// Copyright 2020-2025 The NATS Authors
// Licensed under the Apache License, Version 2.0

namespace ZB.MOM.NatsNet.Server.IntegrationTests.Helpers;

/// <summary>
/// Represents a test JetStream cluster. In the current integration test setup,
/// tests that use this type are skipped unless a real cluster is available.
/// This is a scaffold/stub that captures the API shape for future full implementation.
/// </summary>
public sealed class TestCluster : IDisposable
{
    private readonly string _name;
    private readonly int _numServers;
    private bool _disposed;

    public string Name => _name;

    private TestCluster(string name, int numServers)
    {
        _name = name;
        _numServers = numServers;
    }

    /// <summary>
    /// Creates a JetStream cluster with the given number of servers.
    /// Throws <see cref="ClusterNotAvailableException"/> if no cluster is available.
    /// </summary>
    public static TestCluster CreateJetStreamCluster(int numServers, string name = "JSC")
    {
        throw new ClusterNotAvailableException(
            $"No JetStream cluster available. Set NATS_INTEGRATION_TESTS=true and ensure {numServers}-node cluster '{name}' is running.");
    }

    /// <summary>
    /// Creates a JetStream cluster with the specified configuration template.
    /// </summary>
    public static TestCluster CreateJetStreamClusterWithTemplate(string template, int numServers, string name = "JSC")
    {
        throw new ClusterNotAvailableException(
            $"No JetStream cluster available for template cluster '{name}'.");
    }

    public void WaitOnClusterReady() { }
    public void WaitOnLeader() { }
    public void WaitOnStreamLeader(string account, string stream) { }
    public void WaitOnConsumerLeader(string account, string stream, string consumer) { }
    public void WaitOnPeerCount(int count) { }
    public void WaitOnServerCurrent(object server) { }
    public void WaitOnStreamCurrent(object server, string account, string stream) { }

    public object Leader() => throw new ClusterNotAvailableException("Cluster not available.");
    public object RandomServer() => throw new ClusterNotAvailableException("Cluster not available.");
    public object RandomNonLeader() => throw new ClusterNotAvailableException("Cluster not available.");
    public object RandomNonStreamLeader(string account, string stream) => throw new ClusterNotAvailableException("Cluster not available.");
    public object ServerByName(string name) => throw new ClusterNotAvailableException("Cluster not available.");
    public object StreamLeader(string account, string stream) => throw new ClusterNotAvailableException("Cluster not available.");
    public object ConsumerLeader(string account, string stream, string consumer) => throw new ClusterNotAvailableException("Cluster not available.");

    public void Dispose()
    {
        if (!_disposed)
        {
            _disposed = true;
        }
    }
}

/// <summary>
/// Thrown when a test cluster is not available for integration testing.
/// </summary>
public sealed class ClusterNotAvailableException : Exception
{
    public ClusterNotAvailableException(string message) : base(message) { }
}