/***************************************************************************
 *   Copyright (c) 2007 Werner Mayer <wmayer[at]users.sourceforge.net>     *
 *                                                                         *
 *   This file is part of the FreeCAD CAx development system.              *
 *                                                                         *
 *   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., 59 Temple Place,         *
 *   Suite 330, Boston, MA  02111-1307, USA                                *
 *                                                                         *
 ***************************************************************************/


#ifndef BASE_STREAM_H
#define BASE_STREAM_H

#ifdef __GNUC__
#include <cstdint>
#endif

#include <fstream>
#include <sstream>
#include <string>
#include <vector>
#include "FileInfo.h"


class QByteArray;
class QIODevice;
class QBuffer;
using PyObject = struct _object;

namespace Base
{

class BaseExport Stream
{
public:
    enum ByteOrder
    {
        BigEndian,
        LittleEndian
    };

    ByteOrder byteOrder() const;
    void setByteOrder(ByteOrder);
    virtual ~Stream();

protected:
    Stream();
    Stream(const Stream&) = default;
    Stream(Stream&&) = default;
    Stream& operator=(const Stream&) = default;
    Stream& operator=(Stream&&) = default;

    bool isSwapped() const
    {
        return _swap;
    };

private:
    bool _swap {false};
};

/**
 * The OutputStream class provides writing of binary data to an ostream.
 * @author Werner Mayer
 */
class BaseExport OutputStream: public Stream
{
public:
    explicit OutputStream(std::ostream& rout);
    ~OutputStream() override;

    OutputStream& operator<<(bool b);
    OutputStream& operator<<(int8_t ch);
    OutputStream& operator<<(uint8_t uch);
    OutputStream& operator<<(int16_t s);
    OutputStream& operator<<(uint16_t us);
    OutputStream& operator<<(int32_t i);
    OutputStream& operator<<(uint32_t ui);
    OutputStream& operator<<(int64_t l);
    OutputStream& operator<<(uint64_t ul);
    OutputStream& operator<<(float f);
    OutputStream& operator<<(double d);

    OutputStream& write(const char* s, int n);

    OutputStream(const OutputStream&) = delete;
    OutputStream(OutputStream&&) = delete;
    void operator=(const OutputStream&) = delete;
    void operator=(OutputStream&&) = delete;

private:
    std::ostream& _out;
};

/**
 * The InputStream class provides reading of binary data from an istream.
 * @author Werner Mayer
 */
class BaseExport InputStream: public Stream
{
public:
    explicit InputStream(std::istream& rin);
    ~InputStream() override;

    InputStream& operator>>(bool& b);
    InputStream& operator>>(int8_t& ch);
    InputStream& operator>>(uint8_t& uch);
    InputStream& operator>>(int16_t& s);
    InputStream& operator>>(uint16_t& us);
    InputStream& operator>>(int32_t& i);
    InputStream& operator>>(uint32_t& ui);
    InputStream& operator>>(int64_t& l);
    InputStream& operator>>(uint64_t& ul);
    InputStream& operator>>(float& f);
    InputStream& operator>>(double& d);

    InputStream& read(char* s, int n);

    explicit operator bool() const
    {
        // test if _Ipfx succeeded
        return !_in.eof();
    }

    InputStream(const InputStream&) = delete;
    InputStream(InputStream&&) = delete;
    void operator=(const InputStream&) = delete;
    void operator=(InputStream&&) = delete;

private:
    std::istream& _in;
};

/**
 * The TextInputStream class provides reading of ASCII data from an istream, with custom handling
 * for std::string to make it easier to read a single multi-line (or multi-word) string. This is
 * designed for easy compatibility with the LinkStage3 implementation of the InputStream class, used
 * to store StringHashers for the toponaming mitigation technique.
 */
class BaseExport TextInputStream: public Stream
{
public:
    /** Constructor
     * @param rin: upstream input
     */
    explicit TextInputStream(std::istream& rin)
        : _in(rin)
    {}

    TextInputStream(const TextInputStream&) = delete;

    TextInputStream(const TextInputStream&&) noexcept = delete;

    void operator=(const TextInputStream&) = delete;

    void operator=(const TextInputStream&&) = delete;

    ~TextInputStream() override = default;

    TextInputStream& operator>>(bool& input)
    {
        _in >> input;
        return *this;
    }

    TextInputStream& operator>>(int8_t& ch)
    {
        int index {};
        _in >> index;
        ch = (int8_t)index;
        return *this;
    }

    TextInputStream& operator>>(uint8_t& uch)
    {
        unsigned uns {};
        _in >> uns;
        uch = (uint8_t)uns;
        return *this;
    }

    TextInputStream& operator>>(int16_t& int16)
    {
        _in >> int16;
        return *this;
    }

    TextInputStream& operator>>(uint16_t& us)
    {
        _in >> us;
        return *this;
    }

    TextInputStream& operator>>(int32_t& int32)
    {
        _in >> int32;
        return *this;
    }

    TextInputStream& operator>>(uint32_t& ui)
    {
        _in >> ui;
        return *this;
    }

    TextInputStream& operator>>(int64_t& int64)
    {
        _in >> int64;
        return *this;
    }

    TextInputStream& operator>>(uint64_t& ul)
    {
        _in >> ul;
        return *this;
    }

    TextInputStream& operator>>(float& flt)
    {
        _in >> flt;
        return *this;
    }

    TextInputStream& operator>>(double& dbl)
    {
        _in >> dbl;
        return *this;
    }

    TextInputStream& operator>>(std::string& str);

    TextInputStream& operator>>(char& chr)
    {
        chr = (char)_in.get();
        return *this;
    }

    explicit operator bool() const
    {
        // test if _Ipfx succeeded
        return !_in.eof();
    }

private:
    std::istream& _in;
    std::ostringstream _ss;
};

/**
 * The TextOutputStream class provides writing of ASCII data to an ostream, with custom handling
 * for std::string to make it easier to write a single multi-line (or multi-word) string. This is
 * designed for easy compatibility with the LinkStage3 implementation of the OutputStream class,
 * used to store StringHashers for the toponaming mitigation technique.
 */
class BaseExport TextOutputStream: public Stream
{
public:
    /** Constructor
     * @param rout: upstream output
     */
    explicit TextOutputStream(std::ostream& rout)
        : _out(rout)
    {}

    TextOutputStream(const TextOutputStream&) = delete;

    TextOutputStream(const TextOutputStream&&) noexcept = delete;

    void operator=(const TextOutputStream&) = delete;

    void operator=(const TextOutputStream&&) = delete;

    ~TextOutputStream() override = default;

    template<typename T>
    TextOutputStream& operator<<(T object)
    {
        _out << object << '\n';
        return *this;
    }

    TextOutputStream& operator<<(const char* object)
    {
        std::string_view str(object);

        // Count the lines so that we can deal with potential EOL conversions by external software
        uint32_t lineCount = 0;
        for (const auto character : str) {
            if (character == '\n') {
                ++lineCount;
            }
        }
        // Stores the line count followed by a colon as the delimiter. We don't use
        // whitespace because the input stream may also start with whitespace.
        _out << lineCount << ':';

        // Store the text, and normalize the end of line to a single '\n'.
        bool foundSlashR = false;
        for (const auto character : str) {
            if (character == '\r') {
                foundSlashR = true;
                continue;
            }
            if (foundSlashR) {
                if (character != '\n') {
                    // We allow '\r' if it is not at the end of a line
                    _out.put('\r');
                }
                foundSlashR = false;  // Reset for next time
            }
            _out.put(character);
        }

        // Add an extra newline as the delimiter for the following data.
        _out.put('\n');
        return *this;
    }

    TextOutputStream& operator<<(const std::string& object)
    {
        return (*this) << object.c_str();
    }

    TextOutputStream& operator<<(char object)
    {
        _out.put(object);
        return *this;
    }

    explicit operator bool() const
    {
        // test if _Ipfx succeeded
        return !_out.eof();
    }

private:
    std::ostream& _out;
};

// ----------------------------------------------------------------------------

/**
 * This class implements the streambuf interface to write data to a QByteArray.
 * This class can only be used for writing but not for reading purposes.
 * @author Werner Mayer
 */
class BaseExport ByteArrayOStreambuf: public std::streambuf
{
public:
    explicit ByteArrayOStreambuf(QByteArray& ba);
    ~ByteArrayOStreambuf() override;

protected:
    int_type overflow(std::streambuf::int_type c) override;
    std::streamsize xsputn(const char* s, std::streamsize num) override;
    pos_type seekoff(std::streambuf::off_type off,
                     std::ios_base::seekdir way,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;
    pos_type seekpos(std::streambuf::pos_type pos,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;

public:
    ByteArrayOStreambuf(const ByteArrayOStreambuf&) = delete;
    ByteArrayOStreambuf(ByteArrayOStreambuf&&) = delete;
    ByteArrayOStreambuf& operator=(const ByteArrayOStreambuf&) = delete;
    ByteArrayOStreambuf& operator=(ByteArrayOStreambuf&&) = delete;

private:
    QBuffer* _buffer;
};

/**
 * This class implements the streambuf interface to read data from a QByteArray.
 * This class can only be used for reading but not for writing purposes.
 * @author Werner Mayer
 */
class BaseExport ByteArrayIStreambuf: public std::streambuf
{
public:
    explicit ByteArrayIStreambuf(const QByteArray& data);
    ~ByteArrayIStreambuf() override;

protected:
    int_type uflow() override;
    int_type underflow() override;
    int_type pbackfail(int_type ch) override;
    std::streamsize showmanyc() override;
    pos_type seekoff(std::streambuf::off_type off,
                     std::ios_base::seekdir way,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;
    pos_type seekpos(std::streambuf::pos_type pos,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;

public:
    ByteArrayIStreambuf(const ByteArrayIStreambuf&) = delete;
    ByteArrayIStreambuf(ByteArrayIStreambuf&&) = delete;
    ByteArrayIStreambuf& operator=(const ByteArrayIStreambuf&) = delete;
    ByteArrayIStreambuf& operator=(ByteArrayIStreambuf&&) = delete;

private:
    const QByteArray& _buffer;
    int _beg, _end, _cur;
};

/**
 * Simple class to write data directly into Qt's QIODevice.
 * This class can only be used for writing but not reading purposes.
 * @author Werner Mayer
 */
class BaseExport IODeviceOStreambuf: public std::streambuf
{
public:
    explicit IODeviceOStreambuf(QIODevice* dev);
    ~IODeviceOStreambuf() override;

protected:
    int_type overflow(std::streambuf::int_type c) override;
    std::streamsize xsputn(const char* s, std::streamsize num) override;
    pos_type seekoff(std::streambuf::off_type off,
                     std::ios_base::seekdir way,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;
    pos_type seekpos(std::streambuf::pos_type pos,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;

public:
    IODeviceOStreambuf(const IODeviceOStreambuf&) = delete;
    IODeviceOStreambuf(IODeviceOStreambuf&&) = delete;
    IODeviceOStreambuf& operator=(const IODeviceOStreambuf&) = delete;
    IODeviceOStreambuf& operator=(IODeviceOStreambuf&&) = delete;

private:
    QIODevice* device;
};

/**
 * Simple class to read data directly from Qt's QIODevice.
 * This class can only be used for readihg but not writing purposes.
 * @author Werner Mayer
 */
class BaseExport IODeviceIStreambuf: public std::streambuf
{
public:
    explicit IODeviceIStreambuf(QIODevice* dev);
    ~IODeviceIStreambuf() override;

protected:
    int_type underflow() override;
    pos_type seekoff(std::streambuf::off_type off,
                     std::ios_base::seekdir way,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;
    pos_type seekpos(std::streambuf::pos_type pos,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;

public:
    IODeviceIStreambuf(const IODeviceIStreambuf&) = delete;
    IODeviceIStreambuf(IODeviceIStreambuf&&) = delete;
    IODeviceIStreambuf& operator=(const IODeviceIStreambuf&) = delete;
    IODeviceIStreambuf& operator=(IODeviceIStreambuf&&) = delete;

private:
    QIODevice* device;
    /* data buffer:
     * - at most, pbSize characters in putback area plus
     * - at most, bufSize characters in ordinary read buffer
     */
    static const int pbSize = 4;       // size of putback area
    static const int bufSize = 1024;   // size of the data buffer
    char buffer[bufSize + pbSize] {};  // data buffer
};

class BaseExport PyStreambuf: public std::streambuf
{
    using int_type = std::streambuf::int_type;
    using pos_type = std::streambuf::pos_type;
    using off_type = std::streambuf::off_type;
    using seekdir = std::ios::seekdir;
    using openmode = std::ios::openmode;

public:
    enum Type
    {
        StringIO,
        BytesIO,
        Unknown
    };

    explicit PyStreambuf(PyObject* o, std::size_t buf_size = 256, std::size_t put_back = 8);
    ~PyStreambuf() override;
    void setType(Type t)
    {
        type = t;
    }

protected:
    int_type underflow() override;
    int_type overflow(int_type c = EOF) override;
    std::streamsize xsputn(const char* s, std::streamsize num) override;
    int sync() override;
    pos_type seekoff(off_type offset, seekdir dir, openmode mode) override;
    pos_type seekpos(pos_type offset, openmode mode) override;

private:
    bool flushBuffer();
    bool writeStr(const char* s, std::streamsize num);

public:
    PyStreambuf(const PyStreambuf&) = delete;
    PyStreambuf(PyStreambuf&&) = delete;
    PyStreambuf& operator=(const PyStreambuf&) = delete;
    PyStreambuf& operator=(PyStreambuf&&) = delete;

private:
    PyObject* inp;
    Type type {Unknown};
    const std::size_t put_back;
    std::vector<char> buffer;
};

class BaseExport Streambuf: public std::streambuf
{
public:
    explicit Streambuf(const std::string& data);
    ~Streambuf() override;

protected:
    int_type uflow() override;
    int_type underflow() override;
    int_type pbackfail(int_type ch) override;
    std::streamsize showmanyc() override;
    pos_type seekoff(std::streambuf::off_type off,
                     std::ios_base::seekdir way,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;
    pos_type seekpos(std::streambuf::pos_type pos,
                     std::ios_base::openmode which = std::ios::in | std::ios::out) override;

public:
    Streambuf(const Streambuf&) = delete;
    Streambuf(Streambuf&&) = delete;
    Streambuf& operator=(const Streambuf&) = delete;
    Streambuf& operator=(Streambuf&&) = delete;

private:
    std::string::const_iterator _beg;
    std::string::const_iterator _end;
    std::string::const_iterator _cur;
};

// ----------------------------------------------------------------------------

class FileInfo;

/**
 * The ofstream class is provided for convenience. On Windows
 * platforms it opens a stream with UCS-2 encoded file name
 * while on Linux platforms the file name is UTF-8 encoded.
 * @author Werner Mayer
 */
class ofstream: public std::ofstream
{
public:
    ofstream() = default;
    ofstream(const ofstream&) = delete;
    ofstream(ofstream&&) = delete;
    explicit ofstream(const FileInfo& fi, ios_base::openmode mode = std::ios::out | std::ios::trunc)
#ifdef _MSC_VER
        : std::ofstream(fi.toStdWString().c_str(), mode) {}
#else
        : std::ofstream(fi.filePath().c_str(), mode)
    {}
#endif
        ~ofstream() override = default;
    void open(const FileInfo& fi, ios_base::openmode mode = std::ios::out | std::ios::trunc)
    {
#ifdef _MSC_VER
        std::ofstream::open(fi.toStdWString().c_str(), mode);
#else
        std::ofstream::open(fi.filePath().c_str(), mode);
#endif
    }

    ofstream& operator=(const ofstream&) = delete;
    ofstream& operator=(ofstream&&) = delete;
};

/**
 * The ofstream class is provided for convenience. On Windows
 * platforms it opens a stream with UCS-2 encoded file name
 * while on Linux platforms the file name is UTF-8 encoded.
 * @author Werner Mayer
 */
class ifstream: public std::ifstream
{
public:
    ifstream() = default;
    ifstream(const ifstream&) = delete;
    ifstream(ifstream&&) = delete;
    explicit ifstream(const FileInfo& fi, ios_base::openmode mode = std::ios::in)
#ifdef _MSC_VER
        : std::ifstream(fi.toStdWString().c_str(), mode) {}
#else
        : std::ifstream(fi.filePath().c_str(), mode)
    {}
#endif
        ~ifstream() override = default;
    void open(const FileInfo& fi, ios_base::openmode mode = std::ios::in)
    {
#ifdef _MSC_VER
        std::ifstream::open(fi.toStdWString().c_str(), mode);
#else
        std::ifstream::open(fi.filePath().c_str(), mode);
#endif
    }

    ifstream& operator=(const ifstream&) = delete;
    ifstream& operator=(ifstream&&) = delete;
};

}  // namespace Base

#endif  // BASE_STREAM_H