using System.Collections;
using System.Collections.Generic;
using System.Linq;
using TMPro;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.UI;

namespace Beyond
{

    public class MainMenuDebug : MonoBehaviour
    {
        enum State { MAIN_MENU, LEVEL_SELECTION, LOADING_SCENE};
        State m_state = State.MAIN_MENU;
        public string[] m_levelNames;
        public GameObject m_mainButtons;
        public GameObject m_levelSelector;
        public GameObject m_sceneButtonPrefab;
        public GameObject m_loadingScreen;
        // Start is called before the first frame update
        void Start()
        {
        
        }

        public void OnPlayButton()
        {
            SetState(State.LEVEL_SELECTION);
        }

        void SetState(State state)
        {
            switch (state)
            {
                case State.MAIN_MENU:
                    m_mainButtons.SetActive(true);
                    m_levelSelector.SetActive(false);
                    m_loadingScreen.SetActive(false);
                    break;
                case State.LEVEL_SELECTION:
                    OnLevelSelection();
                    break;
                case State.LOADING_SCENE:
                    m_mainButtons.SetActive(false);
                    m_levelSelector.SetActive(false);
                    m_loadingScreen.SetActive(true);
                    break;
            }
        }

        IEnumerator LoadSceneCooroutine(int sceneNum)
        {
            // The Application loads the Scene in the background as the current Scene runs.
            // This is particularly good for creating loading screens.
            // You could also load the Scene by using sceneBuildIndex. In this case Scene2 has
            // a sceneBuildIndex of 1 as shown in Build Settings.
            //yield return new WaitForSeconds(1f); 
            AsyncOperation asyncLoad = SceneManager.LoadSceneAsync(sceneNum);
            asyncLoad.allowSceneActivation = false;
            // Wait until the asynchronous scene fully loads
            while (!asyncLoad.isDone)
            {
                //m_bar.transform.localScale = new Vector3(asyncLoad.progress, 0.9f, 1);
                if (asyncLoad.progress >= 0.9f)
                {
                    //m_bar.transform.localScale = new Vector3(0.9f, 0.9f, 1);
                    asyncLoad.allowSceneActivation = true;
                }
                yield return null;
            }
            //m_bar.transform.localScale = new Vector3(1.0f, 0.9f, 1);
            yield return null;
        }

        
        void OnLoadLevel(int num)
        {
            Debug.Log("Load level: " + num);
            SetState(State.LOADING_SCENE);
            StartCoroutine(LoadSceneCooroutine(num));
        }

        void OnLevelSelection()
        {
            m_mainButtons.SetActive(false);
            m_levelSelector.SetActive(true);
            for (int i = 0; i < m_levelSelector.transform.childCount; i++)
                Destroy(m_levelSelector.transform.GetChild(i).gameObject);
            //Debug.Log("Number of scenes: " + SceneManager.sceneCountInBuildSettings);
            for (int i=0; i<m_levelNames.Length; i++)
            {
                var prefab = GameObject.Instantiate(m_sceneButtonPrefab);
                var txt = prefab.GetComponentInChildren<TextMeshProUGUI>();
                txt.text = m_levelNames[i];
                prefab.transform.parent = m_levelSelector.transform;
                var button = prefab.GetComponent<Button>();
                int lvlNum = i + 1;
                button.onClick.AddListener(() => OnLoadLevel(lvlNum));
            }
            
        }

        // Update is called once per frame
        void Update()
        {
        
        }
    }
}