<?php
/**
 * Run item entity.
 *
 * @package Recast\WCS
 */

namespace Recast\WCS\Run;

use Recast\WCS\State\Fields;
use Recast\WCS\Support\Gateways;
use Recast\WCS\Support\Json;

defined( 'ABSPATH' ) || exit;

/**
 * One subscription inside a run, with its diff, states, hashes and status.
 */
final class RunItem {

	/**
	 * Row ID.
	 *
	 * @var int
	 */
	public $id = 0;
	/**
	 * Run ID.
	 *
	 * @var int
	 */
	public $run_id = 0;
	/**
	 * Subscription ID.
	 *
	 * @var int
	 */
	public $subscription_id = 0;
	/**
	 * Position in the cohort snapshot.
	 *
	 * @var int
	 */
	public $position = 0;
	/**
	 * Idempotency key.
	 *
	 * @var string
	 */
	public $idem_key = '';
	/**
	 * Item status.
	 *
	 * @var string
	 */
	public $status = ItemStatus::PENDING;
	/**
	 * Fingerprint at preview.
	 *
	 * @var string|null
	 */
	public $before_hash = null;
	/**
	 * Fingerprint after apply (predicted at preview, actual after apply).
	 *
	 * @var string|null
	 */
	public $after_hash = null;
	/**
	 * State at preview.
	 *
	 * @var array<string, mixed>
	 */
	public $before_state = array();
	/**
	 * State after apply.
	 *
	 * @var array<string, mixed>
	 */
	public $after_state = array();
	/**
	 * Predicted field changes.
	 *
	 * @var array<int, array<string, mixed>>
	 */
	public $diff = array();
	/**
	 * Warnings from the operation.
	 *
	 * @var array<int, array{code: string, message: string}>
	 */
	public $warnings = array();
	/**
	 * Error details when stale, failed or invalid.
	 *
	 * @var array<string, mixed>|null
	 */
	public $error = null;
	/**
	 * Apply attempts.
	 *
	 * @var int
	 */
	public $attempts = 0;
	/**
	 * Token of the worker that claimed the row.
	 *
	 * @var string|null
	 */
	public $worker_token = null;
	/**
	 * Claim time.
	 *
	 * @var string|null
	 */
	public $claimed_at = null;
	/**
	 * Apply time.
	 *
	 * @var string|null
	 */
	public $applied_at = null;
	/**
	 * Undo run that reverted this item.
	 *
	 * @var int|null
	 */
	public $reverted_by_run_id = null;

	/**
	 * Builds from a database row.
	 *
	 * @param array<string, mixed>|object $row Row.
	 * @return RunItem
	 */
	public static function from_row( $row ) {
		$row  = (array) $row;
		$item = new self();
		foreach ( array( 'id', 'run_id', 'subscription_id', 'position', 'attempts' ) as $int ) {
			$item->$int = isset( $row[ $int ] ) ? (int) $row[ $int ] : 0;
		}
		$item->idem_key           = isset( $row['idem_key'] ) ? (string) $row['idem_key'] : '';
		$item->status             = isset( $row['status'] ) ? (string) $row['status'] : ItemStatus::PENDING;
		$item->before_hash        = isset( $row['before_hash'] ) ? $row['before_hash'] : null;
		$item->after_hash         = isset( $row['after_hash'] ) ? $row['after_hash'] : null;
		$item->before_state       = Json::decode( isset( $row['before_state'] ) ? $row['before_state'] : null, array() );
		$item->after_state        = Json::decode( isset( $row['after_state'] ) ? $row['after_state'] : null, array() );
		$item->diff               = Json::decode( isset( $row['diff'] ) ? $row['diff'] : null, array() );
		$item->warnings           = Json::decode( isset( $row['warnings'] ) ? $row['warnings'] : null, array() );
		$item->error              = Json::decode( isset( $row['error'] ) ? $row['error'] : null, null );
		$item->worker_token       = isset( $row['worker_token'] ) ? $row['worker_token'] : null;
		$item->claimed_at         = isset( $row['claimed_at'] ) ? $row['claimed_at'] : null;
		$item->applied_at         = isset( $row['applied_at'] ) ? $row['applied_at'] : null;
		$item->reverted_by_run_id = isset( $row['reverted_by_run_id'] ) ? (int) $row['reverted_by_run_id'] : null;
		return $item;
	}

	/**
	 * REST form.
	 *
	 * @return array<string, mixed>
	 */
	public function to_array() {
		return array(
			'id'                 => $this->id,
			'run_id'             => $this->run_id,
			'subscription_id'    => $this->subscription_id,
			'position'           => $this->position,
			'status'             => $this->status,
			'changed_fields'     => array_values( wp_list_pluck( $this->diff, 'field' ) ),
			'diff'               => $this->diff_for_display(),
			'before'             => $this->before_state,
			'after'              => $this->after_state,
			'warnings'           => $this->warnings,
			'error'              => $this->error,
			'attempts'           => $this->attempts,
			'applied_at'         => $this->applied_at,
			'reverted_by_run_id' => $this->reverted_by_run_id,
		);
	}

	/**
	 * The change list for the UI, with current labels. After apply, each written field shows the value
	 * WooCommerce saved, not the value predicted at preview: tax is recalculated and
	 * rounded per line on save, so the two can differ by a cent.
	 *
	 * @return array<int, array<string, mixed>>
	 */
	public function diff_for_display() {
		$saved  = null !== $this->applied_at && ! empty( $this->after_state );
		$fields = wp_list_pluck( $this->diff, 'field' );
		$diff   = array();
		foreach ( $this->diff as $change ) {
			$field = isset( $change['field'] ) ? (string) $change['field'] : '';
			if ( '' === $field ) {
				continue;
			}
			// The gateway row already shows the name; the title row would repeat it.
			if ( Fields::PAYMENT_METHOD_TITLE === $field && in_array( Fields::PAYMENT_METHOD, $fields, true ) ) {
				continue;
			}
			// Labels follow the current wording, not the wording stored when the batch was made.
			$change['label'] = Fields::label( $field );
			if ( $saved && array_key_exists( $field, $this->after_state ) ) {
				$change['after'] = $this->after_state[ $field ];
			}
			if ( Fields::PAYMENT_METHOD === $field ) {
				$change['before_text'] = Gateways::name( (string) $change['before'], $this->state_value( $this->before_state, Fields::PAYMENT_METHOD_TITLE ) );
				$change['after_text']  = Gateways::name( (string) $change['after'], $this->state_value( $this->after_state, Fields::PAYMENT_METHOD_TITLE ) );
			}
			$parsed = Fields::parse( $field );
			if ( $parsed && 'item' === $parsed['kind'] && in_array( $parsed['prop'], array( 'product_id', 'variation_id' ), true ) ) {
				foreach ( array( 'before', 'after' ) as $side ) {
					$id = isset( $change[ $side ] ) ? (int) $change[ $side ] : 0;
					if ( $id <= 0 ) {
						// No variation: the app shows "Not set".
						$change[ $side ] = null;
						continue;
					}
					$change[ $side . '_text' ] = self::product_name( $id );
				}
			}
			$diff[] = $change;
		}
		return $diff;
	}

	/**
	 * The name of a product or variation, or "#id" when the store no longer has it.
	 *
	 * @param int $id Product or variation ID.
	 * @return string
	 */
	private static function product_name( $id ) {
		$product = function_exists( 'wc_get_product' ) ? wc_get_product( $id ) : null;
		return $product ? wp_strip_all_tags( $product->get_name() ) : '#' . $id;
	}

	/**
	 * A value from a recorded state, or an empty string.
	 *
	 * @param array<string, mixed> $state State.
	 * @param string               $field Field key.
	 * @return string
	 */
	private function state_value( array $state, $field ) {
		return isset( $state[ $field ] ) && is_scalar( $state[ $field ] ) ? (string) $state[ $field ] : '';
	}
}