<?php

declare(strict_types=1);

namespace Agent001\Sync;

\defined( 'ABSPATH' ) || exit;

use Agent001\Admin\SyncProgress;
use Agent001\Config\Settings;
use Agent001\Http\Client;

final class IndexingMonitor
{
    private const CHECK_INTERVAL_SECONDS = 5;
    private const TIMEOUT_SECONDS        = 7200;

    private Settings $settings;

    private Client $http;

    private SyncProgress $progress;

    public function __construct( Settings $settings, Client $http, SyncProgress $progress )
    {
        $this->settings = $settings;
        $this->http     = $http;
        $this->progress = $progress;
    }

    public function check(): void
    {
        $progress = $this->progress->current();
        if ( $progress['phase'] !== SyncProgress::PHASE_INDEXING ) {
            return;
        }

        $sessionId = (string) ( $progress['session_id'] ?? '' );
        $processed = (int) $progress['processed'];
        if ( $sessionId === '' ) {
            $this->progress->fail( \__( 'Synchronization state was lost. Please start the synchronization again.', 'agent001-support-assistant-for-woocommerce' ) );
            return;
        }

        if ( time() - (int) ( $progress['checked_at'] ?? 0 ) < self::CHECK_INTERVAL_SECONDS ) {
            return;
        }

        $result = $this->http->getJson(
            $this->settings->syncSessionUrl( $sessionId ),
            [
                'X-API-Key'  => $this->settings->apiKey(),
                'Accept'     => 'application/json',
                'User-Agent' => 'Agent001/' . ( \defined( 'AGENT001_VERSION' ) ? \AGENT001_VERSION : 'dev' ),
            ]
        );

        if ( ! $result->isSuccess() ) {
            $this->handleFailedCheck( $result->status(), $result->error(), (int) ( $progress['indexing_since'] ?? 0 ), $progress );
            return;
        }

        $data   = json_decode( $result->body(), true );
        $status = is_array( $data ) ? (string) ( $data['status'] ?? '' ) : '';

        if ( $status === 'succeeded' ) {
            $this->progress->finish(
                true,
                sprintf(
                    /* translators: %d: number of products synchronized */
                    \_n( 'Synced %d product.', 'Synced %d products.', $processed, 'agent001-support-assistant-for-woocommerce' ),
                    $processed
                ),
                $processed
            );
            return;
        }

        if ( $status === 'failed' ) {
            $error = is_string( $data['error'] ?? null ) ? \sanitize_text_field( $data['error'] ) : '';
            $this->progress->finish(
                false,
                $error !== ''
                    ? \__( 'Indexing failed:', 'agent001-support-assistant-for-woocommerce' ) . ' ' . $error
                    : \__( 'Indexing failed. Please try again.', 'agent001-support-assistant-for-woocommerce' ),
                $processed
            );
            return;
        }

        if ( $this->timedOut( (int) ( $progress['indexing_since'] ?? 0 ) ) ) {
            $this->failTimedOut();
            return;
        }

        $this->progress->indexingChecked(
            (int) ( $data['processed_batches'] ?? 0 ),
            isset( $data['expected_batches'] ) ? (int) $data['expected_batches'] : null
        );
    }

    /**
     * @param array<string, mixed> $progress
     */
    private function handleFailedCheck( int $status, string $error, int $indexingSince, array $progress ): void
    {
        if ( $status === 404 ) {
            $this->progress->fail( \__( 'This synchronization was replaced by a newer one. Please check the latest synchronization.', 'agent001-support-assistant-for-woocommerce' ) );
            return;
        }

        if ( $status >= 400 && $status < 500 && $status !== 408 && $status !== 429 ) {
            $this->progress->fail( $error );
            return;
        }

        if ( $this->timedOut( $indexingSince ) ) {
            $this->failTimedOut();
            return;
        }

        $this->progress->indexingChecked(
            (int) ( $progress['processed_batches'] ?? 0 ),
            isset( $progress['expected_batches'] ) ? (int) $progress['expected_batches'] : null
        );
    }

    private function timedOut( int $indexingSince ): bool
    {
        return $indexingSince > 0 && time() - $indexingSince > self::TIMEOUT_SECONDS;
    }

    private function failTimedOut(): void
    {
        $this->progress->fail( \__( 'Indexing is taking longer than expected. Check the synchronization status in Agent001.', 'agent001-support-assistant-for-woocommerce' ) );
    }
}