using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Rendering;
using UnityEngine.SceneManagement;

namespace Beyond
{
    public class PrefaceScroll : MonoBehaviour
    {

        // Start is called before the first frame update
        public Animator m_scrollAnimator;
        public Canvas m_canvas;
        public Camera m_GUICamera;
        public Camera m_ScrollCamera;


        public bool m_burnIn = false;
        public bool m_isOpen = false;
        public float m_burnInDelay = 1f;
        public float m_moveInTime = 1f;
        public float m_burnInTime = 1f;
        public float m_burnThreshold;
        [Tooltip("Motion curve for first move in")]
        public AnimationCurve m_MotionCurve;
        public AnimationCurve m_BurnInCurve;
        public Vector3 m_startPositionShift = new Vector3(-3f, 0f, 0f);
        private Vector3 m_startPosition;
        private Vector3 m_endPosition;
        private Transform m_scrollTransform;
        private Material m_scrollMat;
        public TMPro.TextMeshProUGUI[] m_pages;
        public float lettersPerSec = 50f;
        private int m_currentPage = -1;
        public string m_sceneName = "Land_01";


        void ActivateObjects(bool activate)
        {
            m_canvas.gameObject.SetActive(activate);
            m_GUICamera.gameObject.SetActive(activate);
            m_ScrollCamera.gameObject.SetActive(activate);
        }

        IEnumerator OpenAndBurnIn()
        {
            //BlockUI(true);
            ActivateObjects(true);

            float time = 0f;
            while (time < m_moveInTime)
            {
                time += Time.deltaTime;
                float val = m_MotionCurve.Evaluate(time / m_moveInTime);
                m_scrollTransform.position = m_startPosition - m_startPositionShift * val;
                yield return null;
            }

            m_scrollAnimator.SetBool("Open", true);
            yield return new WaitForSeconds(m_burnInDelay);
            time = 0f;
            while (time < m_burnInTime)
            {
                time += Time.deltaTime;
                float val = m_BurnInCurve.Evaluate(time / m_burnInTime);
                SetBurnInTh(val);
                yield return null;
            }
            yield return true;
        }

        IEnumerator CloseAndBurnOut()
        {
            float time = 0f;
            while (time < m_burnInTime)
            {
                time += Time.deltaTime;
                float val = m_BurnInCurve.Evaluate(1.0f - time / m_burnInTime);
                SetBurnInTh(val);
                yield return null;
            }

            m_scrollAnimator.SetBool("Open", false);
            time = 0f;
            yield return new WaitForSeconds(m_burnInDelay);

            while (time < m_moveInTime)
            {
                time += Time.deltaTime;
                float val = m_MotionCurve.Evaluate(1.0f - time / m_moveInTime);
                m_scrollTransform.position = m_startPosition - m_startPositionShift * val;
                yield return null;
            }

            //BlockUI(false);
            ActivateObjects(false);

            yield return true;
        }
        IEnumerator DisplayPages()
        {
            float time = 0f;
            for (int i=0; i < m_pages.Length-1; i++)
            {
                yield return new WaitForSeconds(m_pages[i].text.Length/ lettersPerSec);
                time = 0f;
                while (time < m_burnInTime)
                {
                    time += Time.deltaTime;
                    float val = m_BurnInCurve.Evaluate(1.0f - time / m_burnInTime);
                    SetBurnInTh(val);
                    yield return null;
                }
                m_pages[i].gameObject.SetActive(false);
                m_pages[i+1].gameObject.SetActive(true);
                time = 0f;
                while (time < m_burnInTime)
                {
                    time += Time.deltaTime;
                    float val = m_BurnInCurve.Evaluate(time / m_burnInTime);
                    SetBurnInTh(val);
                    yield return null;
                }
            }
            yield return new WaitForSeconds(m_pages[m_pages.Length-1].text.Length / lettersPerSec);
            yield return CloseAndBurnOut();
            SceneManager.LoadScene(m_sceneName, LoadSceneMode.Single);
            yield return null;
            /*
            float time = 0f;
            while (time < m_burnInTime)
            {
                time += Time.deltaTime;
                float val = m_BurnInCurve.Evaluate(1.0f - time / m_burnInTime);
                SetBurnInTh(val);
                yield return null;
            }
            m_panels[(int)m_activePanel].SetActive(false);
            m_panels[(int)panel].SetActive(true);
            time = 0f;
            while (time < m_burnInTime)
            {
                time += Time.deltaTime;
                float val = m_BurnInCurve.Evaluate(time / m_burnInTime);
                SetBurnInTh(val);
                yield return null;
            }
            m_activePanel = (PanelEnum)panel;
            */
            yield return null;
        }
        /*
        public void SwitchPanel(int panel)
        {
            if (panel == (int)m_activePanel)
                return;
            StartCoroutine(SwitchPanelCoroutine((PanelEnum)panel));

        }
        */
        void SetBurnInTh(float burnTh)
        {
            m_scrollMat.SetFloat("_Threshold", burnTh);
        }

        void Awake()
        {
            if (!m_scrollAnimator)
            {
                m_scrollAnimator = transform.GetComponentInChildren<Animator>();
            }
            m_scrollAnimator.SetBool("Open", false);
            m_scrollTransform = m_scrollAnimator.transform.parent;
            m_scrollMat = m_scrollAnimator.transform.GetComponentInChildren<Renderer>().material;

        }

        public void OpenCloseScroll(bool open)
        {
            if (open)
                StartCoroutine(OpenAndBurnIn());
            else
                StartCoroutine(CloseAndBurnOut());
        }

       

        void Start()
        {
            m_endPosition = m_scrollTransform.position;
            m_startPosition = m_endPosition + m_startPositionShift;
            m_scrollTransform.position = m_startPosition;
            OpenCloseScroll(true);
            StartCoroutine(DisplayPages());
            //ActivateObjects(false);
        }

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

}