using System.Text;
using System.Text.Json.Nodes;
using Fleet.Core;
using MoShiro.Probe;

namespace MoShiro.Backend.Tests;

/// <summary>进程内的真实 Probe：用加入令牌注册出来的身份（节点自己生成的两把密钥）启动 <see cref="ProbeApp"/>。</summary>
public sealed class ProbeHarness : IAsyncDisposable
{
    private readonly CancellationTokenSource _stop = new();
    private readonly string _directory;
    private readonly Task _run;
    private readonly EnrolledProbe _enrolled;

    private ProbeHarness(string directory, ProbeApp app, EnrolledProbe enrolled)
    {
        _directory = directory;
        _enrolled = enrolled;
        App = app;
        _run = Task.Run(() => app.RunAsync(_stop.Token), CancellationToken.None);
    }

    public ProbeApp App { get; }

    public string Directory => _directory;

    public string ProbeId { get; init; } = "";

    /// <summary>用加入令牌注册（节点自己生成密钥），把面板地址和身份目录写进 <c>probe.json</c>，然后启动。</summary>
    public static async Task<ProbeHarness> StartAsync(BackendFixture backend, Action<ProbeFile>? configure = null)
    {
        EnrolledProbe enrolled = await backend.CreateProbeAsync();
        string directory = enrolled.Directory;
        string path = Path.Combine(directory, "probe.json");
        var written = new ProbeFile { Fleet = { Server = backend.BaseAddress.ToString(), IdentityDir = directory } };
        await File.WriteAllTextAsync(path, System.Text.Json.JsonSerializer.Serialize(written, ProbeConfigContext.Default.ProbeFile), Encoding.UTF8);

        ProbeFile file = Fleet.Hosting.NodeConfig.Load(path, ProbeConfigContext.Default.ProbeFile);
        configure?.Invoke(file);
        var app = new ProbeApp(file, enrolled.Identity, directory, TimeProvider.System, NullNodeLog.Instance);
        return new ProbeHarness(directory, app, enrolled) { ProbeId = enrolled.ProbeId };
    }

    public async ValueTask DisposeAsync()
    {
        await _stop.CancelAsync();
        try
        {
            await _run.WaitAsync(TimeSpan.FromSeconds(15));
        }
        catch (Exception ex) when (ex is OperationCanceledException or TimeoutException)
        {
            // 停止中
        }

        App.Dispose();
        _enrolled.Dispose();
        _stop.Dispose();
        try
        {
            System.IO.Directory.Delete(_directory, recursive: true);
        }
        catch (IOException)
        {
            // 临时目录清理失败不影响测试结果
        }
    }
}