/**
 * Utils.js
 *
 * Released under LGPL License.
 * Copyright (c) 1999-2015 Ephox Corp. All rights reserved
 *
 * License: http://www.tinymce.com/license
 * Contributing: http://www.tinymce.com/contributing
 */

/**
 * This class contails various utility functions for the paste plugin.
 *
 * @class tinymce.pasteplugin.Utils
 */
define("tinymce/pasteplugin/Utils", [
	"tinymce/util/Tools",
	"tinymce/html/DomParser",
	"tinymce/html/Schema"
], function(Tools, DomParser, Schema) {
	function filter(content, items) {
		Tools.each(items, function(v) {
			if (v.constructor == RegExp) {
				content = content.replace(v, '');
			} else {
				content = content.replace(v[0], v[1]);
			}
		});

		return content;
	}

	/**
	 * Gets the innerText of the specified element. It will handle edge cases
	 * and works better than textContent on Gecko.
	 *
	 * @param {String} html HTML string to get text from.
	 * @return {String} String of text with line feeds.
	 */
	function innerText(html) {
		var schema = new Schema(), domParser = new DomParser({}, schema), text = '';
		var shortEndedElements = schema.getShortEndedElements();
		var ignoreElements = Tools.makeMap('script noscript style textarea video audio iframe object', ' ');
		var blockElements = schema.getBlockElements();

		function walk(node) {
			var name = node.name, currentNode = node;

			if (name === 'br') {
				text += '\n';
				return;
			}

			// img/input/hr
			if (shortEndedElements[name]) {
				text += ' ';
			}

			// Ingore script, video contents
			if (ignoreElements[name]) {
				text += ' ';
				return;
			}

			if (node.type == 3) {
				text += node.value;
			}

			// Walk all children
			if (!node.shortEnded) {
				if ((node = node.firstChild)) {
					do {
						walk(node);
					} while ((node = node.next));
				}
			}

			// Add \n or \n\n for blocks or P
			if (blockElements[name] && currentNode.next) {
				text += '\n';

				if (name == 'p') {
					text += '\n';
				}
			}
		}

		html = filter(html, [
			/<!\[[^\]]+\]>/g // Conditional comments
		]);

		walk(domParser.parse(html));

		return text;
	}

	/**
	 * Trims the specified HTML by removing all WebKit fragments, all elements wrapping the body trailing BR elements etc.
	 *
	 * @param {String} html Html string to trim contents on.
	 * @return {String} Html contents that got trimmed.
	 */
	function trimHtml(html) {
		function trimSpaces(all, s1, s2) {
			// WebKit &nbsp; meant to preserve multiple spaces but instead inserted around all inline tags,
			// including the spans with inline styles created on paste
			if (!s1 && !s2) {
				return ' ';
			}

			return '\u00a0';
		}

		html = filter(html, [
			/^[\s\S]*<body[^>]*>\s*|\s*<\/body[^>]*>[\s\S]*$/g, // Remove anything but the contents within the BODY element
			/<!--StartFragment-->|<!--EndFragment-->/g, // Inner fragments (tables from excel on mac)
			[/( ?)<span class="Apple-converted-space">\u00a0<\/span>( ?)/g, trimSpaces],
			/<br class="Apple-interchange-newline">/g,
			/<br>$/i // Trailing BR elements
		]);

		return html;
	}

	// TODO: Should be in some global class
	function createIdGenerator(prefix) {
		var count = 0;

		return function() {
			return prefix + (count++);
		};
	}

	return {
		filter: filter,
		innerText: innerText,
		trimHtml: trimHtml,
		createIdGenerator: createIdGenerator
	};
});
