<?php
/**
 * Admin Background Controller.
 *
 * Handles background processing and auto-scheduling in admin area.
 *
 * @package Accessibility_Audio_TTS
 */

namespace Accessibility_Audio_TTS\Admin;

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

/**
 * Admin Background Controller - Handles background processing and auto-scheduling.
 * Single Responsibility: Managing background tasks, auto scheduling, and queue processing.
 */
class Admin_Background_Controller {

	/**
	 * Cron manager responsible for background jobs.
	 *
	 * @var Admin_Cron_Manager
	 */
	private $cron_manager;

	/**
	 * Constructor with dependency injection.
	 *
	 * @param Admin_Cron_Manager|null $cron_manager Cron manager instance.
	 */
	public function __construct( ?Admin_Cron_Manager $cron_manager = null ) {
		$this->cron_manager = $cron_manager ?? new Admin_Cron_Manager();
	}

	/**
	 * Process background posts - delegates to cron manager
	 */
	public function process_background_posts() {
		$this->cron_manager->process_background_posts( func_get_args() );
	}

	/**
	 * Execute auto trigger - delegates to cron manager
	 */
	public function execute_auto_trigger() {
		$this->cron_manager->execute_auto_trigger();
	}

	/**
	 * Auto schedule post conversion - delegates to cron manager
	 */
	public function auto_schedule_post_conversion() {
		$args    = func_get_args();
		$post_id = isset( $args[0] ) ? $args[0] : null;
		$post    = isset( $args[1] ) ? $args[1] : null;
		$this->cron_manager->auto_schedule_post_conversion( $post_id, $post );
	}

	/**
	 * Process auto queue - delegates to cron manager
	 */
	public function process_auto_queue() {
		$this->cron_manager->process_auto_queue();
	}

	/**
	 * Check if background processing is enabled.
	 *
	 * @return bool True if background processing is enabled.
	 */
	public function is_background_processing_enabled() {
		$background_enabled = get_option( 'accessibility_audio_tts_background_enabled', '1' );
		if ( '1' !== $background_enabled ) {
			return false;
		}
		$processing_mode = get_option( 'accessibility_audio_tts_processing_mode', 'wp_cron' );
		return 'wp_cron' === $processing_mode;
	}

	/**
	 * Get background processing status
	 *
	 * @return array Background processing status information
	 */
	public function get_background_status() {
		$status = array(
			'enabled'                 => $this->is_background_processing_enabled(),
			'next_background_run'     => wp_next_scheduled( 'accessibility_audio_tts_process_background_posts' ),
			'next_auto_trigger'       => wp_next_scheduled( 'accessibility_audio_tts_execute_auto_trigger' ),
			'next_queue_process'      => wp_next_scheduled( 'accessibility_audio_tts_process_queue' ),
			'auto_conversion_enabled' => get_option( 'accessibility_audio_tts_auto_conversion', false ),
			'processing_mode'         => get_option( 'accessibility_audio_tts_processing_mode', 'wp_cron' ),
		);

		// Format timestamps for display.
		if ( $status['next_background_run'] ) {
			$status['next_background_run_formatted'] = gmdate( 'Y-m-d H:i:s', $status['next_background_run'] );
		}

		if ( $status['next_auto_trigger'] ) {
			$status['next_auto_trigger_formatted'] = gmdate( 'Y-m-d H:i:s', $status['next_auto_trigger'] );
		}

		if ( $status['next_queue_process'] ) {
			$status['next_queue_process_formatted'] = gmdate( 'Y-m-d H:i:s', $status['next_queue_process'] );
		}

		return $status;
	}

	/**
	 * Schedule immediate background processing.
	 *
	 * @param array $post_ids Optional specific post IDs to process.
	 * @return bool Success status.
	 */
	public function schedule_immediate_processing( $post_ids = array() ) {
		if ( ! \Accessibility_Audio_TTS\Admin\Conversion_Processor::background_processing_enabled() ) {
			return false;
		}
		try {
			if ( empty( $post_ids ) ) {
				// Schedule general background processing.
				wp_schedule_single_event( time() + 5, 'accessibility_audio_tts_process_background_posts', array( array( 'post_ids' => array() ) ) );
				accessibility_audio_tts_debug_log( 'Admin_Background_Controller: Scheduled immediate general background processing' );
			} else {
				// Schedule specific posts.
				wp_schedule_single_event( time() + 5, 'accessibility_audio_tts_process_background_posts', array( array( 'post_ids' => $post_ids ) ) );
				accessibility_audio_tts_debug_log( 'Admin_Background_Controller: Scheduled immediate processing for ' . count( $post_ids ) . ' posts' );
			}

			return true;
		} catch ( \Exception $e ) {
			accessibility_audio_tts_debug_log( 'Admin_Background_Controller: Error scheduling immediate processing: ' . $e->getMessage() );
			return false;
		}
	}

	/**
	 * Cancel all scheduled background processing.
	 *
	 * @return bool Success status.
	 */
	public function cancel_all_background_processing() {
		try {
			// Cancel background posts processing.
			$timestamp = wp_next_scheduled( 'accessibility_audio_tts_process_background_posts' );
			while ( false !== $timestamp ) {
				wp_unschedule_event( $timestamp, 'accessibility_audio_tts_process_background_posts' );
				$timestamp = wp_next_scheduled( 'accessibility_audio_tts_process_background_posts' );
			}

			// Cancel auto trigger.
			$timestamp = wp_next_scheduled( 'accessibility_audio_tts_execute_auto_trigger' );
			while ( false !== $timestamp ) {
				wp_unschedule_event( $timestamp, 'accessibility_audio_tts_execute_auto_trigger' );
				$timestamp = wp_next_scheduled( 'accessibility_audio_tts_execute_auto_trigger' );
			}

			// Cancel queue processing.
			$timestamp = wp_next_scheduled( 'accessibility_audio_tts_process_queue' );
			while ( false !== $timestamp ) {
				wp_unschedule_event( $timestamp, 'accessibility_audio_tts_process_queue' );
				$timestamp = wp_next_scheduled( 'accessibility_audio_tts_process_queue' );
			}

			accessibility_audio_tts_debug_log( 'Admin_Background_Controller: All background processing cancelled' );
			return true;
		} catch ( \Exception $e ) {
			accessibility_audio_tts_debug_log( 'Admin_Background_Controller: Error cancelling background processing: ' . $e->getMessage() );
			return false;
		}
	}

	/**
	 * Get statistics about background processing.
	 *
	 * @return array Background processing statistics.
	 */
	public function get_background_statistics() {
		global $wpdb;

		try {
			// Get number of posts without audio.
			$cache_key_wo        = 'accessibility_audio_tts_bg_posts_without_audio';
			$posts_without_audio = wp_cache_get( $cache_key_wo, 'accessibility_audio_tts' );
			if ( false === $posts_without_audio ) {
				// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Aggregated admin stats (read-only; cached below)
				$posts_without_audio = $wpdb->get_var(
					$wpdb->prepare(
						"SELECT COUNT(p.ID)
						 FROM {$wpdb->posts} p
						 LEFT JOIN {$wpdb->postmeta} pm ON p.ID = pm.post_id AND pm.meta_key = %s
						 WHERE p.post_status = %s
						 AND p.post_type IN ('post', 'page')
						 AND pm.meta_id IS NULL",
						'accessibility_audio_tts_generated',
						'publish'
					)
				);
				wp_cache_set( $cache_key_wo, $posts_without_audio, 'accessibility_audio_tts', 120 );
			}

			// Get number of posts with audio.
			$cache_key_w      = 'accessibility_audio_tts_bg_posts_with_audio';
			$posts_with_audio = wp_cache_get( $cache_key_w, 'accessibility_audio_tts' );
			if ( false === $posts_with_audio ) {
				// phpcs:ignore WordPress.DB.DirectDatabaseQuery.DirectQuery, WordPress.DB.DirectDatabaseQuery.NoCaching -- Aggregated admin stats (read-only; cached below)
				$posts_with_audio = $wpdb->get_var(
					$wpdb->prepare(
						"SELECT COUNT(DISTINCT p.ID)
						 FROM {$wpdb->posts} p
						 INNER JOIN {$wpdb->postmeta} pm ON p.ID = pm.post_id
						 WHERE pm.meta_key = %s
						 AND pm.meta_value = %s
						 AND p.post_status = %s",
						'accessibility_audio_tts_generated',
						'1',
						'publish'
					)
				);
				wp_cache_set( $cache_key_w, $posts_with_audio, 'accessibility_audio_tts', 120 );
			}

			return array(
				'posts_without_audio'   => intval( $posts_without_audio ),
				'posts_with_audio'      => intval( $posts_with_audio ),
				'total_posts'           => intval( $posts_without_audio ) + intval( $posts_with_audio ),
				'completion_percentage' => intval( $posts_with_audio ) > 0 ?
					round( ( intval( $posts_with_audio ) / ( intval( $posts_without_audio ) + intval( $posts_with_audio ) ) ) * 100, 2 ) : 0,
			);
		} catch ( \Exception $e ) {
			accessibility_audio_tts_debug_log( 'Admin_Background_Controller: Error getting background statistics: ' . $e->getMessage() );
			return array(
				'posts_without_audio'   => 0,
				'posts_with_audio'      => 0,
				'total_posts'           => 0,
				'completion_percentage' => 0,
			);
		}
	}
}