if (typeof JSDOC == "undefined") JSDOC = {};

/**

	@class Search a {@link JSDOC.TextStream} for language tokens.

*/

JSDOC.TokenReader = function() {

	this.keepDocs = true;

	this.keepWhite = false;

	this.keepComments = false;

}

/**

	@type {JSDOC.Token[]}

 */

JSDOC.TokenReader.prototype.tokenize = function(/**JSDOC.TextStream*/stream) {

	var tokens = [];

	/**@ignore*/ tokens.last    = function() { return tokens[tokens.length-1]; }

	/**@ignore*/ tokens.lastSym = function() {

		for (var i = tokens.length-1; i >= 0; i--) {

			if (!(tokens[i].is("WHIT") || tokens[i].is("COMM"))) return tokens[i];

		}

	}

	while (!stream.look().eof) {

		if (this.read_mlcomment(stream, tokens)) continue;

		if (this.read_slcomment(stream, tokens)) continue;

		if (this.read_dbquote(stream, tokens))   continue;

		if (this.read_snquote(stream, tokens))   continue;

		if (this.read_regx(stream, tokens))      continue;

		if (this.read_numb(stream, tokens))      continue;

		if (this.read_punc(stream, tokens))      continue;

		if (this.read_newline(stream, tokens))   continue;

		if (this.read_space(stream, tokens))     continue;

		if (this.read_word(stream, tokens))      continue;

		// if execution reaches here then an error has happened

		tokens.push(new JSDOC.Token(stream.next(), "TOKN", "UNKNOWN_TOKEN"));

	}

	return tokens;

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_word = function(/**JSDOC.TokenStream*/stream, tokens) {

	var found = "";

	while (!stream.look().eof && JSDOC.Lang.isWordChar(stream.look())) {

		found += stream.next();

	}

	if (found === "") {

		return false;

	}

	else {

		var name;

		if ((name = JSDOC.Lang.keyword(found))) tokens.push(new JSDOC.Token(found, "KEYW", name));

		else tokens.push(new JSDOC.Token(found, "NAME", "NAME"));

		return true;

	}

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_punc = function(/**JSDOC.TokenStream*/stream, tokens) {

	var found = "";

	var name;

	while (!stream.look().eof && JSDOC.Lang.punc(found+stream.look())) {

		found += stream.next();

	}

	if (found === "") {

		return false;

	}

	else {

		tokens.push(new JSDOC.Token(found, "PUNC", JSDOC.Lang.punc(found)));

		return true;

	}

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_space = function(/**JSDOC.TokenStream*/stream, tokens) {

	var found = "";

	while (!stream.look().eof && JSDOC.Lang.isSpace(stream.look())) {

		found += stream.next();

	}

	if (found === "") {

		return false;

	}

	else {

		if (this.collapseWhite) found = " ";

		if (this.keepWhite) tokens.push(new JSDOC.Token(found, "WHIT", "SPACE"));

		return true;

	}

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_newline = function(/**JSDOC.TokenStream*/stream, tokens) {

	var found = "";

	while (!stream.look().eof && JSDOC.Lang.isNewline(stream.look())) {

		found += stream.next();

	}

	if (found === "") {

		return false;

	}

	else {

		if (this.collapseWhite) found = "\n";

		if (this.keepWhite) tokens.push(new JSDOC.Token(found, "WHIT", "NEWLINE"));

		return true;

	}

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_mlcomment = function(/**JSDOC.TokenStream*/stream, tokens) {

	if (stream.look() == "/" && stream.look(1) == "*") {

		var found = stream.next(2);

		while (!stream.look().eof && !(stream.look(-1) == "/" && stream.look(-2) == "*")) {

			found += stream.next();

		}

		// to start doclet we allow /** or /*** but not /**/ or /****

		if (/^\/\*\*([^\/]|\*[^*])/.test(found) && this.keepDocs) tokens.push(new JSDOC.Token(found, "COMM", "JSDOC"));

		else if (this.keepComments) tokens.push(new JSDOC.Token(found, "COMM", "MULTI_LINE_COMM"));

		return true;

	}

	return false;

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_slcomment = function(/**JSDOC.TokenStream*/stream, tokens) {

	var found;

	if (

		(stream.look() == "/" && stream.look(1) == "/" && (found=stream.next(2)))

		|| 

		(stream.look() == "<" && stream.look(1) == "!" && stream.look(2) == "-" && stream.look(3) == "-" && (found=stream.next(4)))

	) {

		while (!stream.look().eof && !JSDOC.Lang.isNewline(stream.look())) {

			found += stream.next();

		}

		if (this.keepComments) {

			tokens.push(new JSDOC.Token(found, "COMM", "SINGLE_LINE_COMM"));

		}

		return true;

	}

	return false;

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_dbquote = function(/**JSDOC.TokenStream*/stream, tokens) {

	if (stream.look() == "\"") {

		// find terminator

		var string = stream.next();

		while (!stream.look().eof) {

			if (stream.look() == "\\") {

				if (JSDOC.Lang.isNewline(stream.look(1))) {

					do {

						stream.next();

					} while (!stream.look().eof && JSDOC.Lang.isNewline(stream.look()));

					string += "\\\n";

				}

				else {

					string += stream.next(2);

				}

			}

			else if (stream.look() == "\"") {

				string += stream.next();

				tokens.push(new JSDOC.Token(string, "STRN", "DOUBLE_QUOTE"));

				return true;

			}

			else {

				string += stream.next();

			}

		}

	}

	return false; // error! unterminated string

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_snquote = function(/**JSDOC.TokenStream*/stream, tokens) {

	if (stream.look() == "'") {

		// find terminator

		var string = stream.next();

		while (!stream.look().eof) {

			if (stream.look() == "\\") { // escape sequence

				string += stream.next(2);

			}

			else if (stream.look() == "'") {

				string += stream.next();

				tokens.push(new JSDOC.Token(string, "STRN", "SINGLE_QUOTE"));

				return true;

			}

			else {

				string += stream.next();

			}

		}

	}

	return false; // error! unterminated string

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_numb = function(/**JSDOC.TokenStream*/stream, tokens) {

	if (stream.look() === "0" && stream.look(1) == "x") {

		return this.read_hex(stream, tokens);

	}

	var found = "";

	while (!stream.look().eof && JSDOC.Lang.isNumber(found+stream.look())){

		found += stream.next();

	}

	if (found === "") {

		return false;

	}

	else {

		if (/^0[0-7]/.test(found)) tokens.push(new JSDOC.Token(found, "NUMB", "OCTAL"));

		else tokens.push(new JSDOC.Token(found, "NUMB", "DECIMAL"));

		return true;

	}

}

/*t:

	requires("../lib/JSDOC/TextStream.js");

	requires("../lib/JSDOC/Token.js");

	requires("../lib/JSDOC/Lang.js");

	plan(3, "testing JSDOC.TokenReader.prototype.read_numb");

	//// setup

	var src = "function foo(num){while (num+8.0 >= 0x20 && num < 0777){}}";

	var tr = new JSDOC.TokenReader();

	var tokens = tr.tokenize(new JSDOC.TextStream(src));

	var hexToken, octToken, decToken;

	for (var i = 0; i < tokens.length; i++) {

		if (tokens[i].name == "HEX_DEC") hexToken = tokens[i];

		if (tokens[i].name == "OCTAL") octToken = tokens[i];

		if (tokens[i].name == "DECIMAL") decToken = tokens[i];

	}

	////

	is(decToken.data, "8.0", "decimal number is found in source.");

	is(hexToken.data, "0x20", "hexdec number is found in source (issue #99).");

	is(octToken.data, "0777", "octal number is found in source.");

*/

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_hex = function(/**JSDOC.TokenStream*/stream, tokens) {

	var found = stream.next(2);

	while (!stream.look().eof) {

		if (JSDOC.Lang.isHexDec(found) && !JSDOC.Lang.isHexDec(found+stream.look())) { // done

			tokens.push(new JSDOC.Token(found, "NUMB", "HEX_DEC"));

			return true;

		}

		else {

			found += stream.next();

		}

	}

	return false;

}

/**

	@returns {Boolean} Was the token found?

 */

JSDOC.TokenReader.prototype.read_regx = function(/**JSDOC.TokenStream*/stream, tokens) {

	var last;

	if (

		stream.look() == "/"

		&& 

		(

			(

				!(last = tokens.lastSym()) // there is no last, the regex is the first symbol

				|| 

				(

					   !last.is("NUMB")

					&& !last.is("NAME")

					&& !last.is("RIGHT_PAREN")

					&& !last.is("RIGHT_BRACKET")

				)

			)

		)

	) {

		var regex = stream.next();

		while (!stream.look().eof) {

			if (stream.look() == "\\") { // escape sequence

				regex += stream.next(2);

			}

			else if (stream.look() == "/") {

				regex += stream.next();

				while (/[gmi]/.test(stream.look())) {

					regex += stream.next();

				}

				tokens.push(new JSDOC.Token(regex, "REGX", "REGX"));

				return true;

			}

			else {

				regex += stream.next();

			}

		}

		// error: unterminated regex

	}

	return false;

}