<?php
declare(strict_types=1);

require_once __DIR__ . '/Config.php';

final class Oauth {
    public static function exchangeCodeForToken(string $code): array {
        return self::httpPost(Config::get('OAUTH_TOKEN_URL'), [
            'grant_type'    => 'authorization_code',
            'code'          => $code,
            'redirect_uri'  => Config::get('OAUTH_REDIRECT_URI'),
            'client_id'     => Config::get('OAUTH_CLIENT_ID'),
            'client_secret' => Config::get('OAUTH_CLIENT_SECRET'),
        ]);
    }

    public static function fetchProfile(string $accessToken): array {
        return self::httpGetBearer(Config::get('OAUTH_PROFILE_URL'), $accessToken);
    }

    private static function httpPost(string $url, array $form): array {
        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_POST           => true,
            CURLOPT_POSTFIELDS     => http_build_query($form),
            CURLOPT_HTTPHEADER     => ['Accept: application/json'],
            CURLOPT_TIMEOUT        => 10,
            CURLOPT_CONNECTTIMEOUT => 5,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_SSL_VERIFYHOST => 2,
        ]);
        $body = curl_exec($ch);
        $err  = curl_error($ch);
        curl_close($ch);
        if ($err || $body === false) {
            error_log('oauth POST failed: ' . $err);
            return [];
        }
        return json_decode((string)$body, true) ?? [];
    }

    private static function httpGetBearer(string $url, string $token): array {
        $ch = curl_init($url);
        curl_setopt_array($ch, [
            CURLOPT_RETURNTRANSFER => true,
            CURLOPT_HTTPHEADER     => [
                'Authorization: Bearer ' . $token,
                'Accept: application/json',
            ],
            CURLOPT_TIMEOUT        => 10,
            CURLOPT_CONNECTTIMEOUT => 5,
            CURLOPT_SSL_VERIFYPEER => true,
            CURLOPT_SSL_VERIFYHOST => 2,
        ]);
        $body = curl_exec($ch);
        $err  = curl_error($ch);
        curl_close($ch);
        if ($err || $body === false) {
            error_log('oauth GET failed: ' . $err);
            return [];
        }
        return json_decode((string)$body, true) ?? [];
    }
}