using UnityEngine;
using UnityEngine.InputSystem;

//Could be a singleton
public class GameFlowManager : MonoBehaviour {
	/// <summary>
	/// True if time is frozen (Start, Pause Menu, Dead)
	/// </summary>
	/// <remarks>Could be renamed appropriately</remarks>
	[field: SerializeField]
	public bool Paused { get; private set; } = true;
	public BaseState CurrentState { get; private set; } = null!;
	bool lastStartButton;

	#region  Unity Messages
	void Awake() => CurrentState = new StartFlowState(this);

	void Start() => CurrentState.EnterState();
	#endregion

	void SetPause(bool value) {
		Paused = value;
		Time.timeScale = value ? 0f : 1f;
	}

	#region Inputs
	public void OnStart(InputAction.CallbackContext ctx) {
		//feels pretty redundant ^^'
		bool newValue = ctx.ReadValueAsButton();
		bool wasJustPressed = !lastStartButton && newValue;
		lastStartButton = newValue;

		if (!wasJustPressed)
			return;

		if (CurrentState is StartFlowState)
			SwitchState(new GameplayFlowState(this));
	}
	#endregion

	#region States
	void SwitchState(BaseState newState) {
		CurrentState.LeaveState();
		CurrentState = newState;
		newState.EnterState();
	}
	
	abstract class GameFlowState : BaseState {
		readonly protected GameFlowManager gameFlowManager; 
		
		protected GameFlowState(GameFlowManager gameFlowManager) {
			this.gameFlowManager = gameFlowManager;
		}
	}

	class StartFlowState : GameFlowState {
		public StartFlowState(GameFlowManager gameFlowManager) : base(gameFlowManager) {}
		
		public override void EnterState() {
			base.EnterState();
			
			Debug.Log("Press Start to start...!");
			gameFlowManager.SetPause(true);
		}

		public override void LeaveState() {
			Debug.Log("Let the games begin!!");
		}
	}
	class GameplayFlowState : GameFlowState {
		public GameplayFlowState(GameFlowManager gameFlowManager) : base(gameFlowManager) {}
		
		public override void EnterState() {
			base.EnterState();
			gameFlowManager.SetPause(false);
		}
	}
	class PauseMenuFlowState : GameFlowState {
		public PauseMenuFlowState(GameFlowManager gameFlowManager) : base(gameFlowManager) {}
		
		public override void EnterState() {
			base.EnterState();
			gameFlowManager.SetPause(true);
		}
	}
	class DeadFlowState : GameFlowState {
		public DeadFlowState(GameFlowManager gameFlowManager) : base(gameFlowManager) {}
		
		public override void EnterState() {
			base.EnterState();
			gameFlowManager.SetPause(true);
		}
	}
	#endregion
}