<?php
/**
 * CMB2 - The core metabox object
 *
 * @category  WordPress_Plugin
 * @package   CMB2
 * @author    WebDevStudios
 * @license   GPL-2.0+
 * @link      http://webdevstudios.com
 *
 * @property-read string $cmb_id
 * @property-read array $meta_box
 * @property-read array $updated
 */
class CMB2 {

	/**
	 * Current field's ID
	 * @var   string
	 * @since 2.0.0
	 */
	protected $cmb_id = '';

	/**
	 * Metabox Config array
	 * @var   array
	 * @since 0.9.0
	 */
	protected $meta_box = array();

	/**
	 * Object ID for metabox meta retrieving/saving
	 * @var   mixed
	 * @since 1.0.0
	 */
	protected $object_id = 0;

	/**
	 * Type of object being saved. (e.g., post, user, or comment)
	 * @var   string
	 * @since 1.0.0
	 */
	protected $object_type = 'post';

	/**
	 * Type of object registered for metabox. (e.g., post, user, or comment)
	 * @var   string
	 * @since 1.0.0
	 */
	protected $mb_object_type = null;

	/**
	 * List of fields that are changed/updated on save
	 * @var   array
	 * @since 1.1.0
	 */
	protected $updated = array();

	/**
	 * Metabox Defaults
	 * @var   array
	 * @since 1.0.1
	 */
	protected $mb_defaults = array(
		'id'           => '',
		'title'        => '',
		'type'         => '',
		'object_types' => array(), // Post type
		'context'      => 'normal',
		'priority'     => 'high',
		'show_names'   => true, // Show field names on the left
		'show_on_cb'   => null, // Callback to determine if metabox should display.
		'show_on'      => array(), // Post IDs or page templates to display this metabox. overrides 'show_on_cb'
		'cmb_styles'   => true, // Include CMB2 stylesheet
		'enqueue_js'   => true, // Include CMB2 JS
		'fields'       => array(),
		'hookup'       => true,
		'save_fields'  => true, // Will not save during hookup if false
		'closed'       => false, // Default to metabox being closed?
		'new_user_section' => 'add-new-user', // or 'add-existing-user'
	);

	/**
	 * Metabox field objects
	 * @var   array
	 * @since 2.0.3
	 */
	protected $fields = array();

	/**
	 * An array of hidden fields to output at the end of the form
	 * @var   array
	 * @since 2.0.0
	 */
	protected $hidden_fields = array();

	/**
	 * Array of key => value data for saving. Likely $_POST data.
	 * @var   array
	 * @since 2.0.0
	 */
	public $data_to_save = array();

	/**
	 * Array of key => value data for saving. Likely $_POST data.
	 * @var   string
	 * @since 2.0.0
	 */
	protected $generated_nonce = '';

	/**
	 * Get started
	 * @since 0.4.0
	 * @param array   $meta_box  Metabox config array
	 * @param integer $object_id Optional object id
	 */
	public function __construct( $meta_box, $object_id = 0 ) {

		if ( empty( $meta_box['id'] ) ) {
			wp_die( __( 'Metabox configuration is required to have an ID parameter', 'cmb2' ) );
		}

		$this->meta_box = wp_parse_args( $meta_box, $this->mb_defaults );
		$this->object_id( $object_id );
		$this->mb_object_type();
		$this->cmb_id = $meta_box['id'];

		CMB2_Boxes::add( $this );

		/**
		 * Hook during initiation of CMB2 object
		 *
		 * The dynamic portion of the hook name, $this->cmb_id, is this meta_box id.
		 *
		 * @param array $cmb This CMB2 object
		 */
		do_action( "cmb2_init_{$this->cmb_id}", $this );
	}

	/**
	 * Loops through and displays fields
	 * @since  1.0.0
	 * @param  int    $object_id   Object ID
	 * @param  string $object_type Type of object being saved. (e.g., post, user, or comment)
	 */
	public function show_form( $object_id = 0, $object_type = '' ) {
		$object_type = $this->object_type( $object_type );
		$object_id = $this->object_id( $object_id );

		$this->nonce_field();

		echo "\n<!-- Begin CMB2 Fields -->\n";

		/**
		 * Hook before form table begins
		 *
		 * @param array  $cmb_id      The current box ID
		 * @param int    $object_id   The ID of the current object
		 * @param string $object_type The type of object you are working with.
		 *	                           Usually `post` (this applies to all post-types).
		 *	                           Could also be `comment`, `user` or `options-page`.
		 * @param array  $cmb         This CMB2 object
		 */
		do_action( 'cmb2_before_form', $this->cmb_id, $object_id, $object_type, $this );

		/**
		 * Hook before form table begins
		 *
		 * The first dynamic portion of the hook name, $object_type, is the type of object
		 * you are working with. Usually `post` (this applies to all post-types).
		 * Could also be `comment`, `user` or `options-page`.
		 *
		 * The second dynamic portion of the hook name, $this->cmb_id, is the meta_box id.
		 *
		 * @param array  $cmb_id      The current box ID
		 * @param int    $object_id   The ID of the current object
		 * @param array  $cmb         This CMB2 object
		 */
		do_action( "cmb2_before_{$object_type}_form_{$this->cmb_id}", $object_id, $this );

		echo '<div class="cmb2-wrap form-table"><div id="cmb2-metabox-', sanitize_html_class( $this->cmb_id ), '" class="cmb2-metabox cmb-field-list">';

		foreach ( $this->prop( 'fields' ) as $field_args ) {

			$field_args['context'] = $this->prop( 'context' );

			if ( 'group' == $field_args['type'] ) {

				if ( ! isset( $field_args['show_names'] ) ) {
					$field_args['show_names'] = $this->prop( 'show_names' );
				}
				$this->render_group( $field_args );

			} elseif ( 'hidden' == $field_args['type'] && $this->get_field( $field_args )->should_show() ) {
				// Save rendering for after the metabox
				$this->add_hidden_field( array(
					'field_args'  => $field_args,
					'object_type' => $this->object_type(),
					'object_id'   => $this->object_id(),
				) );

			} else {

				$field_args['show_names'] = $this->prop( 'show_names' );

				// Render default fields
				$field = $this->get_field( $field_args )->render_field();
			}
		}

		echo '</div></div>';

		$this->render_hidden_fields();

		/**
		 * Hook after form form has been rendered
		 *
		 * @param array  $cmb_id      The current box ID
		 * @param int    $object_id   The ID of the current object
		 * @param string $object_type The type of object you are working with.
		 *	                           Usually `post` (this applies to all post-types).
		 *	                           Could also be `comment`, `user` or `options-page`.
		 * @param array  $cmb         This CMB2 object
		 */
		do_action( 'cmb2_after_form', $this->cmb_id, $object_id, $object_type, $this );

		/**
		 * Hook after form form has been rendered
		 *
		 * The dynamic portion of the hook name, $this->cmb_id, is the meta_box id.
		 *
		 * The first dynamic portion of the hook name, $object_type, is the type of object
		 * you are working with. Usually `post` (this applies to all post-types).
		 * Could also be `comment`, `user` or `options-page`.
		 *
		 * @param int    $object_id   The ID of the current object
		 * @param array  $cmb         This CMB2 object
		 */
		do_action( "cmb2_after_{$object_type}_form_{$this->cmb_id}", $object_id, $this );

		echo "\n<!-- End CMB2 Fields -->\n";

	}

	/**
	 * Render a repeatable group
	 * @param array $args Array of field arguments for a group field parent
	 */
	public function render_group( $args ) {

		if ( ! isset( $args['id'], $args['fields'] ) || ! is_array( $args['fields'] ) ) {
			return;
		}

		$field_group = $this->get_field( $args );

		// If field is requesting to be conditionally shown
		if ( ! $field_group || ! $field_group->should_show() ) {
			return;
		}

		$desc            = $field_group->args( 'description' );
		$label           = $field_group->args( 'name' );
		$sortable        = $field_group->options( 'sortable' ) ? ' sortable' : ' non-sortable';
		$repeat_class    = $field_group->args( 'repeatable' ) ? ' repeatable' : ' non-repeatable';
		$group_val       = (array) $field_group->value();
		$nrows           = count( $group_val );
		$remove_disabled = $nrows <= 1 ? 'disabled="disabled" ' : '';
		$field_group->index = 0;

		$field_group->peform_param_callback( 'before_group' );

		echo '<div class="cmb-row cmb-repeat-group-wrap"><div class="cmb-td"><div id="', $field_group->id(), '_repeat" class="cmb-nested cmb-field-list cmb-repeatable-group', $sortable, $repeat_class, '" style="width:100%;">';

		if ( $desc || $label ) {
			$class = $desc ? ' cmb-group-description' : '';
			echo '<div class="cmb-row', $class, '"><div class="cmb-th">';
				if ( $label ) {
					echo '<h2 class="cmb-group-name">', $label, '</h2>';
				}
				if ( $desc ) {
					echo '<p class="cmb2-metabox-description">', $desc, '</p>';
				}
			echo '</div></div>';
		}

		if ( ! empty( $group_val ) ) {

			foreach ( $group_val as $group_key => $field_id ) {
				$this->render_group_row( $field_group, $remove_disabled );
				$field_group->index++;
			}
		} else {
			$this->render_group_row( $field_group, $remove_disabled );
		}

		if ( $field_group->args( 'repeatable' ) ) {
			echo '<div class="cmb-row"><div class="cmb-td"><p class="cmb-add-row"><button data-selector="', $field_group->id(), '_repeat" data-grouptitle="', $field_group->options( 'group_title' ), '" class="cmb-add-group-row button">', $field_group->options( 'add_button' ), '</button></p></div></div>';
		}

		echo '</div></div></div>';

		$field_group->peform_param_callback( 'after_group' );

	}

	/**
	 * Render a repeatable group row
	 * @since  1.0.2
	 * @param  CMB2_Field $field_group  CMB2_Field group field object
	 * @param  string  $remove_disabled Attribute string to disable the remove button
	 */
	public function render_group_row( $field_group, $remove_disabled ) {

		$field_group->peform_param_callback( 'before_group_row' );
		$closed_class = $field_group->options( 'closed' ) ? ' closed' : '';

		echo '
		<div class="postbox cmb-row cmb-repeatable-grouping', $closed_class, '" data-iterator="', $field_group->index, '">';

			if ( $field_group->args( 'repeatable' ) ) {
				echo '<button ', $remove_disabled, 'data-selector="', $field_group->id(), '_repeat" class="dashicons-before dashicons-no-alt cmb-remove-group-row"></button>';
			}

			echo '
			<div class="cmbhandle" title="' , __( 'Click to toggle', 'cmb2' ), '"><br></div>
			<h3 class="cmb-group-title cmbhandle-title"><span>', $field_group->replace_hash( $field_group->options( 'group_title' ) ), '</span></h3>

			<div class="inside cmb-td cmb-nested cmb-field-list">';
				// Loop and render repeatable group fields
				foreach ( array_values( $field_group->args( 'fields' ) ) as $field_args ) {
					if ( 'hidden' == $field_args['type'] ) {

						// Save rendering for after the metabox
						$this->add_hidden_field( array(
							'field_args'  => $field_args,
							'group_field' => $field_group,
						) );

					} else {

						$field_args['show_names'] = $field_group->args( 'show_names' );
						$field_args['context']    = $field_group->args( 'context' );

						$field = $this->get_field( $field_args, $field_group )->render_field();
					}
				}
				if ( $field_group->args( 'repeatable' ) ) {
					echo '
					<div class="cmb-row cmb-remove-field-row">
						<div class="cmb-remove-row">
							<button ', $remove_disabled, 'data-selector="', $field_group->id(), '_repeat" class="button cmb-remove-group-row alignright">', $field_group->options( 'remove_button' ), '</button>
						</div>
					</div>
					';
				}
			echo '
			</div>
		</div>
		';

		$field_group->peform_param_callback( 'after_group_row' );
	}

	/**
	 * Add a hidden field to the list of hidden fields to be rendered later
	 * @since 2.0.0
	 * @param array  $args Array of arguments to be passed to CMB2_Field
	 */
	public function add_hidden_field( $args ) {
		$this->hidden_fields[] = new CMB2_Types( new CMB2_Field( $args ) );
	}

	/**
	 * Loop through and output hidden fields
	 * @since  2.0.0
	 */
	public function render_hidden_fields() {
		if ( ! empty( $this->hidden_fields ) ) {
			foreach ( $this->hidden_fields as $hidden ) {
				$hidden->render();
			}
		}
	}

	/**
	 * Returns array of sanitized field values (without saving them)
	 * @since  2.0.3
	 * @param  array  $data_to_sanitize Array of field_id => value data for sanitizing (likely $_POST data).
	 */
	public function get_sanitized_values( array $data_to_sanitize ) {
		$this->data_to_save = $data_to_sanitize;
		$stored_id          = $this->object_id();

		// We do this So CMB will sanitize our data for us, but not save it
		$this->object_id( '_' );

		// Ensure temp. data store is empty
		cmb2_options( 0 )->set();

		// Process/save fields
		$this->process_fields();

		// Get data from temp. data store
		$sanitized_values = cmb2_options( 0 )->get_options();

		// Empty out temp. data store again
		cmb2_options( 0 )->set();

		// Reset the object id
		$this->object_id( $stored_id );

		return $sanitized_values;
	}

	/**
	 * Loops through and saves field data
	 * @since  1.0.0
	 * @param  int    $object_id    Object ID
	 * @param  string $object_type  Type of object being saved. (e.g., post, user, or comment)
	 * @param  array  $data_to_save Array of key => value data for saving. Likely $_POST data.
	 */
	public function save_fields( $object_id = 0, $object_type = '', $data_to_save ) {

		$this->data_to_save = $data_to_save;
		$object_id = $this->object_id( $object_id );
		$object_type = $this->object_type( $object_type );

		$this->process_fields();

		// If options page, save the updated options
		if ( 'options-page' == $object_type ) {
			cmb2_options( $object_id )->set();
		}

		/**
		 * Fires after all fields have been saved.
		 *
		 * The dynamic portion of the hook name, $object_type, refers to the metabox/form's object type
		 * 	Usually `post` (this applies to all post-types).
		 *  	Could also be `comment`, `user` or `options-page`.
		 *
		 * @param int    $object_id   The ID of the current object
		 * @param array  $cmb_id      The current box ID
		 * @param string $updated     Array of field ids that were updated.
		 *                            Will only include field ids that had values change.
		 * @param array  $cmb         This CMB2 object
		 */
		do_action( "cmb2_save_{$object_type}_fields", $object_id, $this->cmb_id, $this->updated, $this );

		/**
		 * Fires after all fields have been saved.
		 *
		 * The dynamic portion of the hook name, $this->cmb_id, is the meta_box id.
		 *
		 * The dynamic portion of the hook name, $object_type, refers to the metabox/form's object type
		 * 	Usually `post` (this applies to all post-types).
		 *  	Could also be `comment`, `user` or `options-page`.
		 *
		 * @param int    $object_id   The ID of the current object
		 * @param string $updated     Array of field ids that were updated.
		 *                            Will only include field ids that had values change.
		 * @param array  $cmb         This CMB2 object
		 */
		do_action( "cmb2_save_{$object_type}_fields_{$this->cmb_id}", $object_id, $this->updated, $this );

	}

	/**
	 * Process and save form fields
	 * @since  2.0.0
	 */
	public function process_fields() {

		/**
		 * Fires before fields have been processed/saved.
		 *
		 * The dynamic portion of the hook name, $this->cmb_id, is the meta_box id.
		 *
		 * The dynamic portion of the hook name, $object_type, refers to the metabox/form's object type
		 * 	Usually `post` (this applies to all post-types).
		 *  	Could also be `comment`, `user` or `options-page`.
		 *
		 * @param array $cmb       This CMB2 object
		 * @param int   $object_id The ID of the current object
		 */
		do_action( "cmb2_{$this->object_type()}_process_fields_{$this->cmb_id}", $this, $this->object_id() );

		// Remove the show_on properties so saving works
		$this->prop( 'show_on', array() );

		// save field ids of those that are updated
		$this->updated = array();

		foreach ( $this->prop( 'fields' ) as $field_args ) {
			$this->process_field( $field_args );
		}
	}

	/**
	 * Process and save a field
	 * @since  2.0.0
	 * @param  array  $field_args Array of field arguments
	 */
	public function process_field( $field_args ) {

		switch ( $field_args['type'] ) {

			case 'group':
				$this->save_group( $field_args );
				break;

			case 'title':
				// Don't process title fields
				break;

			default:

				// Save default fields
				$field = new CMB2_Field( array(
					'field_args'  => $field_args,
					'object_type' => $this->object_type(),
					'object_id'   => $this->object_id(),
				) );

				if ( $field->save_field_from_data( $this->data_to_save ) ) {
					$this->updated[] = $field->id();
				}

				break;
		}

	}

	/**
	 * Save a repeatable group
	 */
	public function save_group( $args ) {

		if ( ! isset( $args['id'], $args['fields'], $this->data_to_save[ $args['id'] ] ) || ! is_array( $args['fields'] ) ) {
			return;
		}

		$field_group        = new CMB2_Field( array(
			'field_args'  => $args,
			'object_type' => $this->object_type(),
			'object_id'   => $this->object_id(),
		) );
		$base_id            = $field_group->id();
		$old                = $field_group->get_data();
		// Check if group field has sanitization_cb
		$group_vals         = $field_group->sanitization_cb( $this->data_to_save[ $base_id ] );
		$saved              = array();
		$field_group->index = 0;

		foreach ( array_values( $field_group->fields() ) as $field_args ) {
			$field = new CMB2_Field( array(
				'field_args'  => $field_args,
				'group_field' => $field_group,
			) );
			$sub_id = $field->id( true );

			foreach ( (array) $group_vals as $field_group->index => $post_vals ) {

				// Get value
				$new_val = isset( $group_vals[ $field_group->index ][ $sub_id ] )
					? $group_vals[ $field_group->index ][ $sub_id ]
					: false;

				// Sanitize
				$new_val = $field->sanitization_cb( $new_val );

				if ( 'file' == $field->type() && is_array( $new_val ) ) {
					// Add image ID to the array stack
					$saved[ $field_group->index ][ $new_val['field_id'] ] = $new_val['attach_id'];
					// Reset var to url string
					$new_val = $new_val['url'];
				}

				// Get old value
				$old_val = is_array( $old ) && isset( $old[ $field_group->index ][ $sub_id ] )
					? $old[ $field_group->index ][ $sub_id ]
					: false;

				$is_updated = ( ! empty( $new_val ) && $new_val != $old_val );
				$is_removed = ( empty( $new_val ) && ! empty( $old_val ) );
				// Compare values and add to `$updated` array
				if ( $is_updated || $is_removed ) {
					$this->updated[] = $base_id . '::' . $field_group->index . '::' . $sub_id;
				}

				// Add to `$saved` array
				$saved[ $field_group->index ][ $sub_id ] = $new_val;

			}
			$saved[ $field_group->index ] = array_filter( $saved[ $field_group->index ] );
		}
		$saved = array_filter( $saved );

		$field_group->update_data( $saved, true );
	}

	/**
	 * Get object id from global space if no id is provided
	 * @since  1.0.0
	 * @param  integer $object_id Object ID
	 * @return integer $object_id Object ID
	 */
	public function object_id( $object_id = 0 ) {

		if ( $object_id ) {
			$this->object_id = $object_id;
			return $this->object_id;
		}

		if ( $this->object_id ) {
			return $this->object_id;
		}

		// Try to get our object ID from the global space
		switch ( $this->object_type() ) {
			case 'user':
				$object_id = isset( $_REQUEST['user_id'] ) ? $_REQUEST['user_id'] : $object_id;
				$object_id = ! $object_id && isset( $GLOBALS['user_ID'] ) ? $GLOBALS['user_ID'] : $object_id;
				break;

			case 'comment':
				$object_id = isset( $_REQUEST['c'] ) ? $_REQUEST['c'] : $object_id;
				$object_id = ! $object_id && isset( $GLOBALS['comments']->comment_ID ) ? $GLOBALS['comments']->comment_ID : $object_id;
				break;

			default:
				$object_id = isset( $GLOBALS['post']->ID ) ? $GLOBALS['post']->ID : $object_id;
				$object_id = isset( $_REQUEST['post'] ) ? $_REQUEST['post'] : $object_id;
				break;
		}

		// reset to id or 0
		$this->object_id = $object_id ? $object_id : 0;

		return $this->object_id;
	}

	/**
	 * Sets the $object_type based on metabox settings
	 * @since  1.0.0
	 * @return string Object type
	 */
	public function mb_object_type() {

		if ( null !== $this->mb_object_type ) {
			return $this->mb_object_type;
		}

		if ( $this->is_options_page_mb() ) {
			$this->mb_object_type = 'options-page';
			return $this->mb_object_type;
		}

		if ( ! $this->prop( 'object_types' ) ) {
			$this->mb_object_type = 'post';
			return $this->mb_object_type;
		}

		$type = false;
		// check if 'object_types' is a string
		if ( is_string( $this->prop( 'object_types' ) ) ) {
			$type = $this->prop( 'object_types' );
		}
		// if it's an array of one, extract it
		elseif ( is_array( $this->prop( 'object_types' ) ) && 1 === count( $this->prop( 'object_types' ) ) ) {
			$cpts = $this->prop( 'object_types' );
			$type = is_string( end( $cpts ) )
				? end( $cpts )
				: false;
		}

		if ( ! $type ) {
			$this->mb_object_type = 'post';
			return $this->mb_object_type;
		}

		// Get our object type
		switch ( $type ) {

			case 'user':
			case 'comment':
				$this->mb_object_type = $type;
				break;

			default:
				$this->mb_object_type = 'post';
				break;
		}

		return $this->mb_object_type;
	}

	/**
	 * Determines if metabox is for an options page
	 * @since  1.0.1
	 * @return boolean True/False
	 */
	public function is_options_page_mb() {
		return ( isset( $this->meta_box['show_on']['key'] ) && 'options-page' === $this->meta_box['show_on']['key'] || array_key_exists( 'options-page', $this->meta_box['show_on'] ) );
	}

	/**
	 * Returns the object type
	 * @since  1.0.0
	 * @return string Object type
	 */
	public function object_type( $object_type = '' ) {
		if ( $object_type ) {
			$this->object_type = $object_type;
			return $this->object_type;
		}

		if ( $this->object_type ) {
			return $this->object_type;
		}

		global $pagenow;

		if ( in_array( $pagenow, array( 'user-edit.php', 'profile.php', 'user-new.php' ), true ) ) {
			$this->object_type = 'user';

		} elseif ( in_array( $pagenow, array( 'edit-comments.php', 'comment.php' ), true ) ) {
			$this->object_type = 'comment';

		} else {
			$this->object_type = 'post';
		}

		return $this->object_type;
	}

	/**
	 * Get metabox property and optionally set a fallback
	 * @since  2.0.0
	 * @param  string $property Metabox config property to retrieve
	 * @param  mixed  $fallback Fallback value to set if no value found
	 * @return mixed            Metabox config property value or false
	 */
	public function prop( $property, $fallback = null ) {
		if ( array_key_exists( $property, $this->meta_box ) ) {
			return $this->meta_box[ $property ];
		} elseif ( $fallback ) {
			return $this->meta_box[ $property ] = $fallback;
		}
	}

	/**
	 * Get a field object
	 *
	 * @since  2.0.3
	 *
	 * @param  string|array|CMB2_Field $field       Metabox field id or field config array or CMB2_Field object
	 * @param  CMB2_Field              $field_group (optional) CMB2_Field object (group parent)
	 *
	 * @return CMB2_Field|false CMB2_Field object (or false)
	 */
	public function get_field( $field, $field_group = null ) {
		if ( is_a( $field, 'CMB2_Field' ) ) {
			return $field;
		}

		$field_id = is_string( $field ) ? $field : $field['id'];

		$parent_field_id = ! empty( $field_group ) ? $field_group->id() : '';
		$ids = $this->get_field_ids( $field_id, $parent_field_id, true );

		if ( ! $ids ) {
			return false;
		}

		list( $field_id, $sub_field_id ) = $ids;

		$index = implode( '', $ids ) . ( $field_group ? $field_group->index : '' );
		if ( array_key_exists( $index, $this->fields ) ) {
			return $this->fields[ $index ];
		}

		$this->fields[ $index ] = new CMB2_Field( $this->get_field_args( $field_id, $field, $sub_field_id, $field_group ) );

		return $this->fields[ $index ];
	}

	/**
	 * Handles determining which type of arguments to pass to CMB2_Field
	 * @since  2.0.7
	 * @param  mixed  $field_id     Field (or group field) ID
	 * @param  mixed  $field_args   Array of field arguments
	 * @param  mixed  $sub_field_id Sub field ID (if field_group exists)
	 * @param  mixed  $field_group  If a sub-field, will be the parent group CMB2_Field object
	 * @return array                Array of CMB2_Field arguments
	 */
	public function get_field_args( $field_id, $field_args, $sub_field_id, $field_group ) {

		// Check if group is passed and if fields were added in the old-school fields array
		if ( $field_group && ( $sub_field_id || 0 === $sub_field_id ) ) {

			// Update the fields array w/ any modified properties inherited from the group field
			$this->meta_box['fields'][ $field_id ]['fields'][ $sub_field_id ] = $field_args;

			return array(
				'field_args'  => $field_args,
				'group_field' => $field_group,
			);

		}

		if ( is_array( $field_args ) ) {
			$this->meta_box['fields'][ $field_id ] = array_merge( $field_args, $this->meta_box['fields'][ $field_id ] );
		}

		return array(
			'field_args'  => $this->meta_box['fields'][ $field_id ],
			'object_type' => $this->object_type(),
			'object_id'   => $this->object_id(),
		);
	}

	/**
	 * Add a field to the metabox
	 * @since  2.0.0
	 * @param  array  $field           Metabox field config array
	 * @param  int    $position        (optional) Position of metabox. 1 for first, etc
	 * @return mixed                   Field id or false
	 */
	public function add_field( array $field, $position = 0 ) {
		if ( ! is_array( $field ) || ! array_key_exists( 'id', $field ) ) {
			return false;
		}

		$this->_add_field_to_array(
			$field,
			$this->meta_box['fields'],
			$position
		);

		return $field['id'];
	}

	/**
	 * Add a field to a group
	 * @since  2.0.0
	 * @param  string $parent_field_id The field id of the group field to add the field
	 * @param  array  $field           Metabox field config array
	 * @param  int    $position        (optional) Position of metabox. 1 for first, etc
	 * @return mixed                   Array of parent/field ids or false
	 */
	public function add_group_field( $parent_field_id, array $field, $position = 0 ) {
		if ( ! array_key_exists( $parent_field_id, $this->meta_box['fields'] ) ) {
			return false;
		}

		$parent_field = $this->meta_box['fields'][ $parent_field_id ];

		if ( 'group' !== $parent_field['type'] ) {
			return false;
		}

		if ( ! isset( $parent_field['fields'] ) ) {
			$this->meta_box['fields'][ $parent_field_id ]['fields'] = array();
		}

		$this->_add_field_to_array(
			$field,
			$this->meta_box['fields'][ $parent_field_id ]['fields'],
			$position
		);

		return array( $parent_field_id, $field['id'] );
	}

	/**
	 * Add a field array to a fields array in desired position
	 * @since 2.0.2
	 * @param array   $field    Metabox field config array
	 * @param array   &$fields  Array (passed by reference) to append the field (array) to
	 * @param integer $position Optionally specify a position in the array to be inserted
	 */
	protected function _add_field_to_array( $field, &$fields, $position = 0 ) {
		if ( $position ) {
			cmb2_utils()->array_insert( $fields, array( $field['id'] => $field ), $position );
		} else {
			$fields[ $field['id'] ] = $field;
		}
	}

	/**
	 * Remove a field from the metabox
	 * @since 2.0.0
	 * @param  string $field_id        The field id of the field to remove
	 * @param  string $parent_field_id (optional) The field id of the group field to remove field from
	 * @return bool                    True if field was removed
	 */
	public function remove_field( $field_id, $parent_field_id = '' ) {
		$ids = $this->get_field_ids( $field_id, $parent_field_id );

		if ( ! $ids ) {
			return false;
		}

		list( $field_id, $sub_field_id ) = $ids;

		unset( $this->fields[ implode( '', $ids ) ] );

		if ( ! $sub_field_id ) {
			unset( $this->meta_box['fields'][ $field_id ] );
			return true;
		}

		unset( $this->fields[ $field_id ]->args['fields'][ $sub_field_id ] );
		unset( $this->meta_box['fields'][ $field_id ]['fields'][ $sub_field_id ] );
		return true;
	}

	/**
	 * Update or add a property to a field
	 * @since  2.0.0
	 * @param  string $field_id        Field id
	 * @param  string $property        Field property to set/update
	 * @param  mixed  $value           Value to set the field property
	 * @param  string $parent_field_id (optional) The field id of the group field to remove field from
	 * @return mixed                   Field id. Strict compare to false, as success can return a falsey value (like 0)
	 */
	public function update_field_property( $field_id, $property, $value, $parent_field_id = '' ) {
		$ids = $this->get_field_ids( $field_id, $parent_field_id );

		if ( ! $ids ) {
			return false;
		}

		list( $field_id, $sub_field_id ) = $ids;

		if ( ! $sub_field_id ) {
			$this->meta_box['fields'][ $field_id ][ $property ] = $value;
			return $field_id;
		}

		$this->meta_box['fields'][ $field_id ]['fields'][ $sub_field_id ][ $property ] = $value;
		return $field_id;
	}

	/**
	 * Check if field ids match a field and return the index/field id
	 * @since  2.0.2
	 * @param  string  $field_id        Field id
	 * @param  string  $parent_field_id (optional) Parent field id
	 * @return mixed                    Array of field/parent ids, or false
	 */
	public function get_field_ids( $field_id, $parent_field_id = '' ) {
		$sub_field_id = $parent_field_id ? $field_id : '';
		$field_id     = $parent_field_id ? $parent_field_id : $field_id;
		$fields       =& $this->meta_box['fields'];

		if ( ! array_key_exists( $field_id, $fields ) ) {
			$field_id = $this->search_old_school_array( $field_id, $fields );
		}

		if ( false === $field_id ) {
			return false;
		}

		if ( ! $sub_field_id ) {
			return array( $field_id, $sub_field_id );
		}

		if ( 'group' !== $fields[ $field_id ]['type'] ) {
			return false;
		}

		if ( ! array_key_exists( $sub_field_id, $fields[ $field_id ]['fields'] ) ) {
			$sub_field_id = $this->search_old_school_array( $sub_field_id, $fields[ $field_id ]['fields'] );
		}

		return false === $sub_field_id ? false : array( $field_id, $sub_field_id );
	}

	/**
	 * When using the old array filter, it is unlikely field array indexes will be the field id
	 * @since  2.0.2
	 * @param  string $field_id The field id
	 * @param  array  $fields   Array of fields to search
	 * @return mixed            Field index or false
	 */
	public function search_old_school_array( $field_id, $fields ) {
		$ids = wp_list_pluck( $fields, 'id' );
		$index = array_search( $field_id, $ids );
		return false !== $index ? $index : false;
	}

	/**
	 * Determine whether this cmb object should show, based on the 'show_on_cb' callback.
	 *
	 * @since 2.0.9
	 *
	 * @return bool Whether this cmb should be shown.
	 */
	public function should_show() {
		// Default to showing this cmb
		$show = true;

		// Use the callback to determine showing the cmb, if it exists
		if ( is_callable( $this->prop( 'show_on_cb' ) ) ) {
			$show = (bool) call_user_func( $this->prop( 'show_on_cb' ), $this );
		}

		return $show;
	}

	/**
	 * Generate a unique nonce field for each registered meta_box
	 * @since  2.0.0
	 * @return string unique nonce hidden input
	 */
	public function nonce_field() {
		wp_nonce_field( $this->nonce(), $this->nonce(), false, true );
	}

	/**
	 * Generate a unique nonce for each registered meta_box
	 * @since  2.0.0
	 * @return string unique nonce string
	 */
	public function nonce() {
		if ( $this->generated_nonce ) {
			return $this->generated_nonce;
		}
		$this->generated_nonce = sanitize_html_class( 'nonce_' . basename( __FILE__ ) . $this->cmb_id );
		return $this->generated_nonce;
	}

	/**
	 * Magic getter for our object.
	 * @param string $field
	 * @throws Exception Throws an exception if the field is invalid.
	 * @return mixed
	 */
	public function __get( $field ) {
		switch ( $field ) {
			case 'cmb_id':
			case 'meta_box':
			case 'updated':
				return $this->{$field};
			case 'object_id':
				return $this->object_id();
			default:
				throw new Exception( 'Invalid ' . __CLASS__ . ' property: ' . $field );
		}
	}

}
