<?php
declare(strict_types=1);

function derive_label_webhook_url(array $localEnv): string
{
    $explicit = env_value('N8N_LABEL_WEBHOOK_URL', $localEnv);
    if ($explicit !== '') {
        return $explicit;
    }

    $legacy = env_value('N8N_OUTBOUND_URL_ADRESSE', $localEnv);
    if ($legacy !== '' && str_contains(strtolower($legacy), 'adressetikette')) {
        return $legacy;
    }

    $base = env_value('N8N_BASE_URL', $localEnv);
    if ($base === '') {
        return '';
    }

    $root = preg_replace('#/api/v1/?$#', '', rtrim($base, '/'));
    if (!is_string($root) || $root === '') {
        return '';
    }

    return $root . '/webhook/naurua_erp_adressetikette';
}

function derive_excel_webhook_url(array $localEnv): string
{
    $explicit = env_value('N8N_EXCEL_WEBHOOK_URL', $localEnv);
    if ($explicit !== '') {
        return $explicit;
    }

    $legacy = env_value('N8N_OUTBOUND_URL_ADRESSE', $localEnv);
    if ($legacy !== '' && str_contains(strtolower($legacy), 'excel_befuellen')) {
        return $legacy;
    }

    $base = env_value('N8N_BASE_URL', $localEnv);
    if ($base === '') {
        return '';
    }

    $root = preg_replace('#/api/v1/?$#', '', rtrim($base, '/'));
    if (!is_string($root) || $root === '') {
        return '';
    }

    return $root . '/webhook/excel_befuellen';
}

function post_json(string $url, array $payload, array $headers = [], int $timeoutSeconds = 15): array
{
    $body = json_encode($payload, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES);
    if ($body === false) {
        return ['ok' => false, 'status' => 0, 'body' => '', 'error' => 'Could not encode payload'];
    }

    $headerLines = ['Content-Type: application/json'];
    foreach ($headers as $name => $value) {
        if ($name === '' || $value === '') {
            continue;
        }
        $headerLines[] = $name . ': ' . $value;
    }

    $context = stream_context_create([
        'http' => [
            'method' => 'POST',
            'header' => implode("\r\n", $headerLines),
            'content' => $body,
            'timeout' => $timeoutSeconds,
            'ignore_errors' => true,
        ],
    ]);

    $responseBody = @file_get_contents($url, false, $context);
    $responseHeaders = $http_response_header ?? [];

    $status = 0;
    if (isset($responseHeaders[0]) && preg_match('#HTTP/\S+\s+(\d{3})#', $responseHeaders[0], $m) === 1) {
        $status = (int) $m[1];
    }

    if ($responseBody === false) {
        $responseBody = '';
    }

    return [
        'ok' => $status >= 200 && $status < 300,
        'status' => $status,
        'body' => substr($responseBody, 0, 500),
        'error' => ($status === 0) ? 'Request failed or timed out' : '',
    ];
}

function build_n8n_webhook_headers(array $localEnv): array
{
    $headers = [];
    $secret = env_value('N8N_WEBHOOK_SECRET', $localEnv);
    if ($secret !== '') {
        $headers['X-Webhook-Secret'] = $secret;
        $headers['X-N8N-Secret'] = $secret;
        $headers['X-API-Key'] = $secret;
        $headers['Authorization'] = 'Bearer ' . $secret;
    }

    return $headers;
}

function trigger_shipping_label_flow(array $order, array $localEnv): array
{
    $url = derive_label_webhook_url($localEnv);
    if ($url === '') {
        return [
            'enabled' => false,
            'ok' => false,
            'message' => 'Label webhook URL not configured',
        ];
    }

    $headers = build_n8n_webhook_headers($localEnv);
    throttle_webhook_channel('label', 10);
    $result = post_json($url, $order, $headers, 20);

    return [
        'enabled' => true,
        'ok' => $result['ok'],
        'status' => $result['status'],
        'url' => $url,
        'message' => $result['ok'] ? 'Label webhook triggered' : ($result['error'] !== '' ? $result['error'] : 'Label webhook returned non-2xx'),
        'responseBody' => $result['body'],
    ];
}

function trigger_excel_webhook(string $externalRef, array $localEnv): array
{
    $url = derive_excel_webhook_url($localEnv);
    if ($url === '') {
        return [
            'enabled' => false,
            'ok' => false,
            'message' => 'Excel webhook URL not configured',
        ];
    }

    $headers = build_n8n_webhook_headers($localEnv);
    throttle_webhook_channel('excel', 5);
    $result = post_json($url, ['Bestellnummer' => $externalRef], $headers, 20);

    return [
        'enabled' => true,
        'ok' => $result['ok'],
        'status' => $result['status'],
        'url' => $url,
        'message' => $result['ok'] ? 'Excel webhook triggered' : ($result['error'] !== '' ? $result['error'] : 'Excel webhook returned non-2xx'),
        'responseBody' => $result['body'],
    ];
}

function dispatch_order_import_webhooks(PDO $pdo, array $localEnv, int $limit = 20): array
{
    $url = derive_excel_webhook_url($localEnv);
    if ($url === '') {
        return [
            'enabled' => false,
            'ok' => false,
            'processed' => 0,
            'sent' => 0,
            'failed' => 0,
            'deadLetter' => 0,
            'message' => 'Excel webhook URL not configured',
        ];
    }

    $headers = build_n8n_webhook_headers($localEnv);
    $limit = max(1, min(100, $limit));

    $summary = [
        'enabled' => true,
        'ok' => false,
        'processed' => 0,
        'sent' => 0,
        'failed' => 0,
        'deadLetter' => 0,
        'status' => 0,
        'url' => $url,
        'message' => 'No outbound order.imported event queued',
        'responseBody' => '',
    ];

    try {
        for ($i = 0; $i < $limit; $i++) {
            $pdo->beginTransaction();

        $stmt = $pdo->query(
            "SELECT id, payload, attempt_count
             FROM outbound_webhook_event
             WHERE event_type = 'order.imported'
               AND status IN ('pending', 'failed')
               AND next_attempt_at <= NOW()
             ORDER BY created_at ASC, id ASC
             LIMIT 1
             FOR UPDATE SKIP LOCKED"
        );
        $event = $stmt !== false ? $stmt->fetch(PDO::FETCH_ASSOC) : false;
        if (!is_array($event)) {
            $pdo->commit();
            break;
        }

        $eventId = (int) $event['id'];
        $attemptCount = max(0, (int) $event['attempt_count']) + 1;
        $payloadRaw = $event['payload'];
        $payload = [];
        if (is_string($payloadRaw) && $payloadRaw !== '') {
            try {
                $payload = json_decode($payloadRaw, true, 512, JSON_THROW_ON_ERROR);
            } catch (JsonException) {
                $payload = [];
            }
        } elseif (is_array($payloadRaw)) {
            $payload = $payloadRaw;
        }

        $externalRef = trim((string) ($payload['externalRef'] ?? ''));
        if ($externalRef === '') {
            $update = $pdo->prepare(
                "UPDATE outbound_webhook_event
                 SET status = 'dead_letter',
                     last_attempt_at = NOW(),
                     last_error = :last_error,
                     next_attempt_at = NOW(),
                     attempt_count = :attempt_count
                 WHERE id = :id"
            );
            $update->execute([
                ':last_error' => 'Missing externalRef in outbound payload',
                ':attempt_count' => $attemptCount,
                ':id' => $eventId,
            ]);

            $pdo->commit();
            $summary['processed']++;
            $summary['failed']++;
            $summary['deadLetter']++;
            $summary['ok'] = false;
            $summary['message'] = 'Outbound payload missing externalRef';
            continue;
        }

        throttle_webhook_channel('excel', 5);
        $result = post_json($url, ['Bestellnummer' => $externalRef], $headers, 20);

        $summary['processed']++;
        $summary['status'] = $result['status'];
        $summary['responseBody'] = $result['body'];

        if ($result['ok']) {
            $update = $pdo->prepare(
                "UPDATE outbound_webhook_event
                 SET status = 'sent',
                     last_attempt_at = NOW(),
                     last_error = NULL,
                     sent_at = NOW(),
                     next_attempt_at = NOW(),
                     attempt_count = :attempt_count
                 WHERE id = :id"
            );
            $update->execute([
                ':attempt_count' => $attemptCount,
                ':id' => $eventId,
            ]);

            $pdo->commit();
            $summary['sent']++;
            if ($summary['failed'] === 0) {
                $summary['ok'] = true;
            }
            $summary['message'] = 'Excel webhook triggered';
            continue;
        }

        $backoffSeconds = min(3600, 60 * (2 ** max(0, $attemptCount - 1)));
        $status = $attemptCount >= 5 ? 'dead_letter' : 'failed';
        $nextAttemptAt = (new DateTimeImmutable('now'))
            ->modify('+' . $backoffSeconds . ' seconds')
            ->format('Y-m-d H:i:s');
        $lastError = $result['error'] !== '' ? $result['error'] : ('HTTP ' . $result['status']);
        $update = $pdo->prepare(
            "UPDATE outbound_webhook_event
             SET status = :status,
                 last_attempt_at = NOW(),
                 last_error = :last_error,
                 next_attempt_at = :next_attempt_at,
                 attempt_count = :attempt_count
             WHERE id = :id"
        );
        $update->execute([
            ':status' => $status,
            ':last_error' => $lastError,
            ':next_attempt_at' => $nextAttemptAt,
            ':attempt_count' => $attemptCount,
            ':id' => $eventId,
        ]);

            $pdo->commit();
            $summary['failed']++;
            $summary['ok'] = false;
            if ($status === 'dead_letter') {
                $summary['deadLetter']++;
            }
            $summary['message'] = $lastError;
        }

        return $summary;
    } catch (Throwable $e) {
        if ($pdo->inTransaction()) {
            $pdo->rollBack();
        }

        $summary['ok'] = false;
        $summary['message'] = $e->getMessage();
        return $summary;
    }
}