<?php
/**
 * Plugin Name: Airgentic AI Chat Overlay
 * Plugin URI: https://www.airgentic.com/integrations/wordpress
 * Description: Adds the Airgentic chat widget, Service Hub, and Site Search to your WordPress site.
 * Version: 1.2.0
 * Author: Airgentic Pty Ltd
 * Author URI: https://www.airgentic.com
 * License: GPLv2 or later
 * License URI: http://www.gnu.org/licenses/gpl-2.0.html
 * Text Domain: airgentic
 * Requires at least: 5.8
 * Tested up to: 6.8
 * Requires PHP: 7.4
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit; // Exit if accessed directly
}

define( 'AIRGENTIC_VERSION', '1.2.0' );
define( 'AIRGENTIC_PLUGIN_DIR', plugin_dir_path( __FILE__ ) );
define( 'AIRGENTIC_PLUGIN_URL', plugin_dir_url( __FILE__ ) );

/**
 * Main Airgentic plugin class
 */
final class Airgentic {

	/**
	 * Script handle for wp_enqueue_script
	 *
	 * @var string
	 */
	private const SCRIPT_HANDLE = 'airgentic-widget';

	/**
	 * Option name stored in the wp_options table.
	 *
	 * @var string
	 */
	public const OPTION_NAME = 'airgentic_options';

	/**
	 * Plugin instance
	 *
	 * @var Airgentic
	 */
	private static $instance = null;

	/**
	 * Plugin options
	 *
	 * @var array
	 */
	private $options = array();

	/**
	 * Get plugin instance
	 *
	 * @return Airgentic
	 */
	public static function instance() {
		if ( is_null( self::$instance ) ) {
			self::$instance = new self();
		}
		return self::$instance;
	}

	/**
	 * Default option values.
	 *
	 * @return array
	 */
	public static function default_options() {
		return array(
			'account_id'           => '',
			'service_id'           => '',
			'search_input_id'      => '',
			'search_button_id'     => '',
			'enable_on_front'      => 1,
			'search_mode'          => '',
			'search_page_id'       => 0,
			'rewrite_search_forms' => 1,
			'redirect_s'           => 1,
		);
	}

	/**
	 * Load and normalise plugin options.
	 *
	 * Existing 1.1.0 installs that already filled a search input ID keep overlay
	 * mode so their search popup does not change on upgrade.
	 *
	 * @return array
	 */
	public static function get_plugin_options() {
		$options = wp_parse_args( get_option( self::OPTION_NAME, array() ), self::default_options() );

		$allowed_modes = array( 'none', 'inline', 'overlay' );
		if ( ! in_array( $options['search_mode'], $allowed_modes, true ) ) {
			$options['search_mode'] = ! empty( $options['search_input_id'] ) ? 'overlay' : 'none';
		}

		$options['search_page_id']       = absint( $options['search_page_id'] );
		$options['rewrite_search_forms'] = ! empty( $options['rewrite_search_forms'] ) ? 1 : 0;
		$options['redirect_s']           = ! empty( $options['redirect_s'] ) ? 1 : 0;
		$options['enable_on_front']      = ! empty( $options['enable_on_front'] ) ? 1 : 0;

		return $options;
	}

	/**
	 * Permalink of the configured Site Search page, or empty string.
	 *
	 * @param array|null $options Optional options array.
	 * @return string
	 */
	public static function get_search_page_url( $options = null ) {
		if ( null === $options ) {
			$options = self::get_plugin_options();
		}

		$page_id = absint( $options['search_page_id'] );
		if ( $page_id < 1 ) {
			return '';
		}

		$permalink = get_permalink( $page_id );
		if ( ! $permalink || 'publish' !== get_post_status( $page_id ) ) {
			return '';
		}

		return $permalink;
	}

	/**
	 * Constructor
	 */
	private function __construct() {
		$this->load_dependencies();
		$this->init_hooks();
	}

	/**
	 * Load required dependencies
	 */
	private function load_dependencies() {
		if ( is_admin() ) {
			require_once AIRGENTIC_PLUGIN_DIR . 'includes/admin-settings.php';
		}
	}

	/**
	 * Initialize WordPress hooks
	 */
	private function init_hooks() {
		add_action( 'wp_enqueue_scripts', array( $this, 'enqueue_script' ) );
		add_filter( 'script_loader_tag', array( $this, 'add_data_attributes_to_script' ), 10, 3 );

		add_shortcode( 'airgentic_service_hub', array( $this, 'service_hub_shortcode' ) );
		add_shortcode( 'airgentic_search', array( $this, 'search_shortcode' ) );

		add_filter( 'get_search_form', array( $this, 'rewrite_search_form' ), 20 );
		add_filter( 'render_block', array( $this, 'rewrite_search_block' ), 10, 2 );
		add_action( 'template_redirect', array( $this, 'redirect_wordpress_search' ) );
	}

	/**
	 * Get plugin options
	 *
	 * @return array
	 */
	private function get_options() {
		if ( empty( $this->options ) ) {
			$this->options = self::get_plugin_options();
		}
		return $this->options;
	}

	/**
	 * Whether the front-end script should load.
	 *
	 * @param array $options Plugin options.
	 * @return bool
	 */
	private function is_front_end_enabled( $options ) {
		return ! empty( $options['enable_on_front'] )
			&& ! empty( $options['account_id'] )
			&& ! empty( $options['service_id'] );
	}

	/**
	 * Whether native WordPress search forms should be rewritten for inline search.
	 *
	 * @param array $options Plugin options.
	 * @return bool
	 */
	private function should_rewrite_search_forms( $options ) {
		return $this->is_front_end_enabled( $options )
			&& 'inline' === $options['search_mode']
			&& ! empty( $options['rewrite_search_forms'] )
			&& '' !== self::get_search_page_url( $options );
	}

	/**
	 * Enqueue the Airgentic script
	 */
	public function enqueue_script() {
		$options = $this->get_options();

		if ( ! $this->is_front_end_enabled( $options ) ) {
			return;
		}

		wp_enqueue_script(
			self::SCRIPT_HANDLE,
			'https://chat.airgentic.com/_js/airgentic-1.4.js',
			array(),
			AIRGENTIC_VERSION,
			array( 'in_footer' => false )
		);
	}

	/**
	 * Add data attributes to the Airgentic script tag
	 *
	 * @param string $tag    The script tag.
	 * @param string $handle The script handle.
	 * @param string $src    The script source URL.
	 * @return string Modified script tag with data attributes.
	 */
	public function add_data_attributes_to_script( $tag, $handle, $src ) {
		unset( $src );

		if ( self::SCRIPT_HANDLE !== $handle ) {
			return $tag;
		}

		$options = $this->get_options();

		$data_attrs = 'data-account-id="' . esc_attr( $options['account_id'] ) . '" ' .
			'data-service-id="' . esc_attr( $options['service_id'] ) . '"';

		$mode = $options['search_mode'];

		if ( 'overlay' === $mode ) {
			if ( ! empty( $options['search_input_id'] ) ) {
				$data_attrs .= ' data-search-input-id="' . esc_attr( $options['search_input_id'] ) . '"';
			}
			if ( ! empty( $options['search_button_id'] ) ) {
				$data_attrs .= ' data-search-button-id="' . esc_attr( $options['search_button_id'] ) . '"';
			}
		} elseif ( 'inline' === $mode ) {
			if ( ! empty( $options['rewrite_search_forms'] ) ) {
				$data_attrs .= ' data-search-autocomplete="true"';
			}
			if ( ! empty( $options['search_input_id'] ) ) {
				$data_attrs .= ' data-autocomplete-input-id="' . esc_attr( $options['search_input_id'] ) . '"';
			}
			if ( ! empty( $options['search_button_id'] ) ) {
				$data_attrs .= ' data-autocomplete-button-id="' . esc_attr( $options['search_button_id'] ) . '"';
			}
		}

		$tag = str_replace( 'id="airgentic-widget-js"', 'id="airgentic-script"', $tag );
		$tag = str_replace( "id='airgentic-widget-js'", "id='airgentic-script'", $tag );

		$tag = str_replace( '<script ', '<script async ', $tag );

		$tag = preg_replace( '/\?ver=[^\'"\s>]+/', '', $tag );

		$tag = str_replace( ' src=', ' ' . $data_attrs . ' defer src=', $tag );

		return $tag;
	}

	/**
	 * Service Hub shortcode handler
	 *
	 * @return string
	 */
	public function service_hub_shortcode() {
		return '<div id="airgentic"></div>';
	}

	/**
	 * Site Search shortcode handler
	 *
	 * @return string
	 */
	public function search_shortcode() {
		return '<div data-airgentic="search"></div>';
	}

	/**
	 * Rewrite classic search form HTML for inline search.
	 *
	 * @param string $form Search form HTML.
	 * @return string
	 */
	public function rewrite_search_form( $form ) {
		if ( is_admin() ) {
			return $form;
		}

		$options = $this->get_options();
		if ( ! $this->should_rewrite_search_forms( $options ) ) {
			return $form;
		}

		return $this->rewrite_search_form_html( $form, self::get_search_page_url( $options ) );
	}

	/**
	 * Rewrite the core Search block for inline search.
	 *
	 * @param string $block_content Rendered block HTML.
	 * @param array  $block         Parsed block.
	 * @return string
	 */
	public function rewrite_search_block( $block_content, $block ) {
		if ( is_admin() ) {
			return $block_content;
		}

		if ( empty( $block['blockName'] ) || 'core/search' !== $block['blockName'] ) {
			return $block_content;
		}

		$options = $this->get_options();
		if ( ! $this->should_rewrite_search_forms( $options ) ) {
			return $block_content;
		}

		return $this->rewrite_search_form_html( $block_content, self::get_search_page_url( $options ) );
	}

	/**
	 * Point a search form at the Airgentic search page.
	 *
	 * @param string $html Form HTML.
	 * @param string $url  Search page URL.
	 * @return string
	 */
	private function rewrite_search_form_html( $html, $url ) {
		if ( ! is_string( $html ) || '' === $html || '' === $url ) {
			return $html;
		}

		$quoted_url = esc_url( $url );

		if ( preg_match( '/<form\b[^>]*\baction=/i', $html ) ) {
			$html = preg_replace(
				'/(<form\b[^>]*\baction=)([\'"])[^\'"]*\2/i',
				'$1"' . $quoted_url . '"',
				$html,
				1
			);
		} else {
			$html = preg_replace(
				'/<form\b/i',
				'<form action="' . $quoted_url . '"',
				$html,
				1
			);
		}

		$html = preg_replace(
			'/(<input\b[^>]*\bname=)([\'"])s\2/i',
			'$1$2query$2',
			$html
		);

		if ( false === strpos( $html, 'data-airgentic-autocomplete' ) ) {
			$html = preg_replace(
				'/(<input\b[^>]*\bname=(?:\'query\'|"query")[^>]*)(\/?>)/i',
				'$1 data-airgentic-autocomplete="true"$2',
				$html,
				1
			);
		}

		return $html;
	}

	/**
	 * Redirect native WordPress ?s= searches to the Airgentic search page.
	 */
	public function redirect_wordpress_search() {
		if ( is_admin() || wp_doing_ajax() || is_feed() || is_preview() ) {
			return;
		}

		if ( ! is_search() ) {
			return;
		}

		$options = $this->get_options();
		if ( ! $this->is_front_end_enabled( $options ) ) {
			return;
		}

		if ( 'inline' !== $options['search_mode'] || empty( $options['redirect_s'] ) ) {
			return;
		}

		$search_url = self::get_search_page_url( $options );
		if ( '' === $search_url ) {
			return;
		}

		$query = get_search_query();
		$target = $search_url;
		if ( '' !== $query ) {
			$target = add_query_arg( 'query', $query, $search_url );
		}

		wp_safe_redirect( $target, 302 );
		exit;
	}
}

/**
 * Initialize the plugin
 *
 * @return Airgentic
 */
function airgentic_init() {
	return Airgentic::instance();
}

add_action( 'plugins_loaded', 'airgentic_init' );