<?php
require_once __DIR__ . '/../helpers.php';
require_once __DIR__ . '/../config/stripe.php';
runAuth();

try {
    $data = readJsonBody();

    $businessID = (int) ($data['BusinessID'] ?? 0);
    $orderID = (int) ($data['OrderID'] ?? 0);
    $subtotal = (float) ($data['Subtotal'] ?? 0);
    $tax = (float) ($data['Tax'] ?? 0);
    $tip = (float) ($data['Tip'] ?? 0);
    $customerEmail = $data['CustomerEmail'] ?? '';

    if ($businessID === 0) apiAbort(['OK' => false, 'ERROR' => 'BusinessID is required']);
    if ($orderID === 0) apiAbort(['OK' => false, 'ERROR' => 'OrderID is required']);
    if ($subtotal <= 0) apiAbort(['OK' => false, 'ERROR' => 'Invalid subtotal']);

    $config = getStripeConfig();
    if (empty($config['secretKey'])) apiAbort(['OK' => false, 'ERROR' => 'Stripe is not configured']);

    // Get business Stripe account and fee settings
    $qBusiness = queryOne("SELECT StripeAccountID, StripeOnboardingComplete, Name, PayfritFee FROM Businesses WHERE ID = ?", [$businessID]);
    if (!$qBusiness) apiAbort(['OK' => false, 'ERROR' => 'Business not found']);

    // Get order details
    $qOrder = queryOne("
        SELECT o.DeliveryFee, o.OrderTypeID, o.GrantID, o.GrantOwnerBusinessID,
               o.GrantEconomicsType, o.GrantEconomicsValue, o.StripePaymentIntentID,
               o.UserID, o.BalanceApplied AS PrevBalanceApplied,
               u.StripeCustomerId, u.EmailAddress, u.FirstName, u.LastName, u.Balance
        FROM Orders o
        LEFT JOIN Users u ON u.ID = o.UserID
        WHERE o.ID = ?
    ", [$orderID]);

    $deliveryFee = 0;
    if ($qOrder && (int) $qOrder['OrderTypeID'] === 3) {
        $deliveryFee = (float) ($qOrder['DeliveryFee'] ?? 0);
    }

    // SP-SM: Resolve grant economics
    $grantOwnerFeeCents = 0;
    $grantOwnerBusinessID = 0;
    $grantID = 0;
    if ($qOrder && (int) ($qOrder['GrantID'] ?? 0) > 0) {
        $grantID = (int) $qOrder['GrantID'];
        $grantOwnerBusinessID = (int) ($qOrder['GrantOwnerBusinessID'] ?? 0);
        $grantEconType = $qOrder['GrantEconomicsType'] ?? 'none';
        $grantEconValue = (float) ($qOrder['GrantEconomicsValue'] ?? 0);

        if ($grantEconType === 'flat_fee' && $grantEconValue > 0) {
            $grantOwnerFeeCents = round($grantEconValue * 100);
        } elseif ($grantEconType === 'percent_of_orders' && $grantEconValue > 0) {
            $grantOwnerFeeCents = round($subtotal * ($grantEconValue / 100) * 100);
        }
    }

    $hasStripeConnect = (int) ($qBusiness['StripeOnboardingComplete'] ?? 0) === 1
        && !empty(trim($qBusiness['StripeAccountID'] ?? ''));

    // ============================================================
    // FEE CALCULATION (from Businesses.PayfritFee)
    // ============================================================
    $payfritFee = $qBusiness['PayfritFee'] ?? 0;
    if (!is_numeric($payfritFee) || $payfritFee <= 0) {
        apiAbort(['OK' => false, 'ERROR' => 'Business PayfritFee not configured']);
    }
    $customerFeePercent = (float) $payfritFee;
    $businessFeePercent = $customerFeePercent;
    $cardFeePercent = 0.029;
    $cardFeeFixed = 0.30;

    $payfritCustomerFee = $subtotal * $customerFeePercent;
    $payfritBusinessFee = $subtotal * $businessFeePercent;
    $totalBeforeCardFee = $subtotal + $tax + $tip + $deliveryFee + $payfritCustomerFee;

    // ============================================================
    // AUTO-APPLY USER BALANCE
    // ============================================================
    $balanceApplied = 0;
    $userBalance = (float) ($qOrder['Balance'] ?? 0);
    $orderUserID = (int) ($qOrder['UserID'] ?? 0);
    if ($userBalance > 0 && $orderUserID > 0) {
        $balanceApplied = round(min($userBalance, $totalBeforeCardFee) * 100) / 100;
        $adjustedTest = (($totalBeforeCardFee - $balanceApplied) + $cardFeeFixed) / (1 - $cardFeePercent);
        if ($adjustedTest < 0.50) {
            $maxBalance = $totalBeforeCardFee - ((0.50 * (1 - $cardFeePercent)) - $cardFeeFixed);
            $balanceApplied = round(max(0, min($userBalance, $maxBalance)) * 100) / 100;
        }
        if ($balanceApplied > 0) {
            queryTimed("UPDATE Orders SET BalanceApplied = ? WHERE ID = ?", [$balanceApplied, $orderID]);
        }
    }

    $adjustedBeforeCardFee = $totalBeforeCardFee - $balanceApplied;
    $totalCustomerPays = ($adjustedBeforeCardFee + $cardFeeFixed) / (1 - $cardFeePercent);
    $cardFee = $totalCustomerPays - $adjustedBeforeCardFee;

    $totalAmountCents = round($totalCustomerPays * 100);
    $totalPlatformFeeCents = round(($payfritCustomerFee + $payfritBusinessFee) * 100);

    // ============================================================
    // CHECK FOR EXISTING PAYMENTINTENT
    // ============================================================
    $existingPiId = $qOrder['StripePaymentIntentID'] ?? '';
    if (!empty(trim($existingPiId))) {
        $existingPi = stripeRequest('GET', "https://api.stripe.com/v1/payment_intents/$existingPiId");

        if (!isset($existingPi['error'])) {
            $piStatus = $existingPi['status'] ?? '';
            $reusableStates = ['requires_payment_method', 'requires_confirmation', 'requires_action'];

            if (in_array($piStatus, $reusableStates)) {
                if ((int) $existingPi['amount'] !== $totalAmountCents) {
                    $existingPi = stripeRequest('POST', "https://api.stripe.com/v1/payment_intents/$existingPiId", [
                        'amount' => $totalAmountCents,
                    ]);
                }

                jsonResponse([
                    'OK' => true,
                    'CLIENT_SECRET' => $existingPi['client_secret'],
                    'PAYMENT_INTENT_ID' => $existingPi['id'],
                    'PUBLISHABLE_KEY' => $config['publishableKey'],
                    'REUSED' => true,
                    'FEE_BREAKDOWN' => [
                        'SUBTOTAL' => $subtotal, 'TAX' => $tax, 'TIP' => $tip,
                        'DELIVERY_FEE' => $deliveryFee, 'PAYFRIT_FEE' => $payfritCustomerFee,
                        'CARD_FEE' => $cardFee, 'BALANCE_APPLIED' => $balanceApplied,
                        'TOTAL' => $totalCustomerPays,
                        'TOTAL_BEFORE_BALANCE' => ($balanceApplied > 0) ? $totalCustomerPays + $balanceApplied : 0,
                        'GRANT_OWNER_FEE_CENTS' => $grantOwnerFeeCents,
                    ],
                ]);
            } elseif ($piStatus === 'succeeded') {
                apiAbort(['OK' => false, 'ERROR' => 'already_paid', 'MESSAGE' => 'This order has already been paid.']);
            }
        }
        // Terminal or not found — clear and create new
        queryTimed("UPDATE Orders SET StripePaymentIntentID = NULL WHERE ID = ?", [$orderID]);
    }

    // ============================================================
    // STRIPE CUSTOMER (for saving payment methods)
    // ============================================================
    $stripeCustomerId = '';
    $orderUserID = (int) ($qOrder['UserID'] ?? 0);

    if ($orderUserID > 0) {
        $stripeCustomerId = $qOrder['StripeCustomerId'] ?? '';

        // Validate existing customer
        $needNewCustomer = empty(trim($stripeCustomerId));
        if (!$needNewCustomer) {
            $validateData = stripeRequest('GET', "https://api.stripe.com/v1/customers/$stripeCustomerId");
            if (isset($validateData['error']) || !isset($validateData['id'])) {
                $needNewCustomer = true;
            }
        }

        if ($needNewCustomer) {
            $customerParams = ['metadata[user_id]' => $orderUserID];
            $customerName = trim(($qOrder['FirstName'] ?? '') . ' ' . ($qOrder['LastName'] ?? ''));
            if (!empty($customerName)) $customerParams['name'] = $customerName;
            if (!empty(trim($qOrder['EmailAddress'] ?? ''))) $customerParams['email'] = $qOrder['EmailAddress'];

            $customerData = stripeRequest('POST', 'https://api.stripe.com/v1/customers', $customerParams);
            if (!isset($customerData['error']) && isset($customerData['id'])) {
                $stripeCustomerId = $customerData['id'];
                queryTimed("UPDATE Users SET StripeCustomerId = ? WHERE ID = ?", [$stripeCustomerId, $orderUserID]);
            }
        }
    }

    // ============================================================
    // CREATE PAYMENTINTENT
    // ============================================================
    $piParams = [
        'amount' => $totalAmountCents,
        'currency' => 'usd',
        'automatic_payment_methods[enabled]' => 'true',
        'metadata[order_id]' => $orderID,
        'metadata[business_id]' => $businessID,
        'description' => "Order #$orderID at " . $qBusiness['Name'],
    ];

    if (!empty(trim($stripeCustomerId))) {
        $piParams['customer'] = $stripeCustomerId;
        $piParams['setup_future_usage'] = 'off_session';
    }

    if ($hasStripeConnect) {
        $effectivePlatformFeeCents = $totalPlatformFeeCents + $grantOwnerFeeCents;
        $piParams['application_fee_amount'] = $effectivePlatformFeeCents;
        $piParams['transfer_data[destination]'] = $qBusiness['StripeAccountID'];
    }

    if ($grantOwnerFeeCents > 0) {
        $piParams['metadata[grant_id]'] = $grantID;
        $piParams['metadata[grant_owner_business_id]'] = $grantOwnerBusinessID;
        $piParams['metadata[grant_owner_fee_cents]'] = $grantOwnerFeeCents;
    }

    if (!empty($customerEmail)) {
        $piParams['receipt_email'] = $customerEmail;
    }

    $piHeaders = ['Idempotency-Key' => "pi-order-$orderID"];
    $piData = stripeRequest('POST', 'https://api.stripe.com/v1/payment_intents', $piParams, $piHeaders);

    if (isset($piData['error'])) {
        apiAbort(['OK' => false, 'ERROR' => $piData['error']['message']]);
    }

    // Store PaymentIntent ID on order
    queryTimed("UPDATE Orders SET StripePaymentIntentID = ? WHERE ID = ?", [$piData['id'], $orderID]);

    // Link PaymentIntent to worker payout ledger
    try {
        queryTimed("
            UPDATE WorkPayoutLedgers wpl
            INNER JOIN Tasks t ON t.ID = wpl.TaskID AND t.OrderID = ?
            SET wpl.StripePaymentIntentID = ?
            WHERE wpl.Status = 'pending_charge'
              AND wpl.StripePaymentIntentID IS NULL
        ", [$orderID, $piData['id']]);
    } catch (Exception $e) {
        // Non-fatal
    }

    // ============================================================
    // CREATE CHECKOUT SESSION (for iOS)
    // ============================================================
    $checkoutParams = [
        'mode' => 'payment',
        'line_items[0][price_data][currency]' => 'usd',
        'line_items[0][price_data][product_data][name]' => "Order #$orderID at " . $qBusiness['Name'],
        'line_items[0][price_data][unit_amount]' => $totalAmountCents,
        'line_items[0][quantity]' => '1',
        'success_url' => "payfrit://stripe-redirect?success=true&order_id=$orderID",
        'cancel_url' => "payfrit://stripe-redirect?success=false&error=cancelled&order_id=$orderID",
        'metadata[order_id]' => $orderID,
        'metadata[business_id]' => $businessID,
    ];

    if ($hasStripeConnect) {
        $effectivePlatformFeeCents = $totalPlatformFeeCents + $grantOwnerFeeCents;
        $checkoutParams['payment_intent_data[application_fee_amount]'] = $effectivePlatformFeeCents;
        $checkoutParams['payment_intent_data[transfer_data][destination]'] = $qBusiness['StripeAccountID'];
    }

    $checkoutData = stripeRequest('POST', 'https://api.stripe.com/v1/checkout/sessions', $checkoutParams);
    $checkoutUrl = $checkoutData['url'] ?? '';

    jsonResponse([
        'OK' => true,
        'CLIENT_SECRET' => $piData['client_secret'],
        'PAYMENT_INTENT_ID' => $piData['id'],
        'PUBLISHABLE_KEY' => $config['publishableKey'],
        'CHECKOUT_URL' => $checkoutUrl,
        'FEE_BREAKDOWN' => [
            'SUBTOTAL' => $subtotal,
            'TAX' => $tax,
            'TIP' => $tip,
            'DELIVERY_FEE' => $deliveryFee,
            'PAYFRIT_FEE' => $payfritCustomerFee,
            'CARD_FEE' => $cardFee,
            'BALANCE_APPLIED' => $balanceApplied,
            'TOTAL' => $totalCustomerPays,
            'TOTAL_BEFORE_BALANCE' => ($balanceApplied > 0) ? $totalCustomerPays + $balanceApplied : 0,
            'GRANT_OWNER_FEE_CENTS' => $grantOwnerFeeCents,
        ],
        'STRIPE_CONNECT_ENABLED' => $hasStripeConnect,
    ]);

} catch (Exception $e) {
    jsonResponse(['OK' => false, 'ERROR' => $e->getMessage(), 'DETAIL' => '']);
}