<?php
/**
 * Calendar class
 *
 * @package NepaliDate
 */

namespace Nilambar\NepaliDate;

/**
 * NepaliCalendar class.
 *
 * @since 1.0.0
 */
class NepaliCalendar
{
    /**
     * Nepali date details.
     *
     * @since 1.0.0
     *
     * @var array
     */
    private $bs = array(
        0  => array( 2000, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        1  => array( 2001, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        2  => array( 2002, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        3  => array( 2003, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        4  => array( 2004, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        5  => array( 2005, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        6  => array( 2006, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        7  => array( 2007, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        8  => array( 2008, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 29, 31 ),
        9  => array( 2009, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        10 => array( 2010, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        11 => array( 2011, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        12 => array( 2012, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30 ),
        13 => array( 2013, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        14 => array( 2014, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        15 => array( 2015, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        16 => array( 2016, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30 ),
        17 => array( 2017, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        18 => array( 2018, 31, 32, 31, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        19 => array( 2019, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        20 => array( 2020, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30 ),
        21 => array( 2021, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        22 => array( 2022, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30 ),
        23 => array( 2023, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        24 => array( 2024, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30 ),
        25 => array( 2025, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        26 => array( 2026, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        27 => array( 2027, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        28 => array( 2028, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        29 => array( 2029, 31, 31, 32, 31, 32, 30, 30, 29, 30, 29, 30, 30 ),
        30 => array( 2030, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        31 => array( 2031, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        32 => array( 2032, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        33 => array( 2033, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        34 => array( 2034, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        35 => array( 2035, 30, 32, 31, 32, 31, 31, 29, 30, 30, 29, 29, 31 ),
        36 => array( 2036, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        37 => array( 2037, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        38 => array( 2038, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        39 => array( 2039, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30 ),
        40 => array( 2040, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        41 => array( 2041, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        42 => array( 2042, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        43 => array( 2043, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30 ),
        44 => array( 2044, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        45 => array( 2045, 31, 32, 31, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        46 => array( 2046, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        47 => array( 2047, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30 ),
        48 => array( 2048, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        49 => array( 2049, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30 ),
        50 => array( 2050, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        51 => array( 2051, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30 ),
        52 => array( 2052, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        53 => array( 2053, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30 ),
        54 => array( 2054, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        55 => array( 2055, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        56 => array( 2056, 31, 31, 32, 31, 32, 30, 30, 29, 30, 29, 30, 30 ),
        57 => array( 2057, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        58 => array( 2058, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        59 => array( 2059, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        60 => array( 2060, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        61 => array( 2061, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        62 => array( 2062, 30, 32, 31, 32, 31, 31, 29, 30, 29, 30, 29, 31 ),
        63 => array( 2063, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        64 => array( 2064, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        65 => array( 2065, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        66 => array( 2066, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 29, 31 ),
        67 => array( 2067, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        68 => array( 2068, 31, 31, 32, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        69 => array( 2069, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        70 => array( 2070, 31, 31, 31, 32, 31, 31, 29, 30, 30, 29, 30, 30 ),
        71 => array( 2071, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        72 => array( 2072, 31, 32, 31, 32, 31, 30, 30, 29, 30, 29, 30, 30 ),
        73 => array( 2073, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 31 ),
        74 => array( 2074, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30 ),
        75 => array( 2075, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        76 => array( 2076, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30 ),
        77 => array( 2077, 31, 32, 31, 32, 31, 30, 30, 30, 29, 30, 29, 31 ),
        78 => array( 2078, 31, 31, 31, 32, 31, 31, 30, 29, 30, 29, 30, 30 ),
        79 => array( 2079, 31, 31, 32, 31, 31, 31, 30, 29, 30, 29, 30, 30 ),
        80 => array( 2080, 31, 32, 31, 32, 31, 30, 30, 30, 29, 29, 30, 30 ),
        81 => array( 2081, 31, 31, 32, 32, 31, 30, 30, 30, 29, 30, 30, 30 ),
        82 => array( 2082, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 30, 30 ),
        83 => array( 2083, 31, 31, 32, 31, 31, 30, 30, 30, 29, 30, 30, 30 ),
        84 => array( 2084, 31, 31, 32, 31, 31, 30, 30, 30, 29, 30, 30, 30 ),
        85 => array( 2085, 31, 32, 31, 32, 30, 31, 30, 30, 29, 30, 30, 30 ),
        86 => array( 2086, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 30, 30 ),
        87 => array( 2087, 31, 31, 32, 31, 31, 31, 30, 30, 29, 30, 30, 30 ),
        88 => array( 2088, 30, 31, 32, 32, 30, 31, 30, 30, 29, 30, 30, 30 ),
        89 => array( 2089, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 30, 30 ),
        90 => array( 2090, 30, 32, 31, 32, 31, 30, 30, 30, 29, 30, 30, 30 ),
    );

    /**
     * Calculates whether English year is leap year or not.
     *
     * @since 1.0.0
     *
     * @param integer $year Year.
     * @return boolean True if leap year.
     */
    private function isLeapYear($year)
    {
        $a = $year;

        if (0 === $a % 100) {
            if (0 === $a % 400) {
                return true;
            } else {
                return false;
            }
        } else {
            if (0 === $a % 4) {
                return true;
            } else {
                return false;
            }
        }
    }

    /**
     * Check if given date is in range.
     *
     * @since 1.0.0
     *
     * @param int    $y Year.
     * @param int    $m Month.
     * @param int    $d Day.
     * @param string $type Type.
     * @return bool True if date is in range.
     */
    public function isDateInRange($y, $m, $d, $type = 'ad')
    {
        $output = true;

        $year_start  = 1944;
        $year_end    = 2033;
        $month_start = 1;
        $month_end   = 12;
        $day_start   = 1;
        $day_end     = 31;

        if ('bs' === $type) {
            $year_start  = 2000;
            $year_end    = 2089;
            $month_start = 1;
            $month_end   = 12;
            $day_start   = 1;
            $day_end     = 32;
        }

        if (true !== $this->checkNumberInRange($y, $year_start, $year_end)) {
            $output = false;
        }

        if (true !== $this->checkNumberInRange($m, $month_start, $month_end)) {
            $output = false;
        }

        if (true !== $this->checkNumberInRange($d, $day_start, $day_end)) {
            $output = false;
        }

        return $output;
    }

    /**
     * Check if given number is in range.
     *
     * @since 1.0.0
     *
     * @param int $value Value.
     * @param int $min Minimum number.
     * @param int $max Maximum number.
     * @return bool True if number is in range.
     */
    private function checkNumberInRange($value, $min, $max)
    {
        return ( $min <= $value ) && ( $value <= $max );
    }

    /**
     * Convert English date to Nepali.
     *
     * @since 1.0.0
     *
     * @param int $yy Year.
     * @param int $mm Month.
     * @param int $dd Day.
     * @return array Converted date.
     */
    public function convertEnglishToNepali($yy, $mm, $dd)
    {
        if (true !== $this->isDateInRange($yy, $mm, $dd, 'ad')) {
            return;
        } else {
            // English month data.
            $month  = array( 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 );
            $lmonth = array( 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 );

            // Spear head English date.
            $def_eyy = 1944;
            $def_nyy = 2000;
            $def_nmm = 9;
            // Spear head nepali date.
            $def_ndd     = 17 - 1;
            $total_edays = 0;
            $total_ndays = 0;
            $a           = 0;
            // All the initializations.
            $day     = 7 - 1;
            $m       = 0;
            $y       = 0;
            $i       = 0;
            $j       = 0;
            $num_day = 0;

            // Count total no. of days in terms of year.
            for ($i = 0; $i < ( $yy - $def_eyy ); $i++) {
                if (true === $this->isLeapYear($def_eyy + $i)) {
                    for ($j = 0; $j < 12; $j++) {
                        $total_edays += $lmonth[ $j ];
                    }
                } else {
                    for ($j = 0; $j < 12; $j++) {
                        $total_edays += $month[ $j ];
                    }
                }
            }

            // Count total no. of days in terms of month.
            for ($i = 0; $i < ( $mm - 1 ); $i++) {
                if (true === $this->isLeapYear($yy)) {
                    $total_edays += $lmonth[ $i ];
                } else {
                    $total_edays += $month[ $i ];
                }
            }

            // Count total no. of days in terms of day.
            $total_edays += $dd;

            $i           = 0;
            $j           = $def_nmm;
            $total_ndays = $def_ndd;
            $m           = $def_nmm;
            $y           = $def_nyy;

            // Count Nepali date from array.
            while (0 !== $total_edays) {
                $a = $this->bs[ $i ][ $j ];
                // Count days.
                $total_ndays++;
                // Count the days in terms of 7 days.
                $day++;

                if ($total_ndays > $a) {
                    $m++;
                    $total_ndays = 1;
                    $j++;
                }

                if ($day > 7) {
                    $day = 1;
                }

                if ($m > 12) {
                    $y++;
                    $m = 1;
                }

                if ($j > 12) {
                    $j = 1;
                    $i++;
                }

                $total_edays--;
            }

            $num_day = $day;

            $output = array(
                'year'    => $y,
                'month'   => $m,
                'day'     => $total_ndays,
                'weekday' => $num_day,
            );

            return $output;
        }
    }

    /**
     * Convert Nepali date to English.
     *
     * @since 1.0.0
     *
     * @param int $yy Year.
     * @param int $mm Month.
     * @param int $dd Day.
     * @return array Converted date.
     */
    public function convertNepaliToEnglish($yy, $mm, $dd)
    {
        $def_eyy = 1943;
        $def_emm = 4;
        // Init English date.
        $def_edd = 14 - 1;
        $def_nyy = 2000;
        $def_nmm = 1;
        // Equivalent Nepali date.
        $def_ndd     = 1;
        $total_edays = 0;
        $total_ndays = 0;
        $a           = 0;
        // Initializations.
        $day     = 4 - 1;
        $m       = 0;
        $y       = 0;
        $i       = 0;
        $k       = 0;
        $num_day = 0;

        $month  = array( 0, 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 );
        $lmonth = array( 0, 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 );

        if (true !== $this->isDateInRange($yy, $mm, $dd, 'bs')) {
            return;
        } else {
            // Count total days in terms of year.
            for ($i = 0; $i < ( $yy - $def_nyy ); $i++) {
                for ($j = 1; $j <= 12; $j++) {
                    $total_ndays += $this->bs[ $k ][ $j ];
                }

                $k++;
            }

            // Count total days in terms of month.
            for ($j = 1; $j < $mm; $j++) {
                $total_ndays += $this->bs[ $k ][ $j ];
            }

            // Count total days in terms of day.
            $total_ndays += $dd;

            // Calculation of equivalent English date.
            $total_edays = $def_edd;
            $m           = $def_emm;
            $y           = $def_eyy;

            while (0 !== $total_ndays) {
                if ($this->isLeapYear($y)) {
                    $a = $lmonth[ $m ];
                } else {
                    $a = $month[ $m ];
                }

                $total_edays++;
                $day++;

                if ($total_edays > $a) {
                    $m++;
                    $total_edays = 1;
                    if ($m > 12) {
                        $y++;
                        $m = 1;
                    }
                }

                if ($day > 7) {
                    $day = 1;
                }

                $total_ndays--;
            }

            $num_day = $day;

            $output = array(
                'year'    => $y,
                'month'   => $m,
                'day'     => $total_edays,
                'weekday' => $num_day,
            );

            return $output;
        }
    }
};