using Godot;
using Godot.Collections;
using System;
using System.Data;
using System.Linq;

[GlobalClass]
public partial class CardStateMachine : Node
{
    private State currentState;
    private CardUI cardUI;
    private const float DRAG_MINIMUM_THRESHOLD = 0.05f;
    private bool minimumDragTimeElsapsed = false;
    private bool played;

    [Signal]
    public delegate void TransitionRequestedEventHandler(State from, State to);

    public void Init(CardUI cardUI)
    {
        // construct card states
        currentState = State.Base;
        this.cardUI = cardUI;
        this.Enter();
    }

    public async void Enter(State state = State.None)
    {
        switch (state)
        {
            case State.None:
                this.Enter(currentState);
                break;
            case State.Base:
                if (!cardUI.IsNodeReady())
                {
                    await ToSignal(cardUI, Node.SignalName.Ready);
                }

                cardUI.EmitSignal(CardUI.SignalName.ReparentRequested, cardUI);
                cardUI.color.Color = Color.Color8(0, 128, 0);
                cardUI.state.Text = "BASE";
                cardUI.PivotOffset = Vector2.Zero;
                
                if (cardUI.tapped)
                {
                    cardUI.RotationDegrees = 90.0f;
                    cardUI.Position = new Vector2(cardUI.Position.X + 200.0f, cardUI.Position.Y);
                }
                else
                {
                    cardUI.RotationDegrees = 0.0f;
                }

                break;
            case State.Clicked:
                cardUI.color.Color = Color.Color8(255, 165, 0);
                cardUI.state.Text = "CLICKED";
                cardUI.dropDetector.Monitoring = true;
                break;
            case State.Dragging:
                Node uiLayer = GetTree().GetFirstNodeInGroup("ui_layer");

                if (IsInstanceIdValid(uiLayer.GetInstanceId()))
                {
                    cardUI.Reparent(uiLayer);
                }

                cardUI.color.Color = Color.Color8(0, 0, 128);
                cardUI.state.Text = "DRAGGING";
                minimumDragTimeElsapsed = false;
                SceneTreeTimer thresholdTimer = GetTree().CreateTimer(DRAG_MINIMUM_THRESHOLD, false);
                thresholdTimer.Connect(SceneTreeTimer.SignalName.Timeout, Callable.From(() => minimumDragTimeElsapsed = true));
                break;
            case State.Released:
                cardUI.color.Color = Color.Color8(148, 0, 211);
                cardUI.state.Text = "RELEASED";
                played = false;

                if (cardUI.targetedZone == CardZone.ZoneType.Battlefield)
                {
                    played = true;
                    cardUI.EmitSignal(CardUI.SignalName.ReparentRequested, cardUI);
                    Node topLayer = GetTree().GetFirstNodeInGroup("top_layer");

                    if (topLayer is Main mainNode)
                    {
                        ManaGroveState gameState = mainNode.GetNode<ManaGroveState>("ManaGroveState");
                        gameState.EmitSignal(ManaGroveState.SignalName.MoveCard, [cardUI, (int)cardUI.targetedZone]);
                    }
                }
                else
                {
                    this.EmitSignal(CardStateMachine.SignalName.TransitionRequested, [(int)State.Released, (int)State.Base]);
                }

                break;
        }
    }

    public void Exit(State state = State.None)
    {
        switch (state)
        {
            case State.None:
                this.Exit(currentState);
                break;
        }
    }

	public void OnInput(InputEvent @event)
    {
        switch (currentState)
        {
            case State.Clicked:
                if (cardUI.currentZone == CardZone.ZoneType.Battlefield)
                {
                    if (cardUI.tapped)
                    {   
                        cardUI.Position = new Vector2(cardUI.Position.X - 200.0f, cardUI.Position.Y);
                    }

                    cardUI.tapped = !cardUI.tapped;
                    this.EmitSignal(CardStateMachine.SignalName.TransitionRequested, [(int)State.Clicked, (int)State.Base]);
                }
                else
                {
                    if (@event.IsClass("InputEventMouseMotion"))
                    {
                        this.EmitSignal(CardStateMachine.SignalName.TransitionRequested, [(int)State.Clicked, (int)State.Dragging]);
                    }
                }

                break;
            case State.Dragging:
                bool mouseMotion = @event.IsClass("InputEventMouseMotion");
                bool confirm = @event.IsActionReleased("left_mouse");
                bool canBePlayed = cardUI.CanBePlayed(cardUI.targetedZone);

                if (mouseMotion)
                {
                    cardUI.GlobalPosition = cardUI.GetGlobalMousePosition() - cardUI.PivotOffset;
                }

                if (minimumDragTimeElsapsed && confirm && canBePlayed)
                {
                    GetViewport().SetInputAsHandled();
                    this.EmitSignal(CardStateMachine.SignalName.TransitionRequested, [(int)State.Dragging, (int)State.Released]);
                }
                else if (minimumDragTimeElsapsed && confirm && !canBePlayed)
                {
                    cardUI.targetedZone = CardZone.ZoneType.None;
                    this.EmitSignal(CardStateMachine.SignalName.TransitionRequested, [(int)State.Dragging, (int)State.Base]);
                }

                break;
            case State.Released:
                this.EmitSignal(CardStateMachine.SignalName.TransitionRequested, [(int)State.Released, (int)State.Base]);
                break;
        }
    }

	public void OnGuiInput(InputEvent @event)
    {
        switch (currentState)
        {
            case State.Base:
                if (@event.IsActionPressed("left_mouse"))
                {
                    cardUI.PivotOffset = cardUI.GetGlobalMousePosition() - cardUI.GlobalPosition;
                    this.EmitSignal(CardStateMachine.SignalName.TransitionRequested, [(int)State.Base, (int)State.Clicked]);
                }

                break;
        }
    }

	public void OnMouseEntered()
    {
        
    }

	public void OnMouseExited()
    {
        
    }

	public void OnTransitionRequested(State from, State to)
    {
        if (from != currentState)
        {
            return;
        }

        Exit(from);
        Enter(to);
        currentState = to;
    }
}

public enum State
{
    None = -1,
	Base = 0,
	Clicked,
	Dragging,
	Released
}