/*==LICENSE==*

CyanWorlds.com Engine - MMOG client, server and tools
Copyright (C) 2011  Cyan Worlds, Inc.

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 3 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, see <http://www.gnu.org/licenses/>.

You can contact Cyan Worlds, Inc. by email legal@cyan.com
 or by snail mail at:
      Cyan Worlds, Inc.
      14617 N Newport Hwy
      Mead, WA   99021

*==LICENSE==*/
/*****************************************************************************
*
*   $/Plasma20/Sources/Plasma/NucleusLib/pnAsyncCoreExe/Private/W9x/pnAceW9xFile.cpp
*   
***/

#include "../../Pch.h"
#pragma hdrstop

#include "pnAceW9xInt.h"


namespace W9x {


/****************************************************************************
*
*   FileOp
*
***/

struct FileOp {
    EAsyncNotifyFile    code;
    bool                notify;
    union {
        AsyncNotifyFileFlush    flush;
        AsyncNotifyFileRead     read;
        AsyncNotifyFileSequence sequence;
        AsyncNotifyFileWrite    write;
    } data;
};


/****************************************************************************
*
*   CFile
*
***/

class CFile : public CThreadDispObject {
private:
    CCritSect               m_critSect;
    HANDLE                  m_handle;
    FAsyncNotifyFileProc    m_notifyProc;
    void *                  m_userState;

protected:
    void Complete (void * op, CCritSect * critSect, AsyncId asyncId);
    void Delete (void * op);

public:
    CFile (
        HANDLE                  handle,
        FAsyncNotifyFileProc    notifyProc,
        void *                  userState
    );
    ~CFile ();

    void Read (
        qword    offset,
        void *   buffer,
        unsigned bytes
    );

    void SetLastWriteTime (qword lastWriteTime);

    void Truncate (qword size);

    void Write (
        qword        offset,
        const void * buffer,
        unsigned     bytes
    );

    bool Seek (qword offset, EFileSeekFrom from);
};

//===========================================================================
CFile::CFile (
    HANDLE                  handle,
    FAsyncNotifyFileProc    notifyProc,
    void *                  userState
) :
    m_handle(handle),
    m_notifyProc(notifyProc),
    m_userState(userState)
{
}

//===========================================================================
CFile::~CFile () {
    CloseHandle(m_handle);
    m_handle = INVALID_HANDLE_VALUE;
}

//===========================================================================
void CFile::Complete (void * op, CCritSect * critSect, AsyncId asyncId) {
    FileOp * fileOp = (FileOp *)op;

    // Enter our local critical section and leave the global one
    m_critSect.Enter();
    critSect->Leave();

    // Complete the operation
    switch (fileOp->code) {

        case kNotifyFileFlush: {
            if (fileOp->data.flush.truncateSize != kAsyncFileDontTruncate)
                Truncate(fileOp->data.flush.truncateSize);
            BOOL result = FlushFileBuffers(m_handle);
            fileOp->data.flush.error = result ? kFileSuccess : AsyncGetLastFileError();
        }
        break;

        case kNotifyFileRead:
            Read(
                fileOp->data.read.offset,
                fileOp->data.read.buffer,
                fileOp->data.read.bytes
            );
        break;

        case kNotifyFileWrite:
            Write(
                fileOp->data.write.offset,
                fileOp->data.write.buffer,
                fileOp->data.write.bytes
            );
        break;

    }

    // Leave our local critical section
    m_critSect.Leave();

    // Dispatch a completion notification
    if (fileOp->notify) {
        fileOp->data.flush.asyncId = asyncId;
        m_notifyProc(
            (AsyncFile)this, 
            fileOp->code,
            &fileOp->data.flush,
            &m_userState
        );
    }

}

//===========================================================================
void CFile::Delete (void * op) {
    FileOp * fileOp = (FileOp *)op;
    DEL(fileOp);
}

//===========================================================================
void CFile::Read (
    qword    offset,
    void *   buffer,
    unsigned bytes
) {

    // Seek to the start of the read
    Seek(offset, kFileSeekFromBegin);

    // Perform the read
    DWORD bytesRead;
    BOOL  result = ReadFile(
        m_handle,
        buffer,
        bytes,
        &bytesRead,
        nil  // overlapped
    );

    // Handle errors
    if (bytesRead != bytes)
        MemZero((byte *)buffer + bytesRead, bytes - bytesRead);
    if ( (!result && (GetLastError() != ERROR_IO_PENDING)) ||
         (bytesRead != bytes) )
        LogMsg(kLogFatal, "failed: ReadFile");

}

//===========================================================================
bool CFile::Seek (qword offset, EFileSeekFrom from) {
    COMPILER_ASSERT(kFileSeekFromBegin == FILE_BEGIN);
    COMPILER_ASSERT(kFileSeekFromCurrent == FILE_CURRENT);
    COMPILER_ASSERT(kFileSeekFromEnd == FILE_END);

    LONG  low    = (LONG)(offset % 0x100000000ul);
    LONG  high   = (LONG)(offset / 0x100000000ul);
    dword result = SetFilePointer(m_handle, low, &high, from);
    if ((result == (dword)-1) && (GetLastError() != NO_ERROR)) {
        LogMsg(kLogFatal, "failed: SetFilePointer");
        return false;
    }
    else
        return true;
}

//===========================================================================
void CFile::SetLastWriteTime (qword lastWriteTime) {
    COMPILER_ASSERT(sizeof(lastWriteTime) == sizeof(FILETIME));
    SetFileTime(m_handle, nil, nil, (const FILETIME *)&lastWriteTime);
}

//===========================================================================
void CFile::Truncate (qword size) {
    ASSERT(size != kAsyncFileDontTruncate);

    if (Seek(size, kFileSeekFromBegin) && !SetEndOfFile(m_handle)) 
        LogMsg(kLogFatal, "failed: SetEndOfFile");
}

//===========================================================================
void CFile::Write (
    qword        offset,
    const void * buffer,
    unsigned     bytes
) {

    // Seek to the start of the write
    Seek(offset, kFileSeekFromBegin);

    // Perform the write
    DWORD bytesWritten;
    BOOL  result = WriteFile(
        m_handle,
        buffer,
        bytes,
        &bytesWritten,
        nil  // overlapped
    );

    // Handle errors
    if ( (!result && (GetLastError() != ERROR_IO_PENDING)) ||
         (bytesWritten != bytes) ) {
        LogMsg(kLogFatal, "failed: WriteFile");
        if (!result && (GetLastError() == ERROR_DISK_FULL)) {
            MessageBox(nil, "Disk full!", "Error", MB_ICONSTOP | MB_SYSTEMMODAL);
//            DebugDisableLeakChecking();
            ExitProcess(1);
        }
    }

}


/****************************************************************************
*
*   Exported functions
*
***/

//===========================================================================
void W9xFileClose (
    AsyncFile   file, 
    qword       truncateSize
) {

    // Dereference the object
    CFile * object = (CFile *)file;

    // If requested, truncate the file
    if (truncateSize != kAsyncFileDontTruncate)
        object->Truncate(truncateSize);        

    // Close the file object
    object->Close();

}

//===========================================================================
AsyncId W9xFileCreateSequence (
    AsyncFile   file, 
    bool        notify, 
    void *      param
) {

    // Dereference the object
    CFile * object = (CFile *)file;

    // Queue an operation
    FileOp * op = NEW(FileOp);
    op->code             = kNotifyFileSequence;
    op->notify           = notify;
    op->data.flush.param = param;
    return object->Queue(op);

}

//===========================================================================
AsyncId W9xFileFlushBuffers (
    AsyncFile   file, 
    qword       truncateSize,
    bool        notify,
    void *      param
) {

    // Dereference the object
    CFile * object = (CFile *)file;

    // Queue an operation
    FileOp * op = NEW(FileOp);
    op->code   = kNotifyFileFlush;
    op->notify = notify;
    op->data.flush.param        = param;
    op->data.flush.truncateSize = truncateSize;
    // op->data.flush.error filled in upon completion
    return object->Queue(op);

}

//===========================================================================
AsyncFile W9xFileOpen (
    const wchar             fullPath[],
    FAsyncNotifyFileProc    notifyProc,
    EFileError *            error,
    unsigned                desiredAccess,
    unsigned                openMode,
    unsigned                shareModeFlags,
    void *                  userState,
    qword *                 fileSize,
    qword *                 fileLastWriteTime
) {
    HANDLE fileHandle = CreateFileW(
        fullPath,
        desiredAccess,
        shareModeFlags,
        nil,    // plSecurityAttributes
        openMode,
        0,      // attributeFlags
        nil     // hTemplateFile
    );
    *error = AsyncGetLastFileError();

    if (INVALID_HANDLE_VALUE == fileHandle)
        return nil;

    // don't allow users to open devices like "LPT1", etc.
    if (GetFileType(fileHandle) != FILE_TYPE_DISK) {
        LogMsg(kLogFatal, "failed: !FILE_TYPE_DISK");
        *error = kFileErrorFileNotFound;
        CloseHandle(fileHandle);
        return nil;
    }

    // Get the file size
    DWORD sizeHi, sizeLo = GetFileSize(fileHandle, &sizeHi);
    if ((sizeLo == (DWORD) -1) && (NO_ERROR != GetLastError())) {
        *error = AsyncGetLastFileError();
        LogMsg(kLogFatal, "failed: GetFileSize");
        CloseHandle(fileHandle);
        return nil;
    }
    const qword size = ((qword) sizeHi << (qword) 32) | (qword) sizeLo;

    qword lastWriteTime;
    ASSERT(sizeof(lastWriteTime) >= sizeof(FILETIME));
    GetFileTime(fileHandle, nil, nil, (FILETIME *) &lastWriteTime);

    // Create a file object
    CFile * object = NEW(CFile)(
        fileHandle,
        notifyProc,
        userState
    );

    // return out parameters
    if (fileSize)
        *fileSize = size;
    if (fileLastWriteTime)
        *fileLastWriteTime = lastWriteTime;
    return (AsyncFile)object;
}

//===========================================================================
AsyncId W9xFileRead (
    AsyncFile   file,
    qword       offset,
    void *      buffer,
    unsigned    bytes,
    unsigned    flags,
    void *      param
) {

    // Dereference the object
    CFile * object = (CFile *)file;

    // Perform synchronous operations immediately
    if (flags & kAsyncFileRwSync) {
        object->Read(offset, buffer, bytes);
        return 0;
    }

    // Queue asynchronous operations
    else {
        FileOp * op = NEW(FileOp);
        op->code   = kNotifyFileRead;
        op->notify = (flags & kAsyncFileRwNotify) != 0;
        op->data.read.param  = param;
        op->data.read.offset = offset;
        op->data.read.buffer = (byte *)buffer;
        op->data.read.bytes  = bytes;
        return object->Queue(op);
    }

}

//===========================================================================
void W9xFileSetLastWriteTime (
    AsyncFile   file, 
    qword       lastWriteTime
) {
    
    // Dereference the object
    CFile * object = (CFile *)file;

    // Set the file time
    object->SetLastWriteTime(lastWriteTime);

}

//===========================================================================
qword W9xFileGetLastWriteTime (
    const wchar fileName[]
) {
    WIN32_FILE_ATTRIBUTE_DATA info;
    bool f = GetFileAttributesExW(fileName, GetFileExInfoStandard, &info);
    return f ? *((qword *) &info.ftLastWriteTime) : 0;
}

//===========================================================================
AsyncId W9xFileWrite (
    AsyncFile    file,
    qword        offset,
    const void * buffer,
    unsigned     bytes,
    unsigned     flags,
    void *       param
) {

    // Dereference the object
    CFile * object = (CFile *)file;

    // Perform synchronous operations immediately
    if (flags & kAsyncFileRwSync) {
        object->Write(offset, buffer, bytes);
        return 0;
    }

    // Queue asynchronous operations
    else {
        FileOp * op = NEW(FileOp);
        op->code   = kNotifyFileWrite;
        op->notify = (flags & kAsyncFileRwNotify) != 0;
        op->data.write.param  = param;
        op->data.write.offset = offset;
        op->data.write.buffer = (byte *)buffer;
        op->data.write.bytes  = bytes;
        return object->Queue(op);
    }

}

//============================================================================
bool W9xFileSeek (
    AsyncFile       file,
    qword           distance,
    EFileSeekFrom   from
) {
    CFile * object = (CFile *)file;
    return object->Seek(distance, from);
}


}  // namespace W9x