/*
 * 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
   Islamic 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 Islamic or '16 civil' calendar.
    Based on code from <a href="http://www.iranchamber.com/calendar/converter/iranian_calendar_converter.php">http://www.iranchamber.com/calendar/converter/iranian_calendar_converter.php</a>.
    See also <a href="http://en.wikipedia.org/wiki/Islamic_calendar">http://en.wikipedia.org/wiki/Islamic_calendar</a>.
    @class IslamicCalendar
    @param [language=''] {string} The language code (default English) for localisation. */
function IslamicCalendar(language) {
    this.local = this.regionalOptions[language || ''] || this.regionalOptions[''];
}

IslamicCalendar.prototype = new main.baseCalendar;

assign(IslamicCalendar.prototype, {
    /** The calendar name.
        @memberof IslamicCalendar */
    name: 'Islamic',
    /** Julian date of start of Islamic epoch: 16 July 622 CE.
        @memberof IslamicCalendar */
    jdEpoch: 1948439.5,
    /** Days per month in a common year.
        @memberof IslamicCalendar */
    daysPerMonth: [30, 29, 30, 29, 30, 29, 30, 29, 30, 29, 30, 29],
    /** <code>true</code> if has a year zero, <code>false</code> if not.
        @memberof IslamicCalendar */
    hasYearZero: false,
    /** The minimum month number.
        @memberof IslamicCalendar */
    minMonth: 1,
    /** The first month in the year.
        @memberof IslamicCalendar */
    firstMonth: 1,
    /** The minimum day number.
        @memberof IslamicCalendar */
    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 IslamicCalendar
        @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: 'Islamic',
            epochs: ['BH', 'AH'],
            monthNames: ['Muharram', 'Safar', 'Rabi\' al-awwal', 'Rabi\' al-thani', 'Jumada al-awwal', 'Jumada al-thani',
            'Rajab', 'Sha\'aban', 'Ramadan', 'Shawwal', 'Dhu al-Qi\'dah', 'Dhu al-Hijjah'],
            monthNamesShort: ['Muh', 'Saf', 'Rab1', 'Rab2', 'Jum1', 'Jum2', 'Raj', 'Sha\'', 'Ram', 'Shaw', 'DhuQ', 'DhuH'],
            dayNames: ['Yawm al-ahad', 'Yawm al-ithnayn', 'Yawm ath-thulaathaa\'',
            'Yawm al-arbi\'aa\'', 'Yawm al-khamīs', 'Yawm al-jum\'a', 'Yawm as-sabt'],
            dayNamesShort: ['Aha', 'Ith', 'Thu', 'Arb', 'Kha', 'Jum', 'Sab'],
            dayNamesMin: ['Ah','It','Th','Ar','Kh','Ju','Sa'],
            digits: null,
            dateFormat: 'yyyy/mm/dd',
            firstDay: 6,
            isRTL: false
        }
    },

    /** Determine whether this date is in a leap year.
        @memberof IslamicCalendar
        @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 (date.year() * 11 + 14) % 30 < 11;
    },

    /** Determine the week of the year for a date.
        @memberof IslamicCalendar
        @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 IslamicCalendar
        @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) {
        return (this.leapYear(year) ? 355 : 354);
    },

    /** Retrieve the number of days in a month.
        @memberof IslamicCalendar
        @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) {
        var date = this._validate(year, month, this.minDay, main.local.invalidMonth);
        return this.daysPerMonth[date.month() - 1] +
            (date.month() === 12 && this.leapYear(date.year()) ? 1 : 0);
    },

    /** Determine whether this date is a week day.
        @memberof IslamicCalendar
        @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) !== 5;
    },

    /** Retrieve the Julian date equivalent for this date,
        i.e. days since January 1, 4713 BCE Greenwich noon.
        @memberof IslamicCalendar
        @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();
        year = (year <= 0 ? year + 1 : year);
        return day + Math.ceil(29.5 * (month - 1)) + (year - 1) * 354 +
            Math.floor((3 + (11 * year)) / 30) + this.jdEpoch - 1;
    },

    /** Create a new date from a Julian date.
        @memberof IslamicCalendar
        @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((30 * (jd - this.jdEpoch) + 10646) / 10631);
        year = (year <= 0 ? year - 1 : year);
        var month = Math.min(12, Math.ceil((jd - 29 - this.toJD(year, 1, 1)) / 29.5) + 1);
        var day = jd - this.toJD(year, month, 1) + 1;
        return this.newDate(year, month, day);
    }
});

// Islamic (16 civil) calendar implementation
main.calendars.islamic = IslamicCalendar;