<?php

namespace App\Lib\Helpers;

use Illuminate\Contracts\Encryption\DecryptException;
use Illuminate\Support\Facades\Crypt;
use Uwil\LaravelCommon\Helpers\ToolboxHelper as BaseToolboxHelper;

class ToolboxHelper extends BaseToolboxHelper
{
    /**
     * Calculate the request signature
     *
     * @param string $secret
     * @param string $uri
     * @param string $method
     * @param array  $parameters
     * @return string request signature
     * @throws \RuntimeException If an error occurs.
     */
    public static function signRequest(string $secret, string $uri, string $method, array $parameters): string
    {
        try {
            $uri    = collect(\parse_url($uri));
            $method = \strtolower($method);

            // * Remove signature from parameters to calculate the hashmac.
            $signature = collect([
                'uri' => sprintf(
                    '%s://%s%s',
                    $uri->get('scheme'),
                    $uri->get('host'),
                    $uri->get('path')
                ),
                'method' => $method
            ]);

            $flattenRequestArray = function (array $array) use (&$flattenRequestArray) {
                $out = [];
                foreach ($array as $key => $value) {
                    if (is_array($value)) {
                        $subArray = $flattenRequestArray($value);
                        foreach ($subArray as $subKey => $subValue) {
                            $out["$key.$subKey"] = $subValue;
                        }
                        continue;
                    }
                    $out[$key] = $value;
                }
                return $out;
            };

            $parameters = $flattenRequestArray($parameters);
            $parameters = collect($parameters);

            // * Remove signature from parameters.
            $parameters->pull('signature');

            // * Natural sort all parameters.
            $parameters = $parameters->sortKeys(\SORT_NATURAL)
                ->map(function ($value, $key) {
                    return sprintf('%s=%s', \rawurlencode($key), \rawurlencode($value));
                });

            $signature->push($parameters->implode('&'));

            $calculatedHash = base64_encode(hash_hmac(
                'sha256',
                $signature->implode('\n'),
                Crypt::decryptString($secret),
                true
            ));

            if (!$calculatedHash) {
                throw new \RuntimeException('Failed to calculate requests hash');
            }

            return $calculatedHash;
        } catch (DecryptException $e) {
            throw new \RuntimeException('Failed to decrypt service credentials', 0, $e);
        } catch (\Exception $e) {
            throw new \RuntimeException('An error occured when authenticating service', 0, $e);
        } //end try
    }
}