using Godot;
using System;
using System.Collections.Generic;

public abstract partial class StateMachine : Node
{
	[Export] public CharacterBody2D npc;
	[Export] public NodePath initialState; // Start tilstand skal angives...

	private Dictionary<string, State> _states;  // alle tilstande i denne datastruktur
	private State _currentState;    // nuværende tilstand

	public override void _Ready()
	{

		if (npc == null) {
			GD.Print("You forgot to set NPC..export");
		}

		if (initialState == null)
		{
			GD.Print("You forgot to set initialState..export");
		}

		_states = new Dictionary<string, State>();

		foreach (Node node in this.GetChildren()) {
			if (node is State s) {
				_states[node.Name] = s;
				s.fsm = this;
				s.Ready();
				s.Exit();
			}
		}

		_currentState = GetNode<State>(initialState);
		_currentState.Enter();

		GD.Print("StateMachine is ready.");
	}

	// Der der skiftes tilstand

	public void TransitionTo(string stateName){
		// sikkerheds tjeck at tilstand eksisterer, eller at den allerede er valgt
		if (!_states.ContainsKey(stateName) || _currentState == _states[stateName])
		{
			return;
		}

		// Der skiftes tilstand
		_currentState.Exit(); // vi rydder op efter os !
		_currentState = _states[stateName]; // Vi skifter til den nye tilstands
		_currentState.Enter(); // initialisering..
	}

	public override void _Process(double delta)
	{
		_currentState.Update((float) delta);
	}

	public override void _PhysicsProcess(double delta)
	{
		_currentState.PhysicsUpdate((float)delta);
	}

	// Sender ikke håndterede events videre til nuværende tilstand (State)
	public override void _UnhandledInput(InputEvent @event) {
		_currentState.HandleInput(@event);
	}
}