<?php
/**
 * Main AI Answer Toolkit Class
 *
 * @package AI_Answer_Toolkit
 * @since 1.0.2
 */

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Main AI_Answer_Toolkit Class.
 *
 * @class AI_Answer_Toolkit
 */
final class AI_Answer_Toolkit {

	/**
	 * AI Answer Toolkit version.
	 *
	 * @var string
	 */
	public $version = '1.0.2';

	/**
	 * The single instance of the class.
	 *
	 * @var AI_Answer_Toolkit
	 */
	protected static $_instance = null;

	/**
	 * Main AI_Answer_Toolkit Instance.
	 *
	 * Ensures only one instance of AI_Answer_Toolkit is loaded or can be loaded.
	 *
	 * @static
	 * @return AI_Answer_Toolkit - Main instance.
	 */
	public static function instance() {
		if ( is_null( self::$_instance ) ) {
			self::$_instance = new self();
		}
		return self::$_instance;
	}

	/**
	 * Cloning is forbidden.
	 */
	public function __clone() {
		_doing_it_wrong( __FUNCTION__, esc_html__( 'Cloning is forbidden.', 'ai-answer-toolkit' ), '1.0.2' );
	}

	/**
	 * Unserializing instances of this class is forbidden.
	 */
	public function __wakeup() {
		_doing_it_wrong( __FUNCTION__, esc_html__( 'Unserializing instances is forbidden.', 'ai-answer-toolkit' ), '1.0.2' );
	}

	/**
	 * AI_Answer_Toolkit Constructor.
	 */
	public function __construct() {
		$this->define_constants();
		$this->includes();
		$this->init_hooks();
	}

	/**
	 * Define AI Answer Toolkit Constants.
	 */
	private function define_constants() {
		$this->define( 'AI_ANSWER_TOOLKIT_ABSPATH', dirname( AI_ANSWER_TOOLKIT_PLUGIN_FILE ) . '/' );
	}

	/**
	 * Define constant if not already set.
	 *
	 * @param string      $name  Constant name.
	 * @param string|bool $value Constant value.
	 */
	private function define( $name, $value ) {
		if ( ! defined( $name ) ) {
			define( $name, $value );
		}
	}

	/**
	 * Include required core files.
	 */
	public function includes() {
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-install.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-loader.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-summary.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-score.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-ultimate-score.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-ultimate-hints.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-visibility.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-export.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-pdf-generator.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-content-guidance.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-ai-suggestions.php';
		require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-rest-api.php';

		if ( $this->is_request( 'admin' ) ) {
			require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'admin/class-ai-answer-toolkit-admin.php';
			require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'admin/class-ai-answer-toolkit-unified-meta-box.php';
			require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'admin/class-ai-answer-toolkit-dashboard.php';
			require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'admin/class-ai-answer-toolkit-settings-page.php';
		}

		if ( $this->is_request( 'frontend' ) ) {
			require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'includes/class-ai-answer-toolkit-frontend.php';
			require_once AI_ANSWER_TOOLKIT_PLUGIN_DIR . 'schema/class-ai-answer-toolkit-schema.php';
		}
	}

	/**
	 * Hook into actions and filters.
	 */
	private function init_hooks() {
		register_activation_hook( AI_ANSWER_TOOLKIT_PLUGIN_FILE, array( 'AI_Answer_Toolkit_Install', 'activate' ) );
		register_deactivation_hook( AI_ANSWER_TOOLKIT_PLUGIN_FILE, array( 'AI_Answer_Toolkit_Install', 'deactivate' ) );

		add_action( 'plugins_loaded', array( $this, 'init' ), 0 );
		add_action( 'init', array( $this, 'load_plugin_textdomain' ) );
	}

	/**
	 * Init AI Answer Toolkit when WordPress Initialises.
	 */
	public function init() {
		do_action( 'ai_answer_toolkit_before_init' );

		$this->load_components();

		do_action( 'ai_answer_toolkit_init' );
	}

	/**
	 * Load plugin components.
	 */
	private function load_components() {
		// Initialize REST API
		AI_Answer_Toolkit_REST_API::init();
		
		// Initialize PDF Generator (registers PDF CSS for WordPress.org compliance)
		AI_Answer_Toolkit_PDF_Generator::init();
		
		if ( $this->is_request( 'admin' ) ) {
			AI_Answer_Toolkit_Admin::instance();
		}
	}

	/**
	 * Load Localisation files.
	 * Note: Since WordPress 4.6, translations are automatically loaded from WordPress.org.
	 */
	public function load_plugin_textdomain() {
		// Translations are automatically loaded by WordPress for plugins hosted on WordPress.org.
		// This function is kept for backwards compatibility but no longer calls load_plugin_textdomain().
	}

	/**
	 * What type of request is this?
	 *
	 * @param  string $type admin, ajax, cron or frontend.
	 * @return bool
	 */
	private function is_request( $type ) {
		switch ( $type ) {
			case 'admin':
				return is_admin();
			case 'ajax':
				return defined( 'DOING_AJAX' );
			case 'cron':
				return defined( 'DOING_CRON' );
			case 'frontend':
				return ( ! is_admin() || defined( 'DOING_AJAX' ) ) && ! defined( 'DOING_CRON' );
		}
	}

	/**
	 * Get the plugin url.
	 *
	 * @return string
	 */
	public function plugin_url() {
		return untrailingslashit( plugins_url( '/', AI_ANSWER_TOOLKIT_PLUGIN_FILE ) );
	}

	/**
	 * Get the plugin path.
	 *
	 * @return string
	 */
	public function plugin_path() {
		return untrailingslashit( plugin_dir_path( AI_ANSWER_TOOLKIT_PLUGIN_FILE ) );
	}

	/**
	 * Get Ajax URL.
	 *
	 * @return string
	 */
	public function ajax_url() {
		return admin_url( 'admin-ajax.php', 'relative' );
	}
}