/*******************************************************************************
 * Copyright (c) 2000, 2006 IBM Corporation and others.
 * All rights reserved. This program and the accompanying materials
 * are made available under the terms of the Eclipse Public License v1.0
 * which accompanies this distribution, and is available at
 * http://www.eclipse.org/legal/epl-v10.html
 *
 * Contributors:
 *     IBM Corporation - initial API and implementation
 * Port to the D programming language:
 *     Frank Benoit <benoit@tionex.de>
 *******************************************************************************/
module org.eclipse.swt.internal.image.JPEGQuantizationTable;

import org.eclipse.swt.internal.image.LEDataInputStream;
import org.eclipse.swt.internal.image.JPEGVariableSizeSegment;
import org.eclipse.swt.internal.image.JPEGFileFormat;

import java.lang.System;

final class JPEGQuantizationTable : JPEGVariableSizeSegment {
    public static byte[] DefaultLuminanceQTable = [
        cast(byte)255, cast(byte)219, 0, 67, 0,
        16, 11, 10, 16, 24, 40, 51, 61,
        12, 12, 14, 19, 26, 58, 60, 55,
        14, 13, 16, 24, 40, 57, 69, 56,
        14, 17, 22, 29, 51, 87, 80, 62,
        18, 22, 37, 56, 68, 109, 103, 77,
        24, 35, 55, 64, 81, 104, 113, 92,
        49, 64, 78, 87, 103, 121, 120, 101,
        72, 92, 95, 98, 112, 100, 103, 99
    ];
    public static byte[] DefaultChrominanceQTable = [
        cast(byte)255, cast(byte)219, 0, 67, 1,
        17, 18, 24, 47, 99, 99, 99, 99,
        18, 21, 26, 66, 99, 99, 99, 99,
        24, 26, 56, 99, 99, 99, 99, 99,
        47, 66, 99, 99, 99, 99, 99, 99,
        99, 99, 99, 99, 99, 99, 99, 99,
        99, 99, 99, 99, 99, 99, 99, 99,
        99, 99, 99, 99, 99, 99, 99, 99,
        99, 99, 99, 99, 99, 99, 99, 99
    ];

public this(byte[] reference) {
    super(reference);
}

public this(LEDataInputStream byteStream) {
    super(byteStream);
}

public static JPEGQuantizationTable defaultChrominanceTable() {
    byte[] data = new byte[DefaultChrominanceQTable.length];
    System.arraycopy(DefaultChrominanceQTable, 0, data, 0, data.length);
    return new JPEGQuantizationTable(data);
}

public static JPEGQuantizationTable defaultLuminanceTable() {
    byte[] data = new byte[DefaultLuminanceQTable.length];
    System.arraycopy(DefaultLuminanceQTable, 0, data, 0, data.length);
    return new JPEGQuantizationTable(data);
}

public int[] getQuantizationTablesKeys() {
    int[] keys = new int[4];
    int keysIndex = 0;
    int totalLength = getSegmentLength() - 2;
    int ofs = 4;
    while (totalLength > 64) {
        int tq = reference[ofs] & 0xF;
        int pq = (reference[ofs] & 0xFF) >> 4;
        if (pq is 0) {
            ofs += 65;
            totalLength -= 65;
        } else {
            ofs += 129;
            totalLength -= 129;
        }
        if (keysIndex >= keys.length) {
            int[] newKeys = new int[keys.length + 4];
            System.arraycopy(keys, 0, newKeys, 0, keys.length);
            keys = newKeys;
        }
        keys[keysIndex] = tq;
        keysIndex++;
    }
    int[] newKeys = new int[keysIndex];
    System.arraycopy(keys, 0, newKeys, 0, keysIndex);
    return newKeys;
}

public int[][] getQuantizationTablesValues() {
    int[][] values = new int[][](4);
    int valuesIndex = 0;
    int totalLength = getSegmentLength() - 2;
    int ofs = 4;
    while (totalLength > 64) {
        int[] qk = new int[64];
        int pq = (reference[ofs] & 0xFF) >> 4;
        if (pq is 0) {
            for (int i = 0; i < qk.length; i++) {
                qk[i] = reference[ofs + i + 1] & 0xFF;
            }
            ofs += 65;
            totalLength -= 65;
        } else {
            for (int i = 0; i < qk.length; i++) {
                int idx = (i - 1) * 2 ;
                qk[i] = (reference[ofs + idx + 1] & 0xFF) * 256 + (reference[ofs + idx + 2] & 0xFF);
            }
            ofs += 129;
            totalLength -= 129;
        }
        if (valuesIndex >= values.length) {
            int[][] newValues = new int[][](values.length + 4);
            System.arraycopy(values, 0, newValues, 0, values.length);
            values = newValues;
        }
        values[valuesIndex] = qk;
        valuesIndex++;
    }
    int[][] newValues = new int[][](valuesIndex);
    System.arraycopy(values, 0, newValues, 0, valuesIndex);
    return newValues;
}

public void scaleBy(int qualityFactor) {
    int qFactor = qualityFactor;
    if (qFactor <= 0) {
        qFactor = 1;
    }
    if (qFactor > 100) {
        qFactor = 100;
    }
    if (qFactor < 50) {
        qFactor = 5000 / qFactor;
    } else {
        qFactor = 200 - (qFactor * 2);
    }
    int totalLength = getSegmentLength() - 2;
    int ofs = 4;
    while (totalLength > 64) {
//      int tq = reference[ofs] & 0xFF;
        int pq = (reference[ofs] & 0xFF) >> 4;
        if (pq is 0) {
            for (int i = ofs + 1; i <= ofs + 64; i++) {
                int temp = ((reference[i] & 0xFF) * qFactor + 50) / 100;
                if (temp <= 0) temp = 1;
                if (temp > 255) temp = 255;
                reference[i] = cast(byte)temp;
            }
            ofs += 65;
            totalLength -= 65;
        } else {
            for (int i = ofs + 1; i <= ofs + 128; i += 2) {
                int temp = (((reference[i] & 0xFF) * 256 + (reference[i + 1] & 0xFF)) * qFactor + 50) / 100;
                if (temp <= 0) temp = 1;
                if (temp > 32767) temp = 32767;
                reference[i] = cast(byte)(temp >> 8);
                reference[i + 1] = cast(byte)(temp & 0xFF);
            }
            ofs += 129;
            totalLength -= 129;
        }
    }
}

public override int signature() {
    return JPEGFileFormat.DQT;
}
}