<?php
/**
 * The "RSVP" class manages the RSVP block and its variations,
 * primarily transforming block content and preparing it for output.
 *
 * @package GatherPress\Core
 * @since 1.0.0
 */

namespace GatherPress\Core\Blocks;

// Exit if accessed directly.
defined( 'ABSPATH' ) || exit; // @codeCoverageIgnore

use GatherPress\Core\Block;
use GatherPress\Core\Blocks\Form_Field;
use GatherPress\Core\Blocks\General_Block;
use GatherPress\Core\Event;
use GatherPress\Core\Rsvp_Setup;
use GatherPress\Core\Traits\Singleton;
use GatherPress\Core\Utility;
use WP_HTML_Tag_Processor;

/**
 * Class responsible for managing the "RSVP" block and its variations,
 * including dynamic transformations and enhancements for interactive functionality.
 *
 * @since 1.0.0
 */
class Rsvp {
	/**
	 * Enforces a single instance of this class.
	 */
	use Singleton;

	/**
	 * Constant representing the Block Name.
	 *
	 * @since 1.0.0
	 * @var string
	 */
	const BLOCK_NAME = 'gatherpress/rsvp';

	/**
	 * Class constructor.
	 *
	 * This method initializes the object and sets up necessary hooks.
	 *
	 * @since 1.0.0
	 */
	protected function __construct() {
		$this->setup_hooks();
	}

	/**
	 * Set up hooks for various purposes.
	 *
	 * This method adds hooks for different purposes as needed.
	 *
	 * @since 1.0.0
	 *
	 * @return void
	 */
	protected function setup_hooks(): void {
		$render_block_hook = sprintf( 'render_block_%s', self::BLOCK_NAME );

		add_filter( $render_block_hook, array( $this, 'transform_block_content' ), 10, 2 );
		add_filter( $render_block_hook, array( $this, 'apply_rsvp_button_interactivity' ) );
		// Priority 11 ensures this runs after transform_block_content which modifies the block structure.
		add_filter( $render_block_hook, array( $this, 'apply_guest_count_watch' ), 11 );
		// Priority 9 ensures this runs before transform_block_content to properly register form field hooks.
		add_filter( $render_block_hook, array( $this, 'apply_guests_input_interactivity' ), 9 );

		// Add hooks for conditional form field processing.
		$general_block = General_Block::get_instance();
		add_filter( $render_block_hook, array( $general_block, 'process_guests_field' ), 10, 2 );
		add_filter( $render_block_hook, array( $general_block, 'process_anonymous_field' ), 10, 2 );
	}

	/**
	 * Dynamically transforms and renders the content of the RSVP block and its inner blocks.
	 *
	 * This method processes the RSVP block content, applying dynamic attributes and interactivity
	 * settings. It also handles the rendering of inner blocks based on the current RSVP status
	 * and ensures proper serialization of inner block states for persistence. The method
	 * dynamically adjusts the block content based on the event's status (e.g., past or active).
	 *
	 * Key functionalities:
	 * - Adds `data-wp-interactive` attributes for interactivity.
	 * - Dynamically renders and serializes inner blocks for each RSVP status.
	 * - Ensures proper markup updates based on the RSVP status and event state.
	 *
	 * @since 1.0.0
	 *
	 * @param string $block_content The original HTML content of the block.
	 * @param array  $block         An associative array containing block data, including `blockName` and `attrs`.
	 *
	 * @return string The updated block content with dynamically rendered inner blocks and attributes.
	 */
	public function transform_block_content( string $block_content, array $block ): string {
		$block_instance = Block::get_instance();
		$post_id        = $block_instance->get_post_id( $block );

		// Validate that the post ID is an actual event post type.
		// Only check publish status if not in preview mode.
		if (
			Event::POST_TYPE !== get_post_type( $post_id ) ||
			( ! is_preview() && 'publish' !== get_post_status( $post_id ) )
		) {
			return '';
		}

		$event        = new Event( $post_id );
		$inner_blocks = isset( $block['innerBlocks'] ) ? $block['innerBlocks'] : array();
		$tag          = new WP_HTML_Tag_Processor( $block_content );
		$attributes   = isset( $block['attrs'] ) ? $block['attrs'] : array();

		if ( $tag->next_tag() ) {
			/**
			 * Dynamically render inner blocks based on the saved RSVP status.
			 *
			 * This ensures that the block correctly renders the inner blocks
			 * for the currently selected RSVP status and updates the serialized
			 * inner blocks attribute. It addresses the issue of inner blocks
			 * not persisting properly when switching between statuses.
			 *
			 * The method generates dynamic markup for all statuses, wrapping each
			 * rendered inner block set in a container with a `data-rsvp-status`
			 * attribute.
			 */
			$saved_status = $attributes['selectedStatus'] ?? 'no_status';

			// Decode serialized inner blocks from attributes.
			$serialized_inner_blocks = $attributes['serializedInnerBlocks'] ?? '';
			$serialized_inner_blocks = json_decode( $serialized_inner_blocks, true );

			if ( ! is_array( $serialized_inner_blocks ) ) {
				$serialized_inner_blocks = array();
			}

			// Serialize the current inner blocks for the saved status.
			$serialized_inner_blocks[ $saved_status ] = serialize_blocks( $inner_blocks );

			$user_data = array();

			if ( $event->rsvp ) {
				$user_identifier = Rsvp_Setup::get_instance()->get_user_identifier();

				$user_data = $event->rsvp->get( $user_identifier );
			}

			$filtered_data   = array_intersect_key(
				$user_data,
				array_flip( array( 'status', 'guests', 'anonymous' ) )
			);
			$filtered_status = ! empty( $filtered_data['status'] ) ? $filtered_data['status'] : 'no_status';

			if ( $event->has_event_past() ) {
				$inner_blocks_markup = do_blocks( $serialized_inner_blocks['past'] ?? '' );
			} else {
				unset( $serialized_inner_blocks['past'] );
				// Render inner blocks for all statuses.
				$inner_blocks_markup = '';

				foreach ( $serialized_inner_blocks as $status => $serialized_inner_block ) {
					$class                = $status !== $filtered_status ? 'gatherpress--is-hidden' : '';
					$inner_blocks_markup .= sprintf(
						'<div class="%s" data-rsvp-status="%s">%s</div>',
						esc_attr( $class ),
						esc_attr( $status ),
						do_blocks( $serialized_inner_block )
					);
				}

				// Set dynamic attributes for interactivity.
				$tag->set_attribute( 'data-wp-interactive', 'gatherpress' );
				$tag->set_attribute( 'data-wp-context', wp_json_encode( array( 'postId' => $post_id ) ) );
				$tag->set_attribute( 'data-user-details', wp_json_encode( $filtered_data ) );
				$tag->set_attribute( 'data-wp-watch', 'callbacks.renderRsvpBlock' );
			}

			// Get the updated block content.
			$block_content = $tag->get_updated_html();

			// @todo: Replace this workaround with a method to properly update inner blocks
			// when https://github.com/WordPress/gutenberg/issues/60397 is resolved.
			preg_match( '/<div\b[^>]*>/i', $block_content, $matches );

			// Use the matched opening <div> tag or fallback to a generic <div>.
			$opening_div = $matches[0] ?? '<div>';

			// Close the block with a standard </div>.
			$closing_div = '</div>';

			// Construct the updated block content with the new inner blocks markup.
			$block_content = $opening_div . $inner_blocks_markup . $closing_div;
		}

		return $block_content;
	}

	/**
	 * Adds interactivity to RSVP buttons within the block content.
	 *
	 * This method scans the block content for elements with the class
	 * `gatherpress-rsvp--trigger-update`. If such an element is found, it checks for a
	 * nested `<a>` or `<button>` tag. The appropriate attributes for interactivity
	 * are added to either the nested tag or the containing element if no nested tag
	 * exists.
	 *
	 * @since 1.0.0
	 *
	 * @param string $block_content The original block content as a string.
	 *
	 * @return string The modified block content with interactivity attributes added.
	 */
	public function apply_rsvp_button_interactivity( string $block_content ): string {
		$tag = new WP_HTML_Tag_Processor( $block_content );

		// Process only tags with the specific class 'gatherpress-rsvp--trigger-update'.
		$rsvp_class = 'gatherpress-rsvp--trigger-update';

		while ( $tag->next_tag() ) {
			$class_attr = $tag->get_attribute( 'class' );

			// str_contains is used here to match BEM modifiers that extend the base class.
			// For example, 'gatherpress-rsvp--trigger-update__attending' includes the base class as a prefix.
			if ( $class_attr && str_contains( $class_attr, $rsvp_class ) ) {
				$classes        = preg_split( '/\s+/', trim( $class_attr ) );
				$statuses       = array( 'attending', 'waiting-list', 'not-attending' );
				$matched_status = null;

				foreach ( $statuses as $status ) {
					$target_class = sprintf( '%s__%s', $rsvp_class, $status );
					if ( in_array( $target_class, $classes, true ) ) {
						$matched_status = $status;
						break;
					}
				}

				// Check if current element is an anchor or button.
				$is_actionable_element = in_array( $tag->get_tag(), array( 'A', 'BUTTON' ), true );

				if ( ! $is_actionable_element ) {
					// If not, check if the next element is an anchor or button.
					// @phpstan-ignore-next-line.
					$is_actionable_element = $tag->next_tag() &&
					in_array( $tag->get_tag(), array( 'A', 'BUTTON' ), true );
				}

				$target_found = $is_actionable_element;

				// Apply RSVP attributes if target was found.
				if ( $target_found ) {
					// Links only get role="button", others get full keyboard handling.
					if ( 'A' === $tag->get_tag() ) {
						$tag->set_attribute( 'role', 'button' ); // For links acting as buttons.
					} else {
						$tag->set_attribute( 'tabindex', '0' );
						$tag->set_attribute( 'role', 'button' );
					}

					$tag->set_attribute( 'data-wp-interactive', 'gatherpress' );
					$tag->set_attribute( 'data-wp-on--click', 'actions.updateRsvp' );

					if ( ! empty( $matched_status ) ) {
						$tag->set_attribute( 'data-set-status', str_replace( '-', '_', $matched_status ) );
					}
				}
			}
		}

		return $tag->get_updated_html();
	}

	/**
	 * Adds a data-wp-watch attribute to the Guest Count Display Block.
	 *
	 * This method processes the block content of the Guest Count Display Block and
	 * adds the `data-wp-watch` attribute to enable dynamic updates using the
	 * specified callback.
	 *
	 * @since 1.0.0
	 *
	 * @param string $block_content The original block content.
	 *
	 * @return string The modified block content with the data-wp-watch attribute applied.
	 */
	public function apply_guest_count_watch( string $block_content ): string {
		$tag = new WP_HTML_Tag_Processor( $block_content );

		$tag->next_tag();

		$user_details = ! empty( $tag->get_attribute( 'data-user-details' ) ) ?
			json_decode( $tag->get_attribute( 'data-user-details' ), true ) :
			array();

		while ( $tag->next_tag() ) {
			$class_attr = $tag->get_attribute( 'class' );

			if ( Utility::has_css_class( $class_attr, 'wp-block-gatherpress-rsvp-guest-count-display' ) ) {
				$tag->set_attribute( 'data-wp-watch', 'callbacks.updateGuestCountDisplay' );

				if ( empty( $user_details['guests'] ) ) {
					$tag->set_attribute( 'class', $class_attr . ' gatherpress--is-hidden' );
				}
			}
		}

		return $tag->get_updated_html();
	}

	/**
	 * Apply interactivity attributes to guest count form field.
	 *
	 * Processes form-field blocks within RSVP blocks, applying the guest count form field callback.
	 *
	 * @since 1.0.0
	 *
	 * @param string $block_content The block content to modify.
	 * @return string The modified block content with form field callbacks applied.
	 */
	public function apply_guests_input_interactivity( string $block_content ): string {
		// Apply form field callback for any form-field blocks within this RSVP block.
		$form_field_hook = sprintf( 'render_block_%s', Form_Field::BLOCK_NAME );

		add_filter( $form_field_hook, array( $this, 'handle_rsvp_form_fields' ), 10, 2 );

		return $block_content;
	}

	/**
	 * Handle RSVP-related form field rendering.
	 *
	 * Processes form-field blocks with RSVP-specific field names to either
	 * remove the field (if not permitted) or apply interactivity attributes.
	 *
	 * @since 1.0.0
	 *
	 * @param string $block_content The form field block content.
	 * @param array  $block         The block data including attributes.
	 * @return string The modified block content or empty string if field should be hidden.
	 */
	public function handle_rsvp_form_fields( string $block_content, array $block ): string {
		$attributes = $block['attrs'] ?? array();
		$field_name = $attributes['fieldName'] ?? '';

		// Get the correct post ID for remaining logic.
		$block_instance = Block::get_instance();
		$post_id        = $block_instance->get_post_id( $block );

		// Handle guest count field interactivity.
		if ( 'gatherpress_rsvp_guests' === $field_name ) {
			$max_guest_limit = get_post_meta( $post_id, 'gatherpress_max_guest_limit', true );

			// Apply interactivity attributes and max limit for guest count.
			$tag = new WP_HTML_Tag_Processor( $block_content );

			while ( $tag->next_tag( array( 'tag_name' => 'input' ) ) ) {
				$name_attr = $tag->get_attribute( 'name' );

				if ( 'gatherpress_rsvp_guests' === $name_attr ) {
					$tag->set_attribute( 'data-wp-interactive', 'gatherpress' );
					$tag->set_attribute( 'data-wp-watch', 'callbacks.setGuestCount' );
					$tag->set_attribute( 'data-wp-on--change', 'actions.updateGuestCount' );
					$tag->set_attribute( 'max', (string) $max_guest_limit );
				}
			}

			return $tag->get_updated_html();
		}

		// Handle anonymous checkbox field interactivity.
		if ( 'gatherpress_rsvp_anonymous' === $field_name ) {
			// Apply interactivity attributes for anonymous checkbox.
			$tag = new WP_HTML_Tag_Processor( $block_content );

			while ( $tag->next_tag( array( 'tag_name' => 'input' ) ) ) {
				$name_attr = $tag->get_attribute( 'name' );

				if ( 'gatherpress_rsvp_anonymous' === $name_attr ) {
					$tag->set_attribute( 'data-wp-interactive', 'gatherpress' );
					$tag->set_attribute( 'data-wp-on--change', 'actions.updateAnonymous' );
					$tag->set_attribute( 'data-wp-watch', 'callbacks.monitorAnonymousStatus' );
				}
			}

			return $tag->get_updated_html();
		}

		// Return unmodified content for non-RSVP form fields.
		return $block_content;
	}
}