/*
 * World Calendars
 * https://github.com/alexcjohnson/world-calendars
 *
 * Batch-converted from kbwood/calendars
 * Many thanks to Keith Wood and all of the contributors to the original project!
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 */

/* http://keith-wood.name/calendars.html
   Hebrew calendar for jQuery v2.0.2.
   Written by Keith Wood (wood.keith{at}optusnet.com.au) August 2009.
   Available under the MIT (http://keith-wood.name/licence.html) license. 
   Please attribute the author if you use it. */

var main = require('../main');
var assign = require('object-assign');


/** Implementation of the Hebrew civil calendar.
    Based on code from <a href="http://www.fourmilab.ch/documents/calendar/">http://www.fourmilab.ch/documents/calendar/</a>.
    See also <a href="http://en.wikipedia.org/wiki/Hebrew_calendar">http://en.wikipedia.org/wiki/Hebrew_calendar</a>.
    @class HebrewCalendar
    @param [language=''] {string} The language code (default English) for localisation. */
function HebrewCalendar(language) {
    this.local = this.regionalOptions[language || ''] || this.regionalOptions[''];
}

HebrewCalendar.prototype = new main.baseCalendar;

assign(HebrewCalendar.prototype, {
    /** The calendar name.
        @memberof HebrewCalendar */
    name: 'Hebrew',
    /** Julian date of start of Hebrew epoch: 7 October 3761 BCE.
        @memberof HebrewCalendar */
    jdEpoch: 347995.5,
    /** Days per month in a common year.
        @memberof HebrewCalendar */
    daysPerMonth: [30, 29, 30, 29, 30, 29, 30, 29, 30, 29, 30, 29, 29],
    /** <code>true</code> if has a year zero, <code>false</code> if not.
        @memberof HebrewCalendar */
    hasYearZero: false,
    /** The minimum month number.
        @memberof HebrewCalendar */
    minMonth: 1,
    /** The first month in the year.
        @memberof HebrewCalendar */
    firstMonth: 7,
    /** The minimum day number.
        @memberof HebrewCalendar */
    minDay: 1,

    /** Localisations for the plugin.
        Entries are objects indexed by the language code ('' being the default US/English).
        Each object has the following attributes.
        @memberof HebrewCalendar
        @property name {string} The calendar name.
        @property epochs {string[]} The epoch names.
        @property monthNames {string[]} The long names of the months of the year.
        @property monthNamesShort {string[]} The short names of the months of the year.
        @property dayNames {string[]} The long names of the days of the week.
        @property dayNamesShort {string[]} The short names of the days of the week.
        @property dayNamesMin {string[]} The minimal names of the days of the week.
        @property dateFormat {string} The date format for this calendar.
                See the options on <a href="BaseCalendar.html#formatDate"><code>formatDate</code></a> for details.
        @property firstDay {number} The number of the first day of the week, starting at 0.
        @property isRTL {number} <code>true</code> if this localisation reads right-to-left. */
    regionalOptions: { // Localisations
        '': {
            name: 'Hebrew',
            epochs: ['BAM', 'AM'],
            monthNames: ['Nisan', 'Iyar', 'Sivan', 'Tammuz', 'Av', 'Elul',
            'Tishrei', 'Cheshvan', 'Kislev', 'Tevet', 'Shevat', 'Adar', 'Adar II'],
            monthNamesShort: ['Nis', 'Iya', 'Siv', 'Tam', 'Av', 'Elu', 'Tis', 'Che', 'Kis', 'Tev', 'She', 'Ada', 'Ad2'],
            dayNames: ['Yom Rishon', 'Yom Sheni', 'Yom Shlishi', 'Yom Revi\'i', 'Yom Chamishi', 'Yom Shishi', 'Yom Shabbat'],
            dayNamesShort: ['Ris', 'She', 'Shl', 'Rev', 'Cha', 'Shi', 'Sha'],
            dayNamesMin: ['Ri','She','Shl','Re','Ch','Shi','Sha'],
            digits: null,
            dateFormat: 'dd/mm/yyyy',
            firstDay: 0,
            isRTL: false
        }
    },

    /** Determine whether this date is in a leap year.
        @memberof HebrewCalendar
        @param year {CDate|number} The date to examine or the year to examine.
        @return {boolean} <code>true</code> if this is a leap year, <code>false</code> if not.
        @throws Error if an invalid year or a different calendar used. */
    leapYear: function(year) {
        var date = this._validate(year, this.minMonth, this.minDay, main.local.invalidYear);
        return this._leapYear(date.year());
    },

    /** Determine whether this date is in a leap year.
        @memberof HebrewCalendar
        @private
        @param year {number} The year to examine.
        @return {boolean} <code>true</code> if this is a leap year, <code>false</code> if not.
        @throws Error if an invalid year or a different calendar used. */
    _leapYear: function(year) {
        year = (year < 0 ? year + 1 : year);
        return mod(year * 7 + 1, 19) < 7;
    },

    /** Retrieve the number of months in a year.
        @memberof HebrewCalendar
        @param year {CDate|number} The date to examine or the year to examine.
        @return {number} The number of months.
        @throws Error if an invalid year or a different calendar used. */
    monthsInYear: function(year) {
        this._validate(year, this.minMonth, this.minDay, main.local.invalidYear);
        return this._leapYear(year.year ? year.year() : year) ? 13 : 12;
    },

    /** Determine the week of the year for a date.
        @memberof HebrewCalendar
        @param year {CDate|number} The date to examine or the year to examine.
        @param [month] {number} The month to examine.
        @param [day] {number} The day to examine.
        @return {number} The week of the year.
        @throws Error if an invalid date or a different calendar used. */
    weekOfYear: function(year, month, day) {
        // Find Sunday of this week starting on Sunday
        var checkDate = this.newDate(year, month, day);
        checkDate.add(-checkDate.dayOfWeek(), 'd');
        return Math.floor((checkDate.dayOfYear() - 1) / 7) + 1;
    },

    /** Retrieve the number of days in a year.
        @memberof HebrewCalendar
        @param year {CDate|number} The date to examine or the year to examine.
        @return {number} The number of days.
        @throws Error if an invalid year or a different calendar used. */
    daysInYear: function(year) {
        var date = this._validate(year, this.minMonth, this.minDay, main.local.invalidYear);
        year = date.year();
        return this.toJD((year === -1 ? +1 : year + 1), 7, 1) - this.toJD(year, 7, 1);
    },

    /** Retrieve the number of days in a month.
        @memberof HebrewCalendar
        @param year {CDate|number} The date to examine or the year of the month.
        @param [month] {number} The month.
        @return {number} The number of days in this month.
        @throws Error if an invalid month/year or a different calendar used. */
    daysInMonth: function(year, month) {
        if (year.year) {
            month = year.month();
            year = year.year();
        }
        this._validate(year, month, this.minDay, main.local.invalidMonth);
        return (month === 12 && this.leapYear(year) ? 30 : // Adar I
                (month === 8 && mod(this.daysInYear(year), 10) === 5 ? 30 : // Cheshvan in shlemah year
                (month === 9 && mod(this.daysInYear(year), 10) === 3 ? 29 : // Kislev in chaserah year
                this.daysPerMonth[month - 1])));
    },

    /** Determine whether this date is a week day.
        @memberof HebrewCalendar
        @param year {CDate|number} The date to examine or the year to examine.
        @param [month] {number} The month to examine.
        @param [day] {number} The day to examine.
        @return {boolean} <code>true</code> if a week day, <code>false</code> if not.
        @throws Error if an invalid date or a different calendar used. */
    weekDay: function(year, month, day) {
        return this.dayOfWeek(year, month, day) !== 6;
    },

    /** Retrieve additional information about a date - year type.
        @memberof HebrewCalendar
        @param year {CDate|number} The date to examine or the year to examine.
        @param [month] {number} The month to examine.
        @param [day] {number} The day to examine.
        @return {object} Additional information - contents depends on calendar.
        @throws Error if an invalid date or a different calendar used. */
    extraInfo: function(year, month, day) {
        var date = this._validate(year, month, day, main.local.invalidDate);
        return {yearType: (this.leapYear(date) ? 'embolismic' : 'common') + ' ' +
            ['deficient', 'regular', 'complete'][this.daysInYear(date) % 10 - 3]};
    },

    /** Retrieve the Julian date equivalent for this date,
        i.e. days since January 1, 4713 BCE Greenwich noon.
        @memberof HebrewCalendar
        @param year {CDate)|number} The date to convert or the year to convert.
        @param [month] {number} The month to convert.
        @param [day] {number} The day to convert.
        @return {number} The equivalent Julian date.
        @throws Error if an invalid date or a different calendar used. */
    toJD: function(year, month, day) {
        var date = this._validate(year, month, day, main.local.invalidDate);
        year = date.year();
        month = date.month();
        day = date.day();
        var adjYear = (year <= 0 ? year + 1 : year);
        var jd = this.jdEpoch + this._delay1(adjYear) +
            this._delay2(adjYear) + day + 1;
        if (month < 7) {
            for (var m = 7; m <= this.monthsInYear(year); m++) {
                jd += this.daysInMonth(year, m);
            }
            for (var m = 1; m < month; m++) {
                jd += this.daysInMonth(year, m);
            }
        }
        else {
            for (var m = 7; m < month; m++) {
                jd += this.daysInMonth(year, m);
            }
        }
        return jd;
    },

    /** Test for delay of start of new year and to avoid
        Sunday, Wednesday, or Friday as start of the new year.
        @memberof HebrewCalendar
        @private
        @param year {number} The year to examine.
        @return {number} The days to offset by. */
    _delay1: function(year) {
        var months = Math.floor((235 * year - 234) / 19);
        var parts = 12084 + 13753 * months;
        var day = months * 29 + Math.floor(parts / 25920);
        if (mod(3 * (day + 1), 7) < 3) {
            day++;
        }
        return day;
    },

    /** Check for delay in start of new year due to length of adjacent years.
        @memberof HebrewCalendar
        @private
        @param year {number} The year to examine.
        @return {number} The days to offset by. */
    _delay2: function(year) {
        var last = this._delay1(year - 1);
        var present = this._delay1(year);
        var next = this._delay1(year + 1);
        return ((next - present) === 356 ? 2 : ((present - last) === 382 ? 1 : 0));
    },

    /** Create a new date from a Julian date.
        @memberof HebrewCalendar
        @param jd {number} The Julian date to convert.
        @return {CDate} The equivalent date. */
    fromJD: function(jd) {
        jd = Math.floor(jd) + 0.5;
        var year = Math.floor(((jd - this.jdEpoch) * 98496.0) / 35975351.0) - 1;
        while (jd >= this.toJD((year === -1 ? +1 : year + 1), 7, 1)) {
            year++;
        }
        var month = (jd < this.toJD(year, 1, 1)) ? 7 : 1;
        while (jd > this.toJD(year, month, this.daysInMonth(year, month))) {
            month++;
        }
        var day = jd - this.toJD(year, month, 1) + 1;
        return this.newDate(year, month, day);
    }
});

// Modulus function which works for non-integers.
function mod(a, b) {
    return a - (b * Math.floor(a / b));
}

// Hebrew calendar implementation
main.calendars.hebrew = HebrewCalendar;