/*

    Copyright (C) 2009 Nokia Corporation and/or its subsidiary(-ies)

    This library is free software; you can redistribute it and/or

    modify it under the terms of the GNU Library General Public

    License as published by the Free Software Foundation; either

    version 2 of the License, or (at your option) any later version.

    This library is distributed in the hope that it will be useful,

    but WITHOUT ANY WARRANTY; without even the implied warranty of

    MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the GNU

    Library General Public License for more details.

    You should have received a copy of the GNU Library General Public License

    along with this library; see the file COPYING.LIB.  If not, write to

    the Free Software Foundation, Inc., 51 Franklin Street, Fifth Floor,

    Boston, MA 02110-1301, USA.

*/

#include <QtCore/qmath.h>

#include <QApplication>

#include <QBuffer>

#include <QByteArray>

#include <QImage>

#include <QStringList>

#include <stdio.h>

int main(int argc, char* argv[])

{

    QCoreApplication app(argc, argv);

    qreal tolerance = 0;

    QStringList args = app.arguments();

    for (int i = 0; i < argc; ++i)

        if (args[i] == "-t" || args[i] == "--tolerance")

            tolerance = args[i + 1].toDouble();

    char buffer[2048];

    QImage actualImage;

    QImage baselineImage;

    while (fgets(buffer, sizeof(buffer), stdin)) {

        // remove the CR

        char* newLineCharacter = strchr(buffer, '\n');

        if (newLineCharacter)

            *newLineCharacter = '\0';

        if (!strncmp("Content-Length: ", buffer, 16)) {

            strtok(buffer, " ");

            int imageSize = strtol(strtok(0, " "), 0, 10);

            if (imageSize <= 0) {

                fputs("error, image size must be specified.\n", stdout);

            } else {

                unsigned char buffer[2048];

                QBuffer data;

                // Read all the incoming chunks

                data.open(QBuffer::WriteOnly);

                while (imageSize > 0) {

                    size_t bytesToRead = qMin(imageSize, 2048);

                    size_t bytesRead = fread(buffer, 1, bytesToRead, stdin);

                    data.write(reinterpret_cast<const char*>(buffer), bytesRead);

                    imageSize -= static_cast<int>(bytesRead);

                }

                // Convert into QImage

                QImage decodedImage;

                decodedImage.loadFromData(data.data(), "PNG");

                decodedImage.convertToFormat(QImage::Format_ARGB32);

                // Place it in the right place

                if (actualImage.isNull())

                    actualImage = decodedImage;

                else

                    baselineImage = decodedImage;

            }

        }

        if (!actualImage.isNull() && !baselineImage.isNull()) {

            if (actualImage.size() != baselineImage.size()) {

                fprintf(stderr, "error, test and reference image have different properties.\n");

                fflush(stderr);

            } else {

                int w = actualImage.width();

                int h = actualImage.height();

                QImage diffImage(w, h, QImage::Format_ARGB32);

                int count = 0;

                qreal sum = 0;

                qreal maxDistance = 0;

                for (int x = 0; x < w; ++x)

                    for (int y = 0; y < h; ++y) {

                        QRgb pixel = actualImage.pixel(x, y);

                        QRgb basePixel = baselineImage.pixel(x, y);

                        qreal red = (qRed(pixel) - qRed(basePixel)) / static_cast<float>(qMax(255 - qRed(basePixel), qRed(basePixel)));

                        qreal green = (qGreen(pixel) - qGreen(basePixel)) / static_cast<float>(qMax(255 - qGreen(basePixel), qGreen(basePixel)));

                        qreal blue = (qBlue(pixel) - qBlue(basePixel)) / static_cast<float>(qMax(255 - qBlue(basePixel), qBlue(basePixel)));

                        qreal alpha = (qAlpha(pixel) - qAlpha(basePixel)) / static_cast<float>(qMax(255 - qAlpha(basePixel), qAlpha(basePixel)));

                        qreal distance = qSqrt(red * red + green * green + blue * blue + alpha * alpha) / 2.0f;

                        int gray = distance * qreal(255);

                        diffImage.setPixel(x, y, qRgb(gray, gray, gray));

                        if (distance >= 1 / qreal(255)) {

                            count++;

                            sum += distance;

                            maxDistance = qMax(maxDistance, distance);

                        }

                }

                qreal difference = 0;

                if (count)

                    difference = 100 * sum / static_cast<qreal>(w * h);

                if (difference <= tolerance) {

                    difference = 0;

                } else {

                    difference = qRound(difference * 100) / 100;

                    difference = qMax(difference, qreal(0.01));

                }

                if (!count) {

                    fprintf(stdout, "diff: %01.2f%% passed\n", difference);

                } else {

                    QBuffer buffer;

                    buffer.open(QBuffer::WriteOnly);

                    diffImage.save(&buffer, "PNG");

                    buffer.close();

                    const QByteArray &data = buffer.data();

                    printf("Content-Length: %lu\n", static_cast<unsigned long>(data.length()));

                    fwrite(data.constData(), 1, data.length(), stdout);

                    fprintf(stdout, "diff: %01.2f%% failed\n", difference);

                }

                fflush(stdout);

            }

        }

    }

    return 0;

}