using System.Collections;
using System.Collections.Generic;
using UnityEngine;
using UnityEngine.Events;
using System.Runtime.InteropServices;

#if IMAGINE_URP
using UnityEngine.Rendering;
using UnityEngine.Rendering.Universal;
#endif

namespace Imagine.WebAR
{
    [RequireComponent(typeof(Camera))]
    public class ARCamera : MonoBehaviour
    {
        [DllImport("__Internal")] private static extern void SetWebGLARCameraSettings(string settings);
        [DllImport("__Internal")] private static extern void WebGLStartCamera();
        [DllImport("__Internal")] private static extern bool WebGLIsCameraStarted();
        [DllImport("__Internal")] private static extern void WebGLUnpauseCamera();
        [DllImport("__Internal")] private static extern void WebGLPauseCamera();
        [DllImport("__Internal")] private static extern void WebGLGetCameraTexture(int textureId);
        [DllImport("__Internal")] private static extern string WebGLGetVideoDims();
        [DllImport("__Internal")] private static extern string WebGLSubscribeVideoTexturePtr(int textureId);
        [DllImport("__Internal")] private static extern bool IsWebcamPermissionGranted();
        [DllImport("__Internal")] private static extern void WebGLFlipCamera();
        [DllImport("__Internal")] private static extern bool WebGLIsCameraFlipped();

         public enum VideoPlaneMode {
            NONE,
            TEXTURE_PTR,
        }

        [SerializeField] public VideoPlaneMode videoPlaneMode = VideoPlaneMode.TEXTURE_PTR;
        [SerializeField] private Material videoPlaneMat;
        [SerializeField] private float videoDistance = 100;

        [SerializeField] public UnityEvent<Vector2> OnResized;
        
        [HideInInspector] public Camera cam;
        private GameObject videoBackground;
        private Texture2D videoTexture;
        private int videoTextureId;


        [Space][SerializeField] private bool unpausePauseOnEnableDisable = false;
        [SerializeField] private bool pauseOnDestroy = false;
        private bool paused = false;

        [SerializeField] private bool pauseOnApplicationLostFocus = false;
        [SerializeField][Range(0,1000)]private int resizeDelay = 50;
        
        [SerializeField] public UnityEvent<bool> OnCameraImageFlipped;
        [HideInInspector] public bool isFlipped = false;


        public enum ARCameraOrientation {PORTRAIT, LANDSCAPE};
        [SerializeField] public UnityEvent<ARCameraOrientation> OnCameraOrientationChanged;
        
        [HideInInspector] public ARCameraOrientation orientation;

        private void Awake()
        {
            cam = GetComponent<Camera>();
        }

        private IEnumerator Start()
        {
#if UNITY_WEBGL && !UNITY_EDITOR
            isFlipped = WebGLIsCameraFlipped();
#endif
            OnCameraImageFlipped?.Invoke(isFlipped);
            OnCameraOrientationChanged?.Invoke(Screen.height > Screen.width ? ARCameraOrientation.PORTRAIT : ARCameraOrientation.LANDSCAPE);

            
#if IMAGINE_URP
            //Debug.Log(GraphicsSettings.defaultRenderPipeline.GetType());
            if (GraphicsSettings.currentRenderPipeline != null &&
                 GraphicsSettings.defaultRenderPipeline.GetType().ToString().EndsWith("UniversalRenderPipelineAsset") &&
                 videoPlaneMode == VideoPlaneMode.NONE
                 )
            {
                Debug.Log("URP detected");
                cam.clearFlags = CameraClearFlags.Depth;
                cam.allowHDR = false;
                var camData = GetComponent<UniversalAdditionalCameraData>();
                camData.renderPostProcessing = false;

                Debug.Log(cam.clearFlags + " " + camData.renderPostProcessing);
            }
#endif
            SetARCameraSettings();
            StartCamera();
            yield break;
            
        }

        private void OnEnable(){
            if(unpausePauseOnEnableDisable)
                UnpauseCamera();
        }

        private void OnDisable(){
            if(unpausePauseOnEnableDisable)
                PauseCamera();
        }

        private void OnDestroy(){
            if(pauseOnDestroy)
                PauseCamera();
        }

        void SetARCameraSettings(){

            var json = "{";
            json += "\"UNITY_VIDEOPLANE\":" + (videoPlaneMode != VideoPlaneMode.NONE ? "true" : "false") +  ",";
            json += "\"RESIZE_DELAY\":" + resizeDelay;
            json += "}";
#if UNITY_WEBGL && !UNITY_EDITOR
            SetWebGLARCameraSettings(json);
#endif
        }

        void StartCamera(){
#if UNITY_WEBGL && !UNITY_EDITOR
            if(WebGLIsCameraStarted()){
                Debug.Log("SetVideoDims");
                SetVideoDims();
            }
            else{
                Debug.Log("StartCamera");
                WebGLStartCamera();
            }
#endif  
        }

        void OnStartWebcamSuccess(){
            SetVideoDims();
        }

        void OnStartWebcamFail(){
            Debug.LogError("Webcam failed to start!");
        }

        void SetCameraFov(float fov)
        {
            cam.fieldOfView = fov;
            Debug.Log("SetCameraFov " + cam.fieldOfView);
        }

        public void PauseCamera()
        {
            if(paused)
                return;

            Debug.Log("Pausing Camera...");
#if UNITY_WEBGL && !UNITY_EDITOR
            WebGLPauseCamera();
#endif
            paused = true;
        }

        public void UnpauseCamera()
        {
            if(!paused)
                return;

            Debug.Log("Unpausing Camera...");
#if UNITY_WEBGL && !UNITY_EDITOR
            WebGLUnpauseCamera();
#endif
            paused = false;
        }



        public void Resize(string dims)
        {

// #if UNITY_WEBGL && !UNITY_EDITOR
//             //this will tell arCamera in js if unity is also rendering a videoplane
//             //and will avoid rendering duplicate planes, and save some fps
//             WebGLUseUnityVideoPlane(videoPlaneMode != VideoPlaneMode.NONE);
// #endif

            var vals = dims.Split(new string[] { "," }, System.StringSplitOptions.RemoveEmptyEntries);
            var width = int.Parse(vals[0]);
            var height = int.Parse(vals[1]);

            Debug.Log("Got Video Texture Size - " + width + " x " + height);
            OnResized?.Invoke(new Vector2(width, height));

            if(videoPlaneMode == VideoPlaneMode.NONE)
            {
                //we resize only when videoplane is active
                return;
            }

            if(videoBackground != null){
                Destroy(videoBackground);
            }
            CreateVideoPlane(width, height);

            if(videoTexture != null)
                Destroy(videoTexture);
            
            videoTexture = new Texture2D(width, height);


            videoPlaneMat.mainTexture = videoTexture;
            videoTextureId = (int)videoTexture.GetNativeTexturePtr();

            Debug.Log("Unity WebGLSubscribeVideoTexturePtr -> " + videoTextureId);
#if UNITY_WEBGL && !UNITY_EDITOR
            WebGLSubscribeVideoTexturePtr(videoTextureId);
#endif

        }


        void CreateVideoPlane(int width, int height)
        {
            Debug.Log("Init video plane");

            videoBackground = GameObject.CreatePrimitive(PrimitiveType.Quad);
            videoBackground.name = "VideoBackground";
            videoBackground.transform.parent = transform;

            videoPlaneMat.mainTexture = null;
            videoBackground.GetComponent<Renderer>().material = videoPlaneMat;

            var ar = (float)Screen.width / (float)Screen.height;
            var v_ar = (float)width / (float)height;

            float heightScale = 1;

            if(v_ar > ar){
                Debug.Log("Bleed horizontally");
                heightScale = 2 * videoDistance * Mathf.Tan(cam.fieldOfView * Mathf.Deg2Rad / 2);
            }
            else{
                Debug.Log("Bleed vertically");
                var heightRatio = ar / v_ar;
                heightScale = 2 * videoDistance * Mathf.Tan(cam.fieldOfView * Mathf.Deg2Rad / 2) * heightRatio;
            }

            var widthScale = heightScale * v_ar * (isFlipped ? -1 : 1);

            videoBackground.transform.localScale = new Vector3(widthScale, heightScale, 1);
            videoBackground.transform.localPosition = new Vector3(0, 0, videoDistance);
            videoBackground.transform.localEulerAngles = Vector3.zero;
        }

        void SetVideoDims(){
            Resize( WebGLGetVideoDims());
        }

        // public void DebugDrawDataUrl(string dataUrl, int width, int height){
        //     Resize(width + "," + height);

        //     dataUrl = dataUrl.Replace("data:image/png;base64,", "");
        //     var oldTex = videoPlaneMat.mainTexture;
        //     if( oldTex != null){
        //         Destroy(oldTex);
        //     }

        //     Texture2D tex = new Texture2D (width, height);
        //     tex.LoadImage(System.Convert.FromBase64String(dataUrl));
        //     tex.Apply ();
        //     videoPlaneMat.mainTexture = tex;
        // }

        void OnApplicationFocus(bool hasFocus)
        {
            if(pauseOnApplicationLostFocus){
#if UNITY_WEBGL && !UNITY_EDITOR
                if(WebGLIsCameraStarted()){
                    if(hasFocus)
                        UnpauseCamera();
                    else
                        PauseCamera();
                }
#endif
            }
        }

        void OnApplicationPause(bool pauseStatus)
        {
            if(pauseOnApplicationLostFocus){
#if UNITY_WEBGL && !UNITY_EDITOR
                if(WebGLIsCameraStarted()){
                    if(!pauseStatus)
                        UnpauseCamera();
                    else
                        PauseCamera();
                }
#endif
            }
        }

        public void FlipCamera(){
#if UNITY_WEBGL && !UNITY_EDITOR
            WebGLFlipCamera();
#endif
        }
        void SetFlippedMessage (string message){
            Debug.Log("OnFlippedMessage = " + message);
            isFlipped = message == "true";
            OnCameraImageFlipped?.Invoke(isFlipped);

            //flip videoPlane
            if(videoBackground != null){
                var newScale = videoBackground.transform.localScale;
                newScale.x = Mathf.Abs(newScale.x) * (isFlipped ? -1 : 1);
                videoBackground.transform.localScale = newScale;
            }
        }

        void SetOrientationMessage (string message){
            Debug.Log("OrientationMessage = " + message);
            orientation = message == "PORTRAIT" ? ARCameraOrientation.PORTRAIT : ARCameraOrientation.LANDSCAPE;
            OnCameraOrientationChanged?.Invoke(orientation);
        }
    }
}