<?php
/**
 * Ajax Handler Class
 *
 * Manages all AJAX requests initiated from the plugin's admin interface.
 * Handles actions like starting/cancelling searches, fetching status/logs,
 * testing APIs, toggling settings, and performing maintenance tasks.
 *
 * @package           AINP_AI_Native_Publisher
 * @author            AI News Publisher
 * @copyright         2025, AI News Publisher
 * @license           GPL-2.0+
 */

// Exit if accessed directly.
if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Handles AJAX communications for the plugin.
 */
class AINP_Ajax {

	/**
	 * Reference to the main plugin instance.
	 * @var AINP_Native_Publisher
	 */
	private $plugin;

	/**
	 * Constructor.
	 *
	 * @param AINP_Native_Publisher $plugin The main plugin instance.
	 */
	public function __construct( AINP_Native_Publisher $plugin ) {
		$this->plugin = $plugin;
	}

	/**
	 * Registers all WordPress AJAX action hooks.
	 */
	public function register_ajax_hooks() {
		// Fetch actions
		add_action( 'wp_ajax_ainp_fetch_next_news_item', array( $this, 'handle_fetch_next_news_item_ajax' ) );
		add_action( 'wp_ajax_ainp_start_batch_search', array( $this, 'handle_start_batch_search_ajax' ) );
		add_action( 'wp_ajax_ainp_cancel_search', array( $this, 'handle_cancel_search_ajax' ) ); // Uses maintenance nonce

		// Status and Log polling
		add_action( 'wp_ajax_ainp_get_status', array( $this, 'handle_get_status_ajax' ) );
		add_action( 'wp_ajax_ainp_get_logs', array( $this, 'handle_get_logs_ajax' ) );

		// Diagnostics / Testing
		add_action( 'wp_ajax_ainp_test_api_connection', array( $this, 'handle_test_api_connection_ajax' ) );
		add_action( 'wp_ajax_ainp_test_write_permission', array( $this, 'handle_test_write_permission_ajax' ) );

		// Dashboard Toggles
		add_action( 'wp_ajax_ainp_toggle_auto_search', array( $this, 'handle_toggle_auto_search_ajax' ) );
		add_action( 'wp_ajax_ainp_toggle_image_fallback', array( $this, 'handle_toggle_image_fallback_ajax' ) );
		add_action( 'wp_ajax_ainp_toggle_force_image', array( $this, 'handle_toggle_force_image_ajax' ) );

		// Maintenance Actions (use maintenance nonce)
		add_action( 'wp_ajax_ainp_reset_jobs', array( $this, 'handle_reset_jobs_ajax' ) );
		add_action( 'wp_ajax_ainp_clear_logs', array( $this, 'handle_clear_logs_ajax' ) );
		add_action( 'wp_ajax_ainp_reset_processing_status', array( $this, 'handle_reset_processing_status_ajax' ) );

		// Dismiss Welcome Panel
		add_action( 'wp_ajax_ainp_dismiss_welcome_panel', array( $this, 'handle_dismiss_welcome_panel_ajax' ) );
	}

	/**
	 * Verifies AJAX request nonce and user capabilities. Terminates with JSON error on failure.
	 *
	 * @param string $nonce_action The expected nonce action name. Default 'ainp_nonce'.
	 * @param string $nonce_key    The key used for the nonce in the POST data. Default '_ajax_nonce'.
	 */
	private function verify_ajax_request( $nonce_action = 'ainp_nonce', $nonce_key = '_ajax_nonce' ) {
		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- This is the verification function itself.
		if ( '_ajax_nonce' !== $nonce_key && isset( $_POST[ $nonce_key ] ) ) {
			// A specific key was passed, use it.
		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- This is the verification function itself.
		} elseif ( isset( $_POST['_ajax_nonce'] ) ) {
			$nonce_key = '_ajax_nonce';
		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- This is the verification function itself.
		} elseif ( isset( $_POST['nonce'] ) ) {
			$nonce_key = 'nonce';
		} else {
			$nonce_key = '_ajax_nonce';
		}

		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- We are verifying it right here.
		$nonce = isset( $_POST[ $nonce_key ] ) ? sanitize_text_field( wp_unslash( $_POST[ $nonce_key ] ) ) : '';

		if ( empty( $nonce ) || ! wp_verify_nonce( $nonce, $nonce_action ) ) {
			wp_send_json_error( array( 'message' => __( 'Security check (Nonce) failed.', 'ainp-ai-native-publisher' ) ), 403 );
			wp_die();
		}
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_send_json_error( array( 'message' => __( 'Permission denied.', 'ainp-ai-native-publisher' ) ), 403 );
			wp_die();
		}
	}

	/**
	 * Handles AJAX request to start a batch search process.
	 */
	public function handle_start_batch_search_ajax() {
		$this->verify_ajax_request( 'ainp_nonce' );

		set_transient( 'ainp_manual_context', true, HOUR_IN_SECONDS );

		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- Verified in verify_ajax_request.
		$choice     = isset( $_POST['search_depth_choice'] ) ? sanitize_key( wp_unslash( $_POST['search_depth_choice'] ) ) : '1';
		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- Verified in verify_ajax_request.
		$custom_val = isset( $_POST['search_depth_custom'] ) ? absint( wp_unslash( $_POST['search_depth_custom'] ) ) : 5;

		$this->plugin->load_options();
		$this->plugin->options['manual_search_depth_choice'] = $choice;
		$this->plugin->options['manual_search_depth_custom'] = $custom_val;
		update_option( 'ainp_settings', $this->plugin->options );

		$search_depth = ( 'custom' === $choice ) ? max( 1, $custom_val ) : $choice;

		$this->plugin->logger->add_log_entry( 'info', __( 'Received AJAX request for manual batch search.', 'ainp-ai-native-publisher' ), 'Search depth setting: ' . esc_html( $search_depth ) );

		delete_option( AINP_Status_Logger::CANCEL_FLAG_OPTION );
		update_option( AINP_EXECUTION_START_TIME_OPTION, time() );
		update_option( AINP_PENDING_IMAGE_TASKS_OPTION, 0 );
		$this->plugin->processor->set_posts_awaiting_image_current_run( array() );

		$sources = $this->plugin->options['sources_config'] ?? array();
		if ( empty( $sources ) ) {
			wp_send_json_error( array( 'message' => __( 'Cannot start search: No valid sources configured.', 'ainp-ai-native-publisher' ) ) );
			wp_die();
		}

		$queue_data = array(
			'sources'      => $sources,
			'search_depth' => $search_depth,
		);
		set_transient( AINP_FEED_QUEUE_TRANSIENT, $queue_data, HOUR_IN_SECONDS * 2 );

		$total_sources = count( $sources );
		$this->plugin->logger->update_processing_status( 'processing', 0, $total_sources, __( 'Starting manual batch search...', 'ainp-ai-native-publisher' ) );
		
		/* translators: %d: Number of sources */
		$this->plugin->logger->add_log_entry( 'info', sprintf( __( 'Manual batch search initiated for %d sources.', 'ainp-ai-native-publisher' ), $total_sources ) );

		wp_schedule_single_event( time(), AINP_PROCESS_BATCH_HOOK );

		wp_send_json_success(
			array(
				'message'     => __( 'Background batch search initiated successfully!', 'ainp-ai-native-publisher' ),
				'total_feeds' => $total_sources,
			)
		);
		wp_die();
	}

	/**
	 * Handles AJAX request to fetch and process only the next single news item.
	 */
	public function handle_fetch_next_news_item_ajax() {
		$this->verify_ajax_request( 'ainp_nonce' );
		$this->plugin->logger->add_log_entry( 'info', __( 'Received AJAX request to fetch the next single news item.', 'ainp-ai-native-publisher' ) );
		
		$this->plugin->load_options();
		delete_option( AINP_Status_Logger::CANCEL_FLAG_OPTION );

		$sources = $this->plugin->options['sources_config'] ?? array();
		if ( empty( $sources ) ) {
			wp_send_json_error( array( 'message' => __( 'Cannot fetch: No sources configured.', 'ainp-ai-native-publisher' ) ) );
			wp_die();
		}

		$result_summary = $this->plugin->processor->process_single_source( $sources[0], 1, true );

		$message = sprintf(
			/* translators: 1: created count, 2: skipped count, 3: error count */
			__( 'Processing of the first source complete. %1$d news item(s) created, %2$d skipped (duplicates/filtered), %3$d encountered errors.', 'ainp-ai-native-publisher' ),
			$result_summary['created'],
			$result_summary['skipped'],
			$result_summary['errors']
		);
		$this->plugin->logger->add_log_entry( 'success', __( 'Single item fetch complete.', 'ainp-ai-native-publisher' ), $message );

		$final_status_msg = ( $result_summary['errors'] > 0 ) ? __( 'Completed with errors.', 'ainp-ai-native-publisher' ) : __( 'Completed successfully.', 'ainp-ai-native-publisher' );
		$this->plugin->logger->update_processing_status( 'completed', $result_summary['created'], 1, $final_status_msg );

		wp_send_json_success( array( 'message' => $message ) );
		wp_die();
	}

	/**
	 * Handles AJAX request to cancel the currently running batch search.
	 */
	public function handle_cancel_search_ajax() {
		$this->verify_ajax_request( 'ainp_maintenance_nonce' );

		update_option( AINP_Status_Logger::CANCEL_FLAG_OPTION, true );
		delete_transient( AINP_FEED_QUEUE_TRANSIENT );
		delete_option( AINP_PENDING_IMAGE_TASKS_OPTION );

		$this->plugin->logger->add_log_entry( 'warning', __( 'Search cancellation requested by user.', 'ainp-ai-native-publisher' ) );

		$status = $this->plugin->logger->get_processing_status();
		$this->plugin->logger->update_processing_status( 'idle', $status['current'], $status['total'], __( 'Search cancelled by user.', 'ainp-ai-native-publisher' ) );

		wp_send_json_success( array( 'message' => __( 'Search cancellation initiated. The process will stop shortly.', 'ainp-ai-native-publisher' ) ) );
		wp_die();
	}

	/**
	 * Handles AJAX polling request to get the current processing status.
	 */
	public function handle_get_status_ajax() {
		$this->verify_ajax_request( 'ainp_nonce' );

		$status_data    = $this->plugin->logger->get_processing_status();
		$pending_images = (int) get_option( AINP_PENDING_IMAGE_TASKS_OPTION, 0 );

		if ( 'completed' === $status_data['status'] && $pending_images > 0 ) {
			$status_data['status']  = 'processing_images';
			/* translators: %d: Number of images remaining */
			$status_data['message'] = sprintf( _n( 'Fetch complete. Generating %d image...', 'Fetch complete. Generating %d images...', $pending_images, 'ainp-ai-native-publisher' ), $pending_images );
		}

		$status_display_map = array(
			'idle'              => __( 'Idle', 'ainp-ai-native-publisher' ),
			'processing'        => __( 'Processing Sources...', 'ainp-ai-native-publisher' ),
			'processing_images' => __( 'Generating Images...', 'ainp-ai-native-publisher' ),
			'completed'         => __( 'Completed', 'ainp-ai-native-publisher' ),
		);
		$status_data['status_display'] = $status_display_map[ $status_data['status'] ] ?? ucfirst( $status_data['status'] );

		wp_send_json_success( array( 'status' => $status_data ) );
		wp_die();
	}

	/**
	 * Handles AJAX polling request to get the latest log entries HTML.
	 */
	public function handle_get_logs_ajax() {
		$this->verify_ajax_request( 'ainp_nonce' );
		wp_send_json_success( array( 'logs' => $this->plugin->logger->get_log_entries_html() ) );
		wp_die();
	}

	/**
	 * Handles AJAX request to test connections to configured AI APIs.
	 */
	public function handle_test_api_connection_ajax() {
		$this->verify_ajax_request( 'ainp_nonce' );
		$this->plugin->logger->add_log_entry( 'info', __( 'Starting API connection tests via AJAX.', 'ainp-ai-native-publisher' ) );

		$results = array();

		// --- Test Groq (Active) ---
		$groq_results = $this->plugin->api_handler->test_groq_connection();
		if ( isset( $groq_results['error'] ) ) {
			$results['groq'] = array(
				'provider' => 'Groq (Text)',
				'status'   => 'error',
				'message'  => $groq_results['error'],
				'details'  => array(),
			);
			$this->plugin->logger->add_log_entry( 'warning', 'Groq API test skipped: ' . $groq_results['error'] );
		} else {
			$results['groq'] = array(
				'provider' => 'Groq (Text)',
				'status'   => $groq_results['status'],
				'message'  => $groq_results['message'],
				'details'  => array(),
			);
			$log_level_groq = ( 'error' === $groq_results['status'] ) ? 'error' : 'info';
			$this->plugin->logger->add_log_entry( $log_level_groq, 'Groq API Test Result: ' . wp_strip_all_tags( $groq_results['message'] ) );
		}
		
		// --- Test Unsplash (Active) ---
		$unsplash_results = $this->plugin->api_handler->test_unsplash_connection();
		if ( isset( $unsplash_results['error'] ) ) {
			$results['unsplash'] = array(
				'provider' => 'Unsplash (Images)',
				'status'   => 'error',
				'message'  => $unsplash_results['error'],
				'details'  => array(),
			);
			$this->plugin->logger->add_log_entry( 'warning', 'Unsplash API test skipped: ' . $unsplash_results['error'] );
		} else {
			$results['unsplash'] = array(
				'provider' => 'Unsplash (Images)',
				'status'   => $unsplash_results['status'],
				'message'  => $unsplash_results['message'],
				'details'  => array(),
			);
			$log_level_unsplash = ( 'error' === $unsplash_results['status'] ) ? 'error' : 'info';
			$this->plugin->logger->add_log_entry( $log_level_unsplash, 'Unsplash API Test Result: ' . wp_strip_all_tags( $unsplash_results['message'] ) );
		}

		wp_send_json_success( array( 'results' => $results ) );
		wp_die();
	}


	/**
	 * Generic handler for dashboard toggle switches.
	 */
	private function handle_toggle_ajax( $option_key, $log_msg_enabled, $log_msg_disabled ) {
		$this->verify_ajax_request( 'ainp_nonce' );
		
		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- Verified in verify_ajax_request.
		if ( ! isset( $_POST['is_enabled'] ) ) {
			wp_send_json_error( array( 'message' => __( 'Missing required parameter.', 'ainp-ai-native-publisher' ) ) );
			wp_die();
		}

		// phpcs:ignore WordPress.Security.NonceVerification.Missing -- Verified in verify_ajax_request.
		$is_enabled_raw = sanitize_text_field( wp_unslash( $_POST['is_enabled'] ) );
		$is_enabled     = filter_var( $is_enabled_raw, FILTER_VALIDATE_BOOLEAN );

		$this->plugin->load_options();
		$this->plugin->options[ $option_key ] = $is_enabled;
		update_option( 'ainp_settings', $this->plugin->options );

		if ( 'enable_auto_search' === $option_key ) {
			$this->plugin->cron_handler->schedule_or_clear_auto_search();
		}

		$message = $is_enabled ? $log_msg_enabled : $log_msg_disabled;
		$this->plugin->logger->add_log_entry( 'info', $message );
		wp_send_json_success( array( 'message' => $message ) );
		wp_die();
	}

	public function handle_toggle_auto_search_ajax() {
		$this->handle_toggle_ajax(
			'enable_auto_search',
			__( 'Automatic search enabled via dashboard toggle.', 'ainp-ai-native-publisher' ),
			__( 'Automatic search disabled via dashboard toggle.', 'ainp-ai-native-publisher' )
		);
	}

	public function handle_toggle_image_fallback_ajax() {
		$this->handle_toggle_ajax(
			'module_generate_images',
			__( 'AI image generation fallback ENABLED via dashboard toggle.', 'ainp-ai-native-publisher' ),
			__( 'AI image generation fallback DISABLED via dashboard toggle.', 'ainp-ai-native-publisher' )
		);
	}

	public function handle_toggle_force_image_ajax() {
		$this->handle_toggle_ajax(
			'module_force_ia_image',
			__( 'Force AI image generation ENABLED via dashboard toggle.', 'ainp-ai-native-publisher' ),
			__( 'Force AI image generation DISABLED via dashboard toggle.', 'ainp-ai-native-publisher' )
		);
	}

	/**
	 * Handles AJAX request to reset currently running jobs.
	 */
	public function handle_reset_jobs_ajax() {
		$this->verify_ajax_request( 'ainp_maintenance_nonce' );
		$this->plugin->logger->add_log_entry( 'warning', __( '"Reset Jobs" action triggered by user.', 'ainp-ai-native-publisher' ) );

		update_option( AINP_Status_Logger::CANCEL_FLAG_OPTION, true );
		delete_transient( AINP_FEED_QUEUE_TRANSIENT );
		delete_option( AINP_PENDING_IMAGE_TASKS_OPTION );

		delete_option( AINP_DOMAIN_TIMESTAMPS_OPTION );
		$this->plugin->logger->add_log_entry( 'info', __( 'Domain cooldown timestamps have been reset.', 'ainp-ai-native-publisher' ) );

		$this->plugin->logger->update_processing_status( 'idle', 0, 0, __( 'Running jobs reset by user.', 'ainp-ai-native-publisher' ) );

		wp_send_json_success( array( 'message' => __( 'Running jobs have been flagged to stop. Status and domain cooldowns reset.', 'ainp-ai-native-publisher' ) ) );
		wp_die();
	}

	/**
	 * Handles AJAX request to clear all plugin log entries.
	 */
	public function handle_clear_logs_ajax() {
		$this->verify_ajax_request( 'ainp_maintenance_nonce' );

		delete_option( AINP_Status_Logger::LOG_OPTION_KEY );
		$this->plugin->logger->add_log_entry( 'warning', __( 'Log history cleared by user.', 'ainp-ai-native-publisher' ) );

		wp_send_json_success( array( 'message' => __( 'Log history has been cleared.', 'ainp-ai-native-publisher' ) ) );
		wp_die();
	}

	/**
	 * Handles AJAX request to force reset the processing status to 'idle'.
	 */
	public function handle_reset_processing_status_ajax() {
		$this->verify_ajax_request( 'ainp_maintenance_nonce' );
		$this->plugin->logger->add_log_entry( 'info', __( 'Processing status and image queue manually reset by user.', 'ainp-ai-native-publisher' ) );

		delete_transient( AINP_FEED_QUEUE_TRANSIENT );
		delete_option( AINP_PENDING_IMAGE_TASKS_OPTION );
		delete_option( AINP_Status_Logger::CANCEL_FLAG_OPTION );

		delete_option( AINP_DOMAIN_TIMESTAMPS_OPTION );
		$this->plugin->logger->add_log_entry( 'info', __( 'Domain cooldown timestamps have been reset.', 'ainp-ai-native-publisher' ) );

		$this->plugin->logger->update_processing_status( 'idle', 0, 0, __( 'Processing status manually reset.', 'ainp-ai-native-publisher' ) );

		wp_send_json_success( array( 'message' => __( 'Processing status, related queues, and domain cooldowns have been reset to Idle.', 'ainp-ai-native-publisher' ) ) );
		wp_die();
	}

	/**
	 * Handles AJAX request to test write permissions in the WordPress uploads directory.
	 */
	public function handle_test_write_permission_ajax() {
		$this->verify_ajax_request( 'ainp_nonce' );
		$upload_dir = wp_upload_dir();
		$test_file  = trailingslashit( $upload_dir['path'] ) . 'ainp-write-test.tmp';

		if ( file_put_contents( $test_file, 'test_write' ) !== false ) {
			if ( file_exists( $test_file ) ) {
				wp_delete_file( $test_file );
			}
			wp_send_json_success( array( 'message' => __( 'SUCCESS! The plugin has write permission in the uploads folder.', 'ainp-ai-native-publisher' ) ) );
		} else {
			$error   = error_get_last();
			$message = sprintf(
				/* translators: 1: Uploads folder path, 2: System error message (or N/A) */
				__( 'FAIL: The plugin could not write to the uploads folder (%1$s). Please check the folder permissions on your server. System error: %2$s', 'ainp-ai-native-publisher' ),
				esc_html( $upload_dir['path'] ),
				esc_html( $error['message'] ?? __( 'N/A', 'ainp-ai-native-publisher' ) )
			);
			$this->plugin->logger->add_log_entry( 'error', __( 'Uploads directory write permission test failed.', 'ainp-ai-native-publisher' ), esc_html( $upload_dir['path'] ) );
			wp_send_json_error( array( 'message' => $message ) );
		}
		wp_die();
	}

	/**
	 * Handles AJAX request to save the user's preference for dismissing the welcome panel.
	 */
	public function handle_dismiss_welcome_panel_ajax() {
		$this->verify_ajax_request( 'ainp_nonce' );

		$user_id = get_current_user_id();
		if ( $user_id ) {
			$result = update_user_meta( $user_id, 'ainp_hide_welcome_panel', true );

			if ( false === $result ) {
				$this->plugin->logger->add_log_entry( 'error', 'Failed to update user meta for dismissing welcome panel.', 'User ID: ' . $user_id );
				wp_send_json_error( array( 'message' => 'Failed to save preference.' ) );
			} elseif ( is_numeric( $result ) ) {
				$this->plugin->logger->add_log_entry( 'info', 'Successfully updated user meta for dismissing welcome panel.', 'User ID: ' . $user_id );
				wp_send_json_success();
			} else {
				$this->plugin->logger->add_log_entry( 'info', 'User meta for dismissing welcome panel was already set.', 'User ID: ' . $user_id );
				wp_send_json_success();
			}
		} else {
			$this->plugin->logger->add_log_entry( 'error', 'Could not get user ID in dismiss welcome panel AJAX handler.' );
			wp_send_json_error( array( 'message' => 'Could not identify user.' ) );
		}
		wp_die();
	}

} // End Class AINP_Ajax