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#include "qlinuxfbscreen.h"
#include <QtPlatformSupport/private/qfbcursor_p.h>
#include <QtGui/QPainter>

#include <private/qcore_unix_p.h> // overrides QT_OPEN
#include <qimage.h>
#include <qdebug.h>

#include <unistd.h>
#include <stdlib.h>
#include <sys/ioctl.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <sys/mman.h>
#include <linux/kd.h>
#include <fcntl.h>
#include <errno.h>
#include <stdio.h>
#include <limits.h>
#include <signal.h>

#include <linux/fb.h>

QT_BEGIN_NAMESPACE

static int openFramebufferDevice(const QString &dev)
{
    int fd = -1;

    if (access(dev.toLatin1().constData(), R_OK|W_OK) == 0)
        fd = QT_OPEN(dev.toLatin1().constData(), O_RDWR);

    if (fd == -1) {
        if (access(dev.toLatin1().constData(), R_OK) == 0)
            fd = QT_OPEN(dev.toLatin1().constData(), O_RDONLY);
    }

    return fd;
}

static int determineDepth(const fb_var_screeninfo &vinfo)
{
    int depth = vinfo.bits_per_pixel;
    if (depth== 24) {
        depth = vinfo.red.length + vinfo.green.length + vinfo.blue.length;
        if (depth <= 0)
            depth = 24; // reset if color component lengths are not reported
    } else if (depth == 16) {
        depth = vinfo.red.length + vinfo.green.length + vinfo.blue.length;
        if (depth <= 0)
            depth = 16;
    }
    return depth;
}

static QRect determineGeometry(const fb_var_screeninfo &vinfo, const QRect &userGeometry)
{
    int xoff = vinfo.xoffset;
    int yoff = vinfo.yoffset;
    int w, h;
    if (userGeometry.isValid()) {
        w = userGeometry.width();
        h = userGeometry.height();
        if ((uint)w > vinfo.xres)
            w = vinfo.xres;
        if ((uint)h > vinfo.yres)
            h = vinfo.yres;

        int xxoff = userGeometry.x(), yyoff = userGeometry.y();
        if (xxoff != 0 || yyoff != 0) {
            if (xxoff < 0 || xxoff + w > (int)(vinfo.xres))
                xxoff = vinfo.xres - w;
            if (yyoff < 0 || yyoff + h > (int)(vinfo.yres))
                yyoff = vinfo.yres - h;
            xoff += xxoff;
            yoff += yyoff;
        } else {
            xoff += (vinfo.xres - w)/2;
            yoff += (vinfo.yres - h)/2;
        }
    } else {
        w = vinfo.xres;
        h = vinfo.yres;
    }

    if (w == 0 || h == 0) {
        qWarning("Unable to find screen geometry, using 320x240");
        w = 320;
        h = 240;
    }

    return QRect(xoff, yoff, w, h);
}

static QSizeF determinePhysicalSize(const fb_var_screeninfo &vinfo, const QSize &mmSize, const QSize &res)
{
    int mmWidth = mmSize.width(), mmHeight = mmSize.height();

    if (mmWidth <= 0 && mmHeight <= 0) {
        if (vinfo.width != 0 && vinfo.height != 0
            && vinfo.width != UINT_MAX && vinfo.height != UINT_MAX) {
            mmWidth = vinfo.width;
            mmHeight = vinfo.height;
        } else {
            const int dpi = 72;
            mmWidth = qRound(res.width() * 25.4 / dpi);
            mmHeight = qRound(res.height() * 25.4 / dpi);
        }
    } else if (mmWidth > 0 && mmHeight <= 0) {
        mmHeight = res.height() * mmWidth/res.width();
    } else if (mmHeight > 0 && mmWidth <= 0) {
        mmWidth = res.width() * mmHeight/res.height();
    }

    return QSize(mmWidth, mmHeight);
}

static QImage::Format determineFormat(const fb_var_screeninfo &info, int depth)
{
    const fb_bitfield rgba[4] = { info.red, info.green,
                                  info.blue, info.transp };

    QImage::Format format = QImage::Format_Invalid;

    switch (depth) {
    case 32: {
        const fb_bitfield argb8888[4] = {{16, 8, 0}, {8, 8, 0},
                                         {0, 8, 0}, {24, 8, 0}};
        const fb_bitfield abgr8888[4] = {{0, 8, 0}, {8, 8, 0},
                                         {16, 8, 0}, {24, 8, 0}};
        if (memcmp(rgba, argb8888, 4 * sizeof(fb_bitfield)) == 0) {
            format = QImage::Format_ARGB32;
        } else if (memcmp(rgba, argb8888, 3 * sizeof(fb_bitfield)) == 0) {
            format = QImage::Format_RGB32;
        } else if (memcmp(rgba, abgr8888, 3 * sizeof(fb_bitfield)) == 0) {
            format = QImage::Format_RGB32;
            // pixeltype = BGRPixel;
        }
        break;
    }
    case 24: {
        const fb_bitfield rgb888[4] = {{16, 8, 0}, {8, 8, 0},
                                       {0, 8, 0}, {0, 0, 0}};
        const fb_bitfield bgr888[4] = {{0, 8, 0}, {8, 8, 0},
                                       {16, 8, 0}, {0, 0, 0}};
        if (memcmp(rgba, rgb888, 3 * sizeof(fb_bitfield)) == 0) {
            format = QImage::Format_RGB888;
        } else if (memcmp(rgba, bgr888, 3 * sizeof(fb_bitfield)) == 0) {
            format = QImage::Format_RGB888;
            // pixeltype = BGRPixel;
        }
        break;
    }
    case 18: {
        const fb_bitfield rgb666[4] = {{12, 6, 0}, {6, 6, 0},
                                       {0, 6, 0}, {0, 0, 0}};
        if (memcmp(rgba, rgb666, 3 * sizeof(fb_bitfield)) == 0)
            format = QImage::Format_RGB666;
        break;
    }
    case 16: {
        const fb_bitfield rgb565[4] = {{11, 5, 0}, {5, 6, 0},
                                       {0, 5, 0}, {0, 0, 0}};
        const fb_bitfield bgr565[4] = {{0, 5, 0}, {5, 6, 0},
                                       {11, 5, 0}, {0, 0, 0}};
        if (memcmp(rgba, rgb565, 3 * sizeof(fb_bitfield)) == 0) {
            format = QImage::Format_RGB16;
        } else if (memcmp(rgba, bgr565, 3 * sizeof(fb_bitfield)) == 0) {
            format = QImage::Format_RGB16;
            // pixeltype = BGRPixel;
        }
        break;
    }
    case 15: {
        const fb_bitfield rgb1555[4] = {{10, 5, 0}, {5, 5, 0},
                                        {0, 5, 0}, {15, 1, 0}};
        const fb_bitfield bgr1555[4] = {{0, 5, 0}, {5, 5, 0},
                                        {10, 5, 0}, {15, 1, 0}};
        if (memcmp(rgba, rgb1555, 3 * sizeof(fb_bitfield)) == 0) {
            format = QImage::Format_RGB555;
        } else if (memcmp(rgba, bgr1555, 3 * sizeof(fb_bitfield)) == 0) {
            format = QImage::Format_RGB555;
            // pixeltype = BGRPixel;
        }
        break;
    }
    case 12: {
        const fb_bitfield rgb444[4] = {{8, 4, 0}, {4, 4, 0},
                                       {0, 4, 0}, {0, 0, 0}};
        if (memcmp(rgba, rgb444, 3 * sizeof(fb_bitfield)) == 0)
            format = QImage::Format_RGB444;
        break;
    }
    case 8:
        break;
    case 1:
        format = QImage::Format_Mono; //###: LSB???
        break;
    default:
        break;
    }

    return format;
}

static int openTtyDevice(const QString &device)
{
    const char *const devs[] = { "/dev/tty0", "/dev/tty", "/dev/console", 0 };

    int fd = -1;
    if (device.isEmpty()) {
        for (const char * const *dev = devs; *dev; ++dev) {
            fd = QT_OPEN(*dev, O_RDWR);
            if (fd != -1)
                break;
        }
    } else {
        fd = QT_OPEN(QFile::encodeName(device).constData(), O_RDWR);
    }

    return fd;
}

static bool switchToGraphicsMode(int ttyfd, int *oldMode)
{
    ioctl(ttyfd, KDGETMODE, oldMode);
    if (*oldMode != KD_GRAPHICS) {
       if (ioctl(ttyfd, KDSETMODE, KD_GRAPHICS) != 0)
            return false;
    }

    // No blankin' screen, no blinkin' cursor!, no cursor!
    const char termctl[] = "\033[9;0]\033[?33l\033[?25l\033[?1c";
    QT_WRITE(ttyfd, termctl, sizeof(termctl));
    return true;
}

static void resetTty(int ttyfd, int oldMode)
{
    ioctl(ttyfd, KDSETMODE, oldMode);

    // Blankin' screen, blinkin' cursor!
    const char termctl[] = "\033[9;15]\033[?33h\033[?25h\033[?0c";
    QT_WRITE(ttyfd, termctl, sizeof(termctl));

    QT_CLOSE(ttyfd);
}

static void blankScreen(int fd, bool on)
{
    ioctl(fd, FBIOBLANK, on ? VESA_POWERDOWN : VESA_NO_BLANKING);
}

QLinuxFbScreen::QLinuxFbScreen()
    : mFbFd(-1), mBlitter(0)
{
}

QLinuxFbScreen::~QLinuxFbScreen()
{
    if (mFbFd != -1) {
        munmap(mMmap.data - mMmap.offset, mMmap.size);
        close(mFbFd);
    }

    if (mTtyFd != -1) {
        resetTty(mTtyFd, mOldTtyMode);
        close(mTtyFd);
    }

    delete mBlitter;
}

bool QLinuxFbScreen::initialize(const QStringList &args)
{
    QRegExp ttyRx(QLatin1String("tty=(.*)"));
    QRegExp fbRx(QLatin1String("fb=(.*)"));
    QRegExp mmSizeRx(QLatin1String("mmsize=(\\d+)x(\\d+)"));
    QRegExp sizeRx(QLatin1String("size=(\\d+)x(\\d+)"));
    QRegExp offsetRx(QLatin1String("offset=(\\d+)x(\\d+)"));

    QString fbDevice, ttyDevice;
    QSize userMmSize;
    QRect userGeometry;
    bool doSwitchToGraphicsMode = true;

    // Parse arguments
    foreach (const QString &arg, args) {
        if (arg == QLatin1String("nographicsmodeswitch"))
            doSwitchToGraphicsMode = false;
        else if (sizeRx.indexIn(arg) != -1)
            userGeometry.setSize(QSize(sizeRx.cap(1).toInt(), sizeRx.cap(2).toInt()));
        else if (offsetRx.indexIn(arg) != -1)
            userGeometry.setTopLeft(QPoint(offsetRx.cap(1).toInt(), offsetRx.cap(2).toInt()));
        else if (ttyRx.indexIn(arg) != -1)
            ttyDevice = ttyRx.cap(1);
        else if (fbRx.indexIn(arg) != -1)
            fbDevice = fbRx.cap(1);
        else if (mmSizeRx.indexIn(arg) != -1)
            userMmSize = QSize(mmSizeRx.cap(1).toInt(), mmSizeRx.cap(2).toInt());
    }

    if (fbDevice.isEmpty())
        fbDevice = QLatin1String("/dev/fb0"); // ## auto-detect

    // Open the device
    mFbFd = openFramebufferDevice(fbDevice);
    if (mFbFd == -1) {
        qWarning("Failed to open framebuffer %s : %s", qPrintable(fbDevice), strerror(errno));
        return false;
    }

    // Read the fixed and variable screen information
    fb_fix_screeninfo finfo;
    fb_var_screeninfo vinfo;
    memset(&vinfo, 0, sizeof(vinfo));
    memset(&finfo, 0, sizeof(finfo));

    if (ioctl(mFbFd, FBIOGET_FSCREENINFO, &finfo) != 0) {
        qWarning("Error reading fixed information: %s", strerror(errno));
        return false;
    }

    if (ioctl(mFbFd, FBIOGET_VSCREENINFO, &vinfo)) {
        qWarning("Error reading variable information: %s", strerror(errno));
        return false;
    }

    mDepth = determineDepth(vinfo);
    mBytesPerLine = finfo.line_length;
    mGeometry = determineGeometry(vinfo, userGeometry);
    mFormat = determineFormat(vinfo, mDepth);
    mPhysicalSize = determinePhysicalSize(vinfo, userMmSize, mGeometry.size());

    // mmap the framebuffer
    mMmap.size = finfo.smem_len;
    uchar *data = (unsigned char *)mmap(0, mMmap.size, PROT_READ | PROT_WRITE, MAP_SHARED, mFbFd, 0);
    if ((long)data == -1) {
        qWarning("Failed to mmap framebuffer: %s", strerror(errno));
        return false;
    }

    mMmap.offset = mGeometry.y() * mBytesPerLine + mGeometry.x() * mDepth / 8;
    mMmap.data = data + mMmap.offset;

    QFbScreen::initializeCompositor();
    mFbScreenImage = QImage(data, mGeometry.width(), mGeometry.height(), mBytesPerLine, mFormat);
    mCursor = new QFbCursor(this);

    mTtyFd = openTtyDevice(ttyDevice);
    if (mTtyFd == -1)
        qWarning() << "Failed to open tty" << strerror(errno);

    if (doSwitchToGraphicsMode && !switchToGraphicsMode(mTtyFd, &mOldTtyMode))
        qWarning() << "Failed to set graphics mode" << strerror(errno);

    blankScreen(mFbFd, false);

    return true;
}

QRegion QLinuxFbScreen::doRedraw()
{
    QRegion touched = QFbScreen::doRedraw();

    if (touched.isEmpty())
        return touched;

    if (!mBlitter)
        mBlitter = new QPainter(&mFbScreenImage);

    QVector<QRect> rects = touched.rects();
    for (int i = 0; i < rects.size(); i++)
        mBlitter->drawImage(rects[i], *mScreenImage, rects[i]);
    return touched;
}

QT_END_NAMESPACE