moment-timezone.js

//! moment-timezone.js
//! version : 0.5.4
//! author : Tim Wood
//! license : MIT
//! github.com/moment/moment-timezone

(function (root, factory) {
	"use strict";

	/*global define*/
	if (typeof define === 'function' && define.amd) {
		define(['moment'], factory);                 // AMD
	} else if (typeof module === 'object' && module.exports) {
		module.exports = factory(require('moment')); // Node
	} else {
		factory(root.moment);                        // Browser
	}
}(this, function (moment) {
	"use strict";

	// Do not load moment-timezone a second time.
	if (moment.tz !== undefined) {
		logError('Moment Timezone ' + moment.tz.version + ' was already loaded ' + (moment.tz.dataVersion ? 'with data from ' : 'without any data') + moment.tz.dataVersion);
		return moment;
	}

	var VERSION = "0.5.4",
		zones = {},
		links = {},
		names = {},
		guesses = {},
		cachedGuess,

		momentVersion = moment.version.split('.'),
		major = +momentVersion[0],
		minor = +momentVersion[1];

	// Moment.js version check
	if (major < 2 || (major === 2 && minor < 6)) {
		logError('Moment Timezone requires Moment.js >= 2.6.0. You are using Moment.js ' + moment.version + '. See momentjs.com');
	}

	/************************************
		Unpacking
	************************************/

	function charCodeToInt(charCode) {
		if (charCode > 96) {
			return charCode - 87;
		} else if (charCode > 64) {
			return charCode - 29;
		}
		return charCode - 48;
	}

	function unpackBase60(string) {
		var i = 0,
			parts = string.split('.'),
			whole = parts[0],
			fractional = parts[1] || '',
			multiplier = 1,
			num,
			out = 0,
			sign = 1;

		// handle negative numbers
		if (string.charCodeAt(0) === 45) {
			i = 1;
			sign = -1;
		}

		// handle digits before the decimal
		for (i; i < whole.length; i++) {
			num = charCodeToInt(whole.charCodeAt(i));
			out = 60 * out + num;
		}

		// handle digits after the decimal
		for (i = 0; i < fractional.length; i++) {
			multiplier = multiplier / 60;
			num = charCodeToInt(fractional.charCodeAt(i));
			out += num * multiplier;
		}

		return out * sign;
	}

	function arrayToInt (array) {
		for (var i = 0; i < array.length; i++) {
			array[i] = unpackBase60(array[i]);
		}
	}

	function intToUntil (array, length) {
		for (var i = 0; i < length; i++) {
			array[i] = Math.round((array[i - 1] || 0) + (array[i] * 60000)); // minutes to milliseconds
		}

		array[length - 1] = Infinity;
	}

	function mapIndices (source, indices) {
		var out = [], i;

		for (i = 0; i < indices.length; i++) {
			out[i] = source[indices[i]];
		}

		return out;
	}

	function unpack (string) {
		var data = string.split('|'),
			offsets = data[2].split(' '),
			indices = data[3].split(''),
			untils  = data[4].split(' ');

		arrayToInt(offsets);
		arrayToInt(indices);
		arrayToInt(untils);

		intToUntil(untils, indices.length);

		return {
			name       : data[0],
			abbrs      : mapIndices(data[1].split(' '), indices),
			offsets    : mapIndices(offsets, indices),
			untils     : untils,
			population : data[5] | 0
		};
	}

	/************************************
		Zone object
	************************************/

	function Zone (packedString) {
		if (packedString) {
			this._set(unpack(packedString));
		}
	}

	Zone.prototype = {
		_set : function (unpacked) {
			this.name       = unpacked.name;
			this.abbrs      = unpacked.abbrs;
			this.untils     = unpacked.untils;
			this.offsets    = unpacked.offsets;
			this.population = unpacked.population;
		},

		_index : function (timestamp) {
			var target = +timestamp,
				untils = this.untils,
				i;

			for (i = 0; i < untils.length; i++) {
				if (target < untils[i]) {
					return i;
				}
			}
		},

		parse : function (timestamp) {
			var target  = +timestamp,
				offsets = this.offsets,
				untils  = this.untils,
				max     = untils.length - 1,
				offset, offsetNext, offsetPrev, i;

			for (i = 0; i < max; i++) {
				offset     = offsets[i];
				offsetNext = offsets[i + 1];
				offsetPrev = offsets[i ? i - 1 : i];

				if (offset < offsetNext && tz.moveAmbiguousForward) {
					offset = offsetNext;
				} else if (offset > offsetPrev && tz.moveInvalidForward) {
					offset = offsetPrev;
				}

				if (target < untils[i] - (offset * 60000)) {
					return offsets[i];
				}
			}

			return offsets[max];
		},

		abbr : function (mom) {
			return this.abbrs[this._index(mom)];
		},

		offset : function (mom) {
			return this.offsets[this._index(mom)];
		}
	};

	/************************************
		Current Timezone
	************************************/

	function OffsetAt(at) {
		var timeString = at.toTimeString();
		var abbr = timeString.match(/\([a-z ]+\)/i);
		if (abbr && abbr[0]) {
			// 17:56:31 GMT-0600 (CST)
			// 17:56:31 GMT-0600 (Central Standard Time)
			abbr = abbr[0].match(/[A-Z]/g);
			abbr = abbr ? abbr.join('') : undefined;
		} else {
			// 17:56:31 CST
			// 17:56:31 GMT+0800 (台北標準時間)
			abbr = timeString.match(/[A-Z]{3,5}/g);
			abbr = abbr ? abbr[0] : undefined;
		}

		if (abbr === 'GMT') {
			abbr = undefined;
		}

		this.at = +at;
		this.abbr = abbr;
		this.offset = at.getTimezoneOffset();
	}

	function ZoneScore(zone) {
		this.zone = zone;
		this.offsetScore = 0;
		this.abbrScore = 0;
	}

	ZoneScore.prototype.scoreOffsetAt = function (offsetAt) {
		this.offsetScore += Math.abs(this.zone.offset(offsetAt.at) - offsetAt.offset);
		if (this.zone.abbr(offsetAt.at).replace(/[^A-Z]/g, '') !== offsetAt.abbr) {
			this.abbrScore++;
		}
	};

	function findChange(low, high) {
		var mid, diff;

		while ((diff = ((high.at - low.at) / 12e4 | 0) * 6e4)) {
			mid = new OffsetAt(new Date(low.at + diff));
			if (mid.offset === low.offset) {
				low = mid;
			} else {
				high = mid;
			}
		}

		return low;
	}

	function userOffsets() {
		var startYear = new Date().getFullYear() - 2,
			last = new OffsetAt(new Date(startYear, 0, 1)),
			offsets = [last],
			change, next, i;

		for (i = 1; i < 48; i++) {
			next = new OffsetAt(new Date(startYear, i, 1));
			if (next.offset !== last.offset) {
				change = findChange(last, next);
				offsets.push(change);
				offsets.push(new OffsetAt(new Date(change.at + 6e4)));
			}
			last = next;
		}

		for (i = 0; i < 4; i++) {
			offsets.push(new OffsetAt(new Date(startYear + i, 0, 1)));
			offsets.push(new OffsetAt(new Date(startYear + i, 6, 1)));
		}

		return offsets;
	}

	function sortZoneScores (a, b) {
		if (a.offsetScore !== b.offsetScore) {
			return a.offsetScore - b.offsetScore;
		}
		if (a.abbrScore !== b.abbrScore) {
			return a.abbrScore - b.abbrScore;
		}
		return b.zone.population - a.zone.population;
	}

	function addToGuesses (name, offsets) {
		var i, offset;
		arrayToInt(offsets);
		for (i = 0; i < offsets.length; i++) {
			offset = offsets[i];
			guesses[offset] = guesses[offset] || {};
			guesses[offset][name] = true;
		}
	}

	function guessesForUserOffsets (offsets) {
		var offsetsLength = offsets.length,
			filteredGuesses = {},
			out = [],
			i, j, guessesOffset;

		for (i = 0; i < offsetsLength; i++) {
			guessesOffset = guesses[offsets[i].offset] || {};
			for (j in guessesOffset) {
				if (guessesOffset.hasOwnProperty(j)) {
					filteredGuesses[j] = true;
				}
			}
		}

		for (i in filteredGuesses) {
			if (filteredGuesses.hasOwnProperty(i)) {
				out.push(names[i]);
			}
		}

		return out;
	}

	function rebuildGuess () {

		// use Intl API when available and returning valid time zone
		try {
			var intlName = Intl.DateTimeFormat().resolvedOptions().timeZone;
			if (intlName){
				var name = names[normalizeName(intlName)];
				if (name) {
					return name;
				}
				logError("Moment Timezone found " + intlName + " from the Intl api, but did not have that data loaded.");
			}
		} catch (e) {
			// Intl unavailable, fall back to manual guessing.
		}

		var offsets = userOffsets(),
			offsetsLength = offsets.length,
			guesses = guessesForUserOffsets(offsets),
			zoneScores = [],
			zoneScore, i, j;

		for (i = 0; i < guesses.length; i++) {
			zoneScore = new ZoneScore(getZone(guesses[i]), offsetsLength);
			for (j = 0; j < offsetsLength; j++) {
				zoneScore.scoreOffsetAt(offsets[j]);
			}
			zoneScores.push(zoneScore);
		}

		zoneScores.sort(sortZoneScores);

		return zoneScores.length > 0 ? zoneScores[0].zone.name : undefined;
	}

	function guess (ignoreCache) {
		if (!cachedGuess || ignoreCache) {
			cachedGuess = rebuildGuess();
		}
		return cachedGuess;
	}

	/************************************
		Global Methods
	************************************/

	function normalizeName (name) {
		return (name || '').toLowerCase().replace(/\//g, '_');
	}

	function addZone (packed) {
		var i, name, split, normalized;

		if (typeof packed === "string") {
			packed = [packed];
		}

		for (i = 0; i < packed.length; i++) {
			split = packed[i].split('|');
			name = split[0];
			normalized = normalizeName(name);
			zones[normalized] = packed[i];
			names[normalized] = name;
			if (split[5]) {
				addToGuesses(normalized, split[2].split(' '));
			}
		}
	}

	function getZone (name, caller) {
		name = normalizeName(name);

		var zone = zones[name];
		var link;

		if (zone instanceof Zone) {
			return zone;
		}

		if (typeof zone === 'string') {
			zone = new Zone(zone);
			zones[name] = zone;
			return zone;
		}

		// Pass getZone to prevent recursion more than 1 level deep
		if (links[name] && caller !== getZone && (link = getZone(links[name], getZone))) {
			zone = zones[name] = new Zone();
			zone._set(link);
			zone.name = names[name];
			return zone;
		}

		return null;
	}

	function getNames () {
		var i, out = [];

		for (i in names) {
			if (names.hasOwnProperty(i) && (zones[i] || zones[links[i]]) && names[i]) {
				out.push(names[i]);
			}
		}

		return out.sort();
	}

	function addLink (aliases) {
		var i, alias, normal0, normal1;

		if (typeof aliases === "string") {
			aliases = [aliases];
		}

		for (i = 0; i < aliases.length; i++) {
			alias = aliases[i].split('|');

			normal0 = normalizeName(alias[0]);
			normal1 = normalizeName(alias[1]);

			links[normal0] = normal1;
			names[normal0] = alias[0];

			links[normal1] = normal0;
			names[normal1] = alias[1];
		}
	}

	function loadData (data) {
		addZone(data.zones);
		addLink(data.links);
		tz.dataVersion = data.version;
	}

	function zoneExists (name) {
		if (!zoneExists.didShowError) {
			zoneExists.didShowError = true;
				logError("moment.tz.zoneExists('" + name + "') has been deprecated in favor of !moment.tz.zone('" + name + "')");
		}
		return !!getZone(name);
	}

	function needsOffset (m) {
		var isUnixTimestamp = (m._f === 'X' || m._f === 'x');
		return !!(m._a && (m._tzm === undefined) && !isUnixTimestamp);
	}

	function logError (message) {
		if (typeof console !== 'undefined' && typeof console.error === 'function') {
			console.error(message);
		}
	}

	/************************************
		moment.tz namespace
	************************************/

	function tz (input) {
		var args = Array.prototype.slice.call(arguments, 0, -1),
			name = arguments[arguments.length - 1],
			zone = getZone(name),
			out  = moment.utc.apply(null, args);

		if (zone && !moment.isMoment(input) && needsOffset(out)) {
			out.add(zone.parse(out), 'minutes');
		}

		out.tz(name);

		return out;
	}

	tz.version      = VERSION;
	tz.dataVersion  = '';
	tz._zones       = zones;
	tz._links       = links;
	tz._names       = names;
	tz.add          = addZone;
	tz.link         = addLink;
	tz.load         = loadData;
	tz.zone         = getZone;
	tz.zoneExists   = zoneExists; // deprecated in 0.1.0
	tz.guess        = guess;
	tz.names        = getNames;
	tz.Zone         = Zone;
	tz.unpack       = unpack;
	tz.unpackBase60 = unpackBase60;
	tz.needsOffset  = needsOffset;
	tz.moveInvalidForward   = true;
	tz.moveAmbiguousForward = false;

	/************************************
		Interface with Moment.js
	************************************/

	var fn = moment.fn;

	moment.tz = tz;

	moment.defaultZone = null;

	moment.updateOffset = function (mom, keepTime) {
		var zone = moment.defaultZone,
			offset;

		if (mom._z === undefined) {
			if (zone && needsOffset(mom) && !mom._isUTC) {
				mom._d = moment.utc(mom._a)._d;
				mom.utc().add(zone.parse(mom), 'minutes');
			}
			mom._z = zone;
		}
		if (mom._z) {
			offset = mom._z.offset(mom);
			if (Math.abs(offset) < 16) {
				offset = offset / 60;
			}
			if (mom.utcOffset !== undefined) {
				mom.utcOffset(-offset, keepTime);
			} else {
				mom.zone(offset, keepTime);
			}
		}
	};

	fn.tz = function (name) {
		if (name) {
			this._z = getZone(name);
			if (this._z) {
				moment.updateOffset(this);
			} else {
				logError("Moment Timezone has no data for " + name + ". See http://momentjs.com/timezone/docs/#/data-loading/.");
			}
			return this;
		}
		if (this._z) { return this._z.name; }
	};

	function abbrWrap (old) {
		return function () {
			if (this._z) { return this._z.abbr(this); }
			return old.call(this);
		};
	}

	function resetZoneWrap (old) {
		return function () {
			this._z = null;
			return old.apply(this, arguments);
		};
	}

	fn.zoneName = abbrWrap(fn.zoneName);
	fn.zoneAbbr = abbrWrap(fn.zoneAbbr);
	fn.utc      = resetZoneWrap(fn.utc);

	moment.tz.setDefault = function(name) {
		if (major < 2 || (major === 2 && minor < 9)) {
			logError('Moment Timezone setDefault() requires Moment.js >= 2.9.0. You are using Moment.js ' + moment.version + '.');
		}
		moment.defaultZone = name ? getZone(name) : null;
		return moment;
	};

	// Cloning a moment should include the _z property.
	var momentProperties = moment.momentProperties;
	if (Object.prototype.toString.call(momentProperties) === '[object Array]') {
		// moment 2.8.1+
		momentProperties.push('_z');
		momentProperties.push('_a');
	} else if (momentProperties) {
		// moment 2.7.0
		momentProperties._z = null;
	}

	// INJECT DATA

	return moment;
}));