/*
 *  Copyright (c) 2012 The WebRTC project authors. All Rights Reserved.
 *
 *  Use of this source code is governed by a BSD-style license
 *  that can be found in the LICENSE file in the root of the source
 *  tree. An additional intellectual property rights grant can be found
 *  in the file PATENTS.  All contributing project authors may
 *  be found in the AUTHORS file in the root of the source tree.
 */

package org.webrtc.videoengine;

import java.util.concurrent.locks.ReentrantLock;

import javax.microedition.khronos.egl.EGL10;
import javax.microedition.khronos.egl.EGLConfig;
import javax.microedition.khronos.egl.EGLContext;
import javax.microedition.khronos.egl.EGLDisplay;
import javax.microedition.khronos.opengles.GL10;

import android.app.ActivityManager;
import android.content.Context;
import android.content.pm.ConfigurationInfo;
import android.graphics.PixelFormat;
import android.opengl.GLSurfaceView;
import android.util.Log;

public class ViEAndroidGLES20 extends GLSurfaceView
        implements GLSurfaceView.Renderer {
    private static String TAG = "WEBRTC-JR";
    private static final boolean DEBUG = false;
    // True if onSurfaceCreated has been called.
    private boolean surfaceCreated = false;
    private boolean openGLCreated = false;
    // True if NativeFunctionsRegistered has been called.
    private boolean nativeFunctionsRegisted = false;
    private ReentrantLock nativeFunctionLock = new ReentrantLock();
    // Address of Native object that will do the drawing.
    private long nativeObject = 0;
    private int viewWidth = 0;
    private int viewHeight = 0;

    public static boolean UseOpenGL2(Object renderWindow) {
        return ViEAndroidGLES20.class.isInstance(renderWindow);
    }

    public ViEAndroidGLES20(Context context) {
        super(context);
        init(false, 0, 0);
    }

    public ViEAndroidGLES20(Context context, boolean translucent,
            int depth, int stencil) {
        super(context);
        init(translucent, depth, stencil);
    }

    private void init(boolean translucent, int depth, int stencil) {

        // By default, GLSurfaceView() creates a RGB_565 opaque surface.
        // If we want a translucent one, we should change the surface's
        // format here, using PixelFormat.TRANSLUCENT for GL Surfaces
        // is interpreted as any 32-bit surface with alpha by SurfaceFlinger.
        if (translucent) {
            this.getHolder().setFormat(PixelFormat.TRANSLUCENT);
        }

        // Setup the context factory for 2.0 rendering.
        // See ContextFactory class definition below
        setEGLContextFactory(new ContextFactory());

        // We need to choose an EGLConfig that matches the format of
        // our surface exactly. This is going to be done in our
        // custom config chooser. See ConfigChooser class definition
        // below.
        setEGLConfigChooser( translucent ?
                             new ConfigChooser(8, 8, 8, 8, depth, stencil) :
                             new ConfigChooser(5, 6, 5, 0, depth, stencil) );

        // Set the renderer responsible for frame rendering
        this.setRenderer(this);
        this.setRenderMode(GLSurfaceView.RENDERMODE_WHEN_DIRTY);
    }

    private static class ContextFactory implements GLSurfaceView.EGLContextFactory {
        private static int EGL_CONTEXT_CLIENT_VERSION = 0x3098;
        public EGLContext createContext(EGL10 egl, EGLDisplay display, EGLConfig eglConfig) {
            Log.w(TAG, "creating OpenGL ES 2.0 context");
            checkEglError("Before eglCreateContext", egl);
            int[] attrib_list = {EGL_CONTEXT_CLIENT_VERSION, 2, EGL10.EGL_NONE };
            EGLContext context = egl.eglCreateContext(display, eglConfig,
                    EGL10.EGL_NO_CONTEXT, attrib_list);
            checkEglError("After eglCreateContext", egl);
            return context;
        }

        public void destroyContext(EGL10 egl, EGLDisplay display, EGLContext context) {
            egl.eglDestroyContext(display, context);
        }
    }

    private static void checkEglError(String prompt, EGL10 egl) {
        int error;
        while ((error = egl.eglGetError()) != EGL10.EGL_SUCCESS) {
            Log.e(TAG, String.format("%s: EGL error: 0x%x", prompt, error));
        }
    }

    private static class ConfigChooser implements GLSurfaceView.EGLConfigChooser {

        public ConfigChooser(int r, int g, int b, int a, int depth, int stencil) {
            mRedSize = r;
            mGreenSize = g;
            mBlueSize = b;
            mAlphaSize = a;
            mDepthSize = depth;
            mStencilSize = stencil;
        }

        // This EGL config specification is used to specify 2.0 rendering.
        // We use a minimum size of 4 bits for red/green/blue, but will
        // perform actual matching in chooseConfig() below.
        private static int EGL_OPENGL_ES2_BIT = 4;
        private static int[] s_configAttribs2 =
        {
            EGL10.EGL_RED_SIZE, 4,
            EGL10.EGL_GREEN_SIZE, 4,
            EGL10.EGL_BLUE_SIZE, 4,
            EGL10.EGL_RENDERABLE_TYPE, EGL_OPENGL_ES2_BIT,
            EGL10.EGL_NONE
        };

        public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display) {

            // Get the number of minimally matching EGL configurations
            int[] num_config = new int[1];
            egl.eglChooseConfig(display, s_configAttribs2, null, 0, num_config);

            int numConfigs = num_config[0];

            if (numConfigs <= 0) {
                throw new IllegalArgumentException("No configs match configSpec");
            }

            // Allocate then read the array of minimally matching EGL configs
            EGLConfig[] configs = new EGLConfig[numConfigs];
            egl.eglChooseConfig(display, s_configAttribs2, configs, numConfigs, num_config);

            if (DEBUG) {
                printConfigs(egl, display, configs);
            }
            // Now return the "best" one
            return chooseConfig(egl, display, configs);
        }

        public EGLConfig chooseConfig(EGL10 egl, EGLDisplay display,
                EGLConfig[] configs) {
            for(EGLConfig config : configs) {
                int d = findConfigAttrib(egl, display, config,
                        EGL10.EGL_DEPTH_SIZE, 0);
                int s = findConfigAttrib(egl, display, config,
                        EGL10.EGL_STENCIL_SIZE, 0);

                // We need at least mDepthSize and mStencilSize bits
                if (d < mDepthSize || s < mStencilSize)
                    continue;

                // We want an *exact* match for red/green/blue/alpha
                int r = findConfigAttrib(egl, display, config,
                        EGL10.EGL_RED_SIZE, 0);
                int g = findConfigAttrib(egl, display, config,
                            EGL10.EGL_GREEN_SIZE, 0);
                int b = findConfigAttrib(egl, display, config,
                            EGL10.EGL_BLUE_SIZE, 0);
                int a = findConfigAttrib(egl, display, config,
                        EGL10.EGL_ALPHA_SIZE, 0);

                if (r == mRedSize && g == mGreenSize && b == mBlueSize && a == mAlphaSize)
                    return config;
            }
            return null;
        }

        private int findConfigAttrib(EGL10 egl, EGLDisplay display,
                EGLConfig config, int attribute, int defaultValue) {

            if (egl.eglGetConfigAttrib(display, config, attribute, mValue)) {
                return mValue[0];
            }
            return defaultValue;
        }

        private void printConfigs(EGL10 egl, EGLDisplay display,
            EGLConfig[] configs) {
            int numConfigs = configs.length;
            Log.w(TAG, String.format("%d configurations", numConfigs));
            for (int i = 0; i < numConfigs; i++) {
                Log.w(TAG, String.format("Configuration %d:\n", i));
                printConfig(egl, display, configs[i]);
            }
        }

        private void printConfig(EGL10 egl, EGLDisplay display,
                EGLConfig config) {
            int[] attributes = {
                    EGL10.EGL_BUFFER_SIZE,
                    EGL10.EGL_ALPHA_SIZE,
                    EGL10.EGL_BLUE_SIZE,
                    EGL10.EGL_GREEN_SIZE,
                    EGL10.EGL_RED_SIZE,
                    EGL10.EGL_DEPTH_SIZE,
                    EGL10.EGL_STENCIL_SIZE,
                    EGL10.EGL_CONFIG_CAVEAT,
                    EGL10.EGL_CONFIG_ID,
                    EGL10.EGL_LEVEL,
                    EGL10.EGL_MAX_PBUFFER_HEIGHT,
                    EGL10.EGL_MAX_PBUFFER_PIXELS,
                    EGL10.EGL_MAX_PBUFFER_WIDTH,
                    EGL10.EGL_NATIVE_RENDERABLE,
                    EGL10.EGL_NATIVE_VISUAL_ID,
                    EGL10.EGL_NATIVE_VISUAL_TYPE,
                    0x3030, // EGL10.EGL_PRESERVED_RESOURCES,
                    EGL10.EGL_SAMPLES,
                    EGL10.EGL_SAMPLE_BUFFERS,
                    EGL10.EGL_SURFACE_TYPE,
                    EGL10.EGL_TRANSPARENT_TYPE,
                    EGL10.EGL_TRANSPARENT_RED_VALUE,
                    EGL10.EGL_TRANSPARENT_GREEN_VALUE,
                    EGL10.EGL_TRANSPARENT_BLUE_VALUE,
                    0x3039, // EGL10.EGL_BIND_TO_TEXTURE_RGB,
                    0x303A, // EGL10.EGL_BIND_TO_TEXTURE_RGBA,
                    0x303B, // EGL10.EGL_MIN_SWAP_INTERVAL,
                    0x303C, // EGL10.EGL_MAX_SWAP_INTERVAL,
                    EGL10.EGL_LUMINANCE_SIZE,
                    EGL10.EGL_ALPHA_MASK_SIZE,
                    EGL10.EGL_COLOR_BUFFER_TYPE,
                    EGL10.EGL_RENDERABLE_TYPE,
                    0x3042 // EGL10.EGL_CONFORMANT
            };
            String[] names = {
                    "EGL_BUFFER_SIZE",
                    "EGL_ALPHA_SIZE",
                    "EGL_BLUE_SIZE",
                    "EGL_GREEN_SIZE",
                    "EGL_RED_SIZE",
                    "EGL_DEPTH_SIZE",
                    "EGL_STENCIL_SIZE",
                    "EGL_CONFIG_CAVEAT",
                    "EGL_CONFIG_ID",
                    "EGL_LEVEL",
                    "EGL_MAX_PBUFFER_HEIGHT",
                    "EGL_MAX_PBUFFER_PIXELS",
                    "EGL_MAX_PBUFFER_WIDTH",
                    "EGL_NATIVE_RENDERABLE",
                    "EGL_NATIVE_VISUAL_ID",
                    "EGL_NATIVE_VISUAL_TYPE",
                    "EGL_PRESERVED_RESOURCES",
                    "EGL_SAMPLES",
                    "EGL_SAMPLE_BUFFERS",
                    "EGL_SURFACE_TYPE",
                    "EGL_TRANSPARENT_TYPE",
                    "EGL_TRANSPARENT_RED_VALUE",
                    "EGL_TRANSPARENT_GREEN_VALUE",
                    "EGL_TRANSPARENT_BLUE_VALUE",
                    "EGL_BIND_TO_TEXTURE_RGB",
                    "EGL_BIND_TO_TEXTURE_RGBA",
                    "EGL_MIN_SWAP_INTERVAL",
                    "EGL_MAX_SWAP_INTERVAL",
                    "EGL_LUMINANCE_SIZE",
                    "EGL_ALPHA_MASK_SIZE",
                    "EGL_COLOR_BUFFER_TYPE",
                    "EGL_RENDERABLE_TYPE",
                    "EGL_CONFORMANT"
            };
            int[] value = new int[1];
            for (int i = 0; i < attributes.length; i++) {
                int attribute = attributes[i];
                String name = names[i];
                if (egl.eglGetConfigAttrib(display, config, attribute, value)) {
                    Log.w(TAG, String.format("  %s: %d\n", name, value[0]));
                } else {
                    // Log.w(TAG, String.format("  %s: failed\n", name));
                    while (egl.eglGetError() != EGL10.EGL_SUCCESS);
                }
            }
        }

        // Subclasses can adjust these values:
        protected int mRedSize;
        protected int mGreenSize;
        protected int mBlueSize;
        protected int mAlphaSize;
        protected int mDepthSize;
        protected int mStencilSize;
        private int[] mValue = new int[1];
    }

    // IsSupported
    // Return true if this device support Open GL ES 2.0 rendering.
    public static boolean IsSupported(Context context) {
        ActivityManager am =
                (ActivityManager) context.getSystemService(Context.ACTIVITY_SERVICE);
        ConfigurationInfo info = am.getDeviceConfigurationInfo();
        if(info.reqGlEsVersion >= 0x20000) {
            // Open GL ES 2.0 is supported.
            return true;
        }
        return false;
    }

    public void onDrawFrame(GL10 gl) {
        nativeFunctionLock.lock();
        if(!nativeFunctionsRegisted || !surfaceCreated) {
            nativeFunctionLock.unlock();
            return;
        }

        if(!openGLCreated) {
            if(0 != CreateOpenGLNative(nativeObject, viewWidth, viewHeight)) {
                return; // Failed to create OpenGL
            }
            openGLCreated = true; // Created OpenGL successfully
        }
        DrawNative(nativeObject); // Draw the new frame
        nativeFunctionLock.unlock();
    }

    public void onSurfaceChanged(GL10 gl, int width, int height) {
        surfaceCreated = true;
        viewWidth = width;
        viewHeight = height;

        nativeFunctionLock.lock();
        if(nativeFunctionsRegisted) {
            if(CreateOpenGLNative(nativeObject,width,height) == 0)
                openGLCreated = true;
        }
        nativeFunctionLock.unlock();
    }

    public void onSurfaceCreated(GL10 gl, EGLConfig config) {
    }

    public void RegisterNativeObject(long nativeObject) {
        nativeFunctionLock.lock();
        this.nativeObject = nativeObject;
        nativeFunctionsRegisted = true;
        nativeFunctionLock.unlock();
    }

    public void DeRegisterNativeObject() {
        nativeFunctionLock.lock();
        nativeFunctionsRegisted = false;
        openGLCreated = false;
        this.nativeObject = 0;
        nativeFunctionLock.unlock();
    }

    public void ReDraw() {
        if(surfaceCreated) {
            // Request the renderer to redraw using the render thread context.
            this.requestRender();
        }
    }

    private native int CreateOpenGLNative(long nativeObject,
            int width, int height);
    private native void DrawNative(long nativeObject);

}