/*
Copyright 1991 by the Massachusetts Institute of Technology

Permission to use, copy, modify, and distribute this
software and its documentation for any purpose and without
fee is hereby granted, provided that the above copyright
notice appear in all copies and that both that copyright
notice and this permission notice appear in supporting
documentation, and that the name of M.I.T. not be used in
advertising or publicity pertaining to distribution of the
software without specific, written prior permission.
M.I.T. makes no representations about the suitability of
this software for any purpose.  It is provided "as is"
without express or implied warranty.
*/

/*
**  cache.c:  manage the files in /tmp
**
**  Ensure we have the ones we need, and get rid of the ones no
/*
**  cache.c:  manage the files in /tmp
**
**  Ensure we have the ones we need, and get rid of the ones no
**  longer in use.
**
*/

#include	<stdio.h>
#include	<X11/Intrinsic.h>
#include	<X11/StringDefs.h>
#include	<X11/IntrinsicP.h>
#include	<X11/CoreP.h>
#include	<X11/Xaw/Command.h>
#include	<X11/Xaw/AsciiText.h>
#include	<X11/Xaw/TextP.h>
#include	"xdsc.h"

#define		NUM_CACHED_FILES	5
#define		CACHE_DIR_NEXT          1
#define		CACHE_DIR_PREV          2
#define		CACHE_DIR_NREF          3
#define		CACHE_DIR_PREF          4


static char rcsid[] = "";

extern char	*RunCommand();
extern EntryRec		toplevelbuttons[2][MAX_BUTTONS];
extern TextWidget	bottextW, toptextW;
extern Boolean	debug;
extern char	filebase[];
extern int	topscreen;
extern int	edscversion;
extern Widget	topW;
extern void	TopSelect();
extern Boolean	nocache;
extern char	axis[];

int	next=0, prev=0;
static int	nref = 0, pref=0, fref=0, lref=0;
static int	first=0, last=0;
static int	highestseen;
static int	current;

static int	cache[NUM_CACHED_FILES] = {-1,-1,-1,-1,-1};
static char	currentmtglong[LONGNAMELEN] = "";
static char	currentmtgshort[SHORTNAMELEN] = "";

char	*GetTransactionFile();

char *
CurrentMtg(which)
int	which;
{
	if (which == 0)
		return (currentmtglong);
	else
		return (currentmtgshort);
}

int
SaveMeetingNames(newlong, newshort)
char	*newlong;
char	*newshort;
{
	char	oldlong[LONGNAMELEN];
	char	oldshort[SHORTNAMELEN];
	if (*currentmtglong) {
		MarkLastRead();
		DeleteOldTransactions();
	}

	if (*newlong) {
		strcpy (oldlong, currentmtglong);
		strcpy (currentmtglong, newlong);
		strcpy (oldshort, currentmtgshort);
		strcpy (currentmtgshort, newshort);
		if (SetUpTransactionNumbers() == -1) {
			strcpy (currentmtglong, oldlong);
			strcpy (currentmtgshort, oldshort);
			return (-1);
		}
	}

	else {
		*currentmtglong = '\0';
		*currentmtgshort = '\0';
	}
	return (0);
}

/*
**  GoToTransaction updates the data structures and cache so that
**  we are in a particular transaction.
**
**  if 'update' is True (it usually is) we put the contents of the
**  transaction into the lower text widget.
*/

GoToTransaction (num, update)
int	num;
Boolean	update;
{
	static char	command[LONGNAMELEN + 25];
	char		*filename;
	char		*returndata;
	int		transactionnum;

	if (!num) return;

	if (num < 0)
		transactionnum = TransactionNum(num);
	else
		transactionnum = num;

	if (update && topscreen == LISTTRNS);
		UpdateHighlightedTransaction(transactionnum);

	sprintf (command, "Reading %s [%d-%d], #%d...", 
				currentmtglong, first, last, transactionnum);
	PutUpStatusMessage(command);

	if ((filename = GetTransactionFile(num)) == (char *) -1)
		return (-1);

	if (update)
		FileIntoWidget(filename, bottextW);

	sprintf (command, "(gti %d %s)\n", transactionnum, currentmtglong);
	returndata = RunCommand (command, NULL, NULL, True);

	if ((int) returndata <= 0) goto DONE;

	sscanf (	returndata, 
			"%*c%d%d%d%d%d%d%d%*s",
			&current, &prev, &next, &pref, 
			&nref, &fref, &lref);

	myfree(returndata);
	CheckButtonSensitivity(BUTTONS_UPDATE);

	if (!nocache)
		CacheSurroundingTransactions();

	if ( current >  highestseen)
		highestseen = current;

	if ( next > last || current > last) {
		MarkLastRead();
		(void) SetUpTransactionNumbers();
	}

	if (highestseen == last && topscreen == MAIN)
		RemoveLetterC();
DONE:
	sprintf (command, "Reading %s [%d-%d], #%d", 
				currentmtglong, first, last, transactionnum);
	PutUpStatusMessage(command);
}

DeleteOldTransactions()
{
	char		filename[80];
	unsigned int	fd;

	DeleteTransactionFile(current);
	DeleteTransactionFile(prev);
	DeleteTransactionFile(next);
	DeleteTransactionFile(pref);
	DeleteTransactionFile(nref);

	sprintf (filename, "%s-list", filebase);
	if ((fd = open(filename, O_RDONLY)) != -1) {
		close (fd);
		unlink (filename);
	}

	next=0, prev=0, nref=0;
	pref=0, fref=0, lref=0;
	first=0, last=0, current=0;
}

/*
** Read in the transactions immedidately before and after the
** current one.
*/

CacheSurroundingTransactions()
{

	int		i;

/*
** Remove unnecessary files
*/

	for (i = 0; i < NUM_CACHED_FILES; i++) {
		if (	cache[i] != next && cache[i] != prev &&
			cache[i] != nref && cache[i] != pref &&
			cache[i] != current && cache[i] != -1) {

			DeleteTransactionFile(cache[i]);
		}
	}

/*
** Get the files we need
*/
	(void) GetTransactionFile (next);
	(void) GetTransactionFile (prev);
	(void) GetTransactionFile (nref);
	(void) GetTransactionFile (pref);
	(void) GetTransactionFile (current);

}

/*
** Remove the file from /tmp and the cache.
*/

DeleteTransactionFile(num)
int	num;
{
	char	filename[50];
	int	i;

	sprintf (filename, "%s-%d", filebase, num);
	unlink (filename);

	for (i = 0; i < NUM_CACHED_FILES; i++)
		if (cache[i] == num)
			cache[i] = -1;
}

/*
**  This function behaves differently depending on the version of
**  edsc we're talking to.  
**
**  If edsc is doing the caching, just ask for the transaction and
**  return the filename.
**
**  If we're doing the caching, ask if the file is already in the cache,
**  and return the filename if it is.  Otherwise, run the 
**  edsc command to fetch it, note it as cached, and return the filename.
**
*/

char *
GetTransactionFile(num)
int	num;
{
	static char	filename[50];
	char		command[LONGNAMELEN + 25];
	int		i;
	char		*retval;
	int		transactionnum;
	int		direction;

	if (num == 0)
		return((char *)-1);

/*
** have we been passed a symbol instead of a number?
*/

	if (num < 0)
		transactionnum = TransactionNum(num);
	else
		transactionnum = num;

	if (!nocache)
		sprintf (filename, "%s-%d", filebase, transactionnum);
/*
** See if the file is in our cache.  If so, return its filename;.
*/
	if (!nocache) {
		for (i = 0; i < NUM_CACHED_FILES; i++) {
			if (cache[i] == num) {
				return (filename);
			}
		}
	}

/*
** If file doesn't exist, go get it.
*/
	if (nocache) {
		switch (num) {
		case NEXT:	
			direction = CACHE_DIR_NEXT;
			break;
		case PREV:	
			direction = CACHE_DIR_PREV;
			break;
		case NREF:	
			direction = CACHE_DIR_NREF;
			break;
		case PREF:	
			direction = CACHE_DIR_PREF;
			break;
		default:
			direction = 0;
			break;
		}

		sprintf (	command, "(gtfc %d %d %s)\n", 
				direction, transactionnum, currentmtglong);

		retval = RunCommand (command, NULL, NULL, True);
		if ((int) retval <= 0) 
			return((char *)-1);
		sscanf (retval, "(\"%[^\"]", filename);
	}

	else {
		sprintf (	command, "(gtf %s %d %s)\n", 
				filename, transactionnum, currentmtglong);
		retval = RunCommand (command, NULL, NULL, True);
		if ((int) retval <= 0) 
			return((char *)-1);

		for (i = 0; i < NUM_CACHED_FILES; i++) {
			if (cache[i] == -1) {
				cache[i] = num;
				break;
			}
		}
	}

	myfree (retval);
	return (filename);
}

/*
** Return the highestseen from mtg.  Also set first, last, and highestseen.
** Set current to highestseen if it's not already set (ie, we've just
** entered the meeting)
**
** Return -1 if something went wrong.
*/

int
SetUpTransactionNumbers()
{

	char	command[LONGNAMELEN + 25];
	char	*retval;
	static int	oldhighestseen = 0;

	sprintf (command, "(gmi %s)\n", currentmtglong);

	retval = RunCommand (command, NULL, NULL, True);
	if ((int) retval <= 0) return (-1);

	sscanf (retval, "(\"%*[^\"]\" \"%*[^\"]\" \"%*[^\"]\" %d %d %*d %*d \"%*[^\"]\" \"%*[^\"]\" %*d \"%[^\"]\" %d",
		&first, &last, axis, &highestseen);

	oldhighestseen = highestseen;
			
	if (last == 0 && first == 0) {
		fprintf (stderr,"xdsc:  Reply out of sync with request!\n");
		fprintf (stderr,"xdsc:  requested '%s', got '%s'\n",command, retval);
		PutUpWarning(	"INTERNAL ERROR DETECTED", 
				"I suggest you quit immediately to avoid\npossible corruption of your .meetings file.", True);
		myfree(retval);
		return (-1);
	}
	myfree(retval);

	if (highestseen > last) {
		PutUpWarning(	"WARNING",
				"The highest-read transaction in this\nmeeting no longer exists.\nGoing to end of the meeting.", True);
		highestseen = last;
	}

	if (debug) {
		fprintf (stderr, "highestseen message of %s is %d\n",
				currentmtglong, highestseen);

		fprintf (stderr, "first is %d, last is %d\n",first, last);
	}

	GoToTransaction (highestseen, False);

	return (highestseen);
}

MarkLastRead()
{
	static char	command[LONGNAMELEN + 25];

	if (*currentmtglong)  {
		sprintf (	command, 
				"(ss %d %s)\n", 
				highestseen,
				currentmtglong);
		if (edscversion >= 24)
			(void) RunCommand (command, NULL, NULL, True);
		else
			(void) RunCommand (command, NULL, NULL, False);
	}

}

TransactionNum(arg)
int	arg;
{
	switch (arg) {
		case NEXT:
			return(next);
		case PREV:
			return(prev);
		case NREF:
			return(nref);
		case PREF:
			return(pref);
		case LREF:
			return(lref);
		case FREF:
			return(fref);
		case FIRST:
			return(first);
		case LAST:
			return(last);
		case CURRENT:
			return(current);
		case HIGHESTSEEN:
			return(highestseen);
		default:
			fprintf (stderr, "Unknown arg to TransactionNum: %d\n", arg);
			return(0);
	}
}

MoveToMeeting(which)
int	which;
{
	Arg	args[2];
	Boolean	transactionflag = False;
/*
** If we're currently showing transactions, we have to restore the top-level
** list of meetings.
*/
	if (topscreen == LISTTRNS) {
		XawTextDisableRedisplay(toptextW);
		TopSelect (NULL, 4 + (1 << 4));
		transactionflag = True;
	}

/*
** HighlightNewItem will eventually call SaveMeetingNames and 
** SetUpTransactionNumbers to get the next, prev, etc. vars set.
*/
	if (HighlightNewItem(toptextW, which, True) == 0) {

/*
** Need to restore transaction list?
*/
		if (transactionflag == True) {
			TopSelect (NULL, 4 + (0 << 4));
			XawTextEnableRedisplay(toptextW);
		}

/*
** Clear out bottom text window.
*/
		XtSetArg (args[0], XtNstring, "");
		XtSetArg (args[1], XtNlength, 0);
		XtSetValues (bottextW, args, 1);

/*
** If we're at the end of the meeting, make it so the "next" button
** will show us the last transaction.
*/
		if (next == 0)
			next = last;

		CheckButtonSensitivity(BUTTONS_ON);
		return (0);
	}

	else {
		return (-1);
	}
}

/*
** Make sure bottom buttons are set appropriately, according to context
** and mode.
**
** Mode = BUTTONS_UPDATE: turn on appropriate buttons, if sensitive = True.
** Mode = BUTTONS_OFF:  Turn off all buttons.  Set sensitive = False.
** Mode = BUTTONS_ON:  Turn on appropriate buttons.  Set sensitive = True.
**
*/
CheckButtonSensitivity(mode)
int mode;
{
	static Boolean	sensitive = True;
	Arg		args[2];

	if (mode == BUTTONS_ON) sensitive = True;
	if (mode == BUTTONS_OFF) sensitive = False;

	if (next && sensitive) {
		XtSetArg(args[0], XtNsensitive, True);
		XtSetArg(args[1], XtNborderWidth, 1);
	}
	else {
		XtSetArg(args[0], XtNsensitive, False);
		XtSetArg(args[1], XtNborderWidth, 4);
	}
	XtSetValues ((toplevelbuttons[1][0]).button, args, 2);

	if (prev && sensitive)
		XtSetArg(args[0], XtNsensitive, True);
	else
		XtSetArg(args[0], XtNsensitive, False);
	XtSetValues ((toplevelbuttons[1][1]).button, args, 1);

	if (nref && sensitive)
		XtSetArg(args[0], XtNsensitive, True);
	else
		XtSetArg(args[0], XtNsensitive, False);
	XtSetValues ((toplevelbuttons[1][2]).button, args, 1);

	if (pref && sensitive)
		XtSetArg(args[0], XtNsensitive, True);
	else
		XtSetArg(args[0], XtNsensitive, False);
	XtSetValues ((toplevelbuttons[1][3]).button, args, 1);

	if (topscreen == LISTTRNS && sensitive)
		XtSetArg(args[0], XtNsensitive, True);
	else
		XtSetArg(args[0], XtNsensitive, False);
	XtSetValues ((toplevelbuttons[0][5]).button, args, 1);

	if (axis[0] == ' ' && axis[6] == ' ')
		XtSetArg(args[0], XtNsensitive, False);
	else
		XtSetArg(args[0], XtNsensitive, True);
	XtSetValues ((toplevelbuttons[1][5]).button, args, 1);

	if (axis[0] == ' ')
		XtSetArg(args[0], XtNsensitive, False);
	else
		XtSetArg(args[0], XtNsensitive, True);
	XtSetValues ((toplevelbuttons[1][5]).nextrec->button, args, 1);

	if (axis[6] == ' ')
		XtSetArg(args[0], XtNsensitive, False);
	else
		XtSetArg(args[0], XtNsensitive, True);
	XtSetValues ((toplevelbuttons[1][5]).nextrec->nextrec->button, args, 1);

	XtSetArg(args[0], XtNsensitive, False);
	XtSetValues ((toplevelbuttons[1][6]).nextrec->nextrec->button, args, 1);
}