/* $Id$ */
#include <pj/file_io.h>
#include <pj/errno.h>
#include <pj/assert.h>

#include <windows.h>

#ifndef INVALID_SET_FILE_POINTER
#   define INVALID_SET_FILE_POINTER     ((DWORD)-1)
#endif

/**
 * Check for end-of-file condition on the specified descriptor.
 *
 * @param fd            The file descriptor.
 * @param access        The desired access.
 *
 * @return              Non-zero if file is EOF.
 */
PJ_DECL(pj_bool_t) pj_file_eof(pj_oshandle_t fd, 
                               enum pj_file_access access);


PJ_DEF(pj_status_t) pj_file_open( pj_pool_t *pool,
                                  const char *pathname, 
                                  unsigned flags,
                                  pj_oshandle_t *fd)
{
    HANDLE hFile;
    DWORD dwDesiredAccess = 0;
    DWORD dwShareMode = 0;
    DWORD dwCreationDisposition = 0;
    DWORD dwFlagsAndAttributes = 0;

    PJ_UNUSED_ARG(pool);

    PJ_ASSERT_RETURN(pathname!=NULL, PJ_EINVAL);

    if ((flags & PJ_O_WRONLY) == PJ_O_WRONLY) {
        dwDesiredAccess |= GENERIC_WRITE;
        if ((flags & PJ_O_APPEND) == PJ_O_APPEND) {
            dwDesiredAccess |= FILE_APPEND_DATA;
        } else {
            dwDesiredAccess &= ~(FILE_APPEND_DATA);
            dwCreationDisposition |= CREATE_ALWAYS;
        }
    }
    if ((flags & PJ_O_RDONLY) == PJ_O_RDONLY) {
        dwDesiredAccess |= GENERIC_READ;
        if (flags == PJ_O_RDONLY)
            dwCreationDisposition |= OPEN_EXISTING;
    }

    if (dwDesiredAccess == 0) {
        pj_assert(!"Invalid file open flags");
        return PJ_EINVAL;
    }

    dwShareMode = FILE_SHARE_READ | FILE_SHARE_WRITE;
    dwFlagsAndAttributes = FILE_ATTRIBUTE_NORMAL;

    hFile = CreateFile(pathname, dwDesiredAccess, dwShareMode, NULL,
                       dwCreationDisposition, dwFlagsAndAttributes, NULL);
    if (hFile == INVALID_HANDLE_VALUE) {
        *fd = 0;
        return PJ_RETURN_OS_ERROR(GetLastError());
    }

    *fd = hFile;
    return PJ_SUCCESS;
}

PJ_DEF(pj_status_t) pj_file_close(pj_oshandle_t fd)
{
    if (CloseHandle(fd)==0)
        return PJ_RETURN_OS_ERROR(GetLastError());
    return PJ_SUCCESS;
}

PJ_DEF(pj_status_t) pj_file_write( pj_oshandle_t fd,
                                   const void *data,
                                   pj_ssize_t *size)
{
    BOOL rc;
    DWORD bytesWritten;

    rc = WriteFile(fd, data, *size, &bytesWritten, NULL);
    if (!rc) {
        *size = -1;
        return PJ_RETURN_OS_ERROR(GetLastError());
    }

    *size = bytesWritten;
    return PJ_SUCCESS;
}

PJ_DEF(pj_status_t) pj_file_read( pj_oshandle_t fd,
                                  void *data,
                                  pj_ssize_t *size)
{
    BOOL rc;
    DWORD bytesRead;

    rc = ReadFile(fd, data, *size, &bytesRead, NULL);
    if (!rc) {
        *size = -1;
        return PJ_RETURN_OS_ERROR(GetLastError());
    }

    *size = bytesRead;
    return PJ_SUCCESS;
}

/*
PJ_DEF(pj_bool_t) pj_file_eof(pj_oshandle_t fd, enum pj_file_access access)
{
    BOOL rc;
    DWORD dummy = 0, bytes;
    DWORD dwStatus;

    if ((access & PJ_O_RDONLY) == PJ_O_RDONLY) {
        rc = ReadFile(fd, &dummy, 0, &bytes, NULL);
    } else if ((access & PJ_O_WRONLY) == PJ_O_WRONLY) {
        rc = WriteFile(fd, &dummy, 0, &bytes, NULL);
    } else {
        pj_assert(!"Invalid access");
        return PJ_TRUE;
    }

    dwStatus = GetLastError();
    if (dwStatus==ERROR_HANDLE_EOF)
        return PJ_TRUE;

    return 0;
}
*/

PJ_DEF(pj_status_t) pj_file_setpos( pj_oshandle_t fd,
                                    pj_off_t offset,
                                    enum pj_file_seek_type whence)
{
    DWORD dwMoveMethod;
    DWORD dwNewPos;
    LONG  hi32;

    if (whence == PJ_SEEK_SET)
        dwMoveMethod = FILE_BEGIN;
    else if (whence == PJ_SEEK_CUR)
        dwMoveMethod = FILE_CURRENT;
    else if (whence == PJ_SEEK_END)
        dwMoveMethod = FILE_END;
    else {
        pj_assert(!"Invalid whence in file_setpos");
        return PJ_EINVAL;
    }

    hi32 = (LONG)(offset >> 32);
    dwNewPos = SetFilePointer(fd, (long)offset, &hi32, dwMoveMethod);
    if (dwNewPos == (DWORD)INVALID_SET_FILE_POINTER) {
        DWORD dwStatus = GetLastError();
        if (dwStatus != 0)
            return PJ_RETURN_OS_ERROR(dwStatus);
        /* dwNewPos actually is not an error. */
    }

    return PJ_SUCCESS;
}

PJ_DEF(pj_status_t) pj_file_getpos( pj_oshandle_t fd,
                                    pj_off_t *pos)
{
    LONG hi32 = 0;
    DWORD lo32;

    lo32 = SetFilePointer(fd, 0, &hi32, FILE_CURRENT);
    if (lo32 == (DWORD)INVALID_SET_FILE_POINTER) {
        DWORD dwStatus = GetLastError();
        if (dwStatus != 0)
            return PJ_RETURN_OS_ERROR(dwStatus);
    }

    *pos = hi32;
    *pos = (*pos << 32) + lo32;
    return PJ_SUCCESS;
}