<?php

$rootPath = dirname(dirname(__DIR__));
require_once($rootPath . "/src/config/env.php");
require_once($rootPath . "/src/config/connection.php");
require_once($rootPath . "/src/config/functions.php");

/**
 * ==========================================================
 * Read raw request and headers (DO NOT MODIFY RAW BODY)
 * ==========================================================
 */
$raw = file_get_contents('php://input');

if ($raw === false) {
    http_response_code(400);
    progress_log('iKhokha webhook: unable to read raw input');
    exit('No body');
}

$headers = function_exists('getallheaders') ? getallheaders() : [];
$headers = array_change_key_case($headers, CASE_LOWER);

$ikSign  = $headers['ik-sign']  ?? null;
$ikAppId = $headers['ik-appid'] ?? null;

/**
 * ==========================================================
 * Basic header presence check
 * ==========================================================
 */
if (empty($ikSign) || empty($ikAppId)) {
    http_response_code(400);
    progress_log('iKhokha webhook: missing IK-SIGN or IK-APPID');
    exit('Missing headers');
}

/**
 * ==========================================================
 * Signature verification
 * HMAC_SHA256( path + raw_body, app_secret )
 * ==========================================================
 */
$secret = $_ENV['IKHOKHA_APP_SECRET'] ?? null;

if (empty($secret)) {
    http_response_code(500);
    progress_log('iKhokha webhook: app secret not configured');
    exit('Server misconfigured');
}


// Debug logging (disable once stable)
progress_log('--- iKhokha WEBHOOK DEBUG ---');
progress_log('RAW BODY: ' . $raw);
progress_log('IK-SIGN: ' . $ikSign);

$callbackUrl = $_ENV['IKHOKHA_CALLBACK_URL'] ?? null;
$bypass = ($_ENV['IKHOKHA_BYPASS_SIGNATURE'] ?? 'false') === 'true';

if (!$bypass) {

    if (empty($callbackUrl)) {
        http_response_code(500);
        progress_log('iKhokha webhook: callback URL not configured');
        exit('Server misconfigured');
    }

    $expected = hash_hmac(
        'sha256',
        $callbackUrl . $raw,
        $_ENV['IKHOKHA_APP_SECRET']
    );

    if (!hash_equals($expected, $ikSign)) {
        http_response_code(403);
        progress_log('iKhokha webhook: signature mismatch');
        progress_log('EXPECTED SIGN: ' . $expected);
        progress_log('RECEIVED SIGN: ' . $ikSign);
        exit('Invalid signature');
    }

} else {
    progress_log('⚠️ IKHOKHA SIGNATURE CHECK BYPASSED');
}

/**
 * ==========================================================
 * Decode payload
 * ==========================================================
 */
$payload = json_decode($raw, true);

if (!is_array($payload)) {
    http_response_code(400);
    progress_log('iKhokha webhook: invalid JSON');
    exit('Invalid JSON');
}

/**
 * ==========================================================
 * Extract data safely (iKhokha is inconsistent)
 * ==========================================================
 */
$data = $payload['data'] ?? $payload;

$externalTransactionID =
    $data['externalTransactionID']
    ?? $data['externalTransactionId']
    ?? $data['externalTxId']
    ?? null;

$providerPaymentId =
    $data['paylinkID']
    ?? $data['id']
    ?? null;

$providerStatus =
    $data['status']
    ?? $payload['status']
    ?? null;

progress_log('Parsed externalTransactionID: ' . $externalTransactionID);
progress_log('Parsed providerPaymentId: ' . $providerPaymentId);
progress_log('Parsed providerStatus: ' . print_r($providerStatus, true));

/**
 * ==========================================================
 * Locate local payment
 * ==========================================================
 */
$localPaymentId = null;
$booking_id = null;
$user_id = null;
$description = null;

if ($externalTransactionID) {
    $stmt = $conn->prepare(
        "SELECT payment_id, user_id, booking_id, description
         FROM payments
         WHERE payment_id = ?
         LIMIT 1"
    );

    if ($stmt) {
        $stmt->bind_param('s', $externalTransactionID);
        $stmt->execute();
        $res = $stmt->get_result();
        if ($row = $res->fetch_assoc()) {
            $localPaymentId = $row['payment_id'];
            $booking_id = $row['booking_id'];
            $user_id = $row['user_id'];
            $description = $row['description'];
        }
        $stmt->close();
    }
}

if (!$localPaymentId && $providerPaymentId) {
    $stmt = $conn->prepare(
        "SELECT payment_id, user_id, booking_id, description
         FROM payments
         WHERE provider_payment_id = ?
         LIMIT 1"
    );

    if ($stmt) {
        $stmt->bind_param('s', $providerPaymentId);
        $stmt->execute();
        $res = $stmt->get_result();
        if ($row = $res->fetch_assoc()) {
            $localPaymentId = $row['payment_id'];
            $booking_id = $row['booking_id'];
            $user_id = $row['user_id'];
            $description = $row['description'];
        }
        $stmt->close();
    }
}

if (!$localPaymentId) {
    http_response_code(404);
    progress_log('iKhokha webhook: payment not found');
    progress_log(json_encode([$externalTransactionID, $providerPaymentId]));
    exit('Payment not found');
}

/**
 * ==========================================================
 * Persist provider response
 * ==========================================================
 */
$update = $conn->prepare(
    "UPDATE payments
     SET provider_payment_id = ?,
         provider_status = ?,
         provider_response = ?
     WHERE payment_id = ?"
);

if ($update) {
    $update->bind_param(
        'ssss',
        $providerPaymentId,
        $providerStatus,
        $raw,
        $localPaymentId
    );
    $update->execute();
    $update->close();
}

/**
 * ==========================================================
 * Normalize status and apply business logic
 * ==========================================================
 */
$normalized = strtoupper(trim((string)$providerStatus));

if (in_array($normalized, ['PAID', 'SUCCESS', 'COMPLETED', 'SETTLED'], true)) {

    // Mark payment as PAID
    $setPaid = $conn->prepare(
        "UPDATE payments SET status = 'PAID' WHERE payment_id = ?"
    );
    if ($setPaid) {
        $setPaid->bind_param('s', $localPaymentId);
        $setPaid->execute();
        $setPaid->close();
    }

    // Booking or membership update
    if (!empty($booking_id)) {
        $upd = $conn->prepare(
            "UPDATE bookings SET status = 'PAID' WHERE booking_id = ?"
        );
        if ($upd) {
            $upd->bind_param('i', $booking_id);
            $upd->execute();
            $upd->close();
            sendAdminNotification('4WDCSA.co.za - New Booking - '.getFullName($user_id) , 'We have received a payment for a new booking for '.$description.' from '.getFullName($user_id));
        }
    } else {
        $upd = $conn->prepare(
            "UPDATE membership_fees
             SET payment_status = 'PAID'
             WHERE payment_id = ?"
        );
        if ($upd) {
            $upd->bind_param('s', $localPaymentId);
            $upd->execute();
            $upd->close();
            sendAdminNotification('4WDCSA.co.za - Membership Payment Received  - '.getFullName($user_id) , 'A Membership Payment has been received from '.getFullName($user_id));
        }
    }

    // Send confirmation email
    if (!empty($user_id)) {
        sendPaymentConfirmation(
            getEmail($user_id),
            getFullName($user_id),
            $description
        );
    }
}

/**
 * ==========================================================
 * Acknowledge webhook
 * ==========================================================
 */
http_response_code(200);
echo 'OK';