/*
  ==============================================================================

   This file is part of the Water library.
   Copyright (c) 2016 ROLI Ltd.
   Copyright (C) 2017 Filipe Coelho <falktx@falktx.com>

   Permission is granted to use this software under the terms of the ISC license
   http://www.isc.org/downloads/software-support-policy/isc-license/

   Permission to use, copy, modify, and/or distribute this software for any
   purpose with or without fee is hereby granted, provided that the above
   copyright notice and this permission notice appear in all copies.

   THE SOFTWARE IS PROVIDED "AS IS" AND ISC DISCLAIMS ALL WARRANTIES WITH REGARD
   TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF MERCHANTABILITY AND
   FITNESS. IN NO EVENT SHALL ISC BE LIABLE FOR ANY SPECIAL, DIRECT, INDIRECT,
   OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES WHATSOEVER RESULTING FROM LOSS OF
   USE, DATA OR PROFITS, WHETHER IN AN ACTION OF CONTRACT, NEGLIGENCE OR OTHER
   TORTIOUS ACTION, ARISING OUT OF OR IN CONNECTION WITH THE USE OR PERFORMANCE
   OF THIS SOFTWARE.

  ==============================================================================
*/

#include "FileOutputStream.h"

namespace water {

int64 water_fileSetPosition (void* handle, int64 pos);

//==============================================================================
FileOutputStream::FileOutputStream (const File& f, const size_t bufferSizeToUse)
    : file (f),
      fileHandle (nullptr),
      status (Result::ok()),
      currentPosition (0),
      bufferSize (bufferSizeToUse),
      bytesInBuffer (0)
{
    if (buffer.malloc(jmax (bufferSizeToUse, (size_t) 16)))
        openHandle();
    else
        status = Result::fail ("Allocation failure");
}

FileOutputStream::~FileOutputStream()
{
    flushBuffer();
    closeHandle();
}

int64 FileOutputStream::getPosition()
{
    return currentPosition;
}

bool FileOutputStream::setPosition (int64 newPosition)
{
    if (newPosition != currentPosition)
    {
        flushBuffer();
        currentPosition = water_fileSetPosition (fileHandle, newPosition);
    }

    return newPosition == currentPosition;
}

bool FileOutputStream::flushBuffer()
{
    bool ok = true;

    if (bytesInBuffer > 0)
    {
        ok = (writeInternal (buffer, bytesInBuffer) == (ssize_t) bytesInBuffer);
        bytesInBuffer = 0;
    }

    return ok;
}

void FileOutputStream::flush()
{
    flushBuffer();
    flushInternal();
}

bool FileOutputStream::write (const void* const src, const size_t numBytes)
{
    wassert (src != nullptr && ((ssize_t) numBytes) >= 0);

    if (bytesInBuffer + numBytes < bufferSize)
    {
        memcpy (buffer + bytesInBuffer, src, numBytes);
        bytesInBuffer += numBytes;
        currentPosition += (int64) numBytes;
    }
    else
    {
        if (! flushBuffer())
            return false;

        if (numBytes < bufferSize)
        {
            memcpy (buffer + bytesInBuffer, src, numBytes);
            bytesInBuffer += numBytes;
            currentPosition += (int64) numBytes;
        }
        else
        {
            const ssize_t bytesWritten = writeInternal (src, numBytes);

            if (bytesWritten < 0)
                return false;

            currentPosition += (int64) bytesWritten;
            return bytesWritten == (ssize_t) numBytes;
        }
    }

    return true;
}

bool FileOutputStream::writeRepeatedByte (uint8 byte, size_t numBytes)
{
    wassert (((ssize_t) numBytes) >= 0);

    if (bytesInBuffer + numBytes < bufferSize)
    {
        memset (buffer + bytesInBuffer, byte, numBytes);
        bytesInBuffer += numBytes;
        currentPosition += (int64) numBytes;
        return true;
    }

    return OutputStream::writeRepeatedByte (byte, numBytes);
}

#ifdef CARLA_OS_WIN
void FileOutputStream::openHandle()
{
    HANDLE h = CreateFileA (file.getFullPathName().toUTF8(), GENERIC_WRITE, FILE_SHARE_READ, 0,
                            OPEN_ALWAYS, FILE_ATTRIBUTE_NORMAL, 0);

    if (h != INVALID_HANDLE_VALUE)
    {
        LARGE_INTEGER li;
        li.QuadPart = 0;
        li.LowPart = SetFilePointer (h, 0, &li.HighPart, FILE_END);

        if (li.LowPart != INVALID_SET_FILE_POINTER)
        {
            fileHandle = (void*) h;
            currentPosition = li.QuadPart;
            return;
        }
    }

    status = getResultForLastError();
}

void FileOutputStream::closeHandle()
{
    CloseHandle ((HANDLE) fileHandle);
}

ssize_t FileOutputStream::writeInternal (const void* bufferToWrite, size_t numBytes)
{
    if (fileHandle != nullptr)
    {
        DWORD actualNum = 0;
        if (! WriteFile ((HANDLE) fileHandle, bufferToWrite, (DWORD) numBytes, &actualNum, 0))
            status = getResultForLastError();

        return (ssize_t) actualNum;
    }

    return 0;
}

void FileOutputStream::flushInternal()
{
    if (fileHandle != nullptr)
        if (! FlushFileBuffers ((HANDLE) fileHandle))
            status = getResultForLastError();
}
#else
void FileOutputStream::openHandle()
{
    if (file.exists())
    {
        const int f = open (file.getFullPathName().toUTF8(), O_RDWR, 00644);

        if (f != -1)
        {
            currentPosition = lseek (f, 0, SEEK_END);

            if (currentPosition >= 0)
            {
                fileHandle = fdToVoidPointer (f);
            }
            else
            {
                status = getResultForErrno();
                close (f);
            }
        }
        else
        {
            status = getResultForErrno();
        }
    }
    else
    {
        const int f = open (file.getFullPathName().toUTF8(), O_RDWR + O_CREAT, 00644);

        if (f != -1)
            fileHandle = fdToVoidPointer (f);
        else
            status = getResultForErrno();
    }
}

void FileOutputStream::closeHandle()
{
    if (fileHandle != 0)
    {
        close (getFD (fileHandle));
        fileHandle = 0;
    }
}

ssize_t FileOutputStream::writeInternal (const void* const data, const size_t numBytes)
{
    ssize_t result = 0;

    if (fileHandle != 0)
    {
        result = ::write (getFD (fileHandle), data, numBytes);

        if (result == -1)
            status = getResultForErrno();
    }

    return result;
}

void FileOutputStream::flushInternal()
{
    if (fileHandle != 0)
    {
        if (fsync (getFD (fileHandle)) == -1)
            status = getResultForErrno();
    }
}
#endif

}
