using System.Collections.Immutable;
using SideScrollerGame.Sim.Input;
using SideScrollerGame.Sim.Math;
using SideScrollerGame.Sim.Runtime;

namespace SideScrollerGame.Sim.Tests;

public sealed class SimulationStateTests
{
    [Fact]
    public void PlayerState_CloneAndButtonReleasePreserveIndependentState()
    {
        PlayerState player = new(new(1), new(3, 4), 1, 2, 5, 6, 7, 0, 9, FixPoint16.One, true, 3, 4);
        player.SetButton(InputButton.Dash, true);
        player.ApplyDamage(4);
        player.BufferJump(6);

        var clone = player.Clone();
        player.SetButton(InputButton.Dash, false);
        player.SetPosition(new(8, 9));
        player.SetVerticalVelocity(new(5));

        Assert.NotEqual(player.ButtonMask, clone.ButtonMask);
        Assert.Equal(7, clone.SelectedWeaponSlot);
        Assert.Equal(3, clone.Position.m_X.ToIntRound());
        Assert.Equal(4, clone.Position.m_Y.ToIntRound());
        Assert.Equal(5, clone.Health);
        Assert.Equal(1, clone.VerticalVelocity.ToIntRound());
        Assert.True(clone.IsGrounded);
        Assert.Equal(3, clone.LastGroundedTick);
        Assert.Equal(6, clone.BufferedJumpTick);
    }

    [Fact]
    public void SimulationState_CloneCreatesDeepCopy()
    {
        SimulationState original = new(4, 9, 123UL, 456UL, ImmutableArray.Create(new PlayerState(new(1), new(1, 2), 3, 4, 5, 6, 7, 8, 9, new(2), true, 4, -1)), ImmutableHashSet<string>.Empty.Add("checkpoint_a"));
        var clone = original.Clone();

        original.GetRequiredPlayer(new(1)).SetMoveAxis(9, 9);
        original.ActivateTrigger("checkpoint_b");

        Assert.Equal(4, clone.Tick);
        Assert.Equal(9, clone.Seed);
        Assert.Equal((ulong)123, clone.RandomState);
        Assert.Equal((ulong)456, clone.LastRandomValue);
        Assert.Equal(3, clone.GetRequiredPlayer(new(1)).MoveAxisX);
        Assert.Equal(2, clone.GetRequiredPlayer(new(1)).VerticalVelocity.ToIntRound());
        Assert.DoesNotContain("checkpoint_b", clone.ActivatedTriggerIds);
    }

    [Fact]
    public void SimulationState_AcceptsDefaultPlayerArray()
    {
        SimulationState state = new(0, 1, 1UL, 0UL, default, ImmutableHashSet<string>.Empty);

        Assert.Empty(state.Players);
        Assert.Empty(state.ActivatedTriggerIds);
    }

    [Fact]
    public void SimulationState_AcceptsDefaultTriggerSet()
    {
        SimulationState state = new(0, 1, 1UL, 0UL, ImmutableArray<PlayerState>.Empty, default!);

        Assert.Empty(state.ActivatedTriggerIds);
    }

    [Fact]
    public void ActivateTrigger_ReturnsFalseWhenRepeated()
    {
        SimulationState state = new(0, 1, 1UL, 0UL, ImmutableArray<PlayerState>.Empty, ImmutableHashSet<string>.Empty);

        Assert.True(state.ActivateTrigger("checkpoint_a"));
        Assert.False(state.ActivateTrigger("checkpoint_a"));
    }

    [Fact]
    public void PlayerState_BufferedJumpExpiresOutsideWindow()
    {
        PlayerState player = new(new(1), new(0, 0), 0, 0, 0, 0, 0, 0, 10, FixPoint16.Zero, false, -1, -1);
        player.BufferJump(3);

        Assert.True(player.HasBufferedJump(4, 1));
        Assert.False(player.HasBufferedJump(5, 1));

        player.ConsumeBufferedJump();

        Assert.False(player.HasBufferedJump(5, 5));
    }
}