#define INTUITIONPRIVATE 1
#include <exec/exec.h>
#include <intuition/intuitionbase.h>
#include <functions.h>
#include <libraries/dosextens.h>
#include <libraries/reqbase.h>

struct ReqBase			*ReqBase;
struct FileRequester	MyFileReqStruct;

char					filename[FCHARS+1],
						directoryname[DSIZE+1],
						answerarray[DSIZE+FCHARS+1];


Anfang()
{
	if((ReqBase = (struct ReqBase *)OpenLibrary("req.library", NULL)) == NULL)
		exit(20);

	directoryname[0] = filename[0] = answerarray[0] = 0;
	MyFileReqStruct.PathName = answerarray;
	MyFileReqStruct.Dir = directoryname;
	MyFileReqStruct.File = filename;
	MyFileReqStruct.dirnamescolor = 2;
	MyFileReqStruct.devicenamescolor = 2;
	MyFileReqStruct.Show[0] = 0;
	MyFileReqStruct.Flags = FRQCACHINGM+FRQINFOGADGETM+FRQLOADINGM;
	MyFileReqStruct.Title = "Welche Datei ver-/entschlüsseln?";
}

Ende()
{
	CloseLibrary(ReqBase);
	exit(0);
}

long FileSize(name)
  char *name;
{	struct FileLock *fl = NULL;
	struct FileInfoBlock *fib;
	long size = 0L;

	if(fib = AllocMem((long)sizeof(struct FileInfoBlock), MEMF_PUBLIC+MEMF_CLEAR))
	{	if(fl = Lock(name, ACCESS_READ))
		{	if(Examine(fl, fib))
				size = fib->fib_Size;
			UnLock(fl);
		}
		FreeMem(fib, (long)sizeof(struct FileInfoBlock));
	}
	return size;
}

main()
{	char *text, passwort[32];
	struct FileHandle *fp;
	long j, k, size;
	int pwsize;
	
	Anfang();
	setmem(passwort, 32, 0);
	
	do
	{	text = size = NULL;
		
		if(FileRequester(&MyFileReqStruct))
		{	if(fp = Open(answerarray, MODE_OLDFILE))
			{	size = FileSize(answerarray);
				if(text = AllocMem(size, MEMF_PUBLIC+MEMF_CLEAR ))
					Read(fp, text, size);
				else
					SimpleRequest("Zu wenig freier Speicher.");
				Close(fp);
			}
			else
				SimpleRequest("Ich kann %s nicht öffnen.", answerarray);
		}
		else Ende();		/* Cancel im FR beendet Programm */
		
		if(text)
		{	if(GetString(passwort, "Welches Paßwort?", NULL, 32L, 32L))
			{	if(pwsize = strlen(passwort))
				{	for(j=0L, k=0L; j<size; j++)
					{	text[j] ^= passwort[k];
						if(++k > pwsize) k = 0L;
					}
					
					if(fp = Open(answerarray, MODE_NEWFILE))
					{	Write(fp, text, size);
						Close(fp);
						SimpleRequest("Datei %s wurde mit\nPaßwort %s behandelt.",
							answerarray, passwort);
					}
					else
						SimpleRequest("Ich kann %s nicht überschreiben.", answerarray);
				}
			}
			
			FreeMem(text, size);
		}
		
	} while(1);
}