<?php
$config = require __DIR__ . '/config.php';
require __DIR__ . '/lib/PayPalClient.php';
require __DIR__ . '/lib/Storage.php';

$school = $_GET['school'] ?? '';
$track = $_GET['track'] ?? '';
$pref = $_GET['partner_referral_id'] ?? null;

if (!$school || !$track) {
    header('Location: ' . rtrim($config['base_url'], '/') . '/index.php');
    exit;
}

$client = new PayPalClient($config);
$storage = new Storage($config['storage_path']);

// First, PayPal may append merchantId to the return URL on successful onboarding
$merchantId = $_GET['merchantId']
    ?? $_GET['merchant_id']
    ?? $_GET['merchantIdInPayPal']
    ?? null;

// If not provided, use Partner Lookup API to retrieve merchant info by tracking_id.
// Docs: GET /v1/customer/partners/<partner_merchant_id>/merchant-integrations?tracking_id=
if (!$merchantId) {
    $merchantId = null;
    $lastResp = null;
    // poll up to ~15s total
    for ($i = 0; $i < 15; $i++) {
        $path = '/v1/customer/partners/' . urlencode($config['partner_merchant_id']) . '/merchant-integrations?tracking_id=' . urlencode($track);
        $resp = $client->api('GET', $path);
        $lastResp = $resp;
        if ($resp['status'] >= 200 && $resp['status'] < 300) {
            if (!empty($resp['body']['merchant_id'])) {
                $foundId = $resp['body']['merchant_id'];
                // CRITICAL: Don't accept the partner's own ID as merchant ID
                // This means the merchant hasn't completed onboarding yet
                if (strcasecmp($foundId, $config['partner_merchant_id']) !== 0) {
                    $merchantId = $foundId;
                    break;
                }
            }
        }
        usleep(1000000); 
    }
    if (!$merchantId) {
        $debug = $storage->get('return_debug', []);
        $debug[] = [
            'ts' => time(),
            'query' => $_GET,
            'last_status' => $lastResp['status'] ?? null,
            'last_body' => $lastResp['body'] ?? null,
            'track' => $track,
            'school' => $school,
            'reason' => 'Merchant onboarding not completed or partner ID returned'
        ];
        $storage->set('return_debug', $debug);
    }
}

// Fallback by partner_referral_id if available and still missing
if (!$merchantId) {
    // Load pending entry for additional clues
    $pending = $storage->get('pending_onboarding', []);
    $entry = $pending[$track] ?? [];
    $prefFromStore = $entry['partner_referral_id'] ?? $entry['referral_token'] ?? null;
    $pref = $pref ?: $prefFromStore;
}

if (!$merchantId && $pref) {
    // Try list integrations and filter by partner_referral_id
    $path = '/v1/customer/partners/' . urlencode($config['partner_merchant_id']) . '/merchant-integrations?onboarded=true';
    $resp = $client->api('GET', $path);
    if ($resp['status'] >= 200 && $resp['status'] < 300 && !empty($resp['body']['merchant_integrations'])) {
        foreach ($resp['body']['merchant_integrations'] as $mi) {
            $rid = $mi['partner_referral_id'] ?? ($mi['referral_id'] ?? null);
            $foundId = $mi['merchant_id'] ?? null;
            // Only accept if it's a different merchant ID (not the partner's own)
            if ($rid && strcasecmp($rid, $pref) === 0 && $foundId && strcasecmp($foundId, $config['partner_merchant_id']) !== 0) {
                $merchantId = $foundId;
                break;
            }
        }
        // If still not found, but the list contains exactly one new integration with our tracking id, take it
        if (!$merchantId) {
            foreach ($resp['body']['merchant_integrations'] as $mi) {
                $foundId = $mi['merchant_id'] ?? null;
                if (!empty($mi['tracking_id']) && strcasecmp($mi['tracking_id'], $track) === 0 && $foundId && strcasecmp($foundId, $config['partner_merchant_id']) !== 0) {
                    $merchantId = $foundId;
                    break;
                }
            }
        }
    }
}

// As a last resort, if merchants.json already contains the school mapping, use it
if (!$merchantId) {
    $merchants = $storage->get('merchants', []);
    if (!empty($merchants[$school]['merchant_id'])) {
        $existingId = $merchants[$school]['merchant_id'];
        // Only use if it's not the partner's own ID
        if (strcasecmp($existingId, $config['partner_merchant_id']) !== 0) {
            $merchantId = $existingId;
        }
    }
}

if (!$merchantId) {
    // Mark as incomplete onboarding
    $pending = $storage->get('pending_onboarding', []);
    if (isset($pending[$track])) {
        $pending[$track]['status'] = 'incomplete_onboarding';
        $pending[$track]['last_return_at'] = time();
        $pending[$track]['note'] = 'Merchant did not complete PayPal onboarding. Partner ID was returned instead.';
        $storage->set('pending_onboarding', $pending);
    }
    
    // Not available yet; merchant needs to complete onboarding
    header('Location: ' . rtrim($config['base_url'], '/') . '/index.php?onboard=incomplete');
    exit;
}

// Persist school -> merchant mapping
$merchants = $storage->get('merchants', []);
$merchants[$school] = [
    'merchant_id' => $merchantId,
    'tracking_id' => $track,
    'connected_at' => time(),
];
$storage->set('merchants', $merchants);

// Also annotate the matching pending record so it's visible where you looked
$pending = $storage->get('pending_onboarding', []);
if (!isset($pending[$track])) {
    // if for some reason it's missing, recreate a minimal record
    $pending[$track] = [
        'school' => $school,
        'created_at' => time(),
    ];
}
$pending[$track]['merchant_id'] = $merchantId;
$pending[$track]['status'] = 'connected';
$pending[$track]['connected_at'] = time();
// Store the raw return query for troubleshooting
$pending[$track]['last_return_query'] = $_GET;
$storage->set('pending_onboarding', $pending);

header('Location: ' . rtrim($config['base_url'], '/') . '/index.php?onboard=ok');
exit;