jQuery( function ( $ )
{
    'use strict';

    var $wrapper = $( '#wpbody' );

    /**
     * Functions to handle input's name.
     */
    var input = {
        updateGroupIndex: function ()
        {
            var that = this,
                $clones = $( this ).parents( '.rwmb-group-clone' ),
                totalLevel = $clones.length;
            $clones.each( function ( i, clone )
            {
                var index = parseInt( $( clone ).parent().data( 'next-index' ) ) - 1,
                    level = totalLevel - i;
                input.replaceName.call( that, level, index );

                // Stop each() loop immediately when reach the new clone group.
                if ( $( clone ).data( 'clone-group-new' ) )
                {
                    return false;
                }
            } );
        },
        updateIndex     : function ()
        {
            var $this = $( this );

            // Update index only for sub fields in a group
            if ( !$this.closest( '.rwmb-group-clone' ).length )
            {
                return;
            }

            // Update [group index]
            // input.updateGroupIndex.call( this );

            // Do not update index if field is not cloned
            if ( !$this.closest( '.rwmb-input' ).children( '.rwmb-clone' ).length )
            {
                return;
            }

            var index = parseInt( $this.closest( '.rwmb-input' ).data( 'next-index' ) ) - 1,
                level = $this.parents( '.rwmb-clone' ).length;
            input.replaceName.call( this, level, index );

            // Stop propagation.
            return false;
        },
        // Replace the level-nth [\d] with new index
        replaceName     : function ( level, index )
        {
            var $input = $( this ),
                name = $input.attr( 'name' );
            if ( !name )
            {
                return;
            }

            var regex = new RegExp( '((?:\\[\\d+\\].*?){' + ( level - 1 ) + '}.*?)(\\[\\d+\\])' ),
                newValue = '$1' + '[' + index + ']';

            name = name.replace( regex, newValue );
            $input.attr( 'name', name );
        }
    };

    $wrapper.on( 'clone', ':input[class|="rwmb"]', input.updateIndex );

    /**
     * When clone a group:
     * 1) Remove sub fields' clones and keep only their first clone
     * 2) Reset sub fields' [data-next-index] to 1
     * 3) Set [name] for sub fields (which is done when 'clone' event is fired
     * 4) Repeat steps 1)-3) for sub groups
     */
    $wrapper.on( 'clone_instance', '.rwmb-clone', function ()
    {
        if ( !$( this ).hasClass( 'rwmb-group-clone' ) )
        {
            return false;
        }

        $( this )
            // Add new [data-clone-group-new] to detect which group is cloned. This data is used to update sub inputs' group index
            .data( 'clone-group-new', true )
            // Remove clones, and keep only their first clone. Reset [data-next-index] to 1
            .find( '.rwmb-input' ).each( function ()
            {
                $( this ).data( 'next-index', 1 ).children( '.rwmb-clone:gt(0)' ).remove();
            } ).end()
            // Update [group index] for inputs
            .find( ':input[class|="rwmb"]' ).each( function ()
            {
                input.updateGroupIndex.call( this );
            } );

        // Stop propagation to not trigger the same event on parent's clone.
        return false;
    } );
} );