using System.Numerics;
using AcDream.Core.Chat;
using AcDream.UI.Abstractions.Panels.Chat;

namespace AcDream.UI.Abstractions.Tests.Panels.Chat;

/// <summary>
/// Phase J Tier 2: <see cref="ChatVM"/> tracks the last OUTGOING tell
/// target (for <c>/retell</c>) and exposes optional FpsProvider /
/// PositionProvider callbacks the panel uses to render
/// <c>/framerate</c> and <c>/loc</c> client-side commands without
/// reaching into render-loop state.
/// </summary>
public sealed class ChatVMRetellAndProvidersTests
{
    [Fact]
    public void LastOutgoingTellTarget_StartsNull()
    {
        var log = new ChatLog();
        var vm  = new ChatVM(log);
        Assert.Null(vm.LastOutgoingTellTarget);
    }

    [Fact]
    public void OnSelfSentTell_PopulatesLastOutgoingTellTarget()
    {
        var log = new ChatLog();
        var vm  = new ChatVM(log);

        log.OnSelfSent(ChatKind.Tell, "hi there", targetOrChannel: "Caith");

        Assert.Equal("Caith", vm.LastOutgoingTellTarget);
        // Inbound-tell tracker must NOT pick up an outgoing echo —
        // the SenderGuid==0 discriminator separates the two paths.
        Assert.Null(vm.LastIncomingTellSender);
    }

    [Fact]
    public void IncomingTell_DoesNotTouchOutgoingTarget()
    {
        var log = new ChatLog();
        var vm  = new ChatVM(log);

        log.OnTellReceived("Bestie", "psst", senderGuid: 0x5000_0042);

        Assert.Equal("Bestie", vm.LastIncomingTellSender);
        Assert.Null(vm.LastOutgoingTellTarget);
    }

    [Fact]
    public void OutgoingThenIncoming_TracksBothIndependently()
    {
        var log = new ChatLog();
        var vm  = new ChatVM(log);

        log.OnSelfSent(ChatKind.Tell, "hi", targetOrChannel: "Caith");
        log.OnTellReceived("Bestie", "psst", senderGuid: 0x5000_0042);

        Assert.Equal("Caith",  vm.LastOutgoingTellTarget);
        Assert.Equal("Bestie", vm.LastIncomingTellSender);
    }

    [Fact]
    public void ShowFps_WithProvider_AppendsFormattedLine()
    {
        var log = new ChatLog();
        var vm  = new ChatVM(log) { FpsProvider = () => 144.2f };

        vm.ShowFps();

        var entry = Assert.Single(log.Snapshot());
        Assert.Equal(ChatKind.System, entry.Kind);
        Assert.Equal("Framerate: 144.2 FPS", entry.Text);
    }

    [Fact]
    public void ShowFps_NoProvider_StillProducesDiagnosticLine()
    {
        var log = new ChatLog();
        var vm  = new ChatVM(log);

        vm.ShowFps();

        var entry = Assert.Single(log.Snapshot());
        Assert.Contains("provider unavailable", entry.Text);
    }

    [Fact]
    public void ShowLocation_WithProvider_AppendsFormattedLine()
    {
        var log = new ChatLog();
        var vm  = new ChatVM(log) { PositionProvider = () => new Vector3(123.4f, 567.8f, 60f) };

        vm.ShowLocation();

        var entry = Assert.Single(log.Snapshot());
        Assert.Equal("Location: (123.4, 567.8, 60.0)", entry.Text);
    }

    [Fact]
    public void ShowLocation_NoProvider_StillProducesDiagnosticLine()
    {
        var log = new ChatLog();
        var vm  = new ChatVM(log);

        vm.ShowLocation();

        Assert.Contains("provider unavailable", log.Snapshot()[0].Text);
    }
}