<?php

namespace QuadLayers\WOOCCM\View\Frontend;

use QuadLayers\WOOCCM\Helpers;

/**
 * Fields_Conditional Class
 */
class Fields_Conditional {

	protected static $_instance;

	public function __construct() {
		// Add field attributes
		add_filter( 'wooccm_checkout_field_filter', array( $this, 'add_field_attributes' ) );
		add_action( 'wooccm_billing_fields', array( $this, 'remove_required' ) );
		add_action( 'wooccm_shipping_fields', array( $this, 'remove_required' ) );
		add_action( 'wooccm_additional_fields', array( $this, 'remove_required' ) );
	}

	public static function instance() {
		if ( is_null( self::$_instance ) ) {
			self::$_instance = new self();
		}
		return self::$_instance;
	}

	public function remove_required( $fields ) {

		foreach ( $fields as $field_id => $field ) {

			/**
			 * Continue if it's not a conditional field
			 */
			if ( empty( $field['conditional'] ) ) {
				continue;
			}
			/**
			 * Continue if it doesn't have the conditional parent key
			 */
			if ( empty( $field['conditional_parent_key'] ) ) {
				continue;
			}
			/**
			 * Continue if it's parent of self
			 */
			if ( $field['conditional_parent_key'] == $field['key'] ) {
				continue;
			}
			/**
			 * Continue if parent doesn't exists
			 */
			if ( empty( $fields[ $field['conditional_parent_key'] ] ) ) {
				continue;
			}

			$form_action = Helpers::get_form_action();

			switch ( $form_action ) {
				case 'account':
				case 'save':
					$is_woocommerce_process_checkout_nonce = isset( $_POST['woocommerce-process-checkout-nonce'] ) && wp_verify_nonce( wc_clean( wp_unslash( $_POST['woocommerce-process-checkout-nonce'] ) ), 'woocommerce-process_checkout' );
					$is_woocommerce_edit_address_nonce     = isset( $_POST['woocommerce-edit-address-nonce'] ) && wp_verify_nonce( wc_clean( wp_unslash( $_POST['woocommerce-edit-address-nonce'] ) ), 'woocommerce-edit_address' );
					// Check if is checkout or edit address page
					if ( $is_woocommerce_process_checkout_nonce || $is_woocommerce_edit_address_nonce ) {
						$is_valid_conditional_field = $this->is_valid_conditional_field( $_POST, $field, $fields );
						if ( ! $is_valid_conditional_field ) {
							$fields[ $field['key'] ]['required'] = false;
						}
					}
					break;
				case 'update':
					if ( isset( $_REQUEST['post_data'] ) ) {
						$post_data = array();
						parse_str( wp_unslash( $_REQUEST['post_data'] ), $post_data ); // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
						$is_valid_conditional_field = $this->is_valid_conditional_field( $post_data, $field, $fields );
						if ( ! $is_valid_conditional_field ) {
							$fields[ $field['key'] ]['required'] = false;
						}
						break;
					}
				case 'paypal-payments':
					if ( isset( $GLOBALS['_POST'] ) ) {
						$post_data                  = wp_unslash( $GLOBALS['_POST'] );
						$is_valid_conditional_field = $this->is_valid_conditional_field( $post_data, $field, $fields );
						if ( ! $is_valid_conditional_field ) {
							$fields[ $field['key'] ]['required'] = false;
						}
						break;
					}
			}
		}

		return $fields;
	}

	public function is_valid_conditional_field( $post_data, $field, $all_fields = array() ) {
		/**
		 * Don't remove field if parent doesn't exists in the current form posts
		 */

		if ( ! isset( $post_data[ $field['conditional_parent_key'] ] ) ) {
			return false;
		}
		/**
		 * Don't remove field if conditional parent value is undefined
		 */
		if ( ! isset( $field['conditional_parent_value'] ) ) {
			return false;
		}

		$posted_conditional_parent_value = (array) $post_data[ $field['conditional_parent_key'] ];
		$conditional_parent_value        = (array) $field['conditional_parent_value'];

		/**
		 * Check if current field's parent condition is met
		 */
		if ( ! array_intersect( $conditional_parent_value, $posted_conditional_parent_value ) ) {
			return false;
		}

		/**
		 * Recursively check if all ancestor fields are visible
		 * This ensures that fields with multiple levels of conditional dependencies work correctly
		 */
		if ( ! empty( $all_fields ) && ! empty( $all_fields[ $field['conditional_parent_key'] ] ) ) {
			$parent_field = $all_fields[ $field['conditional_parent_key'] ];

			// If parent is also conditional, check its visibility recursively
			if ( ! empty( $parent_field['conditional'] ) && ! empty( $parent_field['conditional_parent_key'] ) ) {
				return $this->is_valid_conditional_field( $post_data, $parent_field, $all_fields );
			}
		}

		return true;
	}

	public function add_field_attributes( $field ) {
		if ( ! empty( $field['conditional'] ) && ! empty( $field['conditional_parent_key'] ) && isset( $field['conditional_parent_value'] ) && ( $field['conditional_parent_key'] != $field['name'] ) ) {
			$field['class'][]                                      = 'wooccm-conditional-child';
			$field['custom_attributes']['data-conditional-parent'] = $field['conditional_parent_key'];
			$field['custom_attributes']['data-conditional-parent-value'] = $field['conditional_parent_value'];
		}
		return $field;
	}
}