM:SS
     *         | YYYY
     *         | YYYY-MM
     *         | YYYY-MM-DD HH
     *         | YYYY-MM-DD HH:MM
     * @param { timestamps: string } date of value
     * @returns object{ time: xxx, unit: 'day', text: 'minutes ago'}
     */
    static getPastTime(timestamps: string) {
        const dateEnd = new Date();
        const dateBegin = new Date(timestamps)
        const dateDiff = dateEnd.getTime() - dateBegin.getTime()
        const seconds = Math.floor(dateDiff / 1000);
        const minutes = Math.floor(seconds / 60);
        const hours = Math.floor(minutes / 60);
        const days = Math.floor(hours / 24);
        const years = Math.floor(days / 365);
        if (years > 0) {
            return { time: years, unit: 'year', text: 'year ago'};
        } else if (days > 0) {
            return { time: days, unit: 'day', text: 'day ago'};
        } else if (hours > 0) {
            return { time: hours, unit: 'hour', text: 'hour ago'};
        } else if (minutes > 0) {
            return { time: minutes, unit: 'minute', text: 'minutes ago'};
        } else {
            return { time: seconds, unit: 'second',text: 'second ago'};
        }
    }

    // Add missing 0
    static addZero (num: number | string ): number|string {
        return  +num > 9 ? `${num}` : `0${num}`;
    }

    // overload 1
    static zhCnTime (format?: DateFormat): string;
    // overload 2
    static zhCnTime (format?: DateFormat, date?: Date | string): string;

    static zhCnTime (format?: DateFormat, date?: Date | string): string {
        var zhCnTimes = setZhCnTimeStr(format, date)
        return zhCnTimes;
    }
}

const dateKit = DateKit

export {
    dateKit,
    DateKit
}