<?php
/**
 * Single field change.
 *
 * @package Recast\WCS
 */

namespace Recast\WCS\Diff;

use Recast\WCS\State\Fields;

defined( 'ABSPATH' ) || exit;

/**
 * One predicted change: field, before, after.
 */
final class FieldDiff {

	/**
	 * Field key.
	 *
	 * @var string
	 */
	public $field;

	/**
	 * Human label.
	 *
	 * @var string
	 */
	public $label;

	/**
	 * Value type.
	 *
	 * @var string
	 */
	public $type;

	/**
	 * Before value.
	 *
	 * @var mixed
	 */
	public $before;

	/**
	 * After value.
	 *
	 * @var mixed
	 */
	public $after;

	/**
	 * Line item ID for item fields.
	 *
	 * @var int|null
	 */
	public $item_id;

	/**
	 * Item name for display.
	 *
	 * @var string|null
	 */
	public $item_name;

	/**
	 * Constructor.
	 *
	 * @param string      $field     Field key.
	 * @param mixed       $before    Before.
	 * @param mixed       $after     After.
	 * @param string|null $item_name Item name.
	 */
	public function __construct( $field, $before, $after, $item_name = null ) {
		$parsed        = Fields::parse( $field );
		$this->field   = $field;
		$this->label   = 0 === strpos( $field, 'display:' ) ? __( 'Unit price', 'recast-subscriptions' ) : Fields::label( $field );
		$this->type    = 0 === strpos( $field, 'display:' ) ? 'money' : Fields::type( $field );
		$this->before  = $before;
		$this->after   = $after;
		$this->item_id = ( $parsed && 'item' === $parsed['kind'] && '*' !== $parsed['item_id'] ) ? (int) $parsed['item_id'] : null;
		if ( null === $this->item_id && preg_match( '/^display:item:(\d+):/', $field, $m ) ) {
			$this->item_id = (int) $m[1];
		}
		$this->item_name = $item_name;
	}

	/**
	 * Array form for storage / REST.
	 *
	 * @return array<string, mixed>
	 */
	public function to_array() {
		return array(
			'field'     => $this->field,
			'label'     => $this->label,
			'type'      => $this->type,
			'before'    => $this->before,
			'after'     => $this->after,
			'item_id'   => $this->item_id,
			'item_name' => $this->item_name,
		);
	}

	/**
	 * Rebuilds from storage.
	 *
	 * @param array<string, mixed> $data Array form.
	 * @return FieldDiff
	 */
	public static function from_array( array $data ) {
		$diff = new self( (string) $data['field'], $data['before'], $data['after'], isset( $data['item_name'] ) ? $data['item_name'] : null );
		if ( isset( $data['label'] ) ) {
			$diff->label = $data['label'];
		}
		return $diff;
	}
}