/*******************************************************************************
 * Copyright (c) 2000, 2005 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.JPEGFrameHeader;


import org.eclipse.swt.SWT;
import org.eclipse.swt.internal.image.JPEGVariableSizeSegment;
import org.eclipse.swt.internal.image.JPEGFileFormat;
import org.eclipse.swt.internal.image.LEDataInputStream;
import java.lang.all;

final class JPEGFrameHeader : JPEGVariableSizeSegment {
    int maxVFactor;
    int maxHFactor;
    public int[] componentIdentifiers;
    public int[][] componentParameters;

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

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

    public int getSamplePrecision() {
        return reference[4] & 0xFF;
    }

    public int getNumberOfLines() {
        return (reference[5] & 0xFF) << 8 | (reference[6] & 0xFF);
    }

    public int getSamplesPerLine() {
        return (reference[7] & 0xFF) << 8 | (reference[8] & 0xFF);
    }

    public int getNumberOfImageComponents() {
        return reference[9] & 0xFF;
    }

    public void setSamplePrecision(int precision) {
        reference[4] = cast(byte)(precision & 0xFF);
    }

    public void setNumberOfLines(int anInteger) {
        reference[5] = cast(byte)((anInteger & 0xFF00) >> 8);
        reference[6] = cast(byte)(anInteger & 0xFF);
    }

    public void setSamplesPerLine(int samples) {
        reference[7] = cast(byte)((samples & 0xFF00) >> 8);
        reference[8] = cast(byte)(samples & 0xFF);
    }

    public void setNumberOfImageComponents(int anInteger) {
        reference[9] = cast(byte)(anInteger & 0xFF);
    }

    public int getMaxHFactor() {
        return maxHFactor;
    }

    public int getMaxVFactor() {
        return maxVFactor;
    }

    public void setMaxHFactor(int anInteger) {
        maxHFactor = anInteger;
    }

    public void setMaxVFactor(int anInteger) {
        maxVFactor = anInteger;
    }

    /* Used when decoding. */
    void initializeComponentParameters() {
        int nf = getNumberOfImageComponents();
        componentIdentifiers = new int[nf];
        int[][] compSpecParams;
        int hmax = 1;
        int vmax = 1;
        for (int i = 0; i < nf; i++) {
            int ofs = i * 3 + 10;
            int ci = reference[ofs] & 0xFF;
            componentIdentifiers[i] = ci;
            int hi = (reference[ofs + 1] & 0xFF) >> 4;
            int vi = reference[ofs + 1] & 0xF;
            int tqi = reference[ofs + 2] & 0xFF;
            if (hi > hmax) {
                hmax = hi;
            }
            if (vi > vmax) {
                vmax = vi;
            }
            int[] compParam = new int[5];
            compParam[0] = tqi;
            compParam[1] = hi;
            compParam[2] = vi;
            if (compSpecParams.length <= ci) {
                int[][] newParams = new int[][](ci + 1);
                System.arraycopy(compSpecParams, 0, newParams, 0, compSpecParams.length);
                compSpecParams = newParams;
            }
            compSpecParams[ci] = compParam;
        }
        int x = getSamplesPerLine();
        int y = getNumberOfLines();
        int[] multiples = [ 8, 16, 24, 32 ];
        for (int i = 0; i < nf; i++) {
            int[] compParam = compSpecParams[componentIdentifiers[i]];
            int hi = compParam[1];
            int vi = compParam[2];
            int compWidth = (x * hi + hmax - 1) / hmax;
            int compHeight = (y * vi + vmax - 1) / vmax;
            int dsWidth = roundUpToMultiple(compWidth, multiples[hi - 1]);
            int dsHeight = roundUpToMultiple(compHeight, multiples[vi - 1]);
            compParam[3] = dsWidth;
            compParam[4] = dsHeight;
        }
        setMaxHFactor(hmax);
        setMaxVFactor(vmax);
        componentParameters = compSpecParams;
    }

    /* Used when encoding. */
    public void initializeContents() {
        int nf = getNumberOfImageComponents();
        if (nf is 0 || nf !is componentParameters.length) {
            SWT.error(SWT.ERROR_INVALID_IMAGE);
        }
        int hmax = 0;
        int vmax = 0;
        int[][] compSpecParams = componentParameters;
        for (int i = 0; i < nf; i++) {
            int ofs = i * 3 + 10;
            int[] compParam = compSpecParams[componentIdentifiers[i]];
            int hi = compParam[1];
            int vi = compParam[2];
            if (hi * vi > 4) {
                SWT.error(SWT.ERROR_INVALID_IMAGE);
            }
            reference[ofs] = cast(byte)(i + 1);
            reference[ofs + 1] = cast(byte)(hi * 16 + vi);
            reference[ofs + 2] = cast(byte)(compParam[0]);
            if (hi > hmax) hmax = hi;
            if (vi > vmax) vmax = vi;
        }
        int x = getSamplesPerLine();
        int y = getNumberOfLines();
        int[] multiples = [8, 16, 24, 32];
        for (int i = 0; i < nf; i++) {
            int[] compParam = compSpecParams[componentIdentifiers[i]];
            int hi = compParam[1];
            int vi = compParam[2];
            int compWidth = (x * hi + hmax - 1) / hmax;
            int compHeight = (y * vi + vmax - 1) / vmax;
            int dsWidth = roundUpToMultiple(compWidth, multiples[hi - 1]);
            int dsHeight = roundUpToMultiple(compHeight, multiples[vi - 1]);
            compParam[3] = dsWidth;
            compParam[4] = dsHeight;
        }
        setMaxHFactor(hmax);
        setMaxVFactor(vmax);
    }

    int roundUpToMultiple(int anInteger, int mInteger) {
        int a = anInteger + mInteger - 1;
        return a - (a % mInteger);
    }

    /*
     * Verify the information contained in the receiver is correct.
     * Answer true if the header contains a valid marker. Otherwise,
     * answer false. Valid Start Of Frame markers are:
     *  SOF_0  - Baseline DCT, Huffman coding
     *  SOF_1  - Extended sequential DCT, Huffman coding
     *  SOF_2  - Progressive DCT, Huffman coding
     *  SOF_3  - Lossless (sequential), Huffman coding
     *  SOF_5  - Differential sequential, Huffman coding
     *  SOF_6  - Differential progressive, Huffman coding
     *  SOF_7  - Differential lossless, Huffman coding
     *  SOF_9  - Extended sequential DCT, arithmetic coding
     *  SOF_10 - Progressive DCT, arithmetic coding
     *  SOF_11 - Lossless (sequential), arithmetic coding
     *  SOF_13 - Differential sequential, arithmetic coding
     *  SOF_14 - Differential progressive, arithmetic coding
     *  SOF_15 - Differential lossless, arithmetic coding
     */
    public override bool verify() {
        int marker = getSegmentMarker();
        return (marker >= JPEGFileFormat.SOF0 && marker <= JPEGFileFormat.SOF3) ||
            (marker >= JPEGFileFormat.SOF5 && marker <= JPEGFileFormat.SOF7) ||
            (marker >= JPEGFileFormat.SOF9 && marker <= JPEGFileFormat.SOF11) ||
            (marker >= JPEGFileFormat.SOF13 && marker <= JPEGFileFormat.SOF15);
    }

    public bool isProgressive() {
        int marker = getSegmentMarker();
        return marker is JPEGFileFormat.SOF2
            || marker is JPEGFileFormat.SOF6
            || marker is JPEGFileFormat.SOF10
            || marker is JPEGFileFormat.SOF14;
    }

    public bool isArithmeticCoding() {
        return getSegmentMarker() >= JPEGFileFormat.SOF9;
    }
}