FindDisc.pas

//  LEGO(R) Stunt Rally Alternate Installer
//  Created 2013-2014 Triangle717
//  <http://Triangle717.WordPress.com/>
//  Contains source code from Grim Fandango Setup
//  Copyright (c) 2007-2008 Bgbennyboy
//  <http://quick.mixnmojo.com/>

[Code]
var
    DrvLetters: array of AnsiString;

    function GetDriveType( lpDisk: AnsiString ): Integer;
    external 'GetDriveTypeA@kernel32.dll stdcall';

    function GetLogicalDriveStrings( nLenDrives: LongInt; lpDrives: AnsiString ): Integer;
    external 'GetLogicalDriveStringsA@kernel32.dll stdcall';

const
    // Ensure this is a Stunt Rally disc
    UniqueFile_1 = '_avi_\intro.avi';


    DRIVE_UNKNOWN = 0; // The drive type cannot be determined.
    DRIVE_NO_ROOT_DIR = 1; // The root path is invalid. For example, no volume is mounted at the path.
    DRIVE_REMOVABLE = 2; // The disk can be removed from the drive.
    DRIVE_FIXED = 3; // The disk cannot be removed from the drive.
    DRIVE_REMOTE = 4; // The drive is a remote (network) drive.
    DRIVE_CDROM = 5; // The drive is a CD-ROM drive.
    DRIVE_RAMDISK = 6; // The drive is a RAM disk.

//Convert disk type to string
function DriveTypeString( dtype: Integer ): AnsiString ;
begin
    case dtype of
        DRIVE_NO_ROOT_DIR : Result := 'Root path invalid';
        DRIVE_REMOVABLE : Result := 'Removable';
        DRIVE_FIXED : Result := 'Fixed';
        DRIVE_REMOTE : Result := 'Network';
        DRIVE_CDROM : Result := 'CD-ROM';
        DRIVE_RAMDISK : Result := 'Ram disk';
        else
            Result := 'Unknown';
    end;
end;

procedure FindAllCdDrives();
var
    n: Integer;
    drivesletters: AnsiString; lenletters: Integer;
    drive: AnsiString;
    disktype, posnull: Integer;
    sd: AnsiString;
begin
    //get the system drive
    sd := UpperCase(ExpandConstant('{sd}'));

    //get all drives letters of system
    drivesletters := StringOfChar( ' ', 64 );
    lenletters := GetLogicalDriveStrings( 63, drivesletters );
    SetLength( drivesletters , lenletters );

    drive := '';
    n := 0;
    while ( (Length(drivesletters) > 0) ) do
    begin
        posnull := Pos( #0, drivesletters );
        if posnull > 0 then
        begin
            drive:= UpperCase( Copy( drivesletters, 1, posnull - 1 ) );

            // get number type of disk
            disktype := GetDriveType( drive );

            //Make sure its a cd drive
            if disktype = DRIVE_CDROM then
            begin
                SetArrayLength(DrvLetters, N+1);
                DrvLetters[n] := drive;
                n := n + 1;
            end;

            drivesletters := Copy( drivesletters, posnull+1, Length(drivesletters));
        end;
    end;
end;

function FindUniqueFile(): Ansistring;
var
    i: integer;
begin
    for i:=0 to GetArrayLength(DrvLetters) -1 do
    begin
        // A LEGO Stunt Rally disc was detected
        if FileExists( DrvLetters[i] + UniqueFile_1) then
        begin
            result:=DrvLetters[i];
            exit;
        end

    end;

    result:='';
end;

function GetSourceCdDrive(): Ansistring;
begin
    FindAllCdDrives();
    if GetArrayLength(DrvLetters) < 1 then
    begin
        MsgBox('No disc drive was found on your computer.', mbError, MB_OK);
        Abort;
    end;


    if FindUniqueFile() <> '' then
    begin
        //MsgBox('', mbError, MB_OK);
    end
    else
    begin
        while FindUniqueFile() = '' do
        begin
            if MsgBox('Is there a LEGO Stunt Rally CD in your computer? If not, please insert it and press OK.', mbConfirmation, MB_OKCANCEL or MB_DEFBUTTON1) = IDOK then

            else
                Abort;
        end;
    end;

    Result:=FindUniqueFile();
end;