<?php
// Prevent loading this file directly
defined( 'ABSPATH' ) || exit;
require_once EMD_MB_FIELDS_DIR . 'select-advanced.php';
require_once EMD_MB_FIELDS_DIR . 'checkbox-list.php';

if ( ! class_exists( 'EMD_MB_Taxonomy_Field' ) )
{
	class EMD_MB_Taxonomy_Field extends EMD_MB_Field
	{
		/**
		 * Enqueue scripts and styles
		 *
		 * @return void
		 */
		static function admin_enqueue_scripts()
		{
			EMD_MB_Select_Advanced_Field::admin_enqueue_scripts();
			wp_enqueue_style( 'emd-mb-taxonomy', EMD_MB_CSS_URL . 'taxonomy.css', array(), EMD_MB_VER );
			wp_enqueue_script( 'emd-mb-taxonomy', EMD_MB_JS_URL . 'taxonomy.js', array( 'jquery', 'emd-mb-select-advanced', 'wp-ajax-response' ), EMD_MB_VER, true );
		}

		/**
		 * Add default value for 'taxonomy' field
		 *
		 * @param $field
		 *
		 * @return array
		 */
		static function normalize_field( $field )
		{
			$default_args = array(
				'hide_empty' => false,
			);

			// Set default args
			$field['options']['args'] = ! isset( $field['options']['args'] ) ? $default_args : wp_parse_args( $field['options']['args'], $default_args );

			$tax = get_taxonomy( $field['options']['taxonomy'] );
			$field['placeholder'] = empty( $field['placeholder'] ) ? sprintf( __( 'Select a %s' , 'knowledge-center' ), $tax->labels->singular_name ) : $field['placeholder'];

			switch( $field['options']['type'] )
			{
				case 'select_advanced':
					$field = EMD_MB_Select_Advanced_Field::normalize_field( $field );
					break;
				case 'checkbox_list':
				case 'checkbox_tree':
					$field = EMD_MB_Checkbox_List_Field::normalize_field( $field );
					break;
				case 'select':
				case 'select_tree':
					$field = EMD_MB_Select_Field::normalize_field( $field );
					break;
				default:
					$field['options']['type'] = 'select';
					$field = EMD_MB_Select_Field::normalize_field( $field );
			}

			if ( in_array( $field['options']['type'], array( 'checkbox_tree', 'select_tree' ) ) )
			{
				if ( isset( $field['options']['args']['parent'] ) )
				{
					$field['options']['parent'] = $field['options']['args']['parent'];
					unset( $field['options']['args']['parent'] );
				}
				else
				{
					$field['options']['parent'] = 0;
				}
			}

			$field['field_name'] = "{$field['id']}[]";

			return $field;
		}

		/**
		 * Get field HTML
		 *
		 * @param $field
		 * @param $meta
		 *
		 * @return string
		 */
		static function html( $meta, $field )
		{
			$options = $field['options'];
			$terms   = get_terms( $options['taxonomy'], $options['args'] );

			$field['options'] = self::get_options( $terms );

			$html = '';

			switch( $options['type'] )
			{
				case 'checkbox_list':
					$html = EMD_MB_Checkbox_List_Field::html( $meta, $field );
					break;
				case 'checkbox_tree':
					$elements = self::process_terms( $terms );
					$html    .= self::walk_checkbox_tree( $meta, $field, $elements, $options['parent'], true );
					break;
				case 'select_tree':
					$elements = self::process_terms( $terms );
					$html    .= self::walk_select_tree( $meta, $field, $elements, $options['parent'], true );
					break;
				case 'select_advanced':
					$html = EMD_MB_Select_Advanced_Field::html( $meta, $field );
					break;
				case 'select':
				default:
					$html = EMD_MB_Select_Field::html( $meta, $field );
			}

			return $html;
		}

		/**
		 * Walker for displaying checkboxes in tree format
		 *
		 * @param      $meta
		 * @param      $field
		 * @param      $elements
		 * @param int  $parent
		 * @param bool $active
		 *
		 * @return string
		 */
		static function walk_checkbox_tree( $meta, $field, $elements, $parent = 0, $active = false )
		{
			if ( ! isset( $elements[$parent] ) )
				return;
			$terms  = $elements[$parent];
			$field['options'] = self::get_options( $terms );
			$hidden = $active ? '' : 'hidden';

			$html = "<ul class = 'emd-mb-taxonomy-tree {$hidden}'>";
			$li = '<li><label><input type="checkbox" name="%s" value="%s"%s> %s</label>';
			foreach ( $terms as $term )
			{
				$html .= sprintf(
					$li,
					$field['field_name'],
					$term->term_id,
					checked( in_array( $term->term_id, $meta ), true, false ),
					$term->name
				);
				$html .= self::walk_checkbox_tree( $meta, $field, $elements, $term->term_id, $active && in_array( $term->term_id, $meta ) ) . '</li>';
			}
			$html .= '</ul>';

			return $html;
		}

		/**
		 * Walker for displaying select in tree format
		 *
		 * @param        $meta
		 * @param        $field
		 * @param        $elements
		 * @param int    $parent
		 * @param bool   $active
		 *
		 * @return string
		 */
		static function walk_select_tree( $meta, $field, $elements, $parent = 0, $active = false )
		{
			if ( ! isset( $elements[$parent] ) )
				return;
			$terms    = $elements[$parent];
			$field['options'] = self::get_options( $terms );

			$classes = array( 'emd-mb-taxonomy-tree' );
			$classes[] = $active ? 'active' : 'disabled';
			$classes[] = "emd-mb-taxonomy-{$parent}";

			$html  = '<div class="' . implode( ' ', $classes ) . '">';
			$html .= EMD_MB_Select_Field::html( $meta, $field );
			foreach ( $terms as $term )
			{
				$html .= self::walk_select_tree( $meta, $field, $elements, $term->term_id, $active && in_array( $term->term_id, $meta )  );
			}
			$html .= '</div>';

			return $html;
		}

		/**
		 * Processes terms into indexed array for walker functions
		 *
		 * @param $terms
		 *
		 * @internal param $field
		 * @return array
		 */
		static function process_terms( $terms )
		{
			$elements = array();
			foreach ( $terms as $term )
			{
				$elements[$term->parent][] = $term;
			}
			return $elements;
		}

		/**
		 * Get options for selects, checkbox list, etc via the terms
		 *
		 * @param array $terms Array of term objects
		 *
		 * @return array
		 */
		static function get_options( $terms = array() )
		{
			$options = array();
			foreach( $terms as $term )
			{
				$options[$term->term_id] = $term->name;
			}
			return $options;
		}

		/**
		 * Save meta value
		 *
		 * @param mixed $new
		 * @param mixed $old
		 * @param int   $post_id
		 * @param array $field
		 *
		 * @return string
		 */
		static function save( $new, $old, $post_id, $field )
		{
			$new = array_unique( array_map( 'intval', (array) $new ) );
			$new = empty( $new ) ? null : $new;
			wp_set_object_terms( $post_id, $new, $field['options']['taxonomy'] );
		}

		/**
		 * Standard meta retrieval
		 *
		 * @param int   $post_id
		 * @param bool  $saved
		 * @param array $field
		 *
		 * @return array
		 */
		static function meta( $post_id, $saved, $field )
		{
			$options = $field['options'];

			$meta = wp_get_post_terms( $post_id, $options['taxonomy'] );
			$meta = is_array( $meta ) ? $meta : (array) $meta;
			$meta = wp_list_pluck( $meta, 'term_id' );

			return $meta;
		}
	}
}
