/*
 *  Copyright (c) 2009 Boudewijn Rempt <boud@valdyas.org>
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program 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 General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
 */
#include "psd_header.h"

#include <QByteArray>
#include <QIODevice>

#include "psd_utils.h"
#include <QtEndian>

struct Header {
    char signature[4];    // 8PBS
    char version[2];      // 1 or 2
    char padding[6];
    char nChannels[2];    // 1 - 56
    char height[4];       // 1-30,000 or 1 - 300,000
    char width[4];        // 1-30,000 or 1 - 300,000
    char channelDepth[2]; // 1, 8, 16
    char colormode[2];    // 0-9
};


PSDHeader::PSDHeader()
    : version(0)
    , nChannels(0)
    , height(0)
    , width(0)
    , channelDepth(0)
    , colormode(COLORMODE_UNKNOWN)
{
}

bool PSDHeader::read(QIODevice* device)
{
    Header header;
    quint64 bytesRead = device->read((char*)&header, sizeof(Header));
    if (bytesRead != sizeof(Header)) {
        error = "Could not read header: not enough bytes";
        return false;
    }

    signature = QString(header.signature);
    memcpy(&version, header.version, 2);
    version = qFromBigEndian(version);
    memcpy(&nChannels, header.nChannels, 2);
    nChannels = qFromBigEndian(nChannels);
    memcpy(&height, header.height, 4);
    height = qFromBigEndian(height);
    memcpy(&width, header.width, 4);
    width = qFromBigEndian(width);
    memcpy(&channelDepth, header.channelDepth, 2);
    channelDepth = qFromBigEndian(channelDepth);
    memcpy(&colormode, header.colormode, 2);
    colormode = (psd_color_mode)qFromBigEndian((quint16)colormode);

    return valid();
}

bool PSDHeader::write(QIODevice* device)
{
    if (!valid()) return false;
    if (!psdwrite(device, signature)) return false;
    if (!psdwrite(device, version)) return false;
    if (!psdpad(device, 6)) return false;
    if (!psdwrite(device, nChannels)) return false;
    if (!psdwrite(device, height)) return false;
    if (!psdwrite(device, width)) return false;
    if (!psdwrite(device, channelDepth)) return false;
    if (!psdwrite(device, (quint16)colormode)) return false;
    return true;
}

bool PSDHeader::valid()
{
    if (signature != "8BPS") {
        error = "Not a PhotoShop document. Signature is: " + signature;
        return false;
    }
    if (version < 1 || version > 2) {
        error = QString("Wrong version: %1").arg(version);
        return false;
    }
    if (nChannels < 1 || nChannels > 56) {
        error = QString("Channel count out of range: %1").arg(nChannels);
        return false;
    }
    if (version == 1) {
        if (height < 1 || height > 30000) {
            error = QString("Height out of range: %1").arg(height);
            return false;
        }
        if (width < 1 || width > 30000) {
            error = QString("Width out of range: %1").arg(width);
            return false;
        }
    }
    else /* if (version == 2) */ {
        if (height < 1 || height > 300000) {
            error = QString("Height out of range: %1").arg(height);
            return false;
        }
        if (width < 1 || width > 300000) {
            error = QString("Width out of range: %1").arg(width);
            return false;
        }
    }
    if (channelDepth != 1 && channelDepth != 8 && channelDepth != 16) {
        error = QString("Channel depth incorrect: %1").arg(channelDepth);
        return false;
    }
    if (colormode < 0 || colormode > 9) {
        error = QString("Colormode is out of range: %1").arg(colormode);
        return false;
    }

    return true;
}

QDebug operator<<(QDebug dbg, const PSDHeader& header)
{
#ifndef NODEBUG
    dbg.nospace() << "(valid: " << const_cast<PSDHeader*>(&header)->valid();
    dbg.nospace() << ", signature: " << header.signature;
    dbg.nospace() << ", version:" << header.version;
    dbg.nospace() << ", number of channels: " << header.nChannels;
    dbg.nospace() << ", height: " << header.height;
    dbg.nospace() << ", width: " << header.width;
    dbg.nospace() << ", channel depth: " << header.channelDepth;
    dbg.nospace() << ", color mode: ";
    switch(header.colormode) {
    case(Bitmap):
        dbg.nospace() << "Bitmap";
        break;
    case(Grayscale):
        dbg.nospace() << "Grayscale";
        break;
    case(Indexed):
        dbg.nospace() << "Indexed";
        break;
    case(RGB):
        dbg.nospace() << "RGB";
        break;
    case(CMYK):
        dbg.nospace() << "CMYK";
        break;
    case(MultiChannel):
        dbg.nospace() << "MultiChannel";
        break;
    case(DuoTone):
        dbg.nospace() << "DuoTone";
        break;
    case(Lab):
        dbg.nospace() << "Lab";
        break;
    default:
        dbg.nospace() << "Unknown";
    };
    dbg.nospace() << ")";
#endif
    return dbg.nospace();
}
