/**

 * Text pattern plugin for TinyMCE

 *

 * @since 4.3.0

 *

 * This plugin can automatically format text patterns as you type. It includes several groups of patterns.

 *

 * Start of line patterns:

 *  As-you-type:

 *  - Unordered list (`* ` and `- `).

 *  - Ordered list (`1. ` and `1) `).

 *

 *  On enter:

 *  - h2 (## ).

 *  - h3 (### ).

 *  - h4 (#### ).

 *  - h5 (##### ).

 *  - h6 (###### ).

 *  - blockquote (> ).

 *  - hr (---).

 *

 * Inline patterns:

 *  - <code> (`) (backtick).

 *

 * If the transformation in unwanted, the user can undo the change by pressing backspace,

 * using the undo shortcut, or the undo button in the toolbar.

 *

 * Setting for the patterns can be overridden by plugins by using the `tiny_mce_before_init` PHP filter.

 * The setting name is `wptextpattern` and the value is an object containing override arrays for each

 * patterns group. There are three groups: "space", "enter", and "inline". Example (PHP):

 *

 * add_filter( 'tiny_mce_before_init', 'my_mce_init_wptextpattern' );

 * function my_mce_init_wptextpattern( $init ) {

 *   $init['wptextpattern'] = wp_json_encode( array(

 *      'inline' => array(

 *        array( 'delimiter' => '**', 'format' => 'bold' ),

 *        array( 'delimiter' => '__', 'format' => 'italic' ),

 *      ),

 *   ) );

 *

 *   return $init;

 * }

 *

 * Note that setting this will override the default text patterns. You will need to include them

 * in your settings array if you want to keep them working.

 */

( function( tinymce, setTimeout ) {

	if ( tinymce.Env.ie && tinymce.Env.ie < 9 ) {

		return;

	}

	/**

	 * Escapes characters for use in a Regular Expression.

	 *

	 * @param  {String} string Characters to escape

	 *

	 * @return {String}        Escaped characters

	 */

	function escapeRegExp( string ) {

		return string.replace( /[\-\[\]\/\{\}\(\)\*\+\?\.\\\^\$\|]/g, '\\$&' );

	}

	tinymce.PluginManager.add( 'wptextpattern', function( editor ) {

		var VK = tinymce.util.VK;

		var settings = editor.settings.wptextpattern || {};

		var spacePatterns = settings.space || [

			{ regExp: /^[*-]\s/, cmd: 'InsertUnorderedList' },

			{ regExp: /^1[.)]\s/, cmd: 'InsertOrderedList' }

		];

		var enterPatterns = settings.enter || [

			{ start: '##', format: 'h2' },

			{ start: '###', format: 'h3' },

			{ start: '####', format: 'h4' },

			{ start: '#####', format: 'h5' },

			{ start: '######', format: 'h6' },

			{ start: '>', format: 'blockquote' },

			{ regExp: /^(-){3,}$/, element: 'hr' }

		];

		var inlinePatterns = settings.inline || [

			{ delimiter: '`', format: 'code' }

		];

		var canUndo;

		editor.on( 'selectionchange', function() {

			canUndo = null;

		} );

		editor.on( 'keydown', function( event ) {

			if ( ( canUndo && event.keyCode === 27 /* ESCAPE */ ) || ( canUndo === 'space' && event.keyCode === VK.BACKSPACE ) ) {

				editor.undoManager.undo();

				event.preventDefault();

				event.stopImmediatePropagation();

			}

			if ( VK.metaKeyPressed( event ) ) {

				return;

			}

			if ( event.keyCode === VK.ENTER ) {

				enter();

			// Wait for the browser to insert the character.

			} else if ( event.keyCode === VK.SPACEBAR ) {

				setTimeout( space );

			} else if ( event.keyCode > 47 && ! ( event.keyCode >= 91 && event.keyCode <= 93 ) ) {

				setTimeout( inline );

			}

		}, true );

		function inline() {

			var rng = editor.selection.getRng();

			var node = rng.startContainer;

			var offset = rng.startOffset;

			var startOffset;

			var endOffset;

			var pattern;

			var format;

			var zero;

			// We need a non empty text node with an offset greater than zero.

			if ( ! node || node.nodeType !== 3 || ! node.data.length || ! offset ) {

				return;

			}

			var string = node.data.slice( 0, offset );

			var lastChar = node.data.charAt( offset - 1 );

			tinymce.each( inlinePatterns, function( p ) {

				// Character before selection should be delimiter.

				if ( lastChar !== p.delimiter.slice( -1 ) ) {

					return;

				}

				var escDelimiter = escapeRegExp( p.delimiter );

				var delimiterFirstChar = p.delimiter.charAt( 0 );

				var regExp = new RegExp( '(.*)' + escDelimiter + '.+' + escDelimiter + '$' );

				var match = string.match( regExp );

				if ( ! match ) {

					return;

				}

				startOffset = match[1].length;

				endOffset = offset - p.delimiter.length;

				var before = string.charAt( startOffset - 1 );

				var after = string.charAt( startOffset + p.delimiter.length );

				// test*test* => format applied

				// test *test* => applied

				// test* test* => not applied

				if ( startOffset && /\S/.test( before ) ) {

					if ( /\s/.test( after ) || before === delimiterFirstChar ) {

						return;

					}

				}

				// Do not replace when only whitespace and delimiter characters.

				if ( ( new RegExp( '^[\\s' + escapeRegExp( delimiterFirstChar ) + ']+$' ) ).test( string.slice( startOffset, endOffset ) ) ) {

					return;

				}

				pattern = p;

				return false;

			} );

			if ( ! pattern ) {

				return;

			}

			format = editor.formatter.get( pattern.format );

			if ( format && format[0].inline ) {

				editor.undoManager.add();

				editor.undoManager.transact( function() {

					node.insertData( offset, '\uFEFF' );

					node = node.splitText( startOffset );

					zero = node.splitText( offset - startOffset );

					node.deleteData( 0, pattern.delimiter.length );

					node.deleteData( node.data.length - pattern.delimiter.length, pattern.delimiter.length );

					editor.formatter.apply( pattern.format, {}, node );

					editor.selection.setCursorLocation( zero, 1 );

				} );

				// We need to wait for native events to be triggered.

				setTimeout( function() {

					canUndo = 'space';

					editor.once( 'selectionchange', function() {

						var offset;

						if ( zero ) {

							offset = zero.data.indexOf( '\uFEFF' );

							if ( offset !== -1 ) {

								zero.deleteData( offset, offset + 1 );

							}

						}

					} );

				} );

			}

		}

		function firstTextNode( node ) {

			var parent = editor.dom.getParent( node, 'p' ),

				child;

			if ( ! parent ) {

				return;

			}

			while ( child = parent.firstChild ) {

				if ( child.nodeType !== 3 ) {

					parent = child;

				} else {

					break;

				}

			}

			if ( ! child ) {

				return;

			}

			if ( ! child.data ) {

				if ( child.nextSibling && child.nextSibling.nodeType === 3 ) {

					child = child.nextSibling;

				} else {

					child = null;

				}

			}

			return child;

		}

		function space() {

			var rng = editor.selection.getRng(),

				node = rng.startContainer,

				parent,

				text;

			if ( ! node || firstTextNode( node ) !== node ) {

				return;

			}

			parent = node.parentNode;

			text = node.data;

			tinymce.each( spacePatterns, function( pattern ) {

				var match = text.match( pattern.regExp );

				if ( ! match || rng.startOffset !== match[0].length ) {

					return;

				}

				editor.undoManager.add();

				editor.undoManager.transact( function() {

					node.deleteData( 0, match[0].length );

					if ( ! parent.innerHTML ) {

						parent.appendChild( document.createElement( 'br' ) );

					}

					editor.selection.setCursorLocation( parent );

					editor.execCommand( pattern.cmd );

				} );

				// We need to wait for native events to be triggered.

				setTimeout( function() {

					canUndo = 'space';

				} );

				return false;

			} );

		}

		function enter() {

			var rng = editor.selection.getRng(),

				start = rng.startContainer,

				node = firstTextNode( start ),

				i = enterPatterns.length,

				text, pattern, parent;

			if ( ! node ) {

				return;

			}

			text = node.data;

			while ( i-- ) {

				if ( enterPatterns[ i ].start ) {

					if ( text.indexOf( enterPatterns[ i ].start ) === 0 ) {

						pattern = enterPatterns[ i ];

						break;

					}

				} else if ( enterPatterns[ i ].regExp ) {

					if ( enterPatterns[ i ].regExp.test( text ) ) {

						pattern = enterPatterns[ i ];

						break;

					}

				}

			}

			if ( ! pattern ) {

				return;

			}

			if ( node === start && tinymce.trim( text ) === pattern.start ) {

				return;

			}

			editor.once( 'keyup', function() {

				editor.undoManager.add();

				editor.undoManager.transact( function() {

					if ( pattern.format ) {

						editor.formatter.apply( pattern.format, {}, node );

						node.replaceData( 0, node.data.length, ltrim( node.data.slice( pattern.start.length ) ) );

					} else if ( pattern.element ) {

						parent = node.parentNode && node.parentNode.parentNode;

						if ( parent ) {

							parent.replaceChild( document.createElement( pattern.element ), node.parentNode );

						}

					}

				} );

				// We need to wait for native events to be triggered.

				setTimeout( function() {

					canUndo = 'enter';

				} );

			} );

		}

		function ltrim( text ) {

			return text ? text.replace( /^\s+/, '' ) : '';

		}

	} );

} )( window.tinymce, window.setTimeout );