/**

 * Word or character counting functionality. Count words or characters in a

 * provided text string.

 *

 * @namespace wp.utils

 *

 * @since 2.6.0

 * @output wp-admin/js/word-count.js

 */

( function() {

	/**

	 * Word counting utility

	 *

	 * @namespace wp.utils.wordcounter

	 * @memberof  wp.utils

	 *

	 * @class

	 *

	 * @param {Object} settings                                   Optional. Key-value object containing overrides for

	 *                                                            settings.

	 * @param {RegExp} settings.HTMLRegExp                        Optional. Regular expression to find HTML elements.

	 * @param {RegExp} settings.HTMLcommentRegExp                 Optional. Regular expression to find HTML comments.

	 * @param {RegExp} settings.spaceRegExp                       Optional. Regular expression to find irregular space

	 *                                                            characters.

	 * @param {RegExp} settings.HTMLEntityRegExp                  Optional. Regular expression to find HTML entities.

	 * @param {RegExp} settings.connectorRegExp                   Optional. Regular expression to find connectors that

	 *                                                            split words.

	 * @param {RegExp} settings.removeRegExp                      Optional. Regular expression to find remove unwanted

	 *                                                            characters to reduce false-positives.

	 * @param {RegExp} settings.astralRegExp                      Optional. Regular expression to find unwanted

	 *                                                            characters when searching for non-words.

	 * @param {RegExp} settings.wordsRegExp                       Optional. Regular expression to find words by spaces.

	 * @param {RegExp} settings.characters_excluding_spacesRegExp Optional. Regular expression to find characters which

	 *                                                            are non-spaces.

	 * @param {RegExp} settings.characters_including_spacesRegExp Optional. Regular expression to find characters

	 *                                                            including spaces.

	 * @param {RegExp} settings.shortcodesRegExp                  Optional. Regular expression to find shortcodes.

	 * @param {Object} settings.l10n                              Optional. Localization object containing specific

	 *                                                            configuration for the current localization.

	 * @param {string} settings.l10n.type                         Optional. Method of finding words to count.

	 * @param {Array}  settings.l10n.shortcodes                   Optional. Array of shortcodes that should be removed

	 *                                                            from the text.

	 *

	 * @return {void}

	 */

	function WordCounter( settings ) {

		var key,

			shortcodes;

		// Apply provided settings to object settings.

		if ( settings ) {

			for ( key in settings ) {

				// Only apply valid settings.

				if ( settings.hasOwnProperty( key ) ) {

					this.settings[ key ] = settings[ key ];

				}

			}

		}

		shortcodes = this.settings.l10n.shortcodes;

		// If there are any localization shortcodes, add this as type in the settings.

		if ( shortcodes && shortcodes.length ) {

			this.settings.shortcodesRegExp = new RegExp( '\\[\\/?(?:' + shortcodes.join( '|' ) + ')[^\\]]*?\\]', 'g' );

		}

	}

	// Default settings.

	WordCounter.prototype.settings = {

		HTMLRegExp: /<\/?[a-z][^>]*?>/gi,

		HTMLcommentRegExp: /<!--[\s\S]*?-->/g,

		spaceRegExp: / | /gi,

		HTMLEntityRegExp: /&\S+?;/g,

		// \u2014 = em-dash.

		connectorRegExp: /--|\u2014/g,

		// Characters to be removed from input text.

		removeRegExp: new RegExp( [

			'[',

				// Basic Latin (extract).

				'\u0021-\u0040\u005B-\u0060\u007B-\u007E',

				// Latin-1 Supplement (extract).

				'\u0080-\u00BF\u00D7\u00F7',

				/*

				 * The following range consists of:

				 * General Punctuation

				 * Superscripts and Subscripts

				 * Currency Symbols

				 * Combining Diacritical Marks for Symbols

				 * Letterlike Symbols

				 * Number Forms

				 * Arrows

				 * Mathematical Operators

				 * Miscellaneous Technical

				 * Control Pictures

				 * Optical Character Recognition

				 * Enclosed Alphanumerics

				 * Box Drawing

				 * Block Elements

				 * Geometric Shapes

				 * Miscellaneous Symbols

				 * Dingbats

				 * Miscellaneous Mathematical Symbols-A

				 * Supplemental Arrows-A

				 * Braille Patterns

				 * Supplemental Arrows-B

				 * Miscellaneous Mathematical Symbols-B

				 * Supplemental Mathematical Operators

				 * Miscellaneous Symbols and Arrows

				 */

				'\u2000-\u2BFF',

				// Supplemental Punctuation.

				'\u2E00-\u2E7F',

			']'

		].join( '' ), 'g' ),

		// Remove UTF-16 surrogate points, see https://en.wikipedia.org/wiki/UTF-16#U.2BD800_to_U.2BDFFF

		astralRegExp: /[\uD800-\uDBFF][\uDC00-\uDFFF]/g,

		wordsRegExp: /\S\s+/g,

		characters_excluding_spacesRegExp: /\S/g,

		/*

		 * Match anything that is not a formatting character, excluding:

		 * \f = form feed

		 * \n = new line

		 * \r = carriage return

		 * \t = tab

		 * \v = vertical tab

		 * \u00AD = soft hyphen

		 * \u2028 = line separator

		 * \u2029 = paragraph separator

		 */

		characters_including_spacesRegExp: /[^\f\n\r\t\v\u00AD\u2028\u2029]/g,

		l10n: window.wordCountL10n || {}

	};

	/**

	 * Counts the number of words (or other specified type) in the specified text.

	 *

	 * @since 2.6.0

	 *

	 * @memberof wp.utils.wordcounter

	 *

	 * @param {string}  text Text to count elements in.

	 * @param {string}  type Optional. Specify type to use.

	 *

	 * @return {number} The number of items counted.

	 */

	WordCounter.prototype.count = function( text, type ) {

		var count = 0;

		// Use default type if none was provided.

		type = type || this.settings.l10n.type;

		// Sanitize type to one of three possibilities: 'words', 'characters_excluding_spaces' or 'characters_including_spaces'.

		if ( type !== 'characters_excluding_spaces' && type !== 'characters_including_spaces' ) {

			type = 'words';

		}

		// If we have any text at all.

		if ( text ) {

			text = text + '\n';

			// Replace all HTML with a new-line.

			text = text.replace( this.settings.HTMLRegExp, '\n' );

			// Remove all HTML comments.

			text = text.replace( this.settings.HTMLcommentRegExp, '' );

			// If a shortcode regular expression has been provided use it to remove shortcodes.

			if ( this.settings.shortcodesRegExp ) {

				text = text.replace( this.settings.shortcodesRegExp, '\n' );

			}

			// Normalize non-breaking space to a normal space.

			text = text.replace( this.settings.spaceRegExp, ' ' );

			if ( type === 'words' ) {

				// Remove HTML Entities.

				text = text.replace( this.settings.HTMLEntityRegExp, '' );

				// Convert connectors to spaces to count attached text as words.

				text = text.replace( this.settings.connectorRegExp, ' ' );

				// Remove unwanted characters.

				text = text.replace( this.settings.removeRegExp, '' );

			} else {

				// Convert HTML Entities to "a".

				text = text.replace( this.settings.HTMLEntityRegExp, 'a' );

				// Remove surrogate points.

				text = text.replace( this.settings.astralRegExp, 'a' );

			}

			// Match with the selected type regular expression to count the items.

			text = text.match( this.settings[ type + 'RegExp' ] );

			// If we have any matches, set the count to the number of items found.

			if ( text ) {

				count = text.length;

			}

		}

		return count;

	};

	// Add the WordCounter to the WP Utils.

	window.wp = window.wp || {};

	window.wp.utils = window.wp.utils || {};

	window.wp.utils.WordCounter = WordCounter;

} )();