<?php
/**
 * Background task
 *
 * @package WPFunnels\Batch
 */

namespace WPFunnels\Batch;

use WP_Background_Process;

/**
 * Background task
 *
 * @abstract
 *
 * @since 1.0.0
 */
abstract class Wpfnl_Background_Task extends WP_Background_Process {

	/**
	 * Current_item
	 *
	 * @var string
	 */
	protected $current_item;

	/**
	 * Provider
	 *
	 * @var string
	 */
	protected $provider;


	/**
	 * See if the batch limit has been exceeded.
	 *
	 * @return bool
	 */
	protected function batch_limit_exceeded() {
		return $this->time_exceeded() || $this->memory_exceeded();
	}

	/**
	 * Handle.
	 *
	 * Pass each queue item to the task handler, while remaining
	 * within server memory and time limit constraints.
	 */
	protected function handle() {
		$this->lock_process();
		do {
			$batch = $this->get_batch();

			foreach ( $batch->data as $key => $value ) {
				$task = $this->task( $value );

				if ( false !== $task ) {
					$batch->data[ $key ] = $task;
				} else {
					unset( $batch->data[ $key ] );
				}

				if ( $this->batch_limit_exceeded() ) {
					// Batch limits reached.
					break;
				}
			}

			// Update or delete current batch.
			if ( ! empty( $batch->data ) ) {
				$this->update( $batch->key, $batch->data );
			} else {
				$this->delete( $batch->key );
			}
		} while ( ! $this->batch_limit_exceeded() && ! $this->is_queue_empty() );

		$this->unlock_process();

		// Start next batch or complete process.
		if ( ! $this->is_queue_empty() ) {
			$this->dispatch();
		} else {
			$this->complete();
		}
	}


	/**
	 * Dispatch updater.
	 *
	 * Updater will still run via cron job if this fails for any reason.
	 */
	public function dispatch() {
		$dispatched = parent::dispatch();

		if ( is_wp_error( $dispatched ) ) {
			wp_die( esc_attr( $dispatched ) );
		}
	}


	/**
	 * Completes the batch operation.
	 *
	 * This method is called when the batch operation is completed.
	 * It triggers the 'on_batch_completed' event and invokes the parent's 'complete()' method.
	 *
	 * @since 1.0.0
	 */
	protected function complete() {
		$this->on_batch_completed();
		parent::complete();
	}

	/**
	 * Handles the 'batch_completed' event.
	 *
	 * This method is called when the batch operation is completed.
	 * You can override this method in child classes to perform additional actions after batch completion.
	 *
	 * @since 1.0.0
	 */
	private function on_batch_completed() {
	}
}