/*
 * Copyright (c) 2008 Sun Microsystems, Inc. All Rights Reserved.
 * 
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions are
 * met:
 * 
 * - Redistribution of source code must retain the above copyright
 *   notice, this list of conditions and the following disclaimer.
 * 
 * - Redistribution in binary form must reproduce the above copyright
 *   notice, this list of conditions and the following disclaimer in the
 *   documentation and/or other materials provided with the distribution.
 * 
 * Neither the name of Sun Microsystems, Inc. or the names of
 * contributors may be used to endorse or promote products derived from
 * this software without specific prior written permission.
 * 
 * This software is provided "AS IS," without a warranty of any kind. ALL
 * EXPRESS OR IMPLIED CONDITIONS, REPRESENTATIONS AND WARRANTIES,
 * INCLUDING ANY IMPLIED WARRANTY OF MERCHANTABILITY, FITNESS FOR A
 * PARTICULAR PURPOSE OR NON-INFRINGEMENT, ARE HEREBY EXCLUDED. SUN
 * MICROSYSTEMS, INC. ("SUN") AND ITS LICENSORS SHALL NOT BE LIABLE FOR
 * ANY DAMAGES SUFFERED BY LICENSEE AS A RESULT OF USING, MODIFYING OR
 * DISTRIBUTING THIS SOFTWARE OR ITS DERIVATIVES. IN NO EVENT WILL SUN OR
 * ITS LICENSORS BE LIABLE FOR ANY LOST REVENUE, PROFIT OR DATA, OR FOR
 * DIRECT, INDIRECT, SPECIAL, CONSEQUENTIAL, INCIDENTAL OR PUNITIVE
 * DAMAGES, HOWEVER CAUSED AND REGARDLESS OF THE THEORY OF LIABILITY,
 * ARISING OUT OF THE USE OF OR INABILITY TO USE THIS SOFTWARE, EVEN IF
 * SUN HAS BEEN ADVISED OF THE POSSIBILITY OF SUCH DAMAGES.
 * 
 * Sun gratefully acknowledges that this software was originally authored
 * and developed by Kenneth Bradley Russell and Christopher John Kline.
 */

package com.sun.opengl.impl.egl;

import javax.media.opengl.*;
import com.sun.opengl.impl.*;
import com.sun.gluegen.runtime.ProcAddressTable;
import java.nio.*;
import java.util.*;

public class EGLContext extends GLContextImpl {
    private EGLDrawable drawable;
    private long context;
    private boolean eglQueryStringInitialized;
    private boolean eglQueryStringAvailable;
    private EGLExt eglExt;
    // Table that holds the addresses of the native C-language entry points for
    // EGL extension functions.
    private EGLExtProcAddressTable eglExtProcAddressTable;

    public EGLContext(EGLDrawable drawable, GLContext shareWith) {
        super(shareWith);
        this.drawable = drawable;
    }

    public Object getPlatformGLExtensions() {
      return getEGLExt();
    }

    public EGLExt getEGLExt() {
      if (eglExt == null) {
        eglExt = new EGLExtImpl(this);
      }
      return eglExt;
    }

    public final ProcAddressTable getPlatformExtProcAddressTable() {
        return eglExtProcAddressTable;
    }

    public final EGLExtProcAddressTable getEGLExtProcAddressTable() {
        return eglExtProcAddressTable;
    }

    public GLDrawable getGLDrawable() {
        return drawable;
    }

    protected String mapToRealGLFunctionName(String glFunctionName) {
        return glFunctionName;
    }

    protected String mapToRealGLExtensionName(String glExtensionName) {
        return glExtensionName;
    }

    public long getContext() {
        return context;
    }

    private int makeCurrentImplInner() throws GLException {
        boolean created = false;
        if (context == 0) {
            create();
            if (DEBUG) {
                System.err.println(getThreadName() + ": !!! Created GL context 0x" +
                                   Long.toHexString(context) + " for " + getClass().getName());
            }
            created = true;
        }
        if (EGL.eglGetCurrentContext() != context) {
            if (!EGL.eglMakeCurrent(drawable.getDisplay(),
                                    drawable.getSurface(),
                                    drawable.getSurface(),
                                    context)) {
                throw new GLException("Error making context 0x" +
                                      Long.toHexString(context) + " current: error code " + EGL.eglGetError());
            }
        }

        if (created) {
            resetGLFunctionAvailability();
            return CONTEXT_CURRENT_NEW;
        }
        return CONTEXT_CURRENT;
    }

    protected int makeCurrentImpl() throws GLException {
        if(EGL.EGL_NO_DISPLAY==drawable.getDisplay() ) {
            System.err.println("drawable not properly initialized");
            return CONTEXT_NOT_CURRENT;
        }
        drawable.setSurface();

        int lockRes = NativeWindow.LOCK_SUCCESS;
        // FIXME: freezes AWT: int lockRes = drawable.lockSurface();
        boolean exceptionOccurred = false;
        try {
          if (lockRes == NativeWindow.LOCK_SURFACE_NOT_READY) {
            return CONTEXT_NOT_CURRENT;
          }
          if (lockRes == NativeWindow.LOCK_SURFACE_CHANGED) {
            destroyImpl();
          }
          return makeCurrentImplInner();
        } catch (RuntimeException e) {
          exceptionOccurred = true;
          throw e;
        } finally {
          if (exceptionOccurred ||
              (isOptimizable() && lockRes != NativeWindow.LOCK_SURFACE_NOT_READY)) {
            drawable.unlockSurface();
          }
        }
    }

    protected void releaseImpl() throws GLException {
      getGLDrawable().getFactory().lockToolkit();
      try {
        if (!EGL.eglMakeCurrent(drawable.getDisplay(),
                                EGL.EGL_NO_SURFACE,
                                EGL.EGL_NO_SURFACE,
                                EGL.EGL_NO_CONTEXT)) {
            throw new GLException("Error freeing OpenGL context 0x" +
                                  Long.toHexString(context) + ": error code " + EGL.eglGetError());
        }
      } finally {
        getGLDrawable().getFactory().unlockToolkit();
        drawable.unlockSurface();
      }
    }

    protected void destroyImpl() throws GLException {
      getGLDrawable().getFactory().lockToolkit();
      try {
        if (context != 0) {
            if (!EGL.eglDestroyContext(drawable.getDisplay(), context)) {
                throw new GLException("Error destroying OpenGL context 0x" +
                                      Long.toHexString(context) + ": error code " + EGL.eglGetError());
            }
            context = 0;
            GLContextShareSet.contextDestroyed(this);
        }
      } finally {
        getGLDrawable().getFactory().unlockToolkit();
      }
    }

    protected void create() throws GLException {
        long display = drawable.getDisplay();
        long config = drawable.getConfig();
        long shareWith = 0;

        if (display == 0) {
            throw new GLException("Error: attempted to create an OpenGL context without a display connection");
        }
        if (config == 0) {
            throw new GLException("Error: attempted to create an OpenGL context without a graphics configuration");
        }
        EGLContext other = (EGLContext) GLContextShareSet.getShareContext(this);
        if (other != null) {
            shareWith = other.getContext();
            if (shareWith == 0) {
                throw new GLException("GLContextShareSet returned an invalid OpenGL context");
            }
        }

        int[] contextAttrs = null;
        // FIXME: need to determine whether to specify the context
        // attributes based on the EGL version
        if (GLProfile.isGLES2()) {
            contextAttrs = new int[] {
                EGL.EGL_CONTEXT_CLIENT_VERSION, 2,
                EGL.EGL_NONE
            };
        }
        context = EGL.eglCreateContext(display, config, shareWith, contextAttrs, 0);
        if (context == 0) {
            throw new GLException("Error creating OpenGL context");
        }
        GLContextShareSet.contextCreated(this);
        if (DEBUG) {
            System.err.println(getThreadName() + ": !!! Created OpenGL context 0x" +
                               Long.toHexString(context) + " for " + this +
                               ", surface 0x" + Long.toHexString(drawable.getSurface()) +
                               ", sharing with 0x" + Long.toHexString(shareWith));
        }
    }

    public boolean isCreated() {
        return (context != 0);
    }

    protected void resetGLFunctionAvailability() {
        super.resetGLFunctionAvailability();
        if (DEBUG) {
          System.err.println(getThreadName() + ": !!! Initializing EGL extension address table");
        }
        if (eglExtProcAddressTable == null) {
          // FIXME: cache ProcAddressTables by capability bits so we can
          // share them among contexts with the same capabilities
          eglExtProcAddressTable = new EGLExtProcAddressTable();
        }          
        resetProcAddressTable(getEGLExtProcAddressTable());
    }
  
    public synchronized String getPlatformExtensionsString() {
        if (!eglQueryStringInitialized) {
          eglQueryStringAvailable =
            ((GLDrawableFactoryImpl)getGLDrawable().getFactory()).dynamicLookupFunction("eglQueryString") != 0;
          eglQueryStringInitialized = true;
        }
        if (eglQueryStringAvailable) {
          GLDrawableFactory factory = getGLDrawable().getFactory();
          boolean wasLocked = factory.isToolkitLocked();
          if(!wasLocked) {
              factory.lockToolkit();
          }
          try {
            String ret = EGL.eglQueryString(drawable.getNativeWindow().getDisplayHandle(), 
                                            EGL.EGL_EXTENSIONS);
            if (DEBUG) {
              System.err.println("!!! EGL extensions: " + ret);
            }
            return ret;
          } finally {
            if(!wasLocked) {
                factory.unlockToolkit();
            }
          }
        } else {
          return "";
        }
    }

    //----------------------------------------------------------------------
    // Currently unimplemented stuff
    //

    public void copy(GLContext source, int mask) throws GLUnsupportedException {
        throw new GLUnsupportedException("Not yet implemented");
    }

    public void bindPbufferToTexture() {
        throw new GLException("Should not call this");
    }

    public void releasePbufferFromTexture() {
        throw new GLException("Should not call this");
    }

    public ByteBuffer glAllocateMemoryNV(int arg0, float arg1, float arg2, float arg3) {
        throw new GLException("Should not call this");
    }

    public boolean offscreenImageNeedsVerticalFlip() {
        throw new GLException("Should not call this");
    }

    public int getOffscreenContextPixelDataType() {
        throw new GLException("Should not call this");
    }
}