/**
 * 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 );