<?php

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

abstract class AIEO_Batch_Runner {

	
	const RUNNER_ID = '';

	
	const MAX_RETRIES = 10;

	
	const STALE_AFTER = 1800; 

	
	private static $booted = array();

	
	abstract protected static function do_batch( array $args );

	
	protected static function stream_key( array $args ) {
		return isset( $args[0] ) && is_scalar( $args[0] ) ? (string) $args[0] : 'default';
	}

	
	
	

	public static function hook() {
		return 'aieo_' . static::RUNNER_ID . '_tick';
	}

	protected static function opt_running() {
		return 'aieo_' . static::RUNNER_ID . '_running';
	}

	protected static function opt_progress() {
		return 'aieo_' . static::RUNNER_ID . '_progress';
	}

	
	
	

	
	public static function bootstrap_runner() {
		$cls = static::class;
		if ( ! empty( self::$booted[ $cls ] ) ) {
			return;
		}
		self::$booted[ $cls ] = true;
		add_action( static::hook(), array( $cls, 'tick_action' ), 10, 10 );
	}

	
	public static function start_streams( array $streams, $enqueue = true ) {
		global $wpdb;
		$keys = array();
		foreach ( $streams as $args ) {
			$keys[] = static::stream_key( (array) $args );
		}
		if ( empty( $keys ) ) {
			return array( 'started' => false, 'streams' => array(), 'reason' => 'no_streams' );
		}

		
		
		
		$claim = 'aieo_' . static::RUNNER_ID . '_start';
		if ( 1 !== (int) $wpdb->get_var( $wpdb->prepare( 'SELECT GET_LOCK(%s, 2)', $claim ) ) ) {
			return array( 'started' => false, 'streams' => $keys, 'reason' => 'already_running' );
		}
		try {
			$running = get_option( static::opt_running() );
			if ( is_array( $running ) && ! empty( $running['active'] ) && ! static::run_is_stale( $running ) ) {
				return array( 'started' => false, 'streams' => $keys, 'reason' => 'already_running' );
			}
			update_option( static::opt_running(), array(
				'active'     => 1,
				'streams'    => $keys,
				'started_at' => gmdate( 'Y-m-d H:i:s' ),
			), false );
			update_option( static::opt_progress(), array(), false );
		} finally {
			$wpdb->query( $wpdb->prepare( 'SELECT RELEASE_LOCK(%s)', $claim ) );
		}

		if ( $enqueue ) {
			foreach ( $streams as $args ) {
				static::enqueue_tick( (array) $args, 0 );
			}
		}
		return array( 'started' => true, 'streams' => $keys, 'reason' => $enqueue ? 'queued' : 'claimed' );
	}

	
	protected static function run_is_stale( array $running ) {
		$latest = strtotime( (string) ( $running['started_at'] ?? '' ) . ' UTC' );
		$prog   = get_option( static::opt_progress() );
		if ( is_array( $prog ) ) {
			foreach ( $prog as $row ) {
				$t = isset( $row['updated'] ) ? strtotime( (string) $row['updated'] . ' UTC' ) : false;
				if ( false !== $t && $t > (int) $latest ) {
					$latest = $t;
				}
			}
		}
		if ( false === $latest || $latest <= 0 ) {
			return true; 
		}
		return ( time() - $latest ) > static::STALE_AFTER;
	}

	
	public static function tick_action() {
		static::run_tick( func_get_args() );
	}

	
	protected static function run_tick( array $args ) {
		$res = static::execute_tick( $args );
		if ( 'continue' === $res['status'] ) {
			static::enqueue_tick( $args, 0 );
		} elseif ( 'retry' === $res['status'] ) {
			static::enqueue_tick( $args, (int) $res['retry_in'] );
		}
	}

	
	public static function tick_once( array $args ) {
		return static::execute_tick( $args );
	}

	
	protected static function execute_tick( array $args ) {
		global $wpdb;
		$stream = static::stream_key( $args );
		$lock   = 'aieo_' . static::RUNNER_ID . '_' . md5( $stream );
		if ( 1 !== (int) $wpdb->get_var( $wpdb->prepare( 'SELECT GET_LOCK(%s, 0)', $lock ) ) ) {
			
			return array( 'status' => 'locked', 'retry_in' => 0, 'stream' => $stream );
		}
		try {
			$res       = static::do_batch( $args );
			$remaining = max( 0, (int) ( $res['remaining'] ?? 0 ) );
			$total     = (int) ( $res['total'] ?? 0 );
			$row       = array(
				'remaining' => $remaining,
				'total'     => $total,
				'done'      => max( 0, $total - $remaining ),
				'updated'   => gmdate( 'Y-m-d H:i:s' ),
			);
			if ( isset( $res['extra'] ) && is_array( $res['extra'] ) ) {
				$row = array_merge( $row, $res['extra'] );
			}

			if ( ! empty( $res['success'] ) && $remaining > 0 ) {
				$row['retries'] = 0; 
				static::update_progress( $stream, $row );
				return array( 'status' => 'continue', 'retry_in' => 0, 'stream' => $stream );
			}
			if ( empty( $res['success'] ) && (int) ( $res['retry_in'] ?? 0 ) > 0 ) {
				$retries        = static::stream_retries( $stream ) + 1;
				$row['retries'] = $retries;
				static::update_progress( $stream, $row );
				if ( $retries <= static::MAX_RETRIES ) {
					return array( 'status' => 'retry', 'retry_in' => (int) $res['retry_in'], 'stream' => $stream );
				}
				static::mark_stream_done( $stream, 'retries_exhausted' );
				return array( 'status' => 'failed', 'retry_in' => 0, 'stream' => $stream );
			}
			static::update_progress( $stream, $row );
			
			
			$reason = empty( $res['success'] ) ? 'failed' : ( $remaining > 0 ? 'stopped' : '' );
			static::mark_stream_done( $stream, $reason );
			return array(
				'status'   => empty( $res['success'] ) ? 'failed' : 'done',
				'retry_in' => 0,
				'stream'   => $stream,
			);
		} catch ( \Throwable $e ) {
			if ( function_exists( 'aieo_debug_log' ) ) {
				aieo_debug_log( get_called_class() . ' tick failed (' . $stream . '): ' . $e->getMessage() );
			}
			static::mark_stream_done( $stream, 'exception' ); 
			return array( 'status' => 'failed', 'retry_in' => 0, 'stream' => $stream );
		} finally {
			$wpdb->query( $wpdb->prepare( 'SELECT RELEASE_LOCK(%s)', $lock ) );
		}
	}

	
	protected static function enqueue_tick( array $args, $delay = 0 ) {
		$delay = max( 0, (int) $delay );
		if ( 0 === $delay && function_exists( 'as_enqueue_async_action' ) ) {
			as_enqueue_async_action( static::hook(), $args, 'aieo' );
		} elseif ( function_exists( 'as_schedule_single_action' ) ) {
			as_schedule_single_action( time() + max( 5, $delay ), static::hook(), $args, 'aieo' );
		} else {
			wp_schedule_single_event( time() + max( 5, $delay ), static::hook(), $args );
		}
	}

	
	
	

	
	protected static function with_progress_lock( $fn ) {
		global $wpdb;
		$lock = 'aieo_' . static::RUNNER_ID . '_progress';
		$got  = ( 1 === (int) $wpdb->get_var( $wpdb->prepare( 'SELECT GET_LOCK(%s, 3)', $lock ) ) );
		try {
			return $fn(); 
		} finally {
			if ( $got ) {
				$wpdb->query( $wpdb->prepare( 'SELECT RELEASE_LOCK(%s)', $lock ) );
			}
		}
	}

	protected static function update_progress( $stream, array $data ) {
		static::with_progress_lock( static function () use ( $stream, $data ) {
			$prog = get_option( static::opt_progress() );
			$prog = is_array( $prog ) ? $prog : array();
			$prev = ( isset( $prog[ $stream ] ) && is_array( $prog[ $stream ] ) ) ? $prog[ $stream ] : array();
			
			
			$prog[ $stream ] = array_merge( $prev, $data );
			update_option( static::opt_progress(), $prog, false );
		} );
	}

	protected static function stream_retries( $stream ) {
		$prog = get_option( static::opt_progress() );
		return ( is_array( $prog ) && isset( $prog[ $stream ]['retries'] ) ) ? (int) $prog[ $stream ]['retries'] : 0;
	}

	
	protected static function mark_stream_done( $stream, $reason = '' ) {
		static::with_progress_lock( static function () use ( $stream, $reason ) {
			$prog = get_option( static::opt_progress() );
			$prog = is_array( $prog ) ? $prog : array();
			if ( ! isset( $prog[ $stream ] ) ) {
				$prog[ $stream ] = array();
			}
			$prog[ $stream ]['remaining'] = isset( $prog[ $stream ]['remaining'] ) ? (int) $prog[ $stream ]['remaining'] : 0;
			$prog[ $stream ]['finished']  = 1;
			if ( '' !== $reason ) {
				$prog[ $stream ]['stopped_reason'] = $reason;
			}
			$prog[ $stream ]['updated'] = gmdate( 'Y-m-d H:i:s' );
			update_option( static::opt_progress(), $prog, false );

			$running = get_option( static::opt_running() );
			if ( is_array( $running ) && ! empty( $running['active'] ) ) {
				
				
				
				
				
				
				$stream_keys = array();
				if ( ! empty( $running['streams'] ) && is_array( $running['streams'] ) ) {
					$stream_keys = $running['streams'];
				} elseif ( ! empty( $running['post_types'] ) && is_array( $running['post_types'] ) ) {
					$stream_keys = $running['post_types'];
				} else {
					$stream_keys = array_keys( $prog );
				}
				$all_done = true;
				foreach ( $stream_keys as $key ) {
					if ( empty( $prog[ $key ]['finished'] ) ) {
						$all_done = false;
						break;
					}
				}
				if ( $all_done ) {
					$running['active']   = 0;
					$running['ended_at'] = gmdate( 'Y-m-d H:i:s' );
					update_option( static::opt_running(), $running, false );
				}
			}
		} );
	}

	
	public static function runner_status() {
		$running = get_option( static::opt_running() );
		return array(
			'running'  => (bool) ( is_array( $running ) ? ( $running['active'] ?? 0 ) : 0 ),
			'progress' => (array) get_option( static::opt_progress(), array() ),
			
			
			
			
			
			'started_at' => (string) ( is_array( $running ) ? ( $running['started_at'] ?? '' ) : '' ),
			'ended_at'   => (string) ( is_array( $running ) ? ( $running['ended_at'] ?? '' ) : '' ),
		);
	}
}