<?php

declare(strict_types=1);

namespace app\common\service\iam;

use RuntimeException;

class IamHttpClient
{
    /** @var callable|null */
    private $transport;
    private int $timeoutSeconds;

    public function __construct(?callable $transport = null, int $timeoutSeconds = 10)
    {
        $this->transport = $transport;
        $this->timeoutSeconds = $timeoutSeconds;
    }

    /** @return array{status:int,body:array<string,mixed>} */
    public function json(string $method, string $url, array $headers = [], ?array $json = null): array
    {
        $headers[] = 'Accept: application/json';
        $body = null;
        if ($json !== null) {
            $headers[] = 'Content-Type: application/json';
            $body = json_encode($json, JSON_UNESCAPED_UNICODE | JSON_UNESCAPED_SLASHES | JSON_THROW_ON_ERROR);
        }

        return $this->send($method, $url, $headers, $body);
    }

    /** @return array{status:int,body:array<string,mixed>} */
    public function form(string $url, array $form): array
    {
        return $this->send(
            'POST',
            $url,
            ['Accept: application/json', 'Content-Type: application/x-www-form-urlencoded'],
            http_build_query($form, '', '&', PHP_QUERY_RFC3986)
        );
    }

    /** @return array{status:int,body:array<string,mixed>} */
    private function send(string $method, string $url, array $headers, ?string $body): array
    {
        if ($this->transport !== null) {
            $result = ($this->transport)($method, $url, $headers, $body);
            if (!is_array($result) || !isset($result['status'], $result['body'])) {
                throw new RuntimeException('IAM HTTP transport returned an invalid response');
            }
            return $result;
        }

        $curl = curl_init($url);
        if ($curl === false) {
            throw new RuntimeException('Unable to initialize IAM HTTP request');
        }
        curl_setopt_array($curl, [
            CURLOPT_CUSTOMREQUEST => strtoupper($method),
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_FOLLOWLOCATION => false,
            CURLOPT_CONNECTTIMEOUT => min(5, $this->timeoutSeconds),
            CURLOPT_TIMEOUT => $this->timeoutSeconds,
            CURLOPT_HTTPHEADER => $headers,
        ]);
        if ($body !== null) {
            curl_setopt($curl, CURLOPT_POSTFIELDS, $body);
        }
        $raw = curl_exec($curl);
        $status = (int) curl_getinfo($curl, CURLINFO_RESPONSE_CODE);
        $error = curl_error($curl);
        curl_close($curl);
        if ($raw === false) {
            throw new RuntimeException('IAM HTTP request failed: ' . $error);
        }
        $decoded = json_decode((string) $raw, true);
        return [
            'status' => $status,
            'body' => is_array($decoded) ? $decoded : [],
        ];
    }
}