/*
**------------------------------------------------------------------------------
** Module:  Disk Cleanup Applet
** File:    diskutil.cpp
**
** Purpose: Disk utility functions
** Notes:   
** Mod Log: Created by Jason Cobb (2/97)
**
** Copyright (c)1997 Microsoft Corporation, All Rights Reserved
**------------------------------------------------------------------------------
*/

/*
**------------------------------------------------------------------------------
** Project include files
**------------------------------------------------------------------------------
*/
#include "common.h"
#include "diskutil.h"   
#include "msprintf.h"
#include "resource.h"


#define Not_VxD
#include <vwin32.h>



/*
**------------------------------------------------------------------------------
** fIsSingleDrive
**
** Purpose:    gets a drive letter from a drive string
** Mod Log:    Created by Jason Cobb (2/97)
**------------------------------------------------------------------------------
*/
BOOL 
fIsSingleDrive (
    LPTSTR lpDrive
    )
{
    //  
    //Is it a valid drive string ?!?
    //
    if (!fIsValidDriveString(lpDrive))
        return FALSE;

    //  
    //Is it a valid drive ?!?
    //
    BOOL rc = FALSE;

    UINT driveType = GetDriveType (lpDrive);
    switch (driveType)
    {
        case 0:                 // Unknown drive type
        case 1:                 // Invalid drive type
            break;

        case DRIVE_REMOVABLE:   // Removable drive (floppy,bernoulli,syquest,etc)
        case DRIVE_FIXED:       // Hard disk
            // We support removeable and fixed drives
            rc = TRUE;
            break;
      
        case DRIVE_REMOTE:      // Network
        case DRIVE_CDROM:       // CD-ROM
            break;

        case DRIVE_RAMDISK:     // RAM disk
            // We support ram drives, even though it's rather dubious
            rc = TRUE;
            break;

        default:                // Unknown drive type
            break;
    }

    return rc;
}

/*
**------------------------------------------------------------------------------
** fIsValidDriveString
**
** Purpose:    determines if a drive is a valid drive string
** Note:       assumes a drive string consists of a drive letter,
**             colon, and slash characters and nothing else.
**             Example:  "C:\"
** Mod Log:    Created by Jason Cobb (2/97)
**------------------------------------------------------------------------------
*/
BOOL 
fIsValidDriveString(
    const TCHAR * szDrive
    )
{
    //  
    //Make sure we have a valid string
    //
    if ((szDrive == NULL) || (szDrive[0] == 0))
        return FALSE;

    //  
    //Make sure length is equal to length of valid drive string "C:\"
    //
    INT iLen = lstrlen(szDrive);
    if (iLen != 3)
        return FALSE;

    //  
    //Check drive letter
    //
    TCHAR ch = szDrive[0];
    if ((ch >= 'a') && (ch <= 'z'))   
        ;
    else if ((ch >= 'A') && (ch <= 'Z'))
        ;
    else
        return FALSE;

    //  
    //Check colon
    //
    ch = szDrive[1];
    if (ch != ':')
        return FALSE;

    //  
    //Check slash
    //
    ch = szDrive[2];
    if (ch != '\\')
        return FALSE;

    //  
    //Check zero terminating byte
    //
    ch = szDrive[3];
    if (ch != 0)
        return FALSE;

    return TRUE;
}

/*
**------------------------------------------------------------------------------
** GetDriveFromString
**
** Purpose:    gets a drive letter from a drive string
** Mod Log:    Created by Jason Cobb (4/97)
**------------------------------------------------------------------------------
*/
BOOL 
GetDriveFromString(
    const TCHAR * szDrive, 
    drenum & dre
    )
{
    dre = Drive_INV;

    //
    //Make sure we have a valid string
    //
    if ((szDrive == NULL) || (szDrive[0] == 0))
        return FALSE;

    //  
    //Get drive number from drive letter
    //
    TCHAR chDrive = szDrive[0];
    if ((chDrive >= TCHAR('a')) && (chDrive <= TCHAR('z')))
        dre = (drenum)(chDrive - TCHAR('a'));
    else if ((chDrive >= TCHAR('A')) && (chDrive <= TCHAR('Z')))
        dre = (drenum)(chDrive - TCHAR('A'));
    else
        return FALSE;

    return TRUE;
}

/*
**------------------------------------------------------------------------------
** GetDriveIcon
**
** Purpose:    
** Parameters:
**    dre - driver letter
**    bSmallIcon - TRUE if small icon is desired.
** Return:     Drive Icon returned by the shell
** Notes:   
** Mod Log:    Created by Jason Cobb (2/97)
**------------------------------------------------------------------------------
*/
HICON
GetDriveIcon(
    drenum dre,
    BOOL bSmallIcon
    )
{
    TCHAR        szDrive[10];
    SHFILEINFO    fi;

    CreateStringFromDrive(dre, szDrive, sizeof(szDrive));

    if (bSmallIcon)
        SHGetFileInfo(szDrive, 0, &fi, sizeof(fi), SHGFI_ICON | SHGFI_DISPLAYNAME | SHGFI_SMALLICON);
    else
        SHGetFileInfo(szDrive, 0, &fi, sizeof(fi), SHGFI_ICON | SHGFI_DISPLAYNAME | SHGFI_LARGEICON);

    return fi.hIcon;
}

BOOL
GetDriveDescription(
    drenum dre, 
    TCHAR *psz,
    size_t cchDest
    )
{
    TCHAR *desc;
    TCHAR szVolumeName[MAX_PATH];
    TCHAR szDrive[MAX_PATH];
    BOOL bRet = TRUE;

    *szVolumeName = 0;
    CreateStringFromDrive(dre, szDrive, sizeof(szDrive));
    GetVolumeInformation(szDrive, szVolumeName, ARRAYSIZE(szVolumeName), NULL, NULL, NULL, NULL, 0);

    desc = SHFormatMessage( MSG_VOL_NAME_DRIVE_LETTER, szVolumeName, (TCHAR)(dre + 'A'));
    
    if (!SUCCEEDED(StringCchCopy(psz, cchDest, desc)))
    {
        bRet = FALSE;
    }
    
    LocalFree (desc);

    return bRet;
}


/*
**------------------------------------------------------------------------------
** GetHardwareType
**
** Purpose:    
** Parameters:
**    hwHardware  - hardware type of drive
** Return:     TRUE if compatible with our needs
**             FALSE otherwise
** Notes:   
** Mod Log:    Created by Jason Cobb (2/97)
**------------------------------------------------------------------------------
*/
BOOL 
GetHardwareType(
    drenum dre, 
    hardware &hwType
    )
{
    TCHAR szDrive[4];

    hwType = hwINVALID;


    //  
    //Get drive string from drive number
    //
    if (!CreateStringFromDrive(dre, szDrive, 4))
        return FALSE;

    UINT uiType = GetDriveType(szDrive);
    switch (uiType)
    {
        case 0:
            hwType = hwUnknown;
            return FALSE;

        case 1:
            hwType = hwINVALID;
            return FALSE;

        case DRIVE_REMOVABLE:
            hwType = hwRemoveable;
            break;

        case DRIVE_FIXED:
            hwType = hwFixed;
            break;

        case DRIVE_REMOTE:
            hwType = hwNetwork;
            return FALSE;

        case DRIVE_CDROM:
            hwType = hwCDROM;
            return FALSE;

        case DRIVE_RAMDISK:
            hwType = hwRamDrive;
            break;

        default:
            hwType = hwUnknown;
            return FALSE;
    }

    return TRUE;
}

/*
**------------------------------------------------------------------------------
** CreateStringFromDrive
**
** Purpose:    creates a drive string from a drive number
** Mod Log:    Created by Jason Cobb (4/97)
**------------------------------------------------------------------------------
*/
BOOL 
CreateStringFromDrive(
    drenum dre, 
    TCHAR * szDrive, 
    ULONG cLen
    )
{
    if ((szDrive == NULL) || (cLen < 4))
        return FALSE;

    if (dre == Drive_INV)
        return FALSE;

    TCHAR ch = (CHAR)(dre + 'A');

    //
    //Drive string = Drive letter, colon, slash = "C:\"
    //
    szDrive[0] = ch;
    szDrive[1] = ':';
    szDrive[2] = '\\';
    szDrive[3] = 0;

    return TRUE;
}

ULARGE_INTEGER
GetFreeSpaceRatio(
    WORD dwDrive,
    ULARGE_INTEGER cbTotal
    )
{
    // for now, hardcode it as a percentage...
    ULARGE_INTEGER cbMin;
    // for now use 1% as the test to go into aggressive mode...
    cbMin.QuadPart = cbTotal.QuadPart / 100;
    return cbMin;
}