using System.Text.Json;

namespace XFEWarframe.Client;

public sealed record ServerDescription(string Service, string Status, int ApiVersion, string ServerName, string GameUrl);

public static class ServerConnection
{
    public static async Task<ServerDescription> ReadAsync(string origin, CancellationToken cancellation = default)
    {
        origin = ClientProtocol.NormalizeServer(origin);
        using var http = new HttpClient(new HttpClientHandler { AllowAutoRedirect = false }) { Timeout = TimeSpan.FromSeconds(8) };
        using var response = await http.GetAsync(origin + "/health", cancellation).ConfigureAwait(false);
        response.EnsureSuccessStatusCode();
        var bytes = await response.Content.ReadAsByteArrayAsync(cancellation).ConfigureAwait(false);
        var identity = JsonSerializer.Deserialize(bytes, ClientJson.Default.ServerDescription) ?? throw new InvalidDataException("服务器没有返回状态。");
        if (identity.Service != "XFEWarframe" || identity.ApiVersion < 3) throw new InvalidDataException("服务器版本过旧，尚未包含游戏登录修复。请关闭旧服务器并启动同一发行包中的新版 Server。");
        if (identity.Status != "ok") throw new InvalidOperationException("服务器正在维护，请稍后再试。");
        var game = new Uri(ClientProtocol.NormalizeServer(identity.GameUrl));
        if (game.Scheme != "https") throw new InvalidDataException("游戏需要 HTTPS，请在服务端启用 GameListenUrl 和 GamePublicUrl。");
        if (string.IsNullOrWhiteSpace(identity.ServerName) || identity.ServerName.Length > 64 || identity.ServerName.Any(char.IsControl)) throw new InvalidDataException("服务器名称无效。");
        return identity;
    }
}