/* MRBackup: Backup Routines
 * Filename:	Backup.c
 * Author:		Mark R. Rinfret
 * Date:		09/04/87
 *
 * History:		(most recent change first)
 *
 * 09/04/87 -MRR- This package was (finally) extracted from Main.c.
 */

#define MAIN

#include "MRBackup.h"


/* Add a file/directory name to the list.
 * Called with:
 *		name:		filename string
 *		FIB:		pointer to FileInfoBlock for this file or NULL.
 *					If NULL, file is starting directory.
 *		list:		address of list header
 * Returns:
 *		0	=> success, failure status otherwise
 * Notes:
 *		The filename string MUST NOT contain the volume component,
 *		since it is used to build both source and destination
 *		pathnames.  Also note that this routine inserts the name
 *		into the list in sorted order (case sensitive).  Though this
 *		changes the "natural order" of the files, it makes them 
 *		easier to locate on the backup disks.
 */

int 
AddFile(name, FIB, list)
	char *name; struct FileInfoBlock *FIB; T_FILE_LIST *list;
{
	USHORT blks;
	T_FILE *fnode, *tnode;


	/* See if the exclude list exists, and if it does, see if
	 * the name can be matched by one of the patterns.
	 */

	if (excludelist) {
		if (CheckExclude(name)) {
			sprintf(conmsg,"Excluding %s\n", name);
			WriteConsole(conmsg);
			return 0;
		}
	}

	if (!(fnode = (T_FILE *) calloc(1,sizeof(T_FILE)))) {
nomem:
		TypeAndSpeak("AddFile: Out of memory!\n");
		return ERROR_NO_FREE_STORE;
	}
	if (!(fnode->filename = calloc(1, strlen(name)+1))) 
		goto nomem;
	strcpy(fnode->filename, name);		/* copy the filename */

	if (!FIB) {
		blks = 1;
		fnode->is_dir = true;
	}
	else if (fnode->is_dir = (FIB->fib_DirEntryType >= 0) )
		blks = 1;				/* assume 1 block for directory */
	else {
		blks = ((FIB->fib_Size/488)+2);	/* compute file size in blocks */
		blks += (blks/70);
	}
	fnode->blocks = blks;

	if (!list->first_file) {			/* file list is empty? */
		list->first_file = fnode;		/* this is the new head */
	}
	else {
		/* Find the insertion point for this file. */

		for (tnode = list->first_file; tnode; tnode = tnode->next) {
			if (strcmp(fnode->filename, tnode->filename) <= 0) {
				fnode->next = tnode;	/* insert it here */
				if (tnode->previous)
					tnode->previous->next = fnode;
				fnode->previous = tnode->previous;
				tnode->previous = fnode;
				if (list->first_file == tnode)
					list->first_file = fnode;
				return 0;
			}
		}

		/* append to the end of the list */

		fnode->previous = list->last_file;
		list->last_file->next = fnode;
	}
	list->last_file = fnode;
	return 0;
}

/* Main backup routine. */

Backup()
{
	int compare_flag, status = 0;

	Speak("O K,  I'm ready.  Lets back up your disk!");
	DateStamp(now);
	main_list.first_file = main_list.last_file = current_dir = NULL;

	if (do_listing) 
		if ( OpenList(listpath) ) return;

	/* Get the file comparison date.  Only files created on or after
	 * this date are backed up.
	 */
	do {
		*since = *now;
		since->ds_Days -= 1;		/* default interval is 1 day */
		since->ds_Minute = 0;
		since->ds_Tick = 0;
		Speak("Enter the date since your last backup.");
		DateRequest(mywindow, "Backup files since:",since, since);
		if ( (compare_flag = CompareDS(since, now) ) >= 0) 
			DisplayBeep(NULL);
	} while (compare_flag >= 0);

	BreakPath(homepath, srcvol, srcpath);
	BreakPath(backpath, destdrive, destpath);

#ifdef DEBUG
	sprintf(debugmsg, "destdrive = %s, destpath = %s\n",destdrive,destpath);
	DebugWrite(debugmsg);
	sprintf(debugmsg, "srcvol = %s, srcpath = %s\n", srcvol,srcpath);
	DebugWrite(debugmsg);
#endif

	if (*destpath) {
		TypeAndSpeak(
			"On a backup, the backup path must only be a device name");
		status = ERR_ABORT;
		goto done;
	}
	strcat(destdrive,":");

	if (*excludepath)
		if (GetExcludes()) goto done;

	level = 0;
	back = 0;
	size = 0;
	if (*srcpath) {				/* starting path is a directory */
		status = AddFile(srcpath, NULL, &main_list);
	}
	else						/* starting path is a device */
		status = CollectFiles(srcpath,&main_list);

	if (!status) {
		while (main_list.first_file) {	/* while something in the list */
			if (status = BackupFiles(&main_list)) 	break;
			if (status = BackupDirs(&main_list)) 	break;
		}
	}
done:
	if (status == 0) {
		TypeAndSpeak("That was a piece of cake.\n");
	}
	else {
		sprintf(conmsg,"Oops!  Backup terminated with error %d.\n",status);
		TypeAndSpeak(conmsg);
	}
}


/* Process the next directory in the file list.
 * This routine is recursive.
 * Called with:
 *		list:		file list to be processed
 * Returns:
 *		status code	(0 => success)
 */

int
BackupDirs(list)
	T_FILE_LIST *list;
{
	T_FILE *dirnode;
	T_FILE *saved_current_dir;
	int 	status = 0;
	T_FILE_LIST sublist;				/* subdirectory list header */

	sublist.first_file = sublist.last_file = NULL;
	saved_current_dir = current_dir;	/* remember current context */

/* There are a couple of things to note here.  The first is that once
 * we have reached here, there should be NO simple file nodes in "list".
 * That currently is not handled as an error, but probably should be.
 * Second, since this scan modifies the list, a removal of a directory
 * node starts the scan at the beginning of the list since we shouldn't
 * reference the links in the node we're removing.  Since we should be
 * removing the first node in the list anyway, who cares?
 */
	for (dirnode = list->first_file; dirnode; ) {
		if (dirnode->is_dir) {			/* found one */
			current_dir = dirnode;		/* set current directory */
			RemFile(dirnode, list);
			if (status = NewDir(current_dir->filename)) break;
			if (status = CollectFiles(current_dir->filename,&sublist)) 
				break;
			if (status = BackupFiles(&sublist)) break;
			if (status = BackupDirs(&sublist))  break;
			dirnode = list->first_file;
		}
		else							/* should never get here !!! */
			dirnode = dirnode->next;
	}
	current_dir = saved_current_dir;
	return status;
}

/* Backup all simple files in the current list.
 * Called with:
 *		list:		file list header
 * Returns:
 *		status code (0 => success)
 */
int
BackupFiles(list)
	T_FILE_LIST *list;
{
	T_FILE *primary, *secondary;
	int status = 0;

/* The following loop continually scans the file list (from the front),
 * looking for more file entries to process.  If the primary choice
 * fails, an attempt is made to find a file which will fit in the
 * space remaining.  If that attempt fails, then a new disk is formatted.
 */

	while (primary = FindFile(list,false)) {/* find next file to process */
		if (primary->blocks >= size) { 	/* file doesn't fit */
			if (!(secondary = FindFile(list,true))) {
				/* At this point, we know that there's at least one
				 * file to back up, but none that fit.  Start a new
				 * disk.
				 */
				if (status = NewDisk(true)) return status;
				continue;				/* try that file again */
			}
			primary = secondary;		/* use second choice */
		}
		if (status = DoFile(primary)) return status;
		RemFile(primary,list);			/* delete the node */
	}
	if (current_dir) {					/* forget current directory */
		FreeFile(current_dir);
		current_dir = NULL;
	}
	return status;
}

/* Check the file name about to be added against the exclude patterns.
 * Called with:
 *		name:	pathname to be checked
 * Returns:
 *		0 => no match
 *		1 => name was matched, ignore it.
 */

int
CheckExclude(name)
	char *name;
{
	int match = 0;
	T_PATTERN *p;


	for (p = excludelist; p; p = p->next_pattern) {
		if (match = wildcmp(p->pattern, name)) break;
	}
	return match;
}


/* Check the current number of disk blocks (size) available.  If
 * less than 1, it's time to format a new disk.
 * Called with:
 *		create_dir:		true => OK to create continuation directory
 * Returns:
 *		0 => success
 *		1 => failure
 */

int
CheckSize(create_dir)
	int create_dir;
{
	if (size > 0) return 0;
	return NewDisk(create_dir);
}

/* Collect file names from a starting path.
 * Called with:
 *		name:		starting pathname
 *						Note that name may be a null string when copying
 *						the entire home device.
 *		list:		pointer to file list header
 * Returns:
 *		status code (0 => success)
 * Notes:
 *		CollectFiles attempts to collect all file and directory names
 *		for a given level, starting with "name".  If a simple filename
 *		is given as a starting path, only that name will be collected.
 *		If a directory name is given, then all pathnames contained
 *		within that directory (only) will be collected.  For each
 *		directory name collected, CollectFiles will be called again to
 *		collect files for that particular directory.  This iterative
 *		approach (vs. recursive) saves memory and allows us to maintain
 *		order at each directory level.
 */

int
CollectFiles(name, list)
	char *name; T_FILE_LIST *list;
{
	int     status = 0;
	struct FileInfoBlock   *FIB = NULL;
	T_FILE *fnode;			/* file descriptor node */
    struct Lock *lock = NULL;	
	char path[PATH_MAX+1];
	USHORT top_level;

#ifdef DEBUG
	sprintf(debugmsg,"Collecting files from %s\n",name);
	DebugWrite(debugmsg);
#endif

	top_level = (*name == '\0');	/* empty name implies top level */

	if (!(FIB =
		AllocMem((long)sizeof(struct FileInfoBlock),
				 MEMF_CHIP|MEMF_CLEAR))) {
		TypeAndSpeak("CollectFiles: Can not allocate memory for FIB\n");
		return ERROR_NO_FREE_STORE;
	}

	strcpy(path,srcvol);			/* rebuild current home path */
	strcat(path,":");
	strcat(path, name);

	if (!(lock=Lock(path,SHARED_LOCK))) {
		status = IoErr();
		sprintf(conmsg,"CollectFiles can not lock %s; error %d\n",
			path, status);
		TypeAndSpeak(conmsg);
		goto out2;
	}

	if ((Examine(lock,FIB))==0){
		status = IoErr();
		sprintf(conmsg,"CollectFiles can not examine %s; error: %d\n",
				name, status);
		TypeAndSpeak(conmsg);
		goto out2;
	}

	if (FIB->fib_DirEntryType > 0){	/* "name" is a directory */

		while(!status && ExNext(lock,FIB)) {
			if (FIB->fib_DirEntryType < 0) {
				if (CompareDS(&FIB->fib_Date, since) < 0) {
#ifdef DEBUG
					sprintf(debugmsg,"Skipping %s\n",
							&FIB->fib_FileName[0]);
					DebugWrite(debugmsg);
#endif
					continue;
				}
			}
			if (top_level)
				*path = '\0';
			else {
				strcpy(path,name);
				strcat(path,"/");
			}
			strcat(path,&FIB->fib_FileName[0]);
			status = AddFile(path, FIB, list);
		}
		/* !!! Need check here for ERROR_NO_MORE_ENTRIES */
	}
	else {
		if ( CompareDS(&FIB->fib_Date, since ) >= 0 ) 
			status = AddFile(name, FIB, list);
		}
out2: 
	UnLock(lock);
out1: 
	FreeMem(FIB, (long)sizeof(struct FileInfoBlock) );

	/* Don't give up if somebody else is using the file - just
	 * ignore the error.  The user can cancel us if there's a
	 * problem.
	 */

	if (status == ERROR_OBJECT_IN_USE)
		status = 0;
	return status;
}

/* Process one file.
 * Called with:
 *		fnode:			node describing file
 * Returns:
 *		0	=> success
 *		1	=> failure
 */
int
DoFile(fnode)
	T_FILE *fnode;
{
#define MAX_RETRY	3

	int     status = ERR_NONE;
	char    destname[PATH_MAX+1];
	int		oldsize;
	USHORT 	retries = 0;
	char	srcname[PATH_MAX+1];

	oldsize = size;
	size -= fnode->blocks;			/* deduct blocks for file */
	if (CheckSize(true))			/* check disk space */
		return ERR_ABORT;

	if (size > oldsize)				/* we just formatted */
		oldsize = size;

/*#define NOCOPY*/						/* for fast debugging */
	do {
		if (status = CheckStop())	/* does user want out? */
			return status;

		sprintf(srcname,"%s:%s",srcvol,fnode->filename);
		sprintf(conmsg,"Blocks left: %5d   ",oldsize);
		WriteConsole(conmsg);
		if ( !do_compress || IsCompressed(srcname) || fnode->blocks < 4){
			sprintf(destname,"%s%s",destvol,fnode->filename);
			sprintf(conmsg,"Copying %s\n",srcname);
			WriteConsole(conmsg);
#ifndef NOCOPY
			status = CopyFile(srcname,destname);
#endif
		}
		else {
			sprintf(destname,"%s%s.Z",destvol,fnode->filename);
			sprintf(conmsg,"Compressing %s\n",srcname);
			WriteConsole(conmsg);
#ifndef NOCOPY
			if (!(status = compress(srcname,destname)))
				status = CopyFileDate(srcname,destname);
#endif
		}
		if (status) {
/*
			status = GetErrOpt("I/O error during copy or compress",
						ERR_ABORT | ERR_IGNORE | 
						ERR_RETRY_FILE | ERR_RESTART_VOLUME);
*/
			sprintf(conmsg,"!!!I/O error %d on file %s",status,destname);
			ListLine(conmsg);
			unlink(destname);
			if (++retries <= MAX_RETRY) {
				strcat(conmsg," - retrying this file.\n");
				if (retries == MAX_RETRY) size = 0; /* try new output disk */
				status = ERR_RETRY_FILE;
			}
			else {
				strcat(conmsg," - aborting this file.\n");

/* Note that for now, we will proceed by brute force.  A later revision
 * of this program will provide context-saving so we can restart the
 * series of files on this floppy.
 */
				status = ERR_IGNORE;
			}
			WriteConsole(conmsg);
		}
		else
			ListLine(destname);

	} while (status == ERR_RETRY_FILE && (retries < MAX_RETRY));
	if (status == ERR_IGNORE)
		status = ERR_NONE;

#ifndef NOCOPY
	if (!status){
		if ((size = DiskBlocks(destvol)) < 0)	/* update blocks left */
			++status;
	}
#endif
	return status;
}

/* Attempt to find a file node in the file list.  If the check_size
 * parameter is true, only look at files which will fit in the space
 * remaining on the disk.
 * Called with:
 *		list:		pointer to file list to be searched
 *		check_size: false => find first file in the list
 *					true  => test space available
 * Returns:
 *		file node or NULL (not found)
 */

T_FILE *FindFile(list,check_size)
	T_FILE_LIST *list; int check_size;
{
	T_FILE *fnode;

	for (fnode = list->first_file; fnode; fnode = fnode->next) {
		if (!fnode->is_dir) {		/* don't consider directory nodes */
			if (!check_size) break;	/* take this one */
			if (fnode->blocks < size) break;
		}
	}
	return fnode;
}

/* Free memory allocated to a file node.
 * Called with:
 *		node:	file node
 */
FreeFile(node)
	T_FILE *node;
{

	free(node->filename);
	free(node);
}

/* An exclude file pathname has been specified.  Get the patterns it
 * contains.
 * Returns:
 *		status:	0 => success, failure otherwise
 */
int
GetExcludes()
{
	USHORT i, length, nonwild;
	T_PATTERN *p;
	int status = 0;
	char str[PATH_MAX+1];
	FILE *xcld;

	if (! exclude_has_changed)
		return 0;

	if (!(xcld = fopen(excludepath, "r"))) {
		sprintf(conmsg, 
			"I couldn't open the exclude pattern file, error %d.", errno);
		TypeAndSpeak(conmsg);
		return errno;
	}

	/* Release any previous exclude list. */

	for (p = excludelist; p; p = p->next_pattern) {
		free(p->pattern);
		free(p);
	}
	excludelist = lastexclude = NULL;

	while (fgets(str, PATH_MAX, xcld)) {
		if (length = strlen(str)) {
			--length;
			str[length] = '\0';
		}
		if (length && *str != '#') {	/* ignore blank lines and comments */
			nonwild = 0;
			for (i = 0; i < length; ++i) {
				if (str[i] != '*' && str[i] != '?' && str[i] != '/')
					++nonwild;
			}
			if (! nonwild ) {
				sprintf(conmsg,
				"Very funny!  %s will exclude everything!  Ha ha ha!\n",
					str);
				TypeAndSpeak(conmsg);
				status = 1;
				goto done;
			}
			p = (T_PATTERN *) calloc(sizeof(T_PATTERN), 1);
			p->pattern = calloc(length+1, 1);
			strcpy(p->pattern, str);
			if ( ! excludelist ) 
				excludelist = p;
			else
				lastexclude->next_pattern = p;
			lastexclude = p;
		}
	}
done:
	fclose(xcld);
	if (! status )
		exclude_has_changed = false;
	return status;
}

/* Format a new diskette.
 * Called with:
 *		create_dir:	true => create continuation directory, if necessary
 * Returns:
 *		false => success
 *		true  => failure
 */

int
NewDisk(create_dir)
	int create_dir;
{
	char datestr[20];
	int status = 0;

	if (back)						/* not first disk? */
		Delay(TICKS_PER_SECOND * 5L);	/* let disk buffers flush */

	++back;					/* Increment the volume ID */
	Speak("Attention!  I need a disk for formatting.");
	do {
		if (!RequestDisk(mywindow, destdrive))
			return ERR_ABORT;

	 	/* Don't put the colon in the volume name - 
		 * FormatDisk will happily use it as part of 
		 * the name rather than as a delimiter. 
		 */

		DS2Str(datestr, "%02m-%02d-%02y", now);
		sprintf(destvol,"Backup %s.%d", datestr, back);

		Inhibit(destdrive,1);
		if (status = FormatDisk(destdrive,destvol)) {
			TypeAndSpeak("I failed to format the disk.  Sorry.\n");
		}
	} while (status);

	strcat(destvol, ":");			/* add colon */

	if ((size = DiskBlocks(destvol)) < 0)
		status = -size;
	else
		if (create_dir && (current_dir != NULL) )
			status = NewDir(current_dir->filename);

	return status;
}

/* Remove a file node from the list.
 * Called with:
 *		node:		file node pointer
 *		list:		file list header
 * Returns:
 *		nothing
 */
RemFile(node,list)
	T_FILE *node; T_FILE_LIST *list;
{
	if (node->previous)
		node->previous->next = node->next;

	if (node->next)
		node->next->previous = node->previous;

	if (node == list->first_file)
		list->first_file = node->next;

	if (node == list->last_file)
		list->last_file = node->previous;

	if (!node->is_dir) FreeFile(node);
}