using System.IO;
using Backend;
using Xunit;

namespace Backend.Tests;

public class GameProcessTests
{
    private static string LocateCliBinary()
    {
        var dir = AppContext.BaseDirectory;
        while (dir is not null)
        {
            var candidate = Path.Combine(dir, "publish", "GameCli", "GameCli");
            if (File.Exists(candidate)) return candidate;
            var parent = Directory.GetParent(dir);
            if (parent is null) break;
            dir = parent.FullName;
        }
        throw new FileNotFoundException(
            "publish/GameCli/GameCli not found — run `dotnet publish GameCli -c Release -o publish/GameCli`");
    }

    [Fact]
    public async Task StartsAndReadsInitHandshake()
    {
        await using var proc = new GameProcess(LocateCliBinary());
        await proc.StartAsync();
        Assert.Equal(0.02f, proc.Dt);
        Assert.Equal(7,    proc.ObsDim);
        Assert.Equal(4,    proc.NActions);
    }

    [Fact]
    public async Task StepReturnsSevenDimObservation()
    {
        await using var proc = new GameProcess(LocateCliBinary());
        await proc.StartAsync();
        var obs = await proc.StepAsync(action: 0, target: (0.5f, 0.5f));
        Assert.Equal(7, obs.Observation.Length);
        Assert.Equal(1, obs.Step);
    }

    [Fact]
    public async Task ResetClearsStepCounter()
    {
        await using var proc = new GameProcess(LocateCliBinary());
        await proc.StartAsync();
        for (int i = 0; i < 3; i++)
            await proc.StepAsync(action: 0, target: (0.5f, 0.5f));
        var afterReset = await proc.ResetAsync(seed: 42);
        Assert.Equal(0, afterReset.Step);
    }
}