/* note: browser DOM element cannot see mso- style attrs, must parse */
function html_to_sheet(str/*:string*/, _opts)/*:Workbook*/ {
	var opts = _opts || {};
	var dense = (opts.dense != null) ? opts.dense : DENSE;
	var ws/*:Worksheet*/ = ({}/*:any*/); if(dense) ws["!data"] = [];
	str = str.replace(/<!--.*?-->/g, "");
	var mtch/*:any*/ = str.match(/<table/i);
	if(!mtch) throw new Error("Invalid HTML: could not find <table>");
	var mtch2/*:any*/ = str.match(/<\/table/i);
	var i/*:number*/ = mtch.index, j/*:number*/ = mtch2 && mtch2.index || str.length;
	var rows = split_regex(str.slice(i, j), /(:?<tr[^>]*>)/i, "<tr>");
	var R = -1, C = 0, RS = 0, CS = 0;
	var range/*:Range*/ = {s:{r:10000000, c:10000000},e:{r:0,c:0}};
	var merges/*:Array<Range>*/ = [];
	for(i = 0; i < rows.length; ++i) {
		var row = rows[i].trim();
		var hd = row.slice(0,3).toLowerCase();
		if(hd == "<tr") { ++R; if(opts.sheetRows && opts.sheetRows <= R) { --R; break; } C = 0; continue; }
		if(hd != "<td" && hd != "<th") continue;
		var cells = row.split(/<\/t[dh]>/i);
		for(j = 0; j < cells.length; ++j) {
			var cell = cells[j].trim();
			if(!cell.match(/<t[dh]/i)) continue;
			var m = cell, cc = 0;
			/* TODO: parse styles etc */
			while(m.charAt(0) == "<" && (cc = m.indexOf(">")) > -1) m = m.slice(cc+1);
			for(var midx = 0; midx < merges.length; ++midx) {
				var _merge/*:Range*/ = merges[midx];
				if(_merge.s.c == C && _merge.s.r < R && R <= _merge.e.r) { C = _merge.e.c + 1; midx = -1; }
			}
			var tag = parsexmltag(cell.slice(0, cell.indexOf(">")));
			CS = tag.colspan ? +tag.colspan : 1;
			if((RS = +tag.rowspan)>1 || CS>1) merges.push({s:{r:R,c:C},e:{r:R + (RS||1) - 1, c:C + CS - 1}});
			var _t/*:string*/ = tag.t || tag["data-t"] || "";
			/* TODO: generate stub cells */
			if(!m.length) { C += CS; continue; }
			m = htmldecode(m);
			if(range.s.r > R) range.s.r = R; if(range.e.r < R) range.e.r = R;
			if(range.s.c > C) range.s.c = C; if(range.e.c < C) range.e.c = C;
			if(!m.length) { C += CS; continue; }
			var o/*:Cell*/ = {t:'s', v:m};
			if(opts.raw || !m.trim().length || _t == 's'){}
			else if(m === 'TRUE') o = {t:'b', v:true};
			else if(m === 'FALSE') o = {t:'b', v:false};
			else if(!isNaN(fuzzynum(m))) o = {t:'n', v:fuzzynum(m)};
			else if(!isNaN(fuzzydate(m).getDate())) {
				o = ({t:'d', v:parseDate(m)}/*:any*/);
				if(opts.UTC === false) o.v = utc_to_local(o.v);
				if(!opts.cellDates) o = ({t:'n', v:datenum(o.v)}/*:any*/);
				o.z = opts.dateNF || table_fmt[14];
			}
			if(o.cellText !== false) o.w = m;
			if(dense) { if(!ws["!data"][R]) ws["!data"][R] = []; ws["!data"][R][C] = o; }
			else ws[encode_cell({r:R, c:C})] = o;
			C += CS;
		}
	}
	ws['!ref'] = encode_range(range);
	if(merges.length) ws["!merges"] = merges;
	return ws;
}
function make_html_row(ws/*:Worksheet*/, r/*:Range*/, R/*:number*/, o/*:Sheet2HTMLOpts*/)/*:string*/ {
	var M/*:Array<Range>*/ = (ws['!merges'] ||[]);
	var oo/*:Array<string>*/ = [];
	var sp = ({}/*:any*/);
	var dense = ws["!data"] != null;
	for(var C = r.s.c; C <= r.e.c; ++C) {
		var RS = 0, CS = 0;
		for(var j = 0; j < M.length; ++j) {
			if(M[j].s.r > R || M[j].s.c > C) continue;
			if(M[j].e.r < R || M[j].e.c < C) continue;
			if(M[j].s.r < R || M[j].s.c < C) { RS = -1; break; }
			RS = M[j].e.r - M[j].s.r + 1; CS = M[j].e.c - M[j].s.c + 1; break;
		}
		if(RS < 0) continue;
		var coord = encode_col(C) + encode_row(R);
		var cell = dense ? (ws["!data"][R]||[])[C] : ws[coord];
		/* TODO: html entities */
		var w = (cell && cell.v != null) && (cell.h || escapehtml(cell.w || (format_cell(cell), cell.w) || "")) || "";
		sp = ({}/*:any*/);
		if(RS > 1) sp.rowspan = RS;
		if(CS > 1) sp.colspan = CS;
		if(o.editable) w = '<span contenteditable="true">' + w + '</span>';
		else if(cell) {
			sp["data-t"] = cell && cell.t || 'z';
			// note: data-v is unaffected by the timezone interpretation
			if(cell.v != null) sp["data-v"] = cell.v instanceof Date ? cell.v.toISOString() : cell.v;
			if(cell.z != null) sp["data-z"] = cell.z;
			if(cell.l && (cell.l.Target || "#").charAt(0) != "#") w = '<a href="' + escapehtml(cell.l.Target) +'">' + w + '</a>';
		}
		sp.id = (o.id || "sjs") + "-" + coord;
		oo.push(writextag('td', w, sp));
	}
	var preamble = "<tr>";
	return preamble + oo.join("") + "</tr>";
}

var HTML_BEGIN = '<html><head><meta charset="utf-8"/><title>SheetJS Table Export</title></head><body>';
var HTML_END = '</body></html>';

function html_to_workbook(str/*:string*/, opts)/*:Workbook*/ {
	var mtch = str.match(/<table[\s\S]*?>[\s\S]*?<\/table>/gi);
	if(!mtch || mtch.length == 0) throw new Error("Invalid HTML: could not find <table>");
	if(mtch.length == 1) {
		var w = sheet_to_workbook(html_to_sheet(mtch[0], opts), opts);
		w.bookType = "html";
		return w;
	}
	var wb = book_new();
	mtch.forEach(function(s, idx) { book_append_sheet(wb, html_to_sheet(s, opts), "Sheet" + (idx+1)); });
	wb.bookType = "html";
	return wb;
}

function make_html_preamble(ws/*:Worksheet*/, R/*:Range*/, o/*:Sheet2HTMLOpts*/)/*:string*/ {
	var out/*:Array<string>*/ = [];
	return out.join("") + '<table' + (o && o.id ? ' id="' + o.id + '"' : "") + '>';
}

function sheet_to_html(ws/*:Worksheet*/, opts/*:?Sheet2HTMLOpts*//*, wb:?Workbook*/)/*:string*/ {
	var o = opts || {};
	var header = o.header != null ? o.header : HTML_BEGIN;
	var footer = o.footer != null ? o.footer : HTML_END;
	var out/*:Array<string>*/ = [header];
	var r = decode_range(ws['!ref'] || "A1");
	out.push(make_html_preamble(ws, r, o));
	if(ws["!ref"]) for(var R = r.s.r; R <= r.e.r; ++R) out.push(make_html_row(ws, r, R, o));
	out.push("</table>" + footer);
	return out.join("");
}

function sheet_add_dom(ws/*:Worksheet*/, table/*:HTMLElement*/, _opts/*:?any*/)/*:Worksheet*/ {
	var rows/*:HTMLCollection<HTMLTableRowElement>*/ = table.rows;
	if(!rows) {
		/* not an HTML TABLE */
		throw "Unsupported origin when " + table.tagName + " is not a TABLE";
	}

	var opts = _opts || {};
	var dense = ws["!data"] != null;
	var or_R = 0, or_C = 0;
	if(opts.origin != null) {
		if(typeof opts.origin == 'number') or_R = opts.origin;
		else {
			var _origin/*:CellAddress*/ = typeof opts.origin == "string" ? decode_cell(opts.origin) : opts.origin;
			or_R = _origin.r; or_C = _origin.c;
		}
	}

	var sheetRows = Math.min(opts.sheetRows||10000000, rows.length);
	var range/*:Range*/ = {s:{r:0,c:0},e:{r:or_R,c:or_C}};
	if(ws["!ref"]) {
		var _range/*:Range*/ = decode_range(ws["!ref"]);
		range.s.r = Math.min(range.s.r, _range.s.r);
		range.s.c = Math.min(range.s.c, _range.s.c);
		range.e.r = Math.max(range.e.r, _range.e.r);
		range.e.c = Math.max(range.e.c, _range.e.c);
		if(or_R == -1) range.e.r = or_R = _range.e.r + 1;
	}
	var merges/*:Array<Range>*/ = [], midx = 0;
	var rowinfo/*:Array<RowInfo>*/ = ws["!rows"] || (ws["!rows"] = []);
	var _R = 0, R = 0, _C = 0, C = 0, RS = 0, CS = 0;
	if(!ws["!cols"]) ws['!cols'] = [];
	for(; _R < rows.length && R < sheetRows; ++_R) {
		var row/*:HTMLTableRowElement*/ = rows[_R];
		if (is_dom_element_hidden(row)) {
			if (opts.display) continue;
			rowinfo[R] = {hidden: true};
		}
		var elts/*:HTMLCollection<HTMLTableCellElement>*/ = (row.cells);
		for(_C = C = 0; _C < elts.length; ++_C) {
			var elt/*:HTMLTableCellElement*/ = elts[_C];
			if (opts.display && is_dom_element_hidden(elt)) continue;
			var v/*:?string*/ = elt.hasAttribute('data-v') ? elt.getAttribute('data-v') : elt.hasAttribute('v') ? elt.getAttribute('v') : htmldecode(elt.innerHTML);
			var z/*:?string*/ = elt.getAttribute('data-z') || elt.getAttribute('z');
			for(midx = 0; midx < merges.length; ++midx) {
				var m/*:Range*/ = merges[midx];
				if(m.s.c == C + or_C && m.s.r < R + or_R && R + or_R <= m.e.r) { C = m.e.c+1 - or_C; midx = -1; }
			}
			/* TODO: figure out how to extract nonstandard mso- style */
			CS = +elt.getAttribute("colspan") || 1;
			if( ((RS = (+elt.getAttribute("rowspan") || 1)))>1 || CS>1) merges.push({s:{r:R + or_R,c:C + or_C},e:{r:R + or_R + (RS||1) - 1, c:C + or_C + (CS||1) - 1}});
			var o/*:Cell*/ = {t:'s', v:v};
			var _t/*:string*/ = elt.getAttribute("data-t") || elt.getAttribute("t") || "";
			if(v != null) {
				if(v.length == 0) o.t = _t || 'z';
				else if(opts.raw || v.trim().length == 0 || _t == "s"){}
				else if(v === 'TRUE') o = {t:'b', v:true};
				else if(v === 'FALSE') o = {t:'b', v:false};
				else if(!isNaN(fuzzynum(v))) o = {t:'n', v:fuzzynum(v)};
				else if(!isNaN(fuzzydate(v).getDate())) {
					o = ({t:'d', v:parseDate(v)}/*:any*/);
					if(opts.UTC) o.v = local_to_utc(o.v);
					if(!opts.cellDates) o = ({t:'n', v:datenum(o.v)}/*:any*/);
					o.z = opts.dateNF || table_fmt[14];
				}
			}
			if(o.z === undefined && z != null) o.z = z;
			/* The first link is used.  Links are assumed to be fully specified.
			 * TODO: The right way to process relative links is to make a new <a> */
			var l = "", Aelts = elt.getElementsByTagName("A");
			if(Aelts && Aelts.length) for(var Aelti = 0; Aelti < Aelts.length; ++Aelti)	if(Aelts[Aelti].hasAttribute("href")) {
				l = Aelts[Aelti].getAttribute("href"); if(l.charAt(0) != "#") break;
			}
			if(l && l.charAt(0) != "#" &&	l.slice(0, 11).toLowerCase() != 'javascript:') o.l = ({ Target: l });
			if(dense) { if(!ws["!data"][R + or_R]) ws["!data"][R + or_R] = []; ws["!data"][R + or_R][C + or_C] = o; }
			else ws[encode_cell({c:C + or_C, r:R + or_R})] = o;
			if(range.e.c < C + or_C) range.e.c = C + or_C;
			C += CS;
		}
		++R;
	}
	if(merges.length) ws['!merges'] = (ws["!merges"] || []).concat(merges);
	range.e.r = Math.max(range.e.r, R - 1 + or_R);
	ws['!ref'] = encode_range(range);
	if(R >= sheetRows) ws['!fullref'] = encode_range((range.e.r = rows.length-_R+R-1 + or_R,range)); // We can count the real number of rows to parse but we don't to improve the performance
	return ws;
}

function parse_dom_table(table/*:HTMLElement*/, _opts/*:?any*/)/*:Worksheet*/ {
	var opts = _opts || {};
	var ws/*:Worksheet*/ = ({}/*:any*/); if(opts.dense) ws["!data"] = [];
	return sheet_add_dom(ws, table, _opts);
}

function table_to_book(table/*:HTMLElement*/, opts/*:?any*/)/*:Workbook*/ {
	var o = sheet_to_workbook(parse_dom_table(table, opts), opts);
	//o.bookType = "dom"; // TODO: define a type for this
	return o;
}

function is_dom_element_hidden(element/*:HTMLElement*/)/*:boolean*/ {
	var display/*:string*/ = '';
	var get_computed_style/*:?function*/ = get_get_computed_style_function(element);
	if(get_computed_style) display = get_computed_style(element).getPropertyValue('display');
	if(!display) display = element.style && element.style.display;
	return display === 'none';
}

/* global getComputedStyle */
function get_get_computed_style_function(element/*:HTMLElement*/)/*:?function*/ {
	// The proper getComputedStyle implementation is the one defined in the element window
	if(element.ownerDocument.defaultView && typeof element.ownerDocument.defaultView.getComputedStyle === 'function') return element.ownerDocument.defaultView.getComputedStyle;
	// If it is not available, try to get one from the global namespace
	if(typeof getComputedStyle === 'function') return getComputedStyle;
	return null;
}