/*
 *		Search commands.
 * The functions in this file implement the search commands (both plain and 
 * incremental searches are supported) and the query-replace command.
 *
 * The plain old search code is part of the original MicroEMACS "distribution".
 * The incremental search code and the query-replace code is by Rich Ellison.
 */

#include "def.h"

#ifndef NO_MACRO
#include "macro.h"
#endif /* !NO_MACRO */

#define SRCH_BEGIN	(0)	/* Search sub-codes.	 */
#define SRCH_FORW	(-1)
#define SRCH_BACK	(-2)
#define SRCH_NOPR	(-3)
#define SRCH_ACCM	(-4)
#define SRCH_MARK	(-5)

typedef struct {
	int	 s_code;
	LINE	*s_dotp;
	int	 s_doto;
} SRCHCOM;

static int	isearch		__P((int));
static VOID	is_cpush	__P((int));
static VOID	is_lpush	__P((void));
static VOID	is_pop		__P((void));
static int	is_peek		__P((void));
static VOID	is_undo		__P((int *, int *));
static int	is_find		__P((int));
static VOID	is_prompt	__P((int, int, int));
static VOID	is_dspl		__P((char *, int));
static int	eq		__P((int, int));

static SRCHCOM	cmds[NSRCH];
static int	cip;

int		srch_lastdir = SRCH_NOPR;	/* Last search flags.	 */

/*
 * Search forward.  Get a search string from the user, and search for it
 * starting at ".".  If found, "." gets moved to just after the matched 
 * characters, and display does all the hard stuff.  If not found, it just 
 * prints a message.
 */
/* ARGSUSED */
int
forwsearch(f, n)
	int f, n;
{
	int	s;

	if ((s = readpattern("Search")) != TRUE)
		return s;
	if (forwsrch() == FALSE) {
		ewprintf("Search failed: \"%s\"", pat);
		return FALSE;
	}
	srch_lastdir = SRCH_FORW;
	return TRUE;
}

/*
 * Reverse search.  Get a search string from the user, and search, starting 
 * at "." and proceeding toward the front of the buffer.  If found "." is 
 * left pointing at the first character of the pattern [the last character 
 * that was matched].
 */
/* ARGSUSED */
int
backsearch(f, n)
	int f, n;
{
	int	s;

	if ((s = readpattern("Search backward")) != TRUE)
		return (s);
	if (backsrch() == FALSE) {
		ewprintf("Search failed: \"%s\"", pat);
		return FALSE;
	}
	srch_lastdir = SRCH_BACK;
	return TRUE;
}

/*
 * Search again, using the same search string and direction as the last 
 * search command. The direction has been saved in "srch_lastdir", so you 
 * know which way to go.
 */
/* ARGSUSED */
int
searchagain(f, n)
	int f, n;
{
	if (srch_lastdir == SRCH_FORW) {
		if (forwsrch() == FALSE) {
			ewprintf("Search failed: \"%s\"", pat);
			return FALSE;
		}
		return TRUE;
	}
	if (srch_lastdir == SRCH_BACK) {
		if (backsrch() == FALSE) {
			ewprintf("Search failed: \"%s\"", pat);
			return FALSE;
		}
		return TRUE;
	}
	ewprintf("No last search");
	return FALSE;
}

/*
 * Use incremental searching, initially in the forward direction.  
 * isearch ignores any explicit arguments.
 */
/* ARGSUSED */
int
forwisearch(f, n)
	int f, n;
{
	return isearch(SRCH_FORW);
}

/*
 * Use incremental searching, initially in the reverse direction.
 * isearch ignores any explicit arguments.
 */
/* ARGSUSED */
int
backisearch(f, n)
	int f, n;
{
	return isearch(SRCH_BACK);
}

/*
 * Incremental Search.
 *	dir is used as the initial direction to search.
 *	^S	switch direction to forward
 *	^R	switch direction to reverse
 *	^Q	quote next character (allows searching for ^N etc.)
 *	<ESC>	exit from Isearch
 *	<DEL>	undoes last character typed. (tricky job to do this correctly).
 *	other ^ exit search, don't set mark
 *	else	accumulate into search string
 */
static int
isearch(dir)
	int dir;
{
	LINE	*clp;

	int	 c;
	int	 cbo;
	int	 success;
	int	 pptr;

	char	 opat[NPAT];

#ifndef NO_MACRO
	if (macrodef) {
		ewprintf("Can't isearch in macro");
		return FALSE;
	}
#endif /* !NO_MACRO */
	for (cip = 0; cip < NSRCH; cip++)
		cmds[cip].s_code = SRCH_NOPR;

	(VOID)strcpy(opat, pat);
	cip = 0;
	pptr = -1;
	clp = curwp->w_dotp;
	cbo = curwp->w_doto;
	is_lpush();
	is_cpush(SRCH_BEGIN);
	success = TRUE;
	is_prompt(dir, TRUE, success);

	for (;;) {
		update();

		switch (c = getkey(FALSE)) {
		case CCHR('['):
			srch_lastdir = dir;
			curwp->w_markp = clp;
			curwp->w_marko = cbo;
			ewprintf("Mark set");
			return (TRUE);
		case CCHR('G'):
			if (success != TRUE) {
				while (is_peek() == SRCH_ACCM)
					is_undo(&pptr, &dir);
				success = TRUE;
				is_prompt(dir, pptr < 0, success);
				break;
			}
			curwp->w_dotp = clp;
			curwp->w_doto = cbo;
			curwp->w_flag |= WFMOVE;
			srch_lastdir = dir;
			(VOID)ctrlg(FFRAND, 0);
			(VOID)strcpy(pat, opat);
			return ABORT;
		case CCHR(']'):
		case CCHR('S'):
			if (dir == SRCH_BACK) {
				dir = SRCH_FORW;
				is_lpush();
				is_cpush(SRCH_FORW);
				success = TRUE;
			}
			if (success == FALSE && dir == SRCH_FORW)
				break;
			is_lpush();
			pptr = strlen(pat);
			(VOID)forwchar(FFRAND, 1);
			if (is_find(SRCH_FORW) != FALSE)
				is_cpush(SRCH_MARK);
			else {
				(VOID)backchar(FFRAND, 1);
				ttbeep();
				success = FALSE;
			}
			is_prompt(dir, pptr < 0, success);
			break;
		case CCHR('R'):
			if (dir == SRCH_FORW) {
				dir = SRCH_BACK;
				is_lpush();
				is_cpush(SRCH_BACK);
				success = TRUE;
			}
			if (success == FALSE && dir == SRCH_BACK)
				break;
			is_lpush();
			pptr = strlen(pat);
			(VOID)backchar(FFRAND, 1);
			if (is_find(SRCH_BACK) != FALSE)
				is_cpush(SRCH_MARK);
			else {
				(VOID)forwchar(FFRAND, 1);
				ttbeep();
				success = FALSE;
			}
			is_prompt(dir, pptr < 0, success);
			break;
		case CCHR('H'):
		case CCHR('?'):
			is_undo(&pptr, &dir);
			if (is_peek() != SRCH_ACCM)
				success = TRUE;
			is_prompt(dir, pptr < 0, success);
			break;
		case CCHR('\\'):
		case CCHR('Q'):
			c = (char)getkey(FALSE);
			goto addchar;
		case CCHR('M'):
			c = CCHR('J');
			goto addchar;
		default:
			if (ISCTRL(c)) {
				ungetkey(c);
				curwp->w_markp = clp;
				curwp->w_marko = cbo;
				ewprintf("Mark set");
				curwp->w_flag |= WFMOVE;
				return TRUE;
			}	/* and continue */
		case CCHR('I'):
		case CCHR('J'):
	addchar:
			if (pptr == -1)
				pptr = 0;
			if (pptr == 0)
				success = TRUE;
			pat[pptr++] = c;
			if (pptr == NPAT) {
				ewprintf("Pattern too long");
				return FALSE;
			}
			pat[pptr] = '\0';
			is_lpush();
			if (success != FALSE) {
				if (is_find(dir) != FALSE)
					is_cpush(c);
				else {
					success = FALSE;
					ttbeep();
					is_cpush(SRCH_ACCM);
				}
			} else
				is_cpush(SRCH_ACCM);
			is_prompt(dir, FALSE, success);
		}
	}
	/* NOTREACHED */
}

static VOID
is_cpush(cmd)
	int cmd;
{
	if (++cip >= NSRCH)
		cip = 0;
	cmds[cip].s_code = cmd;
}

static VOID
is_lpush()
{
	int	ctp;

	ctp = cip + 1;
	if (ctp >= NSRCH)
		ctp = 0;
	cmds[ctp].s_code = SRCH_NOPR;
	cmds[ctp].s_doto = curwp->w_doto;
	cmds[ctp].s_dotp = curwp->w_dotp;
}

static VOID
is_pop()
{
	if (cmds[cip].s_code != SRCH_NOPR) {
		curwp->w_doto = cmds[cip].s_doto;
		curwp->w_dotp = cmds[cip].s_dotp;
		curwp->w_flag |= WFMOVE;
		cmds[cip].s_code = SRCH_NOPR;
	}
	if (--cip <= 0)
		cip = NSRCH - 1;
}

static int
is_peek()
{
	return cmds[cip].s_code;
}

/* this used to always return TRUE (the return value was checked) */
static VOID
is_undo(pptr, dir)
	int *pptr, *dir;
{
	int	redo = FALSE;

	switch (cmds[cip].s_code) {
	case SRCH_BEGIN:
	case SRCH_NOPR:
		*pptr = -1;
	case SRCH_MARK:
		break;
	case SRCH_FORW:
		*dir = SRCH_BACK;
		redo = TRUE;
		break;
	case SRCH_BACK:
		*dir = SRCH_FORW;
		redo = TRUE;
		break;
	case SRCH_ACCM:
	default:
		*pptr -= 1;
		if (*pptr < 0)
			*pptr = 0;
		pat[*pptr] = '\0';
		break;
	}
	is_pop();
	if (redo)
		is_undo(pptr, dir);
}

static int
is_find(dir)
	int	dir;
{
	int	 plen, odoto;
	LINE	*odotp;

	odoto = curwp->w_doto;
	odotp = curwp->w_dotp;
	plen = strlen(pat);
	if (plen != 0) {
		if (dir == SRCH_FORW) {
			(VOID)backchar(FFARG | FFRAND, plen);
			if (forwsrch() == FALSE) {
				curwp->w_doto = odoto;
				curwp->w_dotp = odotp;
				return FALSE;
			}
			return TRUE;
		}
		if (dir == SRCH_BACK) {
			(VOID)forwchar(FFARG | FFRAND, plen);
			if (backsrch() == FALSE) {
				curwp->w_doto = odoto;
				curwp->w_dotp = odotp;
				return FALSE;
			}
			return TRUE;
		}
		ewprintf("bad call to is_find");
		return FALSE;
	}
	return FALSE;
}

/*
 * If called with "dir" not one of SRCH_FORW or SRCH_BACK, this routine used 
 * to print an error message.  It also used to return TRUE or FALSE, depending 
 * on if it liked the "dir".  However, none of the callers looked at the 
 * status, so I just made the checking vanish.
 */
static VOID
is_prompt(dir, flag, success)
	int dir, flag, success;
{
	if (dir == SRCH_FORW) {
		if (success != FALSE)
			is_dspl("I-search", flag);
		else
			is_dspl("Failing I-search", flag);
	} else if (dir == SRCH_BACK) {
		if (success != FALSE)
			is_dspl("I-search backward", flag);
		else
			is_dspl("Failing I-search backward", flag);
	} else
		ewprintf("Broken call to is_prompt");
}

/*
 * Prompt writing routine for the incremental search.  The "prompt" is just 
 * a string. The "flag" determines whether pat should be printed.
 */
static VOID
is_dspl(prompt, flag)
	char *prompt;
	int flag;
{
	if (flag != FALSE)
		ewprintf("%s: ", prompt);
	else
		ewprintf("%s: %s", prompt, pat);
}

/*
 * Query Replace.
 *	Replace strings selectively.  Does a search and replace operation.
 */
/* ARGSUSED */
int
queryrepl(f, n)
	int f, n;
{
	int	s;
	int	rcnt = 0;		/* replacements made so far	*/
	int	plen;			/* length of found string	*/
	char	news[NPAT];		/* replacement string		*/

#ifndef NO_MACRO
	if (macrodef) {
		ewprintf("Can't query replace in macro");
		return FALSE;
	}
#endif /* !NO_MACRO */

	if ((s = readpattern("Query replace")) != TRUE)
		return (s);
	if ((s = ereply("Query replace %s with: ", news, NPAT, pat)) == ABORT)
		return (s);
	if (s == FALSE)
		news[0] = '\0';
	ewprintf("Query replacing %s with %s:", pat, news);
	plen = strlen(pat);

	/*
	 * Search forward repeatedly, checking each time whether to insert
	 * or not.  The "!" case makes the check always true, so it gets put
	 * into a tighter loop for efficiency.
	 */
	while (forwsrch() == TRUE) {
retry:
		update();
		switch (getkey(FALSE)) {
		case ' ':
			if (lreplace((RSIZE)plen, news, f) == FALSE)
				return (FALSE);
			rcnt++;
			break;
		case '.':
			if (lreplace((RSIZE)plen, news, f) == FALSE)
				return (FALSE);
			rcnt++;
			goto stopsearch;
		/* ^G or ESC */
		case CCHR('G'):
			(VOID)ctrlg(FFRAND, 0);
		case CCHR('['):
			goto stopsearch;
		case '!':
			do {
				if (lreplace((RSIZE)plen, news, f) == FALSE)
					return (FALSE);
				rcnt++;
			} while (forwsrch() == TRUE);
			goto stopsearch;
		case CCHR('H'):
		/* To not replace */
		case CCHR('?'):
			break;
		default:
			ewprintf("<SP> replace, [.] rep-end, <DEL> don't, [!] repl rest <ESC> quit");
			goto retry;
		}
	}
stopsearch:
	curwp->w_flag |= WFHARD;
	update();
	if (rcnt == 0)
		ewprintf("(No replacements done)");
	else if (rcnt == 1)
		ewprintf("(1 replacement done)");
	else
		ewprintf("(%d replacements done)", rcnt);
	return TRUE;
}

/*
 * This routine does the real work of a forward search.  The pattern is sitting 
 * in the external variable "pat".  If found, dot is updated, the window system
 * is notified of the change, and TRUE is returned.  If the string isn't found, 
 * FALSE is returned.
 */
int
forwsrch()
{
	LINE	*clp, *tlp;
	int	 cbo, tbo, c;
	char	*pp;

	clp = curwp->w_dotp;
	cbo = curwp->w_doto;
	for (;;) {
		if (cbo == llength(clp)) {
			if ((clp = lforw(clp)) == curbp->b_linep)
				break;
			cbo = 0;
			c = CCHR('J');
		} else
			c = lgetc(clp, cbo++);
		if (eq(c, pat[0]) != FALSE) {
			tlp = clp;
			tbo = cbo;
			pp = &pat[1];
			while (*pp != 0) {
				if (tbo == llength(tlp)) {
					tlp = lforw(tlp);
					if (tlp == curbp->b_linep)
						goto fail;
					tbo = 0;
					c = CCHR('J');
				} else
					c = lgetc(tlp, tbo++);
				if (eq(c, *pp++) == FALSE)
					goto fail;
			}
			curwp->w_dotp = tlp;
			curwp->w_doto = tbo;
			curwp->w_flag |= WFMOVE;
			return TRUE;
		}
fail:		;
	}
	return FALSE;
}

/*
 * This routine does the real work of a backward search.  The pattern is 
 * sitting in the external variable "pat".  If found, dot is updated, the 
 * window system is notified of the change, and TRUE is returned.  If the
 * string isn't found, FALSE is returned.
 */
int
backsrch()
{
	LINE	*clp, *tlp;
	int	 cbo, tbo, c;
	char	*epp, *pp;

	for (epp = &pat[0]; epp[1] != 0; ++epp);
	clp = curwp->w_dotp;
	cbo = curwp->w_doto;
	for (;;) {
		if (cbo == 0) {
			clp = lback(clp);
			if (clp == curbp->b_linep)
				return FALSE;
			cbo = llength(clp) + 1;
		}
		if (--cbo == llength(clp))
			c = CCHR('J');
		else
			c = lgetc(clp, cbo);
		if (eq(c, *epp) != FALSE) {
			tlp = clp;
			tbo = cbo;
			pp = epp;
			while (pp != &pat[0]) {
				if (tbo == 0) {
					tlp = lback(tlp);
					if (tlp == curbp->b_linep)
						goto fail;
					tbo = llength(tlp) + 1;
				}
				if (--tbo == llength(tlp))
					c = CCHR('J');
				else
					c = lgetc(tlp, tbo);
				if (eq(c, *--pp) == FALSE)
					goto fail;
			}
			curwp->w_dotp = tlp;
			curwp->w_doto = tbo;
			curwp->w_flag |= WFMOVE;
			return TRUE;
		}
fail:		;
	}
	/* NOTREACHED */
}

/*
 * Compare two characters.  The "bc" comes from the buffer.  It has its case 
 * folded out. The "pc" is from the pattern.
 */
static int
eq(bc, pc)
	int bc, pc;
{
	bc = CHARMASK(bc);
	pc = CHARMASK(pc);
	if (bc == pc)
		return TRUE;
	if (ISUPPER(bc))
		return TOLOWER(bc) == pc;
	if (ISUPPER(pc))
		return bc == TOLOWER(pc);
	return FALSE;
}

/*
 * Read a pattern.  Stash it in the external variable "pat".  The "pat" is not 
 * updated if the user types in an empty line.  If the user typed an empty 
 * line, and there is no old pattern, it is an error.  Display the old pattern, 
 * in the style of Jeff Lomicka.  There is some do-it-yourself control 
 * expansion.
 */
int
readpattern(prompt)
	char *prompt;
{
	int	s;
	char	tpat[NPAT];

	if (tpat[0] == '\0')
		s = ereply("%s: ", tpat, NPAT, prompt);
	else
		s = ereply("%s: (default %s) ", tpat, NPAT, prompt, pat);

	/* specified */
	if (s == TRUE)
		(VOID) strcpy(pat, tpat);
	/* CR, but old one */
	else if (s == FALSE && pat[0] != 0)
		s = TRUE;
	return s;
}