/**
* Utility functions for parsing and handling shortcodes in JavaScript.
*
* @output wp-includes/js/shortcode.js
*/

/**
* Ensure the global `wp` object exists.
*
* @namespace wp
*/
window.wp = window.wp || {};

(function(){
wp.shortcode = {
/*
* ### Find the next matching shortcode.
*
* Given a shortcode `tag`, a block of `text`, and an optional starting
* `index`, returns the next matching shortcode or `undefined`.
*
* Shortcodes are formatted as an object that contains the match
* `content`, the matching `index`, and the parsed `shortcode` object.
*/
next: function( tag, text, index ) {
var re = wp.shortcode.regexp( tag ),
match, result;

re.lastIndex = index || 0;
match = re.exec( text );

if ( ! match ) {
return;
}

// If we matched an escaped shortcode, try again.
if ( '[' === match[1] && ']' === match[7] ) {
return wp.shortcode.next( tag, text, re.lastIndex );
}

result = {
index: match.index,
content: match[0],
shortcode: wp.shortcode.fromMatch( match )
};

// If we matched a leading `[`, strip it from the match
// and increment the index accordingly.
if ( match[1] ) {
result.content = result.content.slice( 1 );
result.index++;
}

// If we matched a trailing `]`, strip it from the match.
if ( match[7] ) {
result.content = result.content.slice( 0, -1 );
}

return result;
},

/*
* ### Replace matching shortcodes in a block of text.
*
* Accepts a shortcode `tag`, content `text` to scan, and a `callback`
* to process the shortcode matches and return a replacement string.
* Returns the `text` with all shortcodes replaced.
*
* Shortcode matches are objects that contain the shortcode `tag`,
* a shortcode `attrs` object, the `content` between shortcode tags,
* and a boolean flag to indicate if the match was a `single` tag.
*/
replace: function( tag, text, callback ) {
return text.replace( wp.shortcode.regexp( tag ), function( match, left, tag, attrs, slash, content, closing, right ) {
// If both extra brackets exist, the shortcode has been
// properly escaped.
if ( left === '[' && right === ']' ) {
return match;
}

// Create the match object and pass it through the callback.
var result = callback( wp.shortcode.fromMatch( arguments ) );

// Make sure to return any of the extra brackets if they
// weren't used to escape the shortcode.
return result ? left + result + right : match;
});
},

/*
* ### Generate a string from shortcode parameters.
*
* Creates a `wp.shortcode` instance and returns a string.
*
* Accepts the same `options` as the `wp.shortcode()` constructor,
* containing a `tag` string, a string or object of `attrs`, a boolean
* indicating whether to format the shortcode using a `single` tag, and a
* `content` string.
*/
string: function( options ) {
return new wp.shortcode( options ).string();
},

/*
* ### Generate a RegExp to identify a shortcode.
*
* The base regex is functionally equivalent to the one found in
* `get_shortcode_regex()` in `wp-includes/shortcodes.php`.
*
* Capture groups:
*
* 1. An extra `[` to allow for escaping shortcodes with double `[[]]`.
* 2. The shortcode name.
* 3. The shortcode argument list.
* 4. The self closing `/`.
* 5. The content of a shortcode when it wraps some content.
* 6. The closing tag.
* 7. An extra `]` to allow for escaping shortcodes with double `[[]]`.
*/
regexp: _.memoize( function( tag ) {
return new RegExp( '\\[(\\[?)(' + tag + ')(?![\\w-])([^\\]\\/]*(?:\\/(?!\\])[^\\]\\/]*)*?)(?:(\\/)\\]|\\](?:([^\\[]*(?:\\[(?!\\/\\2\\])[^\\[]*)*)(\\[\\/\\2\\]))?)(\\]?)', 'g' );
}),


/*
* ### Parse shortcode attributes.
*
* Shortcodes accept many types of attributes. These can chiefly be
* divided into named and numeric attributes:
*
* Named attributes are assigned on a key/value basis, while numeric
* attributes are treated as an array.
*
* Named attributes can be formatted as either `name="value"`,
* `name='value'`, or `name=value`. Numeric attributes can be formatted
* as `"value"` or just `value`.
*/
attrs: _.memoize( function( text ) {
var named = {},
numeric = [],
pattern, match;

/*
* This regular expression is reused from `shortcode_parse_atts()`
* in `wp-includes/shortcodes.php`.
*
* Capture groups:
*
* 1. An attribute name, that corresponds to...
* 2. a value in double quotes.
* 3. An attribute name, that corresponds to...
* 4. a value in single quotes.
* 5. An attribute name, that corresponds to...
* 6. an unquoted value.
* 7. A numeric attribute in double quotes.
* 8. A numeric attribute in single quotes.
* 9. An unquoted numeric attribute.
*/
pattern = /([\w-]+)\s*=\s*"([^"]*)"(?:\s|$)|([\w-]+)\s*=\s*'([^']*)'(?:\s|$)|([\w-]+)\s*=\s*([^\s'"]+)(?:\s|$)|"([^"]*)"(?:\s|$)|'([^']*)'(?:\s|$)|(\S+)(?:\s|$)/g;

// Map zero-width spaces to actual spaces.
text = text.replace( /[\u00a0\u200b]/g, ' ' );

// Match and normalize attributes.
while ( (match = pattern.exec( text )) ) {
if ( match[1] ) {
named[ match[1].toLowerCase() ] = match[2];
} else if ( match[3] ) {
named[ match[3].toLowerCase() ] = match[4];
} else if ( match[5] ) {
named[ match[5].toLowerCase() ] = match[6];
} else if ( match[7] ) {
numeric.push( match[7] );
} else if ( match[8] ) {
numeric.push( match[8] );
} else if ( match[9] ) {
numeric.push( match[9] );
}
}

return {
named: named,
numeric: numeric
};
}),

/*
* ### Generate a Shortcode Object from a RegExp match.
*
* Accepts a `match` object from calling `regexp.exec()` on a `RegExp`
* generated by `wp.shortcode.regexp()`. `match` can also be set
* to the `arguments` from a callback passed to `regexp.replace()`.
*/
fromMatch: function( match ) {
var type;

if ( match[4] ) {
type = 'self-closing';
} else if ( match[6] ) {
type = 'closed';
} else {
type = 'single';
}

return new wp.shortcode({
tag: match[2],
attrs: match[3],
type: type,
content: match[5]
});
}
};


/*
* Shortcode Objects
* -----------------
*
* Shortcode objects are generated automatically when using the main
* `wp.shortcode` methods: `next()`, `replace()`, and `string()`.
*
* To access a raw representation of a shortcode, pass an `options` object,
* containing a `tag` string, a string or object of `attrs`, a string
* indicating the `type` of the shortcode ('single', 'self-closing',
* or 'closed'), and a `content` string.
*/
wp.shortcode = _.extend( function( options ) {
_.extend( this, _.pick( options || {}, 'tag', 'attrs', 'type', 'content' ) );

var attrs = this.attrs;

// Ensure we have a correctly formatted `attrs` object.
this.attrs = {
named: {},
numeric: []
};

if ( ! attrs ) {
return;
}

// Parse a string of attributes.
if ( _.isString( attrs ) ) {
this.attrs = wp.shortcode.attrs( attrs );

// Identify a correctly formatted `attrs` object.
} else if ( _.difference( _.keys( attrs ), [ 'named', 'numeric' ] ).length === 0 ) {
this.attrs = _.defaults( attrs, this.attrs );

// Handle a flat object of attributes.
} else {
_.each( options.attrs, function( value, key ) {
this.set( key, value );
}, this );
}
}, wp.shortcode );

_.extend( wp.shortcode.prototype, {
/*
* ### Get a shortcode attribute.
*
* Automatically detects whether `attr` is named or numeric and routes
* it accordingly.
*/
get: function( attr ) {
return this.attrs[ _.isNumber( attr ) ? 'numeric' : 'named' ][ attr ];
},

/*
* ### Set a shortcode attribute.
*
* Automatically detects whether `attr` is named or numeric and routes
* it accordingly.
*/
set: function( attr, value ) {
this.attrs[ _.isNumber( attr ) ? 'numeric' : 'named' ][ attr ] = value;
return this;
},

// ### Transform the shortcode match into a string.
string: function() {
var text = '[' + this.tag;

_.each( this.attrs.numeric, function( value ) {
if ( /\s/.test( value ) ) {
text += ' "' + value + '"';
} else {
text += ' ' + value;
}
});

_.each( this.attrs.named, function( value, name ) {
text += ' ' + name + '="' + value + '"';
});

// If the tag is marked as `single` or `self-closing`, close the
// tag and ignore any additional content.
if ( 'single' === this.type ) {
return text + ']';
} else if ( 'self-closing' === this.type ) {
return text + ' /]';
}

// Complete the opening tag.
text += ']';

if ( this.content ) {
text += this.content;
}

// Add the closing tag.
return text + '[/' + this.tag + ']';
}
});
}());

/*
* HTML utility functions
* ----------------------
*
* Experimental. These functions may change or be removed in the future.
*/
(function(){
wp.html = _.extend( wp.html || {}, {
/*
* ### Parse HTML attributes.
*
* Converts `content` to a set of parsed HTML attributes.
* Utilizes `wp.shortcode.attrs( content )`, which is a valid superset of
* the HTML attribute specification. Reformats the attributes into an
* object that contains the `attrs` with `key:value` mapping, and a record
* of the attributes that were entered using `empty` attribute syntax (i.e.
* with no value).
*/
attrs: function( content ) {
var result, attrs;

// If `content` ends in a slash, strip it.
if ( '/' === content[ content.length - 1 ] ) {
content = content.slice( 0, -1 );
}

result = wp.shortcode.attrs( content );
attrs = result.named;

_.each( result.numeric, function( key ) {
if ( /\s/.test( key ) ) {
return;
}

attrs[ key ] = '';
});

return attrs;
},

// ### Convert an HTML-representation of an object to a string.
string: function( options ) {
var text = '<' + options.tag,
content = options.content || '';

_.each( options.attrs, function( value, attr ) {
text += ' ' + attr;

// Convert boolean values to strings.
if ( _.isBoolean( value ) ) {
value = value ? 'true' : 'false';
}

text += '="' + value + '"';
});

// Return the result if it is a self-closing tag.
if ( options.single ) {
return text + ' />';
}

// Complete the opening tag.
text += '>';

// If `content` is an object, recursively call this function.
text += _.isObject( content ) ? wp.html.string( content ) : content;

return text + '</' + options.tag + '>';
}
});
}());