using System;
using UnityEngine;

public class KitchenGameManager : MonoBehaviour {
    public static KitchenGameManager Instance { get; private set; }
    public event EventHandler OnStateChanged;
    public event EventHandler OnGamePaused;
    public event EventHandler OnGameUnpaused;

    private enum State {
        WaitingToStart,
        CountdownToStart,
        GamePlaying,
        GameOver
    }

    private State state;
    private float waitingToStartTimer = 1f;
    private float countdownToStartTimer = 3f;
    private float gamePlayingTimer;
    private const float gamePlayingTimerMax = 10f;
    private bool isGamePaused;

    private void Awake() {
        Instance = this;
        state = State.WaitingToStart;
        gamePlayingTimer = gamePlayingTimerMax;
    }

    private void Start() => GameInput.Instance.OnPauseAction += GameInput_OnPauseAction;

    private void GameInput_OnPauseAction(object sender, EventArgs e) => TogglePauseGame();

    private void TogglePauseGame() {
        isGamePaused = !isGamePaused;
        if (isGamePaused) {
            Time.timeScale = 0f;
            OnGamePaused?.Invoke(this, EventArgs.Empty);
        }
        else {
            Time.timeScale = 1f;
            OnGameUnpaused?.Invoke(this, EventArgs.Empty);
        }
    }

    private void Update() {
        switch (state) {
            case State.WaitingToStart:
                waitingToStartTimer -= Time.deltaTime;
                if (waitingToStartTimer > 0f) return;
                state = State.CountdownToStart;
                OnStateChanged?.Invoke(this, EventArgs.Empty);
                break;
            case State.CountdownToStart:
                countdownToStartTimer -= Time.deltaTime;
                if (countdownToStartTimer > 0f) return;
                state = State.GamePlaying;
                OnStateChanged?.Invoke(this, EventArgs.Empty);
                break;
            case State.GamePlaying:
                gamePlayingTimer -= Time.deltaTime;
                if (gamePlayingTimer > 0f) return;
                state = State.GameOver;
                gamePlayingTimer = gamePlayingTimerMax;
                OnStateChanged?.Invoke(this, EventArgs.Empty);
                break;
            case State.GameOver:
                break;
        }

        Debug.Log(state);
    }

    public bool IsGamePlaying() => state == State.GamePlaying;
    public bool IsCountToStartActive() => state == State.CountdownToStart;
    public float GetCountdownToStartTimer() => countdownToStartTimer;
    public bool IsGameOver() => state == State.GameOver;
    public float GetGamePlayingTimerNormalized() => 1 - (gamePlayingTimer / gamePlayingTimerMax);
}