/*
 * replace.c
 *
 * Functions, formerly in search.c, which handle the search and replace
 * functionality.
 */

#include <stdio.h>
#include "estruct.h"
#include "eproto.h"
#include "edef.h"
#include "elang.h"

static int	replen;		/* length of replacement string */
static char	*oldpatmatch = NULL;	/* allocated memory for un-do.*/

/*
 * sreplace -- Search and replace.
 */
int PASCAL NEAR sreplace(f, n)
int f;					/* default flag */
int n;					/* # of repetitions wanted */
{
	return(replaces(FALSE, f, n));
}

/*
 * qreplace -- search and replace with query.
 */
int PASCAL NEAR qreplace(f, n)
int f;					/* default flag */
int n;					/* # of repetitions wanted */
{
	return(replaces(TRUE, f, n));
}

/*
 * replaces -- Search for a string and replace it with another
 *	string.  Query might be enabled (according to kind).
 */
int PASCAL NEAR	replaces(kind, f, n)
int	kind;				/* Query enabled flag */
int	f;					/* default flag */
int	n;					/* # of repetitions wanted */
{
	register int status;	/* success flag on pattern inputs */
	register int nummatch;	/* number of found matches */
	long numsub;			/* number of substitutions */
	int nlflag;			/* last char of search string a <NL>? */
	int nlrepl;			/* was a replace done on the last line? */
	char c;				/* input char for query */
	LINE *origline;		/* original "." position */
	int origoff;		/* and offset (for . query option) */
	LINE *lastline;		/* position of last replace and */
	int lastoff;		/* offset (for 'u' query option) */
	int oldmatchlen;	/* Closure may alter the match length.*/

	/*
	 * Don't allow this command if we are
	 * in read only mode.
	 */
	if (curbp->b_mode & MDVIEW)
		return (rdonly());

	/* Check for negative repetitions.
	 */
	if (f && n < 0)
		return (FALSE);

	/* Ask the user for the text of a pattern.
	 */
	if ((status = readpattern(kind ? TEXT85 : TEXT84, (char *) &pat[0], TRUE)) != TRUE)
/*				"Replace" */
/*						"Query replace" */
		return (status);

	/* Ask for the replacement string, and get its length.
	 */
	if ((status = readpattern(TEXT86, (char *) &rpat[0], FALSE)) == ABORT)
/*				"with" */
		return (status);

	/* Set up flags so we can make sure not to do a recursive
	 * replace on the last line.
	 */
	nlflag = (pat[strlen((char*)pat) - 1] == '\r');
	nlrepl = FALSE;

	/* Save original . position, reset the number of matches and
	 * substitutions, and scan through the file.
	 */
	origline = curwp->w_dotp;
	origoff = curwp->w_doto;
	numsub = 0L;
	nummatch = 0;
	lastline = (LINE *) NULL;
	mmove_flag = FALSE;	/* disable mouse move events		  */

	while ((f == FALSE || n > nummatch) &&
		(nlflag == FALSE || nlrepl == FALSE))
	{
		/* let the undo checkpoint out position each q-replacement */
		if (kind)
			undo_insert(OP_CMND, 1, obj);

		/* Search for the pattern.
		 * If we search with a regular expression,
		 * matchlen is reset to the true length of
		 * the matched string.
		 */
#if	MAGIC
		if (magical && (curwp->w_bufp->b_mode & MDMAGIC)) {
			if (!mcscanner(&mcpat[0], FORWARD, PTBEG, 1))
				break;
		}
		else
			if (!mcscanner(&mcdeltapat[0], FORWARD, PTBEG, 1))
				break;	/* all done */
#else
		if (!scanner(FORWARD, PTBEG, 1))
			break;	/* all done */
#endif

		++nummatch;		/* Increment # of matches */

		/* Check if we are on the last line.
		 */
		nlrepl = (lforw(curwp->w_dotp) == curwp->w_bufp->b_linep);

		/* Check for query.
		 */
		if (kind) {
			/* Get the query.
			 */
pprompt:	mlrquery();
qprompt:
			/* Show the proposed place to change, and
			 * update the position on the modeline if needed.
			 */
			if (posflag)
				upmode();
			update(TRUE);
			c = tgetc();	/* and input */
			mlerase();	/* and clear it */

			/* And respond appropriately.
			 */
			switch (c) {
#if	FRENCH
				case 'o':	/* oui, substitute */
				case 'O':
#endif
			case 'y':	/* yes, substitute */
			case 'Y':
			case 'l':	/* last substitute */
			case 'L':
			case ' ':
				break;

			case 'n':	/* no, onward */
			case 'N':
				forwchar(FALSE, 1);
				continue;

			case '!':	/* yes/stop asking */
				kind = FALSE;
				break;

			case 'u':	/* undo last and re-prompt */
			case 'U':
				/* Restore old position.
				 */
				if (lastline == (LINE *) NULL) {
					/* There is nothing to undo.
					 */
					TTbeep();
					goto pprompt;
				}
				curwp->w_dotp = lastline;
				curwp->w_doto = lastoff;
				lastline = NULL;
				lastoff = 0;

				/* Delete the new string,
				 * restore the old match.
				 */
				backchar(FALSE, replen);
				status = delins(replen, oldpatmatch, FALSE);
				if (status != TRUE) {
					mmove_flag = TRUE;
					return (status);
				}

				/* Record one less substitution,
				 * backup, save our place, and
				 * reprompt.
				 */
				--numsub;
				backchar(FALSE, oldmatchlen);
				matchlen = oldmatchlen;
				matchline = curwp->w_dotp;
				matchoff = curwp->w_doto;
				continue;

			case '.':	/* abort! and return */
				/* restore old position */
				curwp->w_dotp = origline;
				curwp->w_doto = origoff;
				curwp->w_flag |= WFMOVE;

			case BELL:	/* abort! and stay */
				mlwrite(TEXT89);
/*						"Aborted!" */
				mmove_flag = TRUE;
				return (FALSE);

			default:	/* bitch and beep */
				TTbeep();

			case '?':	/* help me */
				mlwrite(TEXT90);
/*"(Y)es, (N)o, (!)Do rest, (U)ndo last, (^G)Abort, (.)Abort back, (?)Help: "*/
				goto qprompt;

			}		/* end of switch */
		}		/* end of "if kind" */

		/* if this is the point origin, flag so we a can reset it */
		if (curwp->w_dotp == origline) {
			origline = NULL;
			lastline = lback(curwp->w_dotp);
		}

		/* Delete the sucker, and insert its
		 * replacement.
		 */
#if	MAGIC
		status = delins(matchlen, (char *)&rpat[0], rmagical);
#else
		status = delins(matchlen, (char *)&rpat[0], FALSE);
#endif
		if (origline == NULL) {
			origline = lforw(lastline);
			origoff = 0;
		}

		if (status != TRUE) {
			mmove_flag = TRUE;
			return (status);
		}

		numsub++;		/* increment # of substitutions */

		/* Save our position, the match length, and the string
		 * matched if we are query-replacing, as we may undo
		 * the replacement. If we are not querying, check to
		 * make sure that we didn't replace an empty string
		 * (possible in MAGIC mode), because we'll infinite loop.
		 */
		if (kind) {
			if (c == 'l' || c == 'L')
				break;
			lastline = curwp->w_dotp;
			lastoff = curwp->w_doto;
			oldmatchlen = matchlen;	/* Save the length for un-do.*/

			if ((oldpatmatch = reroom(oldpatmatch, matchlen + 1)) == NULL) {
				mlabort(TEXT94);
/*					"%%Out of memory" */
				mmove_flag = TRUE;
				return(ABORT);
			}
			strcpy(oldpatmatch, patmatch);
		}
		else if (matchlen == 0) {
			mlwrite(TEXT91);
/*				"Empty string replaced, stopping." */
			mmove_flag = TRUE;
			return (FALSE);
		}
	}

	/* And report the results.
	 */
	mlwrite(TEXT92, numsub);
/*		"%d substitutions" */
	mmove_flag = TRUE;
	return (TRUE);
}

/*
 * mlrquery -- The prompt for query-replace-string.
 */
VOID PASCAL NEAR mlrquery()
{
	register int	tcol;
#if	MAGIC
	register RMC	*rmcptr;
#endif

	mlwrite(TEXT87);
/*		"Replace '" */

	tcol = echostring(patmatch, strlen(TEXT87), NPAT / 2);

	mlputs(TEXT88);
/*		"' with '" */
	tcol += strlen(TEXT88);

#if	MAGIC
	if (rmagical && (curwp->w_bufp->b_mode & MDMAGIC)) {
		rmcptr = &rmcpat[0];

		while (rmcptr->mc_type != MCNIL && tcol < NPAT - 8) {
			if (rmcptr->mc_type == LITSTRING)
				tcol = echostring(rmcptr->u.rstr, tcol, NPAT - 8);
			else if (rmcptr->mc_type == DITTO)
				tcol = echostring(patmatch, tcol, NPAT - 8);
			else
				tcol = echostring(grpmatch[rmcptr->u.group_no],
					tcol, NPAT - 8);
			rmcptr++;
		}
	}
	else
#endif
		echostring((char *) rpat, tcol, NPAT - 8);

	mlputs("'? ");
}

/*
 * delins -- Delete a specified length from the current point
 *	then either insert the string directly, or make use of
 *	replacement meta-array.
 */
int PASCAL NEAR delins(dlength, instr, use_rmc)
int	dlength;
char	*instr;
int	use_rmc;
{
	register int	status;
	register char	*rstr;
#if	MAGIC
	register RMC	*rmcptr;
#endif

	replen = 0;

	/* Zap what we gotta,
	 * and insert its replacement.
	 */
	if ((status = ldelete((long) dlength, FALSE)) != TRUE)
		mlwrite(TEXT93);
/*			"%%ERROR while deleting" */
	else
#if	MAGIC
		if (use_rmc && (curwp->w_bufp->b_mode & MDMAGIC)) {
			rmcptr = &rmcpat[0];
			while (rmcptr->mc_type != MCNIL && status == TRUE) {
				if (rmcptr->mc_type == LITSTRING)
					status = linstr(rstr = rmcptr->u.rstr);
				else if (rmcptr->mc_type == DITTO)
					status = linstr(rstr = patmatch);
				else
					status = linstr(rstr = fixnull(grpmatch[rmcptr->u.group_no]));
				replen += strlen(rstr);
				rmcptr++;
			}
		}
		else
#endif
		{
			status = linstr(instr);
			replen = strlen(instr);
		}

	return (status);
}
#if MAGIC
/*
 * rmcstr -- Set up the replacement 'magic' array.  Note that if there
 *	are no meta-characters encountered in the replacement string,
 *	the array is never actually created - we will just use the
 *	character array rpat[] as the replacement string.
 */
int PASCAL NEAR rmcstr()
{
	RMC	*rmcptr;
	char	*patptr;
	int	pchr;
	int	status = TRUE;
	int	mj;

	patptr = (char *) &rpat[0];
	rmcptr = &rmcpat[0];
	mj = 0;
	rmagical = FALSE;

	while (*patptr && status == TRUE) {
		switch (*patptr) {
		case MC_DITTO:

			/* If there were non-magical characters in
			 * the string before reaching this character
			 * plunk it in the replacement array before
			 * processing the current meta-character.
			 */
			if (mj != 0) {
				rmcptr->mc_type = LITSTRING;
				if ((rmcptr->u.rstr = room(mj + 1)) == NULL) {
					mlabort(TEXT94);
/*							"%%Out of memory" */
					status = FALSE;
					break;
				}
				bytecopy(rmcptr->u.rstr, patptr - mj, mj);
				rmcptr++;
				mj = 0;
			}
			rmcptr->mc_type = DITTO;
			rmcptr++;
			rmagical = TRUE;
			break;

		case MC_ESC:
			pchr = *(patptr + 1);	/* peek at next char.*/
			if (pchr <= '9' && pchr >= '1') {
				if (mj != 0) {
					rmcptr->mc_type = LITSTRING;
					if ((rmcptr->u.rstr = room(mj + 1)) == NULL) {
						mlabort(TEXT94);
/*							"%%Out of memory" */
						status = FALSE;
						break;
					}
					bytecopy(rmcptr->u.rstr, patptr - mj, mj);
					rmcptr++;
					mj = 0;
				}
				rmcptr->mc_type = GROUP;
				rmcptr->u.group_no = pchr - '0';
				patptr++;
			}
			else
			{
				rmcptr->mc_type = LITSTRING;

				/* We room mj plus two here, instead
				 * of one, because we have to count the
				 * current character.
				 */
				if ((rmcptr->u.rstr = room(mj + 2)) == NULL) {
					mlabort(TEXT94);
/*						"%%Out of memory" */
					status = FALSE;
					break;
				}

				bytecopy(rmcptr->u.rstr, patptr - mj, mj + 1);

				/* If MC_ESC is not the last character
				 * in the string, find out what it is
				 * escaping, and overwrite the last
				 * character with it.
				 */
				if (pchr != '\0') {
					*((rmcptr->u.rstr) + mj) = pchr;
					patptr++;
				}
				mj = 0;
			}

			rmcptr++;
			rmagical = TRUE;
			break;

		default:
			mj++;
		}
		patptr++;
	}

	if (rmagical && mj > 0) {
		rmcptr->mc_type = LITSTRING;
		if ((rmcptr->u.rstr = room(mj + 1)) == NULL) {
			mlabort(TEXT94);
/*				"%%Out of memory" */
			status = FALSE;
		}
		bytecopy(rmcptr->u.rstr, patptr - mj, mj);
		rmcptr++;
	}

	rmcptr->mc_type = MCNIL;
#if DEBUG_SEARCH
	rmc_list(0,0);
#endif
	return (status);
}

/*
 * rmcclear -- Free up any strings, and MCNIL the RMC array.
 */
VOID PASCAL NEAR rmcclear()
{
	register RMC	*rmcptr;

	rmcptr = &rmcpat[0];

	while (rmcptr->mc_type != MCNIL) {
		if (rmcptr->mc_type == LITSTRING)
			free(rmcptr->u.rstr);
		rmcptr++;
	}

	rmcpat[0].mc_type = MCNIL;
	rmagical = FALSE;
	if (oldpatmatch != NULL)
		free(oldpatmatch);
	oldpatmatch = NULL;
}
#endif
