<?php

declare(strict_types=1);

namespace SHServ\Integrations\GAuth\Http;

use Psr\Http\Client\ClientExceptionInterface;
use Psr\Http\Client\ClientInterface;
use Psr\Http\Message\RequestInterface;
use Psr\Http\Message\ResponseInterface;

final class CurlHttpClient implements ClientInterface
{
    private int $timeout;
    private bool $verifySsl;

    public function __construct(int $timeout = 30, bool $verifySsl = true)
    {
        $this->timeout = $timeout;
        $this->verifySsl = $verifySsl;
    }

    public function sendRequest(RequestInterface $request): ResponseInterface
    {
        $ch = curl_init();
        if ($ch === false) {
            throw new ClientException('Failed to initialize cURL');
        }

        $headers = [];
        foreach ($request->getHeaders() as $name => $values) {
            $headers[] = $name . ': ' . implode(', ', $values);
        }

        $body = (string) $request->getBody();

        $options = [
            CURLOPT_URL => (string) $request->getUri(),
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_HEADER => true,
            CURLOPT_FOLLOWLOCATION => true,
            CURLOPT_TIMEOUT => $this->timeout,
            CURLOPT_CONNECTTIMEOUT => min(10, $this->timeout),
            CURLOPT_SSL_VERIFYPEER => $this->verifySsl,
            CURLOPT_SSL_VERIFYHOST => $this->verifySsl ? 2 : 0,
            CURLOPT_HTTPHEADER => $headers,
        ];

        if ($request->getMethod() !== 'GET') {
            $options[CURLOPT_CUSTOMREQUEST] = $request->getMethod();
        }

        if ($body !== '') {
            $options[CURLOPT_POSTFIELDS] = $body;
        }

        curl_setopt_array($ch, $options);

        $rawResponse = curl_exec($ch);

        if ($rawResponse === false) {
            $error = curl_error($ch);
            curl_close($ch);
            throw new ClientException('cURL error: ' . $error);
        }

        $headerSize = curl_getinfo($ch, CURLINFO_HEADER_SIZE);
        $statusCode = curl_getinfo($ch, CURLINFO_HTTP_CODE);
        curl_close($ch);

        $rawHeaders = substr($rawResponse, 0, $headerSize);
        $responseBody = substr($rawResponse, $headerSize);

        $parsedHeaders = $this->parseHeaders($rawHeaders);

        return new Psr7Response($statusCode, $parsedHeaders, new Psr7Stream($responseBody));
    }

    private function parseHeaders(string $rawHeaders): array
    {
        $headers = [];
        $lines = explode("\r\n", trim($rawHeaders));
        foreach ($lines as $line) {
            if (strpos($line, ':') === false) {
                continue;
            }
            [$name, $value] = explode(':', $line, 2);
            $name = trim($name);
            $value = trim($value);
            if (!isset($headers[$name])) {
                $headers[$name] = [];
            }
            $headers[$name][] = $value;
        }
        return $headers;
    }
}

final class ClientException extends \Exception implements ClientExceptionInterface
{
}