using System.Collections.Generic;
using System.Diagnostics;
using System.Linq;
using DonkeysAndDroids;
using Godot;
using RobotAndDonkey.Game;
using RobotAndDonkey.Game.Execution;
using RobotAndDonkey.Game.Execution.Commands;
using RobotAndDonkey.Game.Execution.Requests;
using RobotAndDonkey.Game.Execution.Results;
using RobotAndDonkey.Game.GameState;
using RobotAndDonkey.Game.Utils;

public partial class Main : CanvasLayer
{
    public enum EScreenId
    {
        Logo,
        MetaGame,
        CoreLoop,
        Victory
    }

    public override void _Ready()
    {
#if DEBUG
        if (!Trace.Listeners.OfType<DefaultTraceListener>().Any())
            Trace.Listeners.Add(new DefaultTraceListener());
#endif
        Instance = this;

        m_Runtime = new();
        m_Runtime.Published += (_, e) => OnGameEvent(e);

        m_Background = GetNode<Background>("Background");
        m_LogoScreen = GetNode<LogoScreen>("LogoScreen");
        m_MetaGameScreen = GetNode<MetaGameScreen>("MetaGameScreen");
        m_CoreLoopScreen = GetNode<CoreLoopScreen>("CoreLoopScreen");
        m_VictoryScreen = GetNode<VictoryScreen>("VictoryScreen");
        OptionsMenu = GetNode<OptionsMenu>("OptionsMenu");
        m_CurrentScreen = m_LogoScreen;

        Music.Init(this);
        Music.PlaySong(MusicManager.ESong.MetaGame);
    }

    public void StartMetaGame()
    {
        Music.PlaySong(MusicManager.ESong.MetaGame);
        var tween = GetTree().CreateTween();
        TransitionScreen(m_MetaGameScreen, tween);
    }

    public void TransitionScreen<T>(T newScreen, Tween tween) where T : Control, IScreen
    {
        newScreen.EnableInputs();
        if (m_CurrentScreen == newScreen)
            return;

        MoveChild(newScreen, 1);
        var oldControl = (Control)m_CurrentScreen;
        var oldScreen = m_CurrentScreen;
        m_CurrentScreen = newScreen;
        newScreen.Modulate = new(1, 1, 1);
        newScreen.Visible = true;
        newScreen.Activate();
        tween.TweenProperty(oldControl, "modulate", new Color(0, 0, 0, 0), 0.25);
        tween.TweenCallback(Callable.From(() =>
        {
            oldScreen.Deactivate();
            oldControl.Visible = false;
            oldControl.Modulate = new(1, 1, 1);
        }));
    }

    public void StartCoreLoop(int seed, EDifficulty difficulty, ERobotType selectedRobot)
    {
        Seed = seed;
        CoreLoop = new(new((ulong)seed), new(selectedRobot, difficulty, seed));
        m_Runtime.Start(CoreLoop);
    }

    private void OnGameEvent(GameEvent gameEvent)
    {
        switch (gameEvent.Payload)
        {
            case NextStepIssued { Step: { } request }:
            {
                m_NextRequest = request;
                if (m_Tween != null)
                    break;

                ProcessNextRequest();
                break;
            }

            case StepApplied { Results: var results }:
            {
                GD.Print("Results available");
                foreach (var result in results)
                {
                    Results.Enqueue(result);
                }

                break;
            }

            case StateChanged:
            {
                GD.Print("State changed");
                m_Tween = GetTree().CreateTween();
                while (Results.TryDequeue(out var result))
                {
                    GD.Print(result.ToString());
                    if (m_CurrentScreen.HandleResult(result, m_Tween))
                        m_Tween.SetParallel(false);
                    else
                        GD.Print("> Unhandled result!");
                }

                m_Tween.TweenCallback(Callable.From(() =>
                {
                    m_Tween = null;
                    ProcessNextRequest();
                }));

                break;
            }

            case StepRejected r:
            {
                GD.Print($"Invalid action: {r.Reason}");
                break;
            }

            case GameOver:
            {
                GD.Print("Game over");
                break;
            }
        }
    }

    private void ProcessNextRequest()
    {
        m_CurrentScreen.DisableInputs();
        CurrentRequest = m_NextRequest;
        m_NextRequest = null;
        GD.Print($"Next step: {CurrentRequest}");
        m_Tween = GetTree().CreateTween();
        var tween = m_Tween;
        switch (CurrentRequest)
        {
            case DrawGlitchRequest drawCardRequest:
            {
                Music.PlaySong(MusicManager.ESong.Shop);
                TransitionScreen(m_CoreLoopScreen, tween);
                m_CoreLoopScreen.DrawGlitch(drawCardRequest.Card, tween);
                break;
            }
            case ImproveRequest:
            {
                TransitionScreen(m_CoreLoopScreen, tween);
                m_CoreLoopScreen.Improve(tween);
                break;
            }
            case GambleRequest:
            {
                TransitionScreen(m_CoreLoopScreen, tween);
                m_CoreLoopScreen.CosmicRays(CoreLoop.BoosterPack, tween);
                break;
            }
            case BufferOverflowRequest:
            {
                TransitionScreen(m_CoreLoopScreen, tween);
                m_CoreLoopScreen.BufferOverflow(tween);
                break;
            }
            case ExecuteProgramRequest:
            {
                Music.PlaySong(MusicManager.ESong.CoreLoop);
                TransitionScreen(m_CoreLoopScreen, tween);
                m_CoreLoopScreen.ExecuteProgram(tween);
                break;
            }
            case ScoringRequest:
            {
                Music.PlaySong(MusicManager.ESong.Scoring);
                TransitionScreen(m_VictoryScreen, tween);
                m_VictoryScreen.Configure(CoreLoop, tween);
                break;
            }
        }
    }

    public void Execute(Command command)
    {
        if (command == null)
            return;

        GD.Print($"Execute {command}");
        m_Runtime.Submit(command);
    }

    public static Main Instance { get; set; }

    public Request CurrentRequest { get; private set; } = Request.s_Empty;

    public Queue<Result> Results { get; } = [];

    public CoreLoop CoreLoop { get; private set; }

    public int Seed { get; private set; }

    public string StringSeed => SeedString.ToString(Seed);

    public MusicManager Music { get; } = new();

    public OptionsMenu OptionsMenu { get; private set; }

    private Background m_Background;
    private CoreLoopScreen m_CoreLoopScreen;
    private IScreen m_CurrentScreen;
    private LogoScreen m_LogoScreen;
    private MetaGameScreen m_MetaGameScreen;
    private Request m_NextRequest;

    private GameRuntime m_Runtime;

    private Tween m_Tween;
    private VictoryScreen m_VictoryScreen;
}