/* ============================================================
*
* This file is part of the KDE project
*
* Date        : 2009-11-13
* Description : Sane interface for KDE
*
* Copyright (C) 2009 by Kare Sars <kare dot sars at iki dot fi>
* Copyright (C) 2014 by Gregor Mitsch: port to KDE5 frameworks
*
* This library is free software; you can redistribute it and/or
* modify it under the terms of the GNU Lesser General Public
* License as published by the Free Software Foundation; either
* version 2.1 of the License, or (at your option) version 3, or any
* later version accepted by the membership of KDE e.V. (or its
* successor approved by the membership of KDE e.V.), which shall
* act as a proxy defined in Section 6 of version 3 of the license.
*
* 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
* Lesser General Public License for more details.
*
* You should have received a copy of the GNU Lesser General Public
* License along with this program.  If not, see <http://www.gnu.org/licenses/>.
*
* ============================================================ */

#include "ksanepreviewthread.h"

#include <QMutexLocker>
#include <QDebug>
#include <QImage>

namespace KSaneIface
{
KSanePreviewThread::KSanePreviewThread(SANE_Handle handle, QImage *img):
    QThread(),
    status(SANE_STATUS_GOOD),
    m_frameSize(0),
    m_frameRead(0),
    m_dataSize(0),
    m_frame_t_count(0),
    m_pixel_x(0),
    m_pixel_y(0),
    m_px_c_index(0),
    m_img(img),
    m_saneHandle(handle),
    m_invertColors(false),
    m_readStatus(READ_READY),
//    m_scanProgress(0),
    m_saneStartDone(false),
    m_imageResized(false)
{
    m_px_colors[0] = 0;
    m_px_colors[1] = 0;
    m_px_colors[2] = 0;
}

void KSanePreviewThread::setPreviewInverted(bool inverted)
{
    m_invertColors = inverted;
}

void KSanePreviewThread::cancelScan()
{
    m_readStatus = READ_CANCEL;
}

void KSanePreviewThread::run()
{
    m_dataSize = 0;
    m_readStatus = READ_ON_GOING;
    m_saneStartDone = false;

    // Start the scanning with sane_start
    status = sane_start(m_saneHandle);

    if (status != SANE_STATUS_GOOD) {
        qDebug() << "sane_start=" << sane_strstatus(status);
        sane_cancel(m_saneHandle);
        m_readStatus = READ_ERROR;
        return;
    }

    // Read image parameters
    status = sane_get_parameters(m_saneHandle, &m_params);
    if (status != SANE_STATUS_GOOD) {
        qDebug() << "sane_get_parameters=" << sane_strstatus(status);
        sane_cancel(m_saneHandle);
        m_readStatus = READ_ERROR;
        return;
    }

    // calculate data size
    m_frameSize  = m_params.lines * m_params.bytes_per_line;
    if ((m_params.format == SANE_FRAME_RED) ||
            (m_params.format == SANE_FRAME_GREEN) ||
            (m_params.format == SANE_FRAME_BLUE)) {
        // this is unfortunately calculated again for every frame....
        m_dataSize = m_frameSize * 3;
    } else {
        m_dataSize = m_frameSize;
    }

    // create a new image if necessary
    if ((m_img->height() != m_params.lines) ||
            (m_img->width()  != m_params.pixels_per_line)) {
        // just hope that the frame size is not changed between different frames of the same image.
        if (m_params.lines > 0) {
            *m_img = QImage(m_params.pixels_per_line, m_params.lines, QImage::Format_RGB32);
        } else {
            // handscanners have the number of lines -1 -> make room for something
            *m_img = QImage(m_params.pixels_per_line, m_params.pixels_per_line, QImage::Format_RGB32);
        }
        m_img->fill(0xFFFFFFFF);
    }
    m_imageResized = false;
    m_pixel_x     = 0;
    m_pixel_y     = 0;
    m_frameRead   = 0;
    m_px_c_index  = 0;
    m_frame_t_count = 0;

    // set the m_saneStartDone here so the new QImage gets allocated before updating the preview.
    m_saneStartDone = true;

    while (m_readStatus == READ_ON_GOING) {
        readData();
    }
}

int KSanePreviewThread::scanProgress()
{
    // handscanners have negative data size
    if (m_dataSize <= 0) {
        return 0;
    }

    int bytesRead;

    if (m_frameSize < m_dataSize) {
        bytesRead = m_frameRead + (m_frameSize * m_frame_t_count);
    } else {
        bytesRead = m_frameRead;
    }

    return (int)(((float)bytesRead * 100.0) / m_dataSize);
}

void KSanePreviewThread::readData()
{
    SANE_Int readBytes;
    status = sane_read(m_saneHandle, m_readData, PREVIEW_READ_CHUNK_SIZE, &readBytes);

    switch (status) {
    case SANE_STATUS_GOOD:
        // continue to parsing the data
        break;

    case SANE_STATUS_EOF:
        // (handscanners have negative frame size)
        if (m_frameRead < m_frameSize) {
            qDebug() << "frameRead =" << m_frameRead  << ", frameSize =" << m_frameSize;
            m_readStatus = READ_ERROR;
            return;
        }
        if (m_params.last_frame == SANE_TRUE) {
            // this is where it all ends well :)
            m_readStatus = READ_READY;
            return;
        } else {
            // start reading next frame
            SANE_Status status = sane_start(m_saneHandle);
            if (status != SANE_STATUS_GOOD) {
                qDebug() << "sane_start =" << sane_strstatus(status);
                m_readStatus = READ_ERROR;
                return;
            }
            status = sane_get_parameters(m_saneHandle, &m_params);
            if (status != SANE_STATUS_GOOD) {
                qDebug() << "sane_get_parameters =" << sane_strstatus(status);
                m_readStatus = READ_ERROR;
                sane_cancel(m_saneHandle);
                return;
            }
            //qDebug() << "New Frame";
            m_frameRead = 0;
            m_pixel_x     = 0;
            m_pixel_y     = 0;
            m_px_c_index  = 0;
            m_frame_t_count++;
            break;
        }
    default:
        qDebug() << "sane_read=" << status << "=" << sane_strstatus(status);
        m_readStatus = READ_ERROR;
        sane_cancel(m_saneHandle);
        return;
    }

    copyToPreviewImg(readBytes);
}

#define inc_pixel(x,y,ppl) { x++; if (x>=ppl) { y++; x=0;} }
#define inc_color_index(index) { index++; if (index==3) index=0;}

#define index_red8_to_argb8(i)   (i*4 + 2)
#define index_red16_to_argb8(i)  (i*2 + 2)

#define index_green8_to_argb8(i)  (i*4 + 1)
#define index_green16_to_argb8(i) (i*2 + 1)

#define index_blue8_to_argb8(i)  (i*4)
#define index_blue16_to_argb8(i) (i*2)

void KSanePreviewThread::copyToPreviewImg(int read_bytes)
{
    QMutexLocker locker(&imgMutex);
    int index;
    uchar *imgBits = m_img->bits();
    if (m_invertColors) {
        if (m_params.depth >= 8) {
            for (int i = 0; i < read_bytes; i++) {
                m_readData[i] = 255 - m_readData[i];
            }
        }
        if (m_params.depth == 1) {
            for (int i = 0; i < read_bytes; i++) {
                m_readData[i] = ~m_readData[i];
            }
        }
    }
    switch (m_params.format) {
    case SANE_FRAME_GRAY:
        if (m_params.depth == 1) {
            int i, j;
            for (i = 0; i < read_bytes; i++) {
                if (m_pixel_y >= m_img->height()) {
                    // resize the image
                    *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                    m_imageResized = true;
                }
                for (j = 7; j >= 0; --j) {
                    if ((m_readData[i] & (1 << j)) == 0) {
                        m_img->setPixel(m_pixel_x,
                                        m_pixel_y,
                                        qRgb(255, 255, 255));
                    } else {
                        m_img->setPixel(m_pixel_x,
                                        m_pixel_y,
                                        qRgb(0, 0, 0));
                    }
                    m_pixel_x++;
                    if (m_pixel_x >= m_params.pixels_per_line) {
                        m_pixel_x = 0;
                        m_pixel_y++;
                        break;
                    }
                    if (m_pixel_y >= m_params.lines) {
                        break;
                    }
                }
                m_frameRead++;
            }
            return;
        } else if (m_params.depth == 8) {
            for (int i = 0; i < read_bytes; i++) {
                index = m_frameRead * 4;
                if ((index + 2) > m_img->byteCount()) {
                    // resize the image
                    *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                    imgBits = m_img->bits();
                    m_imageResized = true;
                }
                imgBits[index    ] = m_readData[i];
                imgBits[index + 1] = m_readData[i];
                imgBits[index + 2] = m_readData[i];
                m_frameRead++;
            }
            return;
        } else if (m_params.depth == 16) {
            for (int i = 0; i < read_bytes; i++) {
                if (m_frameRead % 2 == 0) {
                    index = m_frameRead * 2;
                    if ((index + 2) > m_img->byteCount()) {
                        // resize the image
                        *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                        imgBits = m_img->bits();
                        m_imageResized = true;
                    }
                    imgBits[index    ] = m_readData[i + 1];
                    imgBits[index + 1] = m_readData[i + 1];
                    imgBits[index + 2] = m_readData[i + 1];
                }
                m_frameRead++;
            }
            return;
        }
        break;

    case SANE_FRAME_RGB:
        if (m_params.depth == 8) {
            for (int i = 0; i < read_bytes; i++) {
                m_px_colors[m_px_c_index] = m_readData[i];
                inc_color_index(m_px_c_index);
                m_frameRead++;
                if (m_px_c_index == 0) {
                    if (m_pixel_y >= m_img->height()) {
                        // resize the image
                        *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                        m_imageResized = true;
                    }
                    m_img->setPixel(m_pixel_x,
                                    m_pixel_y,
                                    qRgb(m_px_colors[0],
                                         m_px_colors[1],
                                         m_px_colors[2]));
                    inc_pixel(m_pixel_x, m_pixel_y, m_params.pixels_per_line);
                }
            }
            return;
        } else if (m_params.depth == 16) {
            for (int i = 0; i < read_bytes; i++) {
                m_frameRead++;
                if (m_frameRead % 2 == 0) {
                    m_px_colors[m_px_c_index] = m_readData[i];
                    inc_color_index(m_px_c_index);
                    if (m_px_c_index == 0) {
                        if (m_pixel_y >= m_img->height()) {
                            // resize the image
                            *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                            m_imageResized = true;
                        }
                        m_img->setPixel(m_pixel_x,
                                        m_pixel_y,
                                        qRgb(m_px_colors[0],
                                             m_px_colors[1],
                                             m_px_colors[2]));
                        inc_pixel(m_pixel_x, m_pixel_y, m_params.pixels_per_line);
                    }
                }
            }
            return;
        }
        break;

    case SANE_FRAME_RED:
        if (m_params.depth == 8) {
            for (int i = 0; i < read_bytes; i++) {
                if (index_red8_to_argb8(m_frameRead) > m_img->byteCount()) {
                    // resize the image
                    *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                    imgBits = m_img->bits();
                    m_imageResized = true;
                }
                imgBits[index_red8_to_argb8(m_frameRead)] = m_readData[i];
                m_frameRead++;
            }
            return;
        } else if (m_params.depth == 16) {
            for (int i = 0; i < read_bytes; i++) {
                if (m_frameRead % 2 == 0) {
                    if (index_red16_to_argb8(m_frameRead) > m_img->byteCount()) {
                        // resize the image
                        *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                        imgBits = m_img->bits();
                        m_imageResized = true;
                    }
                    imgBits[index_red16_to_argb8(m_frameRead)] = m_readData[i + 1];
                }
                m_frameRead++;
            }
            return;
        }
        break;

    case SANE_FRAME_GREEN:
        if (m_params.depth == 8) {
            for (int i = 0; i < read_bytes; i++) {
                if (index_green8_to_argb8(m_frameRead) > m_img->byteCount()) {
                    // resize the image
                    *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                    imgBits = m_img->bits();
                    m_imageResized = true;
                }
                imgBits[index_green8_to_argb8(m_frameRead)] = m_readData[i];
                m_frameRead++;
            }
            return;
        } else if (m_params.depth == 16) {
            for (int i = 0; i < read_bytes; i++) {
                if (m_frameRead % 2 == 0) {
                    if (index_green16_to_argb8(m_frameRead) > m_img->byteCount()) {
                        // resize the image
                        *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                        imgBits = m_img->bits();
                        m_imageResized = true;
                    }
                    imgBits[index_green16_to_argb8(m_frameRead)] = m_readData[i + 1];
                }
                m_frameRead++;
            }
            return;
        }
        break;

    case SANE_FRAME_BLUE:
        if (m_params.depth == 8) {
            for (int i = 0; i < read_bytes; i++) {
                if (index_blue8_to_argb8(m_frameRead) > m_img->byteCount()) {
                    // resize the image
                    *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                    imgBits = m_img->bits();
                    m_imageResized = true;
                }
                imgBits[index_blue8_to_argb8(m_frameRead)] = m_readData[i];
                m_frameRead++;
            }
            return;
        } else if (m_params.depth == 16) {
            for (int i = 0; i < read_bytes; i++) {
                if (m_frameRead % 2 == 0) {
                    if (index_blue16_to_argb8(m_frameRead) > m_img->byteCount()) {
                        // resize the image
                        *m_img = m_img->copy(0, 0, m_img->width(), m_img->height() + m_img->width());
                        imgBits = m_img->bits();
                        m_imageResized = true;
                    }
                    imgBits[index_blue16_to_argb8(m_frameRead)] = m_readData[i + 1];
                }
                m_frameRead++;
            }
            return;
        }
        break;
    }

    qWarning() << "Format" << m_params.format
               << "and depth" << m_params.format
               << "is not yet suppoeted by libksane!";
    m_readStatus = READ_ERROR;
    return;
}

bool KSanePreviewThread::saneStartDone()
{
    return   m_saneStartDone;
}

bool KSanePreviewThread::imageResized()
{
    if (m_imageResized) {
        m_imageResized = false;
        return true;
    }
    return false;
}

}  // NameSpace KSaneIface
