package com.camilstaps.common;

import android.util.Log;

import java.text.ParseException;
import java.util.Calendar;
import java.util.regex.Matcher;
import java.util.regex.Pattern;

/**
 * Created by camilstaps on 7-4-15.
 */
public class Date implements Comparable<Date> {

    private int year, month, day;

    public Date() {
        Calendar cal = Calendar.getInstance();
        year = cal.get(Calendar.YEAR);
        month = cal.get(Calendar.MONTH) + 1;
        day = cal.get(Calendar.DAY_OF_MONTH);
    }

    public Date(int year, int month, int day) {
        this.year = year;
        this.month = month;
        this.day = day;
    }

    public Date(String format) throws ParseException {
        Pattern pat = Pattern.compile("(\\d*)-(\\d*)-(\\d*)");
        Matcher match = pat.matcher(format);
        if (match.find()) {
            year = Integer.parseInt(match.group(1));
            month = Integer.parseInt(match.group(2));
            day = Integer.parseInt(match.group(3));
        } else {
            throw new ParseException("Wrong date format", 0);
        }
    }

    public Date(Date copy) {
        year = copy.year;
        month = copy.month;
        day = copy.day;
    }

    public int getYear() {
        return year;
    }

    public int getMonth() {
        return month;
    }

    public int getDay() {
        return day;
    }

    public void addYears(int n) {
        year += n;
    }

    public void addMonths(int n) {
        for (int i = 0; i < n; i++) {
            month++;
            if (month >= 13) {
                month = 1;
                addYears(1);
            }
        }
    }

    public void addDays(int n) {
        for (int i = 0; i < n; i++) {
            day++;
            if (day >= daysOfMonth()) {
                day = 1;
                addMonths(1);
            }
        }
    }

    public boolean equals(Date date) {
        return year == date.year && month == date.month && day == date.day;
    }

    @Override
    public String toString() {
        return Integer.toString(year) + "-" + Integer.toString(month) + "-" + Integer.toString(day);
    }

    public static boolean isLeapYear(int year) {
        if (year % 4 != 0)
            return false;
        if (year % 100 != 0)
            return true;
        if (year % 400 != 0)
            return false;
        return true;
    }

    public boolean isLeapYear() {
        return isLeapYear(year);
    }

    public static int daysOfYear(int year) {
        return isLeapYear(year) ? 366 : 365;
    }

    public int daysOfYear() {
        return daysOfYear(year);
    }

    public static int daysOfMonth(int year, int month) {
        switch (month) {
            case 2: return isLeapYear(year) ? 29 : 28;
            case 1:
            case 3:
            case 5:
            case 8:
            case 10:
            case 12:
                return 31;
            default:
                return 30;
        }
    }

    public int daysOfMonth() {
        return daysOfMonth(year, month);
    }

    public int diffDays(Date withDate) {
        Date smaller, bigger;
        if (compareTo(withDate) > 0) {
            smaller = new Date(this);
            bigger = new Date(withDate);
        } else {
            smaller = new Date(withDate);
            bigger = new Date(this);
        }
        if (smaller.equals(bigger)) {
            return 0;
        }
        int i = 0;
        while (!smaller.equals(bigger)) {
            smaller.addDays(1);
            i++;
        }
        return i;
    }

    @Override
    public int compareTo(Date another) {
        if (another.year != year)
            return Integer.compare(another.year, year);
        if (another.month != month)
            return Integer.compare(another.month, month);
        if (another.day != day)
            return Integer.compare(another.day, day);
        return 0;
    }

    public int getDayOfWeek() {
        // See: http://en.wikipedia.org/wiki/Determination_of_the_day_of_the_week#A_tabular_method_to_calculate_the_day_of_the_week
        int months[] = {isLeapYear() ? 6 : 0, isLeapYear() ? 2 : 3, 3, 6, 1, 4, 6, 2, 5, 0, 3, 5};
        return (day + months[month - 1] + (year % 100) + (int) Math.floor((year % 100) / 4) + 2 * (3 - ((int) Math.floor(year / 100) % 4))) % 7;
    }

    public String getDayOfWeekName() {
        String days[] = {"Sunday","Monday","Tuesday","Wednesday","Thursday","Friday","Saturday"};
        return days[getDayOfWeek()];
    }

    public String getMonthName() {
        String months[] = {"January","February","March","April","May","June","July","August","September","October","November","December"};
        return months[month - 1];
    }

    public String toNiceString() {
        return getDayOfWeekName() + ", " + day + " " + getMonthName() + " " + year;
    }
}