<?php
$config = require __DIR__ . '/config.php';
require __DIR__ . '/lib/PayPalClient.php';
require __DIR__ . '/lib/Storage.php';

if ($_SERVER['REQUEST_METHOD'] !== 'POST') {
    http_response_code(405);
    echo 'Method Not Allowed';
    exit;
}

$school = trim($_POST['school'] ?? '');
$amount = (string)($_POST['amount'] ?? '0');

if ($school === '' || !is_numeric($amount) || (float)$amount <= 0) {
    http_response_code(400);
    echo 'Invalid input';
    exit;
}

$storage = new Storage($config['storage_path']);
$merchants = $storage->get('merchants', []);
$merchantId = $merchants[$school]['merchant_id'] ?? null;
if (!$merchantId) {
    http_response_code(400);
    echo 'School not onboarded';
    exit;
}

$client = new PayPalClient($config);

$returnUrl = rtrim($config['base_url'], '/') . '/capture_order.php';
$cancelUrl = rtrim($config['base_url'], '/') . '/index.php';

// Orders v2 create, routing funds to payee.merchant_id
$payload = [
    'intent' => 'CAPTURE',
    'purchase_units' => [[
        'amount' => [
            'currency_code' => 'USD',
            'value' => number_format((float)$amount, 2, '.', ''),
        ],
        'payee' => [
            'merchant_id' => $merchantId,
        ],
        'description' => 'School Lunch Payment for ' . $school,
    ]],
    'application_context' => [
        'brand_name' => 'School Lunch Service',
        'landing_page' => 'LOGIN',
        'shipping_preference' => 'NO_SHIPPING',
        'user_action' => 'PAY_NOW',
        'return_url' => $returnUrl,
        'cancel_url' => $cancelUrl,
    ],
];

$resp = $client->api('POST', '/v2/checkout/orders', $payload);
if ($resp['status'] < 200 || $resp['status'] >= 300) {
    http_response_code(500);
    echo 'Create order failed: ' . htmlspecialchars(json_encode($resp));
    exit;
}

$order = $resp['body'];
$approve = null;
foreach (($order['links'] ?? []) as $lnk) {
    if (($lnk['rel'] ?? '') === 'approve') { $approve = $lnk['href']; break; }
}

if (!$approve) {
    http_response_code(500);
    echo 'Missing approval link';
    exit;
}

// Save a minimal order record for demo
$orders = $storage->get('orders', []);
$orders[$order['id']] = [
    'school' => $school,
    'amount' => $payload['purchase_units'][0]['amount']['value'],
    'merchant_id' => $merchantId,
    'status' => 'CREATED',
];
$storage->set('orders', $orders);

header('Location: ' . $approve);
exit;