/* df - summarize free disk space
   Copyright (C) 1995-1998 Steven Pritchard <steve@silug.org>
   Portions Copyright (C) 91, 95, 1996 Free Software Foundation, 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 2, 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., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA.  */

/* Written by Steven Pritchard <steve@silug.org>.
   "Inspired" by df.c from GNU fileutils 3.9 and 3.16.  */

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <windows.h>
#include <winioctl.h>

static void print_header(void);
static void print_DOS_header(void);
int getOS(void);
int show_dev_NT(unsigned int, char *);
int show_dev_DOS(unsigned int, char *, char *);

static int kilobyte_blocks=1;

int main(int argc, char **argv)
{
    DWORD drive_mask;
    unsigned int n;
    char root[7];
    char *NT_device=NULL;
    char *label=NULL;
    int isNT;
    unsigned long total, avail;
    DWORD sectors, bytes, free_clusters, total_clusters;

    isNT=getOS();
    if (isNT==-1)
    {
        fprintf(stderr, "Unable to determine OS type\n");
        exit(EXIT_FAILURE);
    }

    if (isNT)
    {
        print_header();
    }
    else
    {
        print_DOS_header();
    }

    drive_mask=GetLogicalDrives();
    SetErrorMode(SEM_FAILCRITICALERRORS);
    for (n=0;n<26;n++)
    {
        if (drive_mask & (1<<n))
        {
            sprintf(root, "%c:\\", 'A'+n);
            /*
            printf("\nGetDriveType returned %u\n",
                   GetDriveType(root));
            */
            if (GetDiskFreeSpace((LPCTSTR)root, &sectors, &bytes,
                                 &free_clusters, &total_clusters))
            {
                if (isNT)
                {
                    if (!NT_device)
                    {
                        NT_device=malloc(MAX_PATH);
                    }
		    show_dev_NT(n, NT_device);
                }
                else
                {
                    /* First we want the volume label */
                    if (!label)
                    {
                        label=malloc(MAX_PATH);
                    }
		    show_dev_DOS(n, root, label);
                }
                total=total_clusters*sectors*bytes;
                avail=free_clusters*sectors*bytes;
                printf(" %7ld %7ld  %7ld  %5ld%% ",
                       total/1024, (total-avail)/1024, avail/1024,
		       /* I haven't figured out why I have to do the math
		          like this, but this appears to be the only thing
			  BC 5 will compile properly. */
                       (long)(((long double)(total-avail)/total)*100));
                printf("  %c:\n", 'A'+n);
            }
        }

    }
    if (NT_device)
    {
        free(NT_device);
    }
    if (label)
    {
        free(label);
    }
    return 0;
}

static void print_header(void)
{
    printf("Filesystem         %s  Used Available Capacity",
    kilobyte_blocks ? "1024-blocks" : " 512-blocks");
    printf (" Mounted on\n");
}

static void print_DOS_header(void)
{
    printf("Label              %s  Used Available Capacity",
    kilobyte_blocks ? "1024-blocks" : " 512-blocks");
    printf (" Mounted on\n");
}

int getOS(void)
{
    OSVERSIONINFO ver;

    ver.dwOSVersionInfoSize=sizeof(OSVERSIONINFO);

    if (GetVersionEx(&ver))
    {
        return (ver.dwPlatformId==VER_PLATFORM_WIN32_NT) ? 1 : 0;
    }
    else
    {
        return -1;
    }
}

int show_dev_NT(unsigned int n, char *NT_device)
{
    DWORD cbDevice;
    char dosdrive[6];
    char *buf;

    sprintf(dosdrive, "%c:", 'A'+n);
    cbDevice=QueryDosDevice(dosdrive, NT_device, MAX_PATH);
    if (cbDevice)
    {
        /*
        printf("Device name: \"%s\"\n\n", NT_device);
        printf("%-20s\n", NT_device);
        */
        if (strncmp(NT_device, "\\Device\\", 8)==0)
        {
            buf=NT_device+8;
            if (strncmp(buf, "LanmanRedirector\\", 17)==0)
            {
                printf("\\%-19s", buf+19);
            }
            else
            {
                printf("%-20s", buf);
            }
	    return 0;
        }
        else
        {
            fprintf(stderr, "Unrecognized device %s, skipping\n",
                            NT_device);
            return 1;
        }
    }
    else
    {
        return 1;
    }
}

int show_dev_DOS(unsigned int n, char *root, char *label)
{
    DWORD serial, max_file, flags;
    char fsname[256];

    if (GetVolumeInformation((LPCTSTR)root, (LPTSTR)label,
                             MAX_PATH, &serial, &max_file,
                             &flags, (LPTSTR)fsname, 256))
    {
        printf("%-20s", (strlen(label) ? label : "No label"));
	return 0;
    }
    else
    {
        fprintf(stderr,
                "GetVolumeInformation() failed on %c:!\n",
                'A'+n);
        /*
        printf("%-20s", "No label");
        printf(" last-error=%lx", GetLastError());
        */
        return 1;
    }
    /*
    printf("\n");
    */
}