using OpenAC.MosswartMassacre.Tests.Fakes;

namespace OpenAC.MosswartMassacre.Tests.Backend;

/// <summary>
/// The socket's status and error lines reach the player's chat, worded as the
/// original worded them, and only through the tick: the socket thread never
/// writes to chat itself.
/// </summary>
public sealed class BackendChatStatusTests
{
    private const string P = "[Mosswart Massacre] ";

    [Fact]
    public async Task Enable_shows_connecting_then_connected_and_registered_on_the_next_tick()
    {
        using var server = new TestSocketServer();
        using var harness = new PluginHarness("Mossy");
        harness.Login();
        harness.Context.Settings.Current.BackendUrl = server.Uri.ToString();

        harness.Context.Commands.Dispatch("ws enable");

        Assert.Equal([P + "[WebSocket] connecting…", P + "WS streaming ENABLED."], Tail(harness, 2));

        server.NextFrame();
        Assert.True(await BackendClientTests.WaitAsync(() => harness.Context.Backend.IsConnected));
        Assert.DoesNotContain(P + "[WebSocket] CONNECTED", harness.ChatLines);

        int before = harness.ChatLines.Count;
        int tickThread = Environment.CurrentManagedThreadId;
        harness.Tick(0.01);

        Assert.Equal(
            [P + "[WebSocket] CONNECTED", P + "[WebSocket] REGISTERED", P + "[WebSocket] Starting telemetry loop"],
            Tail(harness, 3));
        AssertPostedOn(harness, before, tickThread);
    }

    [Fact]
    public async Task Streaming_saved_on_connects_at_login_and_says_so()
    {
        using var server = new TestSocketServer();
        using var harness = new PluginHarness("Mossy");
        harness.Context.Settings.Current.WebSocketEnabled = true;
        harness.Context.Settings.Current.BackendUrl = server.Uri.ToString();
        harness.Context.Settings.Save();

        harness.Host.Automation.Character.IsInWorld = true;
        harness.Plugin.OnLogin();

        Assert.Contains(P + "[WebSocket] connecting…", harness.ChatLines);
        Assert.Equal("{\"type\":\"register\",\"player_name\":\"Mossy\"}", server.NextFrame());
        Assert.True(await BackendClientTests.WaitAsync(() => harness.Context.Backend.IsConnected));
        harness.Tick(0.01);
        Assert.Contains(P + "[WebSocket] REGISTERED", harness.ChatLines);
    }

    [Fact]
    public async Task A_failed_connect_shows_the_error_cleanup_and_reconnect_on_the_next_tick()
    {
        using var harness = new PluginHarness("Mossy");
        harness.Login();
        // Nothing listens on port 1: the connect is refused.
        harness.Context.Settings.Current.BackendUrl = "ws://127.0.0.1:1/websocket/";
        var log = (RecordingLogger)harness.Host.Log;

        harness.Context.Commands.Dispatch("ws enable");
        Assert.True(await BackendClientTests.WaitAsync(
            () => log.Any(line => line.Contains("[WebSocket] Reconnecting in 2 seconds...")), 15000));
        Assert.DoesNotContain(harness.ChatLines, line => line.Contains("Connection error"));

        int before = harness.ChatLines.Count;
        int tickThread = Environment.CurrentManagedThreadId;
        harness.Tick(0.01);

        string[] tail = Tail(harness, 3);
        Assert.StartsWith(P + "[WebSocket] Connection error: ", tail[0]);
        Assert.StartsWith(P + "[WebSocket] Cleaning up connection - Final state: ", tail[1]);
        Assert.Equal(P + "[WebSocket] Reconnecting in 2 seconds...", tail[2]);
        AssertPostedOn(harness, before, tickThread);
    }

    [Fact]
    public async Task Disable_shows_disabled_before_the_command_reply()
    {
        using var server = new TestSocketServer();
        using var harness = new PluginHarness("Mossy");
        harness.Login();
        harness.Context.Settings.Current.BackendUrl = server.Uri.ToString();
        harness.Context.Commands.Dispatch("ws enable");
        server.NextFrame();
        Assert.True(await BackendClientTests.WaitAsync(() => harness.Context.Backend.IsConnected));
        harness.Tick(0.01);

        harness.Context.Commands.Dispatch("ws disable");

        Assert.Equal([P + "[WebSocket] DISABLED", P + "WS streaming DISABLED."], Tail(harness, 2));
    }

    [Fact]
    public void A_reconnect_with_sharing_on_says_it_re_subscribed_even_without_verbose_logging()
    {
        using var harness = new PluginHarness("Mossy");
        harness.Login();
        harness.Context.Settings.Current.VitalSharingEnabled = true;
        harness.Context.Settings.Current.VerboseLogging = false;

        harness.SimulateConnected();

        Assert.Equal(
            [P + "[WebSocket] Vital sharing re-subscribed", P + "[WebSocket] Starting telemetry loop"],
            Tail(harness, 2));
    }

    /// <summary>Every chat line from <paramref name="from"/> on was written on <paramref name="threadId"/>, the thread that ran the tick.</summary>
    private static void AssertPostedOn(PluginHarness harness, int from, int threadId) =>
        Assert.All(harness.Host.Automation.Chat.PostedThreadIds.Skip(from), id => Assert.Equal(threadId, id));

    private static string[] Tail(PluginHarness harness, int count) =>
        [.. harness.ChatLines.Skip(Math.Max(0, harness.ChatLines.Count - count))];
}