"use strict";

exports.register = function (linter) {
	// Check for properties named __proto__. This special property was
	// deprecated and then re-introduced for ES6.

	linter.on("Identifier", function style_scanProto(data) {
		if (linter.getOption("proto")) {
			return;
		}

		if (data.name === "__proto__") {
			linter.warn("W103", {
				line: data.line,
				char: data.char,
				data: [ data.name ]
			});
		}
	});

	// Check for properties named __iterator__. This is a special property
	// available only in browsers with JavaScript 1.7 implementation.

	linter.on("Identifier", function style_scanIterator(data) {
		if (linter.getOption("iterator")) {
			return;
		}

		if (data.name === "__iterator__") {
			linter.warn("W104", {
				line: data.line,
				char: data.char,
				data: [ data.name ]
			});
		}
	});

	// Check for dangling underscores.

	linter.on("Identifier", function style_scanDangling(data) {
		if (!linter.getOption("nomen")) {
			return;
		}

		// Underscore.js
		if (data.name === "_") {
			return;
		}

		// In Node, __dirname and __filename should be ignored.
		if (linter.getOption("node")) {
			if (/^(__dirname|__filename)$/.test(data.name) && !data.isProperty) {
				return;
			}
		}

		if (/^(_+.*|.*_+)$/.test(data.name)) {
			linter.warn("W105", {
				line: data.line,
				char: data.from,
				data: [ "dangling '_'", data.name ]
			});
		}
	});

	// Check that all identifiers are using camelCase notation.
	// Exceptions: names like MY_VAR and _myVar.

	linter.on("Identifier", function style_scanCamelCase(data) {
		if (!linter.getOption("camelcase")) {
			return;
		}

		if (data.name.replace(/^_+|_+$/g, "").indexOf("_") > -1 && !data.name.match(/^[A-Z0-9_]*$/)) {
			linter.warn("W106", {
				line: data.line,
				char: data.from,
				data: [ data.name ]
			});
		}
	});

	// Enforce consistency in style of quoting.

	linter.on("String", function style_scanQuotes(data) {
		var quotmark = linter.getOption("quotmark");
		var code;

		if (!quotmark) {
			return;
		}

		// If quotmark is set to 'single' warn about all double-quotes.

		if (quotmark === "single" && data.quote !== "'") {
			code = "W109";
		}

		// If quotmark is set to 'double' warn about all single-quotes.

		if (quotmark === "double" && data.quote !== "\"") {
			code = "W108";
		}

		// If quotmark is set to true, remember the first quotation style
		// and then warn about all others.

		if (quotmark === true) {
			if (!linter.getCache("quotmark")) {
				linter.setCache("quotmark", data.quote);
			}

			if (linter.getCache("quotmark") !== data.quote) {
				code = "W110";
			}
		}

		if (code) {
			linter.warn(code, {
				line: data.line,
				char: data.char,
			});
		}
	});

	linter.on("Number", function style_scanNumbers(data) {
		if (data.value.charAt(0) === ".") {
			// Warn about a leading decimal point.
			linter.warn("W008", {
				line: data.line,
				char: data.char,
				data: [ data.value ]
			});
		}

		if (data.value.substr(data.value.length - 1) === ".") {
			// Warn about a trailing decimal point.
			linter.warn("W047", {
				line: data.line,
				char: data.char,
				data: [ data.value ]
			});
		}

		if (/^00+/.test(data.value)) {
			// Multiple leading zeroes.
			linter.warn("W046", {
				line: data.line,
				char: data.char,
				data: [ data.value ]
			});
		}
	});

	// Warn about script URLs.

	linter.on("String", function style_scanJavaScriptURLs(data) {
		var re = /^(?:javascript|jscript|ecmascript|vbscript|mocha|livescript)\s*:/i;

		if (linter.getOption("scripturl")) {
			return;
		}

		if (re.test(data.value)) {
			linter.warn("W107", {
				line: data.line,
				char: data.char
			});
		}
	});
};