<?php
/**
 * Divi 5 Visual Builder context bridge.
 *
 * This class deliberately contains no model provider or AI credential. It turns
 * the live Builder state into a small, permission-checked context contract that
 * the local Divi Powers Builder AI workflow can read.
 *
 * @package DiviPowers
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

final class Divi_Powers_Builder_Bridge {
	private const TRANSIENT_PREFIX = 'divi_powers_builder_context_';
	private const ACTIVE_PREFIX    = 'divi_powers_builder_active_';
	private const CONTEXT_TTL      = 10 * MINUTE_IN_SECONDS;

	/** @var Divi_Powers_Plugin */
	private $plugin;

	/** @param Divi_Powers_Plugin $plugin Shared plugin service. */
	public function __construct( $plugin ) {
		$this->plugin = $plugin;
	}

	/** Register Builder and authenticated AJAX hooks. */
	public function register() {
		if ( ! $this->plugin->is_power_enabled( 'builder_bridge' ) ) {
			return;
		}

		add_action( 'divi_visual_builder_assets_before_enqueue_scripts', array( $this, 'register_builder_asset' ), 15 );
		add_action( 'wp_enqueue_scripts', array( $this, 'render_builder_config' ), 5 );
		add_action( 'wp_ajax_divi_powers_builder_get_context', array( $this, 'ajax_get_context' ) );
		add_action( 'wp_ajax_divi_powers_builder_update_selection', array( $this, 'ajax_update_selection' ) );
		add_filter( 'divi_powers_capability_definitions', array( $this, 'register_capability_definitions' ) );
	}

	/** Register the app-window bridge through Divi 5's package manager. */
	public function register_builder_asset() {
		if (
			! function_exists( 'et_builder_d5_enabled' )
			|| ! function_exists( 'et_core_is_fb_enabled' )
			|| ! et_builder_d5_enabled()
			|| ! et_core_is_fb_enabled()
			|| ! class_exists( '\\ET\\Builder\\VisualBuilder\\Assets\\PackageBuildManager' )
		) {
			return;
		}

		\ET\Builder\VisualBuilder\Assets\PackageBuildManager::register_package_build(
			array(
				'name'    => 'divi-powers-builder-bridge',
				'version' => DIVI_POWERS_VERSION,
				'script'  => array(
					'src'                => DIVI_POWERS_URL . 'assets/js/builder-bridge.js',
					'deps'               => array( 'wp-i18n' ),
					'enqueue_top_window' => false,
					'enqueue_app_window' => true,
					'args'               => array( 'in_footer' => true ),
				),
			)
		);
		wp_set_script_translations( 'divi-powers-builder-bridge', '5d-powers-for-divi' );
	}

	/** Place authenticated bridge configuration into the Builder page. */
	public function render_builder_config() {
		if ( ! $this->is_builder_request() || ! current_user_can( 'edit_posts' ) ) {
			return;
		}

		$post_id = absint( get_queried_object_id() );
		if ( ! $post_id || ! current_user_can( 'edit_post', $post_id ) ) {
			return;
		}

		$config = array(
			'version'        => DIVI_POWERS_VERSION,
			'ajaxUrl'        => admin_url( 'admin-ajax.php' ),
			'nonce'          => wp_create_nonce( 'divi_powers_builder_bridge' ),
			'postId'         => $post_id,
			'pageTitle'      => get_the_title( $post_id ),
			'contextEvent'   => 'divi-powers:builder-context',
			'assistantEvent' => 'divi-powers:assistant-open',
		);

		$this->remember_active_page( $post_id );

		wp_register_script( 'fivedp-bridge-config', false, array(), DIVI_POWERS_VERSION, false );
		wp_enqueue_script( 'fivedp-bridge-config' );
		wp_add_inline_script( 'fivedp-bridge-config', 'window.diviPowersBuilderBridge=' . wp_json_encode( $config, JSON_HEX_TAG | JSON_HEX_AMP | JSON_HEX_APOS | JSON_HEX_QUOT ) . ';' );
	}

	/** Return the saved page plus the most recent live selection. */
	public function ajax_get_context() {
		check_ajax_referer( 'divi_powers_builder_bridge', 'nonce' );
		$post_id = isset( $_POST['post_id'] ) ? absint( $_POST['post_id'] ) : 0;

		if ( ! $post_id || ! current_user_can( 'edit_post', $post_id ) ) {
			wp_send_json_error( array( 'message' => __( 'You cannot inspect this page.', '5d-powers-for-divi' ) ), 403 );
		}

		wp_send_json_success( $this->page_context( $post_id, true ) );
	}

	/** Save a short-lived snapshot of the currently selected Builder element. */
	public function ajax_update_selection() {
		check_ajax_referer( 'divi_powers_builder_bridge', 'nonce' );
		$post_id = isset( $_POST['post_id'] ) ? absint( $_POST['post_id'] ) : 0;

		if ( ! $post_id || ! current_user_can( 'edit_post', $post_id ) ) {
			wp_send_json_error( array( 'message' => __( 'You cannot update context for this page.', '5d-powers-for-divi' ) ), 403 );
		}

		$raw       = isset( $_POST['selection'] ) ? wp_unslash( $_POST['selection'] ) : ''; // phpcs:ignore WordPress.Security.ValidatedSanitizedInput.InputNotSanitized
		$selection = json_decode( (string) $raw, true );
		$selection = $this->sanitize_selection( is_array( $selection ) ? $selection : array() );
		$snapshot  = array(
			'post_id'    => $post_id,
			'user_id'    => get_current_user_id(),
			'updated_at' => gmdate( 'c' ),
			'selection'  => $selection,
		);

		set_transient( $this->transient_key( get_current_user_id(), $post_id ), $snapshot, self::CONTEXT_TTL );
		set_transient( $this->active_key( get_current_user_id() ), $snapshot, self::CONTEXT_TTL );
		wp_send_json_success( array( 'stored' => true, 'updated_at' => $snapshot['updated_at'] ) );
	}

	/**
	 * Return the page most recently kept alive by this editor's Builder.
	 *
	 * @return int
	 */
	public function latest_post_id() {
		$user_id = get_current_user_id();
		$active  = $user_id ? get_transient( $this->active_key( $user_id ) ) : false;
		$post_id = is_array( $active ) && isset( $active['post_id'] ) ? absint( $active['post_id'] ) : 0;

		if ( ! $post_id || ! get_post( $post_id ) || ! current_user_can( 'edit_post', $post_id ) ) {
			return 0;
		}

		return $post_id;
	}

	/**
	 * Server-readable context seam for local Builder AI operations.
	 *
	 * @param int  $post_id        Page ID.
	 * @param bool $include_content Include saved Divi content.
	 * @return array<string,mixed>
	 */
	public function page_context( $post_id, $include_content = false ) {
		$post = get_post( $post_id );
		if ( ! $post ) {
			return array();
		}

		$content = (string) $post->post_content;
		$context = array(
			'contract_version' => '1.0',
			'post_id'          => (int) $post->ID,
			'title'            => get_the_title( $post ),
			'status'           => (string) $post->post_status,
			'url'              => get_permalink( $post ),
			'modified_gmt'     => (string) $post->post_modified_gmt,
			'builder'          => false !== strpos( $content, '<!-- wp:divi/' ) ? 'divi5_blocks' : ( false !== strpos( $content, '[et_pb_' ) ? 'classic_divi_shortcode' : 'wordpress_content' ),
			'content_sha256'   => hash( 'sha256', $content ),
			'live_context'     => get_transient( $this->transient_key( get_current_user_id(), $post_id ) ) ?: null,
		);

		if ( $include_content ) {
			$context['content'] = $content;
		}

		return $context;
	}

	/** Advertise stable capabilities without coupling them to a provider. */
	public function register_capability_definitions( $definitions ) {
		$definitions = is_array( $definitions ) ? $definitions : array();
		$definitions['divi_powers_get_builder_context'] = array(
			'version'   => '1.0',
			'read_only' => true,
			'description' => 'Read the saved Divi page plus the current Visual Builder selection for an authorized editor.',
			'input' => array(
				'post_id'         => array( 'type' => 'integer', 'required' => false ),
				'include_content' => array( 'type' => 'boolean', 'required' => false ),
			),
		);

		return $definitions;
	}

	/** Keep browser-provided context small and free of executable markup. */
	private function sanitize_selection( $selection ) {
		$allowed = array( 'source', 'type', 'label', 'moduleName', 'moduleType', 'blockName', 'clientId', 'diviId', 'moduleId', 'fieldName', 'fieldLabel', 'text' );
		$output  = array();
		foreach ( $allowed as $key ) {
			if ( isset( $selection[ $key ] ) && is_scalar( $selection[ $key ] ) ) {
				$output[ $key ] = substr( sanitize_textarea_field( (string) $selection[ $key ] ), 0, 'text' === $key ? 2000 : 300 );
			}
		}

		$output['fields'] = array();
		if ( isset( $selection['fields'] ) && is_array( $selection['fields'] ) ) {
			foreach ( array_slice( $selection['fields'], 0, 20 ) as $field ) {
				if ( ! is_array( $field ) ) {
					continue;
				}
				$output['fields'][] = array(
					'path'  => substr( sanitize_text_field( isset( $field['path'] ) ? (string) $field['path'] : '' ), 0, 300 ),
					'label' => substr( sanitize_text_field( isset( $field['label'] ) ? (string) $field['label'] : '' ), 0, 200 ),
					'text'  => substr( sanitize_textarea_field( isset( $field['text'] ) ? (string) $field['text'] : '' ), 0, 1000 ),
				);
			}
		}

		return $output;
	}

	/** Return a user- and page-specific transient key. */
	private function transient_key( $user_id, $post_id ) {
		return self::TRANSIENT_PREFIX . absint( $user_id ) . '_' . absint( $post_id );
	}

	/** Keep the active page discoverable without requiring a copied page ID. */
	private function remember_active_page( $post_id ) {
		$user_id = get_current_user_id();
		if ( ! $user_id ) {
			return;
		}

		$snapshot = get_transient( $this->transient_key( $user_id, $post_id ) );
		$snapshot = is_array( $snapshot ) ? $snapshot : array();
		$snapshot = array_merge(
			$snapshot,
			array(
				'post_id'    => absint( $post_id ),
				'user_id'    => $user_id,
				'updated_at' => gmdate( 'c' ),
			)
		);

		set_transient( $this->active_key( $user_id ), $snapshot, self::CONTEXT_TTL );
	}

	/** Return the current editor's active-Builder transient key. */
	private function active_key( $user_id ) {
		return self::ACTIVE_PREFIX . absint( $user_id );
	}

	/** Whether this is an active Divi frontend Builder request. */
	private function is_builder_request() {
		return function_exists( 'et_core_is_fb_enabled' ) && et_core_is_fb_enabled();
	}
}