<?php

function trackPurchaseGA4($order, $orderId, $currentState)
{

    if ($currentState !== 'order-created') {
        logDebug("Skipping event because state is $currentState");
        return;
    }

    $orderId = str_replace('-01', '', $order['orderId']);

    $lockFile = sys_get_temp_dir() . "/ga4_lock_{$orderId}.lock";
    $fp = fopen($lockFile, 'c');
    if (!$fp || !flock($fp, LOCK_EX | LOCK_NB)) {
        logDebug("Order $orderId is already being processed. Lock in place.");
        return;
    }

    try {

        if (isOrderAlreadyTracked($orderId)) {
            logDebug("Order $orderId already tracked. Skipping GA4.");
            return;
        }

        $currency = 'BRL';
        $affiliation = $order['sellers'][0]['name'] ?? 'Artelasse';

        $totalValue = ($order['value'] ?? 0) / 100;
        $totalValue = round($totalValue, 2);
        $totalValue = number_format($totalValue, 2, '.', '');

        $shippingValue = 0;
        foreach ($order['totals'] ?? [] as $total) {
            if ($total['id'] === 'Shipping') {
                $shippingValue = $total['value'] / 100;
                break;
            }
        }

        $items = [];
        foreach ($order['items'] ?? [] as $item) {
            $id = (string)($item['id'] ?? '');
            $variant = (string)($item['refId'] ?? $id);
            $quantity = (int)($item['quantity'] ?? 1);
            $brand = $item['additionalInfo']['brandName'] ?? 'ARTELASSE';
            $categories = $item['additionalInfo']['categories'] ?? [];

            $category1 = $categories[0]['name'] ?? null;
            $category2 = $categories[1]['name'] ?? null;

            $unitPrice = ($item['sellingPrice'] ?? 0) / 100;
            $unitPrice = round($unitPrice, 2);
            $unitPrice = number_format($unitPrice, 2, '.', '');

            // Differentiate items by ID + Variant
            $key = $id . '-' . $variant;
            if (isset($items[$key])) {
                $items[$key]['quantity'] += $quantity;
            } else {
                $items[$key] = [
                    'item_id' => $id,
                    'item_name' => $item['name'] ?? '',
                    'item_brand' => $brand,
                    'item_variant' => $variant,
                    'price' => $unitPrice,
                    'quantity' => $quantity,
                    'item_category' => $category1 ?? '',
                    'item_category2' => $category2 ?? ''
                ];
            }
        }

        $clientId = '000000.000000';
        $sessionId = (int)(microtime(true) * 1000);

        if (!empty($order['marketingData']['utmiPart'])) {
            $utmiPartRaw = $order['marketingData']['utmiPart'];
            $utmiPartDecoded = json_decode($utmiPartRaw, true);

            $clientId = $utmiPartDecoded[0]['client_id'];
            $sessionId = $utmiPartDecoded[0]['session_id'];
        }

        logDebug("UTM PART: " . json_encode($order['marketingData']));

        $clientEmail = $order['clientProfileData']['email'] ?? '';
        $timestampMicros = strtotime($order['creationDate'] ?? 'now') * 1000000;
        $utm = $order['marketingData'] ?? [];

        $utm_source = $utm['utmSource'] ?? '';

        $params = [
            "transaction_id" => str_replace('-01', '', $orderId),
            "affiliation" => $affiliation,
            "value" => floatval($totalValue),
            "currency" => $currency,
            "shipping" => $shippingValue,
            "tax" => 0,
            "payment_type" => $order['paymentData']['transactions'][0]['payments'][0]['paymentSystemName'] ?? 'unknown',
            "coupon" => $utm['coupon'] ?? '',
            "engagement_time_msec" => 100,
            "session_id" => intval($sessionId),
            "purchase_source" => "server",
            "items" => array_values($items)
        ];

        if (!empty($shippingTier)) {
            $params['shipping_tier'] = $shippingTier;
        }

        if (!empty($shippingEstimated)) {
            $params['shipping_estimate'] = $shippingEstimated;
        }

        $payload = [
            "client_id" => $clientId,
            "timestamp_micros" => $timestampMicros,
            "user_properties" => [
                "email" => ["value" => $customerEmailDecrypted ??  $clientEmail],
                "utm_source" => ["value" => $utm['utmSource'] ?? ''],
                "utm_medium" => ["value" => $utm['utmMedium'] ?? ''],
                "utm_campaign" => ["value" => $utm['utmCampaign'] ?? ''],
                "utm_term" => ["value" => $utm['utmTerm'] ?? ''],
                "utm_content" => ["value" =>  $utm['utmContent'] ?? ''],
            ],
            "events" => [[
                "name" => "purchase",
                "params" => $params
            ]]
        ];

        //$measurement_id = 'G-H1FVEVWLLQ';
        //$api_secret = 'wI6--Vh_RlKRucKFOtTrJQ';
        $measurement_id = 'G-9CMQYGE1DQ';
        $api_secret = 'noGnn87DQLaWX3zHgRnR7g';

        $ga4Url = "https://www.google-analytics.com/mp/collect?measurement_id=$measurement_id&api_secret=$api_secret&cs={$utm_source}";

        $response = sendGA4Request($ga4Url, $payload);
        logDebug("GA4 Payload Sent: " . json_encode($payload));
        logDebug("GA4 Response: " . $response);

        $saveSuccess = saveOrderTracked($orderId);
        if ($saveSuccess) {
            logDebug("Order $orderId successfully saved to Master Data.");
        } else {
            logDebug("Failed to save order $orderId to Master Data.");
        }
    } finally {
        flock($fp, LOCK_UN);
        fclose($fp);
        if (file_exists($lockFile)) {
            unlink($lockFile);
        }
    }
}