/**
 * Copyright 2010 JogAmp Community. All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification, are
 * permitted provided that the following conditions are met:
 *
 *    1. Redistributions of source code must retain the above copyright notice, this list of
 *       conditions and the following disclaimer.
 *
 *    2. Redistributions 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.
 *
 * THIS SOFTWARE IS PROVIDED BY JogAmp Community ``AS IS'' AND ANY EXPRESS OR IMPLIED
 * WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND
 * FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL JogAmp Community OR
 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR
 * SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON
 * ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 *
 * The views and conclusions contained in the software and documentation are those of the
 * authors and should not be interpreted as representing official policies, either expressed
 * or implied, of JogAmp Community.
 */

package com.jogamp.opengl.util;

import java.nio.Buffer;
import java.nio.ByteBuffer;
import java.nio.FloatBuffer;
import java.nio.IntBuffer;
import java.nio.ShortBuffer;

import javax.media.opengl.GL;
import javax.media.opengl.GL2ES1;
import javax.media.opengl.GL2ES2;
import javax.media.opengl.GLArrayData;
import javax.media.opengl.GLException;
import javax.media.opengl.GLProfile;
import javax.media.opengl.fixedfunc.GLPointerFuncUtil;

import com.jogamp.common.nio.Buffers;

import jogamp.opengl.Debug;

public class GLArrayDataWrapper implements GLArrayData {
  public static final boolean DEBUG = Debug.debug("GLArrayData");

  /**
   * Create a VBO, using a predefined fixed function array index, wrapping the given data.
   *
   * @param index The GL array index
   * @param comps The array component number
   * @param dataType The array index GL data type
   * @param normalized Whether the data shall be normalized
   * @param stride
   * @param buffer the user define data
   * @param vboName
   * @param vboOffset
   * @param vboUsage {@link GL2ES2#GL_STREAM_DRAW}, {@link GL#GL_STATIC_DRAW} or {@link GL#GL_DYNAMIC_DRAW}
   * @param vboTarget {@link GL#GL_ARRAY_BUFFER} or {@link GL#GL_ELEMENT_ARRAY_BUFFER}
   * @return the new create instance
   *
   * @throws GLException
   */
  public static GLArrayDataWrapper createFixed(int index, int comps, int dataType, boolean normalized, int stride,
                                               Buffer buffer, int vboName, long vboOffset, int vboUsage, int vboTarget)
    throws GLException
  {
      GLArrayDataWrapper adc = new GLArrayDataWrapper();
      adc.init(null, index, comps, dataType, normalized, stride, buffer, 0 /* mappedElementCount */,
               false, vboName, vboOffset, vboUsage, vboTarget);
      return adc;
  }

  /**
   * Create a VBO, using a predefined fixed function array index, wrapping the mapped data characteristics.
   *
   * @param index The GL array index
   * @param comps The array component number
   * @param dataType The array index GL data type
   * @param normalized Whether the data shall be normalized
   * @param stride
   * @param mappedElementCount
   * @param vboName
   * @param vboOffset
   * @param vboUsage {@link GL2ES2#GL_STREAM_DRAW}, {@link GL#GL_STATIC_DRAW} or {@link GL#GL_DYNAMIC_DRAW}
   * @param vboTarget {@link GL#GL_ARRAY_BUFFER} or {@link GL#GL_ELEMENT_ARRAY_BUFFER}
   * @return the new create instance
   *
   * @throws GLException
   */
  public static GLArrayDataWrapper createFixed(int index, int comps, int dataType, boolean normalized, int stride,
                                               int mappedElementCount, int vboName, long vboOffset, int vboUsage, int vboTarget)
    throws GLException
  {
      GLArrayDataWrapper adc = new GLArrayDataWrapper();
      adc.init(null, index, comps, dataType, normalized, stride, null, mappedElementCount,
               false, vboName, vboOffset, vboUsage, vboTarget);
      return adc;
  }

  /**
   * Create a VBO, using a custom GLSL array attribute name, wrapping the given data.
   *
   * @param name  The custom name for the GL attribute, maybe null if gpuBufferTarget is {@link GL#GL_ELEMENT_ARRAY_BUFFER}
   * @param comps The array component number
   * @param dataType The array index GL data type
   * @param normalized Whether the data shall be normalized
   * @param stride
   * @param buffer the user define data
   * @param vboName
   * @param vboOffset
   * @param vboUsage {@link GL2ES2#GL_STREAM_DRAW}, {@link GL#GL_STATIC_DRAW} or {@link GL#GL_DYNAMIC_DRAW}
   * @param vboTarget {@link GL#GL_ARRAY_BUFFER} or {@link GL#GL_ELEMENT_ARRAY_BUFFER}
   * @return the new create instance
   * @throws GLException
   */
  public static GLArrayDataWrapper createGLSL(String name, int comps, int dataType, boolean normalized, int stride,
                                             Buffer buffer, int vboName, long vboOffset, int vboUsage, int vboTarget)
    throws GLException
  {
      GLArrayDataWrapper adc = new GLArrayDataWrapper();
      adc.init(name, -1, comps, dataType, normalized, stride, buffer, 0  /* mappedElementCount */,
              true, vboName, vboOffset, vboUsage, vboTarget);
      return adc;
  }

  /**
   * Create a VBO, using a custom GLSL array attribute name, wrapping the mapped data characteristics.
   *
   * @param name  The custom name for the GL attribute, maybe null if gpuBufferTarget is {@link GL#GL_ELEMENT_ARRAY_BUFFER}
   * @param comps The array component number
   * @param dataType The array index GL data type
   * @param normalized Whether the data shall be normalized
   * @param stride
   * @param mappedElementCount
   * @param vboName
   * @param vboOffset
   * @param vboUsage {@link GL2ES2#GL_STREAM_DRAW}, {@link GL#GL_STATIC_DRAW} or {@link GL#GL_DYNAMIC_DRAW}
   * @param vboTarget {@link GL#GL_ARRAY_BUFFER} or {@link GL#GL_ELEMENT_ARRAY_BUFFER}
   * @return the new create instance
   * @throws GLException
   */
  public static GLArrayDataWrapper createGLSL(String name, int comps, int dataType, boolean normalized, int stride,
                                              int mappedElementCount, int vboName, long vboOffset, int vboUsage, int vboTarget)
    throws GLException
  {
      GLArrayDataWrapper adc = new GLArrayDataWrapper();
      adc.init(name, -1, comps, dataType, normalized, stride, null, mappedElementCount,
              true, vboName, vboOffset, vboUsage, vboTarget);
      return adc;
  }

  /**
   * Validates this instance's parameter. Called automatically by {@link GLArrayDataClient} and {@link GLArrayDataServer}.
   * {@link GLArrayDataWrapper} does not validate it's instance by itself.
   *
   * @param glp the GLProfile to use
   * @param throwException whether to throw an exception if this instance has invalid parameter or not
   * @return true if this instance has invalid parameter, otherwise false
   */
  public final boolean validate(GLProfile glp, boolean throwException) {
    if(!alive) {
        if(throwException) {
            throw new GLException("Instance !alive "+this);
        }
        return false;
    }
    if(this.isVertexAttribute() && !glp.hasGLSL()) {
        if(throwException) {
            throw new GLException("GLSL not supported on "+glp+", "+this);
        }
        return false;
    }
    return glp.isValidArrayDataType(getIndex(), getComponentCount(), getComponentType(), isVertexAttribute(), throwException);
  }

  @Override
  public void associate(Object obj, boolean enable) {
      // nop
  }

  //
  // Data read access
  //

  @Override
  public final boolean isVertexAttribute() { return isVertexAttribute; }

  @Override
  public final int getIndex() { return index; }

  @Override
  public final int getLocation() { return location; }

  @Override
  public final int setLocation(int v) { location = v; return location; }

  @Override
  public final int setLocation(GL2ES2 gl, int program) {
      location = gl.glGetAttribLocation(program, name);
      return location;
  }

  @Override
  public final int setLocation(GL2ES2 gl, int program, int location) {
      this.location = location;
      gl.glBindAttribLocation(program, location, name);
      return location;
  }

  @Override
  public final String getName() { return name; }

  @Override
  public final long getVBOOffset() { return vboEnabled?vboOffset:0; }

  @Override
  public final int getVBOName() { return vboEnabled?vboName:0; }

  @Override
  public final boolean isVBO() { return vboEnabled; }

  @Override
  public final int getVBOUsage() { return vboEnabled?vboUsage:0; }

  @Override
  public final int getVBOTarget() { return vboEnabled?vboTarget:0; }

  @Override
  public Buffer getBuffer() { return buffer; }

  @Override
  public final int getComponentCount() { return componentsPerElement; }

  @Override
  public final int getComponentType() { return componentType; }

  @Override
  public final int getComponentSizeInBytes() { return componentByteSize; }

  @Override
  public final int getElementCount() {
    if( 0 != mappedElementCount ) {
        return mappedElementCount;
    } else if( null != buffer ) {
        final int remainingComponents = ( 0 == buffer.position() ) ? buffer.limit() : buffer.position();
        return ( remainingComponents * componentByteSize ) / strideB ;
    } else {
        return 0;
    }
  }

  @Override
  public final int getSizeInBytes() {
    if( 0 != mappedElementCount ) {
        return mappedElementCount * componentsPerElement * componentByteSize ;
    } else if( null != buffer ) {
        return ( buffer.position()==0 ) ? ( buffer.limit() * componentByteSize ) : ( buffer.position() * componentByteSize ) ;
    } else {
        return 0;
    }
  }

  @Override
  public final boolean getNormalized() { return normalized; }

  @Override
  public final int getStride() { return strideB; }

  public final Class<?> getBufferClass() { return componentClazz; }

  @Override
  public void destroy(GL gl) {
    buffer = null;
    vboName=0;
    vboEnabled=false;
    vboOffset=0;
    alive = false;
  }

  @Override
  public String toString() {
    return "GLArrayDataWrapper["+name+
                       ", index "+index+
                       ", location "+location+
                       ", isVertexAttribute "+isVertexAttribute+
                       ", dataType 0x"+Integer.toHexString(componentType)+
                       ", bufferClazz "+componentClazz+
                       ", elements "+getElementCount()+
                       ", components "+componentsPerElement+
                       ", stride "+strideB+"b "+strideL+"c"+
                       ", mappedElementCount "+mappedElementCount+
                       ", buffer "+buffer+
                       ", vboEnabled "+vboEnabled+
                       ", vboName "+vboName+
                       ", vboUsage 0x"+Integer.toHexString(vboUsage)+
                       ", vboTarget 0x"+Integer.toHexString(vboTarget)+
                       ", vboOffset "+vboOffset+
                       ", alive "+alive+
                       "]";
  }

  public static final Class<?> getBufferClass(int dataType) {
    switch(dataType) {
        case GL.GL_BYTE:
        case GL.GL_UNSIGNED_BYTE:
            return ByteBuffer.class;
        case GL.GL_SHORT:
        case GL.GL_UNSIGNED_SHORT:
            return ShortBuffer.class;
        case GL.GL_UNSIGNED_INT:
        case GL2ES1.GL_FIXED:
        case GL2ES2.GL_INT:
            return IntBuffer.class;
        case GL.GL_FLOAT:
            return FloatBuffer.class;
        default:
            throw new GLException("Given OpenGL data type not supported: "+dataType);
    }
  }

  @Override
  public void setName(String newName) {
    location = -1;
    name = newName;
  }

  /**
   * Enable or disable use of VBO.
   * Only possible if a VBO buffer name is defined.
   * @see #setVBOName(int)
   */
  public void setVBOEnabled(boolean vboEnabled) {
    this.vboEnabled=vboEnabled;
  }

  /**
   * Set the VBO buffer name, if valid (!= 0) enable use of VBO,
   * otherwise (==0) disable VBO usage.
   *
   * @see #setVBOEnabled(boolean)
   */
  public void    setVBOName(int vboName) {
    this.vboName=vboName;
    setVBOEnabled(0!=vboName);
  }

 /**
  * @param vboUsage {@link GL2ES2#GL_STREAM_DRAW}, {@link GL#GL_STATIC_DRAW} or {@link GL#GL_DYNAMIC_DRAW}
  */
  public void setVBOUsage(int vboUsage) {
      this.vboUsage = vboUsage;
  }

  /**
   * @param vboTarget either {@link GL#GL_ARRAY_BUFFER} or {@link GL#GL_ELEMENT_ARRAY_BUFFER}
   */
  public void setVBOTarget(int vboTarget) {
      this.vboTarget = vboTarget;
  }

  protected void init(String name, int index, int componentsPerElement, int componentType,
                      boolean normalized, int stride, Buffer data, int mappedElementCount,
                      boolean isVertexAttribute, int vboName, long vboOffset, int vboUsage, int vboTarget)
    throws GLException
  {
    if( 0<mappedElementCount && null != data ) {
        throw new IllegalArgumentException("mappedElementCount:="+mappedElementCount+" specified, but passing non null buffer");
    }
    this.isVertexAttribute = isVertexAttribute;
    this.index = index;
    this.location = -1;
    // We can't have any dependence on the FixedFuncUtil class here for build bootstrapping reasons

    if( GL.GL_ELEMENT_ARRAY_BUFFER == vboTarget ) {
        // OK ..
    } else if( ( 0 == vboUsage && 0 == vboTarget ) || GL.GL_ARRAY_BUFFER == vboTarget ) {
        // Set/Check name .. - Required for GLSL case. Validation and debug-name for FFP.
        this.name = ( null == name ) ? GLPointerFuncUtil.getPredefinedArrayIndexName(index) : name ;
        if(null == this.name ) {
            throw new GLException("Not a valid array buffer index: "+index);
        }
    } else if( 0 < vboTarget ) {
        throw new GLException("Invalid GPUBuffer target: 0x"+Integer.toHexString(vboTarget));
    }

    this.componentType = componentType;
    componentClazz = getBufferClass(componentType);
    if( GLBuffers.isGLTypeFixedPoint(componentType) ) {
        this.normalized = normalized;
    } else {
        this.normalized = false;
    }
    componentByteSize = GLBuffers.sizeOfGLType(componentType);
    if(0 > componentByteSize) {
        throw new GLException("Given componentType not supported: "+componentType+":\n\t"+this);
    }
    if(0 >= componentsPerElement) {
        throw new GLException("Invalid number of components: " + componentsPerElement);
    }
    this.componentsPerElement = componentsPerElement;

    if(0<stride && stride<componentsPerElement*componentByteSize) {
        throw new GLException("stride ("+stride+") lower than component bytes, "+componentsPerElement+" * "+componentByteSize);
    }
    if(0<stride && stride%componentByteSize!=0) {
        throw new GLException("stride ("+stride+") not a multiple of bpc "+componentByteSize);
    }
    this.buffer = data;
    this.mappedElementCount = mappedElementCount;
    this.strideB=(0==stride)?componentsPerElement*componentByteSize:stride;
    this.strideL=strideB/componentByteSize;
    this.vboName= vboName;
    this.vboEnabled= 0 != vboName ;
    this.vboOffset=vboOffset;

    switch(vboUsage) {
        case 0: // nop
        case GL.GL_STATIC_DRAW:
        case GL.GL_DYNAMIC_DRAW:
        case GL2ES2.GL_STREAM_DRAW:
            break;
        default:
            throw new GLException("invalid gpuBufferUsage: "+vboUsage+":\n\t"+this);
    }
    switch(vboTarget) {
        case 0: // nop
        case GL.GL_ARRAY_BUFFER:
        case GL.GL_ELEMENT_ARRAY_BUFFER:
            break;
        default:
            throw new GLException("invalid gpuBufferTarget: "+vboTarget+":\n\t"+this);
    }
    this.vboUsage=vboUsage;
    this.vboTarget=vboTarget;
    this.alive=true;
  }

  protected GLArrayDataWrapper() { }

  /**
   * Copy Constructor
   * <p>
   * Buffer is {@link Buffers#slice(Buffer) sliced}, i.e. sharing content but using own state.
   * </p>
   * <p>
   * All other values are simply copied.
   * </p>
   */
  public GLArrayDataWrapper(GLArrayDataWrapper src) {
    this.alive = src.alive;
    this.index = src.index;
    this.location = src.location;
    this.name = src.name;
    this.componentsPerElement = src.componentsPerElement;
    this.componentType = src.componentType;
    this.componentClazz = src.componentClazz;
    this.componentByteSize = src.componentByteSize;
    this.normalized = src.normalized;
    this.strideB = src.strideB;
    this.strideL = src.strideL;
    if( null != src.buffer ) {
        if( src.buffer.position() == 0 ) {
            this.buffer = Buffers.slice(src.buffer);
        } else {
            this.buffer = Buffers.slice(src.buffer, 0, src.buffer.limit());
        }
    } else {
        this.buffer = null;
    }
    this.mappedElementCount = src.mappedElementCount;
    this.isVertexAttribute = src.isVertexAttribute;
    this.vboOffset = src.vboOffset;
    this.vboName = src.vboName;
    this.vboEnabled = src.vboEnabled;
    this.vboUsage = src.vboUsage;
    this.vboTarget = src.vboTarget;
  }

  protected boolean alive;
  protected int index;
  protected int location;
  protected String name;
  protected int componentsPerElement;
  protected int componentType;
  protected Class<?> componentClazz;
  protected int componentByteSize;
  protected boolean normalized;
  /** stride in bytes; strideB >= componentsPerElement * componentByteSize */
  protected int strideB;
  /** stride in logical components */
  protected int strideL;
  protected Buffer buffer;
  protected int mappedElementCount;
  protected boolean isVertexAttribute;
  protected long vboOffset;
  protected int vboName;
  protected boolean vboEnabled;
  protected int vboUsage;
  protected int vboTarget;
}