<?php

defined('BASEPATH') or exit('No direct script access allowed');

/**
 * Verify Paystack webhook signature
 */
function verify_paystack_webhook_signature($payload, $signature)
{
    $secret_key = get_option('paystack_webhook_secret');
    $calculated_signature = hash_hmac('sha512', $payload, $secret_key);

    return hash_equals($calculated_signature, $signature);
}

/**
 * Validate Paystack API response
 */
function validate_paystack_api_response($response)
{
    if (!is_object($response)) {
        return [
            'valid' => false,
            'message' => 'Invalid response format'
        ];
    }

    if (!isset($response->status) || $response->status !== true) {
        return [
            'valid' => false,
            'message' => isset($response->message) ? $response->message : 'Invalid response status'
        ];
    }

    return [
        'valid' => true,
        'data' => $response->data
    ];
}

/**
 * Sanitize API keys
 */
function sanitize_paystack_keys($key)
{
    return preg_replace('/[^a-zA-Z0-9_]/', '', $key);
}

/**
 * Validate amount
 */
function validate_paystack_amount($amount)
{
    return is_numeric($amount) && $amount > 0;
}

/**
 * Encrypt sensitive data
 */
function encrypt_paystack_data($data)
{
    $CI = &get_instance();
    $CI->load->library('encryption');
    return $CI->encryption->encrypt($data);
}

/**
 * Decrypt sensitive data
 */
function decrypt_paystack_data($data)
{
    $CI = &get_instance();
    $CI->load->library('encryption');
    return $CI->encryption->decrypt($data);
}