/**
 * Copyright (c) 2011, The University of Southampton and the individual contributors.
 * All rights reserved.
 *
 * Redistribution and use in source and binary forms, with or without modification,
 * are permitted provided that the following conditions are met:
 *
 *   *  Redistributions of source code must retain the above copyright notice,
 *      this list of conditions and the following disclaimer.
 *
 *   *  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.
 *
 *   *  Neither the name of the University of Southampton nor the names of its
 *      contributors may be used to endorse or promote products derived from this
 *      software without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "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 THE COPYRIGHT OWNER 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.
 */
package org.openimaj.math.matrix;

import java.io.DataInput;
import java.io.DataOutput;
import java.io.IOException;
import java.io.PrintWriter;
import java.lang.reflect.Field;
import java.util.Scanner;

import org.openimaj.io.ReadWriteable;

import Jama.Matrix;

/**
 * A wrapper around a JAMA Matrix that is read-writeable by
 * OpenIMAJ IOUtils.
 * 
 * @author Jonathon Hare (jsh2@ecs.soton.ac.uk)
 *
 */
public class ReadWriteableMatrix extends Matrix implements ReadWriteable {
        private static final long serialVersionUID = 1L;

        /**
         * Construct a new matrix of zero size. Only for IOUtils use.
         */
        protected ReadWriteableMatrix() {
                super(0, 0);
        }
        
        /**
         * Construct a matrix using the provided 2-D double array.
         * The array is assigned internally and is not copied.
         * 
         * @param data the data
         */
        public ReadWriteableMatrix(double[][] data) {
                super(data);
        }

        /**
         * Construct a new matrix of the given size
         * @param rows Number of rows
         * @param cols Number of columns
         */
        public ReadWriteableMatrix(int rows, int cols) {
                super(rows, cols);
        }
        
        /**
         * Construct a matrix using the provided matrix.
         * The matrix data is assigned internally and is not copied.
         * 
         * @param data the data
         */
        public ReadWriteableMatrix(Matrix data) {
                this(data.getArray());
        }

        @Override
        public void readASCII(Scanner in) throws IOException {
                final int rows = in.nextInt();
                final int cols = in.nextInt();
                
                double[][] data = new double[rows][cols];
                for (int r=0; r<rows; r++)
                        for (int c=0; c<cols; c++)
                                data[r][c] = in.nextDouble();
                
                setData(rows, cols, data);              
        }

        @Override
        public String asciiHeader() {
                return this.getClass().getName() + " ";
        }

        @Override
        public void readBinary(DataInput in) throws IOException {
                final int rows = in.readInt();
                final int cols = in.readInt();
                
                double[][] data = new double[rows][cols];
                for (int r=0; r<rows; r++)
                        for (int c=0; c<cols; c++)
                                data[r][c] = in.readDouble();
                
                setData(rows, cols, data);
        }
        
        protected void setData(int m, int n, double[][] data) {
                Class<Matrix> clz = Matrix.class;
                try {
                        Field mField = clz.getDeclaredField("m");
                        mField.setAccessible(true);
                        mField.setInt(this, m);
                        
                        Field nField = clz.getDeclaredField("n");
                        nField.setAccessible(true);
                        nField.setInt(this, n);
                        
                        Field AField = clz.getDeclaredField("A");
                        AField.setAccessible(true);
                        AField.set(this, data);
                } catch (Exception e) {
                        throw new RuntimeException(e);
                }
        }

        @Override
        public byte[] binaryHeader() {
                return "RWMAT".getBytes();
        }

        @Override
        public void writeASCII(PrintWriter out) throws IOException {
                final int rows = this.getRowDimension();
                final int cols = this.getColumnDimension();
                final double[][] data = this.getArray(); 
                
                out.print(rows + " " + cols);
                out.println();
                
                for (int r=0; r<rows; r++) {
                        for (int c=0; c<cols; c++) {
                                out.print(data[r][c] + " ");
                        }
                        out.println();
                }
        }

        @Override
        public void writeBinary(DataOutput out) throws IOException {
                final int rows = this.getRowDimension();
                final int cols = this.getColumnDimension();
                final double[][] data = this.getArray(); 
                
                out.writeInt(rows);
                out.writeInt(cols);
                
                for (int r=0; r<rows; r++)
                        for (int c=0; c<cols; c++)
                                out.writeDouble(data[r][c]);
        }
}