var _chr = function(c) { return String.fromCharCode(c); };
var _ord = function(c) { return c.charCodeAt(0); };
var attregexg=/([\w:]+)=((?:")([^"]*)(?:")|(?:')([^']*)(?:'))/g;
var attregex=/([\w:]+)=((?:")(?:[^"]*)(?:")|(?:')(?:[^']*)(?:'))/;
function parsexmltag(tag) {
	var words = tag.split(/\s+/);
	var z = {'0': words[0]};
	if(words.length === 1) return z;
	(tag.match(attregexg) || []).map(function(x){
		var y=x.match(attregex);
		y[1] = y[1].replace(/xmlns:/,"xmlns");
		z[y[1].replace(/^[a-zA-Z]*:/,"")] = y[2].substr(1,y[2].length-2);
	});
	return z;
}

var encodings = {
	'"': '"',
	''': "'",
	'>': '>',
	'&lt;': '<',
	'&amp;': '&'
};
var rencoding = evert(encodings);
var rencstr = "&<>'\"".split("");

// TODO: CP remap (need to read file version to determine OS)
function unescapexml(text){
	var s = text + '';
	for(var y in encodings) s = s.replace(new RegExp(y,'g'), encodings[y]);
	return s.replace(/_x([0-9a-fA-F]*)_/g,function(m,c) {return _chr(parseInt(c,16));});
}
function escapexml(text){
	var s = text + '';
	rencstr.forEach(function(y){s=s.replace(new RegExp(y,'g'), rencoding[y]);});
	s = s.replace(/[\u0000-\u0007]/g,function(s) { return "_x" + ("0000"+_ord(s).toString(16)).substr(-4) + "_";}); /* TODO: verify range */
	return s;
}


function parsexmlbool(value, tag) {
	switch(value) {
		case '0': case 0: case 'false': case 'FALSE': return false;
		case '1': case 1: case 'true': case 'TRUE': return true;
		default: throw "bad boolean value " + value + " in "+(tag||"?");
	}
}

var utf8read = function(orig) {
	var out = [], i = 0, c = 0, c1 = 0, c2 = 0, c3 = 0;
	while (i < orig.length) {
		c = orig.charCodeAt(i++);
		if (c < 128) out.push(_chr(c));
		else {
			c2 = orig.charCodeAt(i++);
			if (c>191 && c<224) out.push(_chr((c & 31) << 6 | c2 & 63));
			else {
				c3 = orig.charCodeAt(i++);
				out.push(_chr((c & 15) << 12 | (c2 & 63) << 6 | c3 & 63));
			}
		}
	}
	return out.join("");
};

// matches <foo>...</foo> extracts content
function matchtag(f,g) {return new RegExp('<(?:\\w+:)?'+f+'(?: xml:space="preserve")?(?:[^>]*)>([^\u2603]*)</(?:\\w+:)?'+f+'>',(g||"")+"m");}

function parseVector(data) {
	var h = parsexmltag(data);

	var matches = data.match(new RegExp("<vt:" + h.baseType + ">(.*?)</vt:" + h.baseType + ">", 'g'))||[];
	if(matches.length != h.size) throw "unexpected vector length " + matches.length + " != " + h.size;
	var res = [];
	matches.forEach(function(x) {
		var v = x.replace(/<[/]?vt:variant>/g,"").match(/<vt:([^>]*)>(.*)</);
		res.push({v:v[2], t:v[1]});
	});
	return res;
}

function writetag(f,g) {return '<' + f + (g.match(/(^\s|\s$|\n)/)?' xml:space="preserve"' : "") + '>' + g + '</' + f + '>';}

/*jshint -W041 */
function writextag(f,g,h) { return '<' + f + (h != null ? keys(h).map(function(k) { return " " + k + '="' + h[k] + '"';}).join("") : "") + (g == null ? "/" : (g.match(/(^\s|\s$|\n)/)?' xml:space="preserve"' : "") + '>' + g + '</' + f) + '>';}

function write_w3cdtf(d, t) { try { return d.toISOString().replace(/\.\d*/,""); } catch(e) { if(t) throw e; } }

function write_vt(s) {
	if(typeof s == 'string') return writextag('vt:lpwstr', s);
	if(typeof s == 'number') return writextag((s|0)==s?'vt:i4':'vt:r8', String(s));
	if(typeof s == 'boolean') return writextag('vt:bool', s?'true':'false');
	if(s instanceof Date) return writextag('vt:filetime', write_w3cdtf(s));
	throw new Error("Unable to serialize " + s);
}

var XML_HEADER = '<?xml version="1.0" encoding="UTF-8" standalone="yes"?>\r\n';
var XMLNS = {
	'dc': 'http://purl.org/dc/elements/1.1/',
	'dcterms': 'http://purl.org/dc/terms/',
	'dcmitype': 'http://purl.org/dc/dcmitype/',
	'mx': 'http://schemas.microsoft.com/office/mac/excel/2008/main',
	'r': 'http://schemas.openxmlformats.org/officeDocument/2006/relationships',
	'sjs': 'http://schemas.openxmlformats.org/package/2006/sheetjs/core-properties',
	'vt': 'http://schemas.openxmlformats.org/officeDocument/2006/docPropsVTypes',
	'xsi': 'http://www.w3.org/2001/XMLSchema-instance',
	'xsd': 'http://www.w3.org/2001/XMLSchema'
};

XMLNS.main = [
	'http://schemas.openxmlformats.org/spreadsheetml/2006/main',
	'http://purl.oclc.org/ooxml/spreadsheetml/main',
	'http://schemas.microsoft.com/office/excel/2006/main',
	'http://schemas.microsoft.com/office/excel/2006/2'
];