package com.serenegiant.glutils;
/*
 * libcommon
 * utility/helper classes for myself
 *
 * Copyright (c) 2014-2018 saki t_saki@serenegiant.com
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
*/

import android.annotation.SuppressLint;
import android.annotation.TargetApi;
import android.graphics.SurfaceTexture;
import android.opengl.EGL14;
import android.opengl.EGLConfig;
import android.opengl.EGLContext;
import android.opengl.EGLDisplay;
import android.opengl.EGLExt;
import android.opengl.EGLSurface;
import android.opengl.GLES10;
import android.opengl.GLES20;
import android.os.Build;
import android.util.Log;
import android.view.Surface;
import android.view.SurfaceHolder;
import android.view.SurfaceView;

import androidx.annotation.NonNull;

import com.serenegiant.utils.BuildCheck;

/**
 * EGLレンダリングコンテキストを生成＆使用するためのヘルパークラス
 */
@TargetApi(Build.VERSION_CODES.JELLY_BEAN_MR2)
/*package*/ class EGLBase14 extends EGLBase {	// API >= 17
//	private static final boolean DEBUG = false;	// TODO set false on release
	private static final String TAG = "EGLBase14";

	private static final Context EGL_NO_CONTEXT = new Context(EGL14.EGL_NO_CONTEXT);

    private Config mEglConfig = null;
    @NonNull private Context mContext = EGL_NO_CONTEXT;
//	private EGLContext mEglContext = EGL14.EGL_NO_CONTEXT;
	private EGLDisplay mEglDisplay = EGL14.EGL_NO_DISPLAY;
	private EGLContext mDefaultContext = EGL14.EGL_NO_CONTEXT;
	private int mGlVersion = 2;

	/**
	 * EGLレンダリングコンテキストのホルダークラス
	 */
	public static class Context extends IContext {
		public final EGLContext eglContext;

		private Context(final EGLContext context) {
			eglContext = context;
		}
		
		@Override
		@SuppressLint("NewApi")
		public long getNativeHandle() {
			return eglContext != null ?
				(BuildCheck.isLollipop()
					? eglContext.getNativeHandle() : eglContext.getHandle()) : 0L;
		}
	
		@Override
		public Object getEGLContext() {
			return eglContext;
		}
	}

	public static class Config extends IConfig {
		public final EGLConfig eglConfig;

		private Config(final EGLConfig eglConfig) {
			this.eglConfig = eglConfig;
		}
	}

	/**
	 * EGLレンダリングコンテキストに紐付ける描画オブジェクト
	 */
	public static class EglSurface implements IEglSurface {
		private final EGLBase14 mEglBase;
		private EGLSurface mEglSurface = EGL14.EGL_NO_SURFACE;

		private EglSurface(final EGLBase14 eglBase, final Object surface)
			throws IllegalArgumentException {

//			if (DEBUG) Log.v(TAG, "EglSurface:");
			mEglBase = eglBase;
			if ((surface instanceof Surface)
				|| (surface instanceof SurfaceHolder)
				|| (surface instanceof SurfaceTexture)
				|| (surface instanceof SurfaceView)) {
				mEglSurface = mEglBase.createWindowSurface(surface);
			} else {
				throw new IllegalArgumentException("unsupported surface");
			}
		}

		/**
		 * 指定した大きさを持つオフスクリーンEglSurface(PBuffer)
		 * @param eglBase
		 * @param width
		 * @param height
		 */
		private EglSurface(final EGLBase14 eglBase,
			final int width, final int height) {

//			if (DEBUG) Log.v(TAG, "EglSurface:");
			mEglBase = eglBase;
			if ((width <= 0) || (height <= 0)) {
				mEglSurface = mEglBase.createOffscreenSurface(1, 1);
			} else {
				mEglSurface = mEglBase.createOffscreenSurface(width, height);
			}
		}

		@Override
		public void makeCurrent() {
			mEglBase.makeCurrent(mEglSurface);
			if (mEglBase.getGlVersion() >= 2) {
				GLES20.glViewport(0, 0,
					mEglBase.getSurfaceWidth(mEglSurface),
					mEglBase.getSurfaceHeight(mEglSurface));
			} else {
				GLES10.glViewport(0, 0,
					mEglBase.getSurfaceWidth(mEglSurface),
					mEglBase.getSurfaceHeight(mEglSurface));
			}
		}

		@Override
		public void swap() {
			mEglBase.swap(mEglSurface);
		}

		@Override
		public void swap(final long presentationTimeNs) {
			mEglBase.swap(mEglSurface, presentationTimeNs);
		}

		public void setPresentationTime(final long presentationTimeNs) {
			EGLExt.eglPresentationTimeANDROID(mEglBase.mEglDisplay,
				mEglSurface, presentationTimeNs);
		}

		@Override
		public IContext getContext() {
			return mEglBase.getContext();
		}

		@Override
		public boolean isValid() {
			return (mEglSurface != null)
				&& (mEglSurface != EGL14.EGL_NO_SURFACE)
				&& (mEglBase.getSurfaceWidth(mEglSurface) > 0)
				&& (mEglBase.getSurfaceHeight(mEglSurface) > 0);
		}

		@Override
		public void release() {
//			if (DEBUG) Log.v(TAG, "EglSurface:release:");
			mEglBase.makeDefault();
			mEglBase.destroyWindowSurface(mEglSurface);
	        mEglSurface = EGL14.EGL_NO_SURFACE;
		}
	}

	/**
	 * コンストラクタ
	 * @param maxClientVersion
	 * @param sharedContext
	 * @param withDepthBuffer
	 * @param isRecordable
	 */
	public EGLBase14(final int maxClientVersion,
		final Context sharedContext, final boolean withDepthBuffer,
		final int stencilBits, final boolean isRecordable) {

//		if (DEBUG) Log.v(TAG, "Constructor:");
		init(maxClientVersion, sharedContext, withDepthBuffer, stencilBits, isRecordable);
	}

	/**
	 * 関連するリソースを破棄する
	 */
	@Override
    public void release() {
//		if (DEBUG) Log.v(TAG, "release:");
        if (mEglDisplay != EGL14.EGL_NO_DISPLAY) {
	    	destroyContext();
	        EGL14.eglTerminate(mEglDisplay);
	        EGL14.eglReleaseThread();
        }
        mEglDisplay = EGL14.EGL_NO_DISPLAY;
        mContext = EGL_NO_CONTEXT;
    }

	/**
	 * 指定したSurfaceからEglSurfaceを生成する
	 * 生成したEglSurfaceをmakeCurrentした状態で戻る
	 * @param nativeWindow Surface/SurfaceTexture/SurfaceHolder
	 * @return
	 */
	@Override
	public EglSurface createFromSurface(final Object nativeWindow) {
//		if (DEBUG) Log.v(TAG, "createFromSurface:");
		final EglSurface eglSurface = new EglSurface(this, nativeWindow);
		eglSurface.makeCurrent();
		return eglSurface;
	}

	/**
	 * 指定した大きさのオフスクリーンEglSurfaceを生成する
	 * 生成したEglSurfaceをmakeCurrentした状態で戻る
	 * @param width PBufferオフスクリーンのサイズ(0以下はだめ)
	 * @param height
	 * @return
	 */
	@Override
	public EglSurface createOffscreen(final int width, final int height) {
//		if (DEBUG) Log.v(TAG, "createOffscreen:");
		final EglSurface eglSurface = new EglSurface(this, width, height);
		eglSurface.makeCurrent();
		return eglSurface;
	}

	/**
	 * GLESに文字列を問い合わせる
	 * @param what
	 * @return
	 */
 	public String queryString(final int what) {
		return EGL14.eglQueryString(mEglDisplay, what);
	}

	/**
	 * GLESバージョンを取得する
	 * @return 1, 2または3
	 */
	@Override
	public int getGlVersion() {
		return mGlVersion;
	}

	/**
	 * EGLレンダリングコンテキストを取得する
	 * このEGLBaseインスタンスを使って生成したEglSurfaceをmakeCurrentした状態で
	 * eglGetCurrentContextを呼び出すのと一緒
	 * @return
	 */
	@Override
	public Context getContext() {
		return mContext;
	}

	/**
	 * EGLコンフィグを取得する
	 * @return
	 */
	@Override
	public Config getConfig() {
		return mEglConfig;
	}

	/**
	 * EGLレンダリングコンテキストとスレッドの紐付けを解除する
	 */
	@Override
	public void makeDefault() {
//		if (DEBUG) Log.v(TAG, "makeDefault:");
        if (!EGL14.eglMakeCurrent(mEglDisplay,
        	EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_CONTEXT)) {

            Log.w("TAG", "makeDefault" + EGL14.eglGetError());
        }
	}

	/**
	 * eglWaitGLとeglWaitNativeを呼ぶ
	 *
	 * eglWaitGL: コマンドキュー内のコマンドをすべて転送する, GLES20.glFinish()と同様の効果
	 * eglWaitNative: GPU側の描画処理が終了するまで実行をブロックする
	 */
	@Override
	public void sync() {
		EGL14.eglWaitGL();	// GLES20.glFinish()と同様の効果
		EGL14.eglWaitNative(EGL14.EGL_CORE_NATIVE_ENGINE);
	}

	private void init(final int maxClientVersion, Context sharedContext,
		final boolean withDepthBuffer, final int stencilBits, final boolean isRecordable) {

//		if (DEBUG) Log.v(TAG, "init:");
        if (mEglDisplay != EGL14.EGL_NO_DISPLAY) {
            throw new RuntimeException("EGL already set up");
        }

        mEglDisplay = EGL14.eglGetDisplay(EGL14.EGL_DEFAULT_DISPLAY);
        if (mEglDisplay == EGL14.EGL_NO_DISPLAY) {
            throw new RuntimeException("eglGetDisplay failed");
        }
		// EGLのバージョンを取得
		final int[] version = new int[2];
        if (!EGL14.eglInitialize(mEglDisplay, version, 0, version, 1)) {
        	mEglDisplay = null;
            throw new RuntimeException("eglInitialize failed");
        }

		sharedContext = (sharedContext != null) ? sharedContext : EGL_NO_CONTEXT;

		EGLConfig config;
		if (maxClientVersion >= 3) {
			// GLES3で取得できるかどうか試してみる
			config = getConfig(3, withDepthBuffer, stencilBits, isRecordable);
			if (config != null) {
				final EGLContext context = createContext(sharedContext, config, 3);
				if (EGL14.eglGetError() == EGL14.EGL_SUCCESS) {
					// ここは例外生成したくないのでcheckEglErrorの代わりに自前でチェック
					mEglConfig = new Config(config);
					mContext = new Context(context);
					mGlVersion = 3;
				}
			}
		}
		// GLES3で取得できなかった時はGLES2を試みる
		if ((maxClientVersion >= 2)
			&& ((mContext == null) || (mContext.eglContext == EGL14.EGL_NO_CONTEXT))) {

			config = getConfig(2, withDepthBuffer, stencilBits, isRecordable);
			if (config == null) {
				throw new RuntimeException("chooseConfig failed");
			}
			try {
				// create EGL rendering context
				final EGLContext context = createContext(sharedContext, config, 2);
				checkEglError("eglCreateContext");
				mEglConfig = new Config(config);
				mContext = new Context(context);
				mGlVersion = 2;
			} catch (final Exception e) {
				if (isRecordable) {
					config = getConfig(2, withDepthBuffer, stencilBits, false);
					if (config == null) {
						throw new RuntimeException("chooseConfig failed");
					}
					// create EGL rendering context
					final EGLContext context = createContext(sharedContext, config, 2);
					checkEglError("eglCreateContext");
					mEglConfig = new Config(config);
					mContext = new Context(context);
					mGlVersion = 2;
				}
			}
        }
        if ((mContext == null) || (mContext.eglContext == EGL14.EGL_NO_CONTEXT)) {
			config = getConfig(1, withDepthBuffer, stencilBits, isRecordable);
			if (config == null) {
				throw new RuntimeException("chooseConfig failed");
			}
			// create EGL rendering context
			final EGLContext context = createContext(sharedContext, config, 1);
			checkEglError("eglCreateContext");
			mEglConfig = new Config(config);
			mContext = new Context(context);
			mGlVersion = 1;
		}
        // confirm whether the EGL rendering context is successfully created
        final int[] values = new int[1];
        EGL14.eglQueryContext(mEglDisplay,
        	mContext.eglContext, EGL14.EGL_CONTEXT_CLIENT_VERSION, values, 0);
        Log.d(TAG, "EGLContext created, client version " + values[0]);
        makeDefault();	// makeCurrent(EGL14.EGL_NO_SURFACE);
	}

	/**
	 * change context to draw this window surface
	 * @return
	 */
	private boolean makeCurrent(final EGLSurface surface) {
//		if (DEBUG) Log.v(TAG, "makeCurrent:");
/*        if (mEglDisplay == null) {
			if (DEBUG) Log.d(TAG, "makeCurrent:eglDisplay not initialized");
        } */
        if (surface == null || surface == EGL14.EGL_NO_SURFACE) {
            final int error = EGL14.eglGetError();
            if (error == EGL14.EGL_BAD_NATIVE_WINDOW) {
                Log.e(TAG, "makeCurrent:returned EGL_BAD_NATIVE_WINDOW.");
            }
            return false;
        }
        // attach EGL rendering context to specific EGL window surface
        if (!EGL14.eglMakeCurrent(mEglDisplay, surface, surface, mContext.eglContext)) {
            Log.w("TAG", "eglMakeCurrent" + EGL14.eglGetError());
            return false;
        }
        return true;
	}

	private int swap(final EGLSurface surface) {
//		if (DEBUG) Log.v(TAG, "swap:");
        if (!EGL14.eglSwapBuffers(mEglDisplay, surface)) {
        	final int err = EGL14.eglGetError();
//        	if (DEBUG) Log.w(TAG, "swap:err=" + err);
            return err;
        }
        return EGL14.EGL_SUCCESS;
    }

    private int swap(final EGLSurface surface, final long presentationTimeNs) {
//		if (DEBUG) Log.v(TAG, "swap:");
		EGLExt.eglPresentationTimeANDROID(mEglDisplay, surface, presentationTimeNs);
        if (!EGL14.eglSwapBuffers(mEglDisplay, surface)) {
        	final int err = EGL14.eglGetError();
//        	if (DEBUG) Log.w(TAG, "swap:err=" + err);
            return err;
        }
        return EGL14.EGL_SUCCESS;
	}

    private EGLContext createContext(final Context sharedContext,
    	final EGLConfig config, final int version) {

//		if (DEBUG) Log.v(TAG, "createContext:");

        final int[] attrib_list = {
        	EGL14.EGL_CONTEXT_CLIENT_VERSION, version,
        	EGL14.EGL_NONE
        };
		final EGLContext context = EGL14.eglCreateContext(mEglDisplay,
			config, sharedContext.eglContext, attrib_list, 0);
//		checkEglError("eglCreateContext");
        return context;
    }

    private void destroyContext() {
//		if (DEBUG) Log.v(TAG, "destroyContext:");

        if (!EGL14.eglDestroyContext(mEglDisplay, mContext.eglContext)) {
            Log.e("destroyContext", "display:" + mEglDisplay
            	+ " context: " + mContext.eglContext);
            Log.e(TAG, "eglDestroyContext:" + EGL14.eglGetError());
        }
        mContext = EGL_NO_CONTEXT;
        if (mDefaultContext != EGL14.EGL_NO_CONTEXT) {
	        if (!EGL14.eglDestroyContext(mEglDisplay, mDefaultContext)) {
	            Log.e("destroyContext", "display:" + mEglDisplay
	            	+ " context: " + mDefaultContext);
	            Log.e(TAG, "eglDestroyContext:" + EGL14.eglGetError());
	        }
	        mDefaultContext = EGL14.EGL_NO_CONTEXT;
        }
    }

	private final int[] mSurfaceDimension = new int[2];
	private final int getSurfaceWidth(final EGLSurface surface) {
		final boolean ret = EGL14.eglQuerySurface(mEglDisplay,
			surface, EGL14.EGL_WIDTH, mSurfaceDimension, 0);
		if (!ret) mSurfaceDimension[0] = 0;
		return mSurfaceDimension[0];
	}

	private final int getSurfaceHeight(final EGLSurface surface) {
		final boolean ret = EGL14.eglQuerySurface(mEglDisplay,
			surface, EGL14.EGL_HEIGHT, mSurfaceDimension, 1);
		if (!ret) mSurfaceDimension[1] = 0;
		return mSurfaceDimension[1];
	}

	/**
	 * nativeWindow should be one of the Surface, SurfaceHolder and SurfaceTexture
	 * @param nativeWindow
	 * @return
	 */
    private final EGLSurface createWindowSurface(final Object nativeWindow) {
//		if (DEBUG) Log.v(TAG, "createWindowSurface:nativeWindow=" + nativeWindow);

        final int[] surfaceAttribs = {
			EGL14.EGL_NONE
        };
		EGLSurface result = null;
		try {
			result = EGL14.eglCreateWindowSurface(mEglDisplay,
				mEglConfig.eglConfig, nativeWindow, surfaceAttribs, 0);
			if (result == null || result == EGL14.EGL_NO_SURFACE) {
				final int error = EGL14.eglGetError();
				if (error == EGL14.EGL_BAD_NATIVE_WINDOW) {
					Log.e(TAG, "createWindowSurface returned EGL_BAD_NATIVE_WINDOW.");
				}
				throw new RuntimeException("createWindowSurface failed error=" + error);
			}
			makeCurrent(result);
			// 画面サイズ・フォーマットの取得
		} catch (final Exception e) {
			Log.e(TAG, "eglCreateWindowSurface", e);
			throw new IllegalArgumentException(e);
		}
		return result;
	}

    /**
     * Creates an EGL surface associated with an offscreen buffer.
     */
    private final EGLSurface createOffscreenSurface(final int width, final int height) {
//		if (DEBUG) Log.v(TAG, "createOffscreenSurface:");
        final int[] surfaceAttribs = {
                EGL14.EGL_WIDTH, width,
                EGL14.EGL_HEIGHT, height,
                EGL14.EGL_NONE
        };
		EGLSurface result = null;
		try {
			result = EGL14.eglCreatePbufferSurface(mEglDisplay,
				mEglConfig.eglConfig, surfaceAttribs, 0);
	        checkEglError("eglCreatePbufferSurface");
	        if (result == null) {
	            throw new RuntimeException("surface was null");
	        }
		} catch (final IllegalArgumentException e) {
			Log.e(TAG, "createOffscreenSurface", e);
		} catch (final RuntimeException e) {
			Log.e(TAG, "createOffscreenSurface", e);
		}
		return result;
    }

	private void destroyWindowSurface(EGLSurface surface) {
//		if (DEBUG) Log.v(TAG, "destroySurface:");

        if (surface != EGL14.EGL_NO_SURFACE) {
        	EGL14.eglMakeCurrent(mEglDisplay,
        		EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_SURFACE, EGL14.EGL_NO_CONTEXT);
        	EGL14.eglDestroySurface(mEglDisplay, surface);
        }
        surface = EGL14.EGL_NO_SURFACE;
//		if (DEBUG) Log.v(TAG, "destroySurface:finished");
	}

    private void checkEglError(final String msg) {
        int error;
        if ((error = EGL14.eglGetError()) != EGL14.EGL_SUCCESS) {
            throw new RuntimeException(msg + ": EGL error: 0x" + Integer.toHexString(error));
        }
    }

    private EGLConfig getConfig(final int version,
    	final boolean hasDepthBuffer, final int stencilBits, final boolean isRecordable) {

		int renderableType = EGL_OPENGL_ES2_BIT;
		if (version >= 3) {
			renderableType |= EGL_OPENGL_ES3_BIT_KHR;
		}
        final int[] attribList = {
			EGL14.EGL_RENDERABLE_TYPE, renderableType,
			EGL14.EGL_RED_SIZE, 8,
			EGL14.EGL_GREEN_SIZE, 8,
			EGL14.EGL_BLUE_SIZE, 8,
			EGL14.EGL_ALPHA_SIZE, 8,
//        	EGL14.EGL_SURFACE_TYPE, EGL14.EGL_WINDOW_BIT | swapBehavior,
			EGL14.EGL_NONE, EGL14.EGL_NONE,	//EGL14.EGL_STENCIL_SIZE, 8,
			// this flag need to recording of MediaCodec
			EGL14.EGL_NONE, EGL14.EGL_NONE,	//EGL_RECORDABLE_ANDROID, 1,
			EGL14.EGL_NONE,	EGL14.EGL_NONE,	//	with_depth_buffer ? EGL14.EGL_DEPTH_SIZE : EGL14.EGL_NONE,
											// with_depth_buffer ? 16 : 0,
			EGL14.EGL_NONE
        };
        int offset = 10;
        if (stencilBits > 0) {	// ステンシルバッファ(常時未使用)
        	attribList[offset++] = EGL14.EGL_STENCIL_SIZE;
        	attribList[offset++] = stencilBits;
        }
        if (hasDepthBuffer) {	// デプスバッファ
        	attribList[offset++] = EGL14.EGL_DEPTH_SIZE;
        	attribList[offset++] = 16;
        }
        if (isRecordable && BuildCheck.isAndroid4_3()) {// MediaCodecの入力用Surfaceの場合
        	attribList[offset++] = EGL_RECORDABLE_ANDROID;
        	attribList[offset++] = 1;
        }
        for (int i = attribList.length - 1; i >= offset; i--) {
        	attribList[i] = EGL14.EGL_NONE;
        }
        EGLConfig config = internalGetConfig(attribList);
		if ((config == null) && (version == 2)) {
			if (isRecordable) {
				// EGL_RECORDABLE_ANDROIDをつけると失敗する機種もあるので取り除く
				final int n = attribList.length;
				for (int i = 10; i < n - 1; i += 2) {
					if (attribList[i] == EGL_RECORDABLE_ANDROID) {
						for (int j = i; j < n; j++) {
							attribList[j] = EGL14.EGL_NONE;
						}
						break;
					}
				}
				config = internalGetConfig(attribList);
			}
		}
		if (config == null) {
			Log.w(TAG, "try to fallback to RGB565");
			attribList[3] = 5;
			attribList[5] = 6;
			attribList[7] = 5;
			config = internalGetConfig(attribList);
		}
        return config;
    }

	private EGLConfig internalGetConfig(final int[] attribList) {
		final EGLConfig[] configs = new EGLConfig[1];
		final int[] numConfigs = new int[1];
		if (!EGL14.eglChooseConfig(mEglDisplay,
			attribList, 0, configs, 0, configs.length, numConfigs, 0)) {
			return null;
		}
		return configs[0];
	}
}