/* Copyright (c) 2003-2004 krzYszcz and others.
 * For information on usage and redistribution, and for a DISCLAIMER OF ALL
 * WARRANTIES, see the file, "LICENSE.txt," in this distribution.  */

#include <stdio.h>
#include <string.h>
#ifdef UNIX
#include <unistd.h>
#endif
#ifdef NT
#include <io.h>
#endif
#include "m_pd.h"
#include "g_canvas.h"
#include "common/loud.h"
#include "common/grow.h"
#include "common/props.h"
#include "scriptlet.h"

//#define SCRIPTLET_DEBUG

#define SCRIPTLET_INISIZE   1024
#define SCRIPTLET_MARGIN      64
#define SCRIPTLET_MAXARGS      9  /* do not increase (parser's constraint) */
#define SCRIPTLET_MAXPUSH  20000  /* cf SOCKSIZE in t_tkcmd.c, LATER revisit */

enum { SCRIPTLET_CVOK, SCRIPTLET_CVUNKNOWN, SCRIPTLET_CVMISSING };

struct _scriptlet
{
    t_pd             *s_owner;
    t_glist          *s_glist;     /* containing glist (empty allowed) */
    t_symbol         *s_rptarget;  /* reply target */
    t_symbol         *s_cbtarget;  /* callback target */
    t_symbol         *s_item;
    t_scriptlet_cvfn  s_cvfn;      /* if empty, passing resolveall is a bug */
    t_canvas         *s_cv;        /* as returned by cvfn */
    int               s_cvstate;
    int     s_locked;  /* append lock, for filtering, when reading from file */
    int     s_size;
    char   *s_buffer;
    char    s_bufini[SCRIPTLET_INISIZE];
    char   *s_head;       /* ptr to the command part of a scriptlet */
    char   *s_tail;
    char    s_separator;  /* current separator, set before a new token */
    int     s_ac;                     /* the actual count */
    t_atom  s_av[SCRIPTLET_MAXARGS];  /* always padded with zeros (if used) */
};

static t_canvas *scriptlet_canvasvalidate(t_scriptlet *sp, int visedonly)
{
    t_canvas *cv;
    if (sp->s_cvstate == SCRIPTLET_CVUNKNOWN)
    {
	if (sp->s_cvfn)
	    cv = sp->s_cv = sp->s_cvfn(sp->s_owner);
	else
	{
	    bug("scriptlet_canvasvalidate");
	    return (0);
	}
	if (cv && (!visedonly || glist_isvisible(cv)))
	    sp->s_cvstate = SCRIPTLET_CVOK;
	else
	    sp->s_cvstate = SCRIPTLET_CVMISSING;
    }
    else cv = sp->s_cv;
    return (sp->s_cvstate == SCRIPTLET_CVOK ? cv : 0);
}

static int scriptlet_ready(t_scriptlet *sp)
{
    int len = sp->s_tail - sp->s_head;
    if (len > 0 && *sp->s_head && sp->s_cvstate != SCRIPTLET_CVMISSING)
    {
	if (len < SCRIPTLET_MAXPUSH)
	    return (1);
	else
	    loud_error(sp->s_owner,
		       "scriptlet too long to be pushed (%d bytes)", len);
    }
    return (0);
}

static int scriptlet_doappend(t_scriptlet *sp, char *buf)
{
    if (buf && !sp->s_locked)
    {
	int nprefix = sp->s_head - sp->s_buffer;
	int nused = sp->s_tail - sp->s_buffer;
	int newsize = nused + strlen(buf) + SCRIPTLET_MARGIN;
	if (newsize > sp->s_size)
	{
	    int nrequested = newsize;
	    sp->s_buffer = grow_withdata(&nrequested, &nused,
					 &sp->s_size, sp->s_buffer,
					 SCRIPTLET_INISIZE, sp->s_bufini,
					 sizeof(*sp->s_buffer));
	    if (nrequested != newsize)
	    {
		scriptlet_reset(sp);
		return (0);
	    }
	    sp->s_head = sp->s_buffer + nprefix;
	    sp->s_tail = sp->s_buffer + nused;
	}
	if (sp->s_separator && sp->s_tail > sp->s_head)
	    *sp->s_tail++ = sp->s_separator;
	*sp->s_tail = 0;
	strcpy(sp->s_tail, buf);
	sp->s_tail += strlen(sp->s_tail);
    }
    sp->s_separator = 0;
    return (1);
}

static char *scriptlet_dedot(t_scriptlet *sp, char *ibuf, char *obuf,
			     int resolveall, int visedonly,
			     int ac, t_atom *av, t_props *argprops)
{
    int len = 0;
    switch (*ibuf)
    {
    case '#':
	/* ac is ignored -- assuming av is padded to SCRIPTLET_MAXARGS atoms */
	if (resolveall)
	{
	    int which = ibuf[1] - '1';
	    if (which >= 0 && which < SCRIPTLET_MAXARGS)
	    {
		if (av)
		{
		    if (av[which].a_type == A_FLOAT)
		    {
			sprintf(obuf, "%g", av[which].a_w.w_float);
			len = 2;
		    }
		    else if (av[which].a_type == A_SYMBOL)
		    {
			strcpy(obuf, av[which].a_w.w_symbol->s_name);
			len = 2;
		    }
		}
	    }
	    else if (argprops)
	    {
		char *iptr, *optr, c;
		int cnt;
		for (iptr = ibuf + 1, c = *iptr, cnt = 1; c;
		     iptr++, c = *iptr, cnt++)
		{
		    if ((c < 'A' || c > 'Z') && (c < 'a' || c > 'z'))
		    {
			*iptr = 0;
			break;
		    }
		}
		if (optr = props_getvalue(argprops, ibuf + 1))
		{
		    strcpy(obuf, optr);
		    len = cnt;
		}
		if (c) *iptr = c;
	    }
	}
	break;
    case '-':
	if (resolveall && sp->s_item)
	{
	    t_canvas *cv;
	    if (cv = scriptlet_canvasvalidate(sp, visedonly))
	    {
		sprintf(obuf, ".x%x.c.%s%x", (int)cv, sp->s_item->s_name,
			(int)sp->s_owner);
		len = 1;
	    }
	}
	break;
    case '^':
	if (resolveall)
	{
	    t_canvas *cv;
	    if (cv = scriptlet_canvasvalidate(sp, visedonly))
	    {
		sprintf(obuf, ".x%x", (int)cv);
		len = 1;
	    }
	}
	break;
    case '|':
	if (resolveall)
	{
	    strcpy(obuf, sp->s_cbtarget->s_name);
	    len = 1;
	}
	break;
    case '~':  /* FIXME, the dot-tilde stuff is purely experimental. */
	if (resolveall)
	{
	    t_canvas *cv;
	    if (cv = scriptlet_canvasvalidate(sp, 0))
	    {
		t_glist *glist;
		if (!strncmp(&ibuf[1], "tag", 3))
		{
		    t_rtext *rt;
		    glist = cv->gl_owner;
		    if (glist && glist_isvisible(glist) && glist->gl_editor
			&& (rt = glist_findrtext(glist, (t_object *)cv)))
			sprintf(obuf, "%s", rtext_gettag(rt));
		    else
			obuf[0] = 0;
		    len = 4;
		}
		else if (!strncmp(&ibuf[1], "parent", 6))
		{
		    glist = cv->gl_owner;
		    if (glist && glist_isvisible(glist))
			sprintf(obuf, ".x%x", (int)glist);
		    else
			obuf[0] = 0;
		    len = 7;
		}
		else if (!strncmp(&ibuf[1], "root", 4))
		{
		    glist = canvas_getrootfor(cv);
		    if (glist && glist_isvisible(glist))
			sprintf(obuf, ".x%x", (int)glist);
		    else
			obuf[0] = 0;
		    len = 5;
		}
		else if (!strncmp(&ibuf[1], "owner", 5))
		{
		    if (glist = canvas_getrootfor(cv))
			glist = glist->gl_owner;
		    if (glist && glist_isvisible(glist))
			sprintf(obuf, ".x%x", (int)glist);
		    else
			obuf[0] = 0;
		    len = 6;
		}
		else if (!strncmp(&ibuf[1], "top", 3))
		{
		    glist = cv;
		    while (glist->gl_owner) glist = glist->gl_owner;
		    if (glist && glist_isvisible(glist))
			sprintf(obuf, ".x%x", (int)glist);
		    else
			obuf[0] = 0;
		    len = 4;
		}
		/* LATER find out when gl_<coords> are updated,
		   think how to better sync them to Tk. */
		else if (!strncmp(&ibuf[1], "x1", 2))
		{
		    sprintf(obuf, "%d", cv->gl_screenx1);
		    len = 3;
		}
		else if (!strncmp(&ibuf[1], "x2", 2))
		{
		    sprintf(obuf, "%d", cv->gl_screenx2);
		    len = 3;
		}
		else if (!strncmp(&ibuf[1], "y1", 2))
		{
		    sprintf(obuf, "%d", cv->gl_screeny1);
		    len = 3;
		}
		else if (!strncmp(&ibuf[1], "y2", 2))
		{
		    sprintf(obuf, "%d", cv->gl_screeny2);
		    len = 3;
		}
		else if (!strncmp(&ibuf[1], "edit", 4))
		{
		    sprintf(obuf, "%d", cv->gl_edit);
		    len = 5;
		}
		else if (!strncmp(&ibuf[1], "gop", 3))
		{
		    sprintf(obuf, "%d", glist_isgraph(cv));
		    len = 4;
		}
		else if (!strncmp(&ibuf[1], "dir", 3))
		{
		    sprintf(obuf, "%s", canvas_getdir(cv)->s_name);
		    len = 4;
		}
		else loud_error(sp->s_owner, "bad field '%s'", &ibuf[1]);
	    }
	}
	break;
    case '`':
	sprintf(obuf, "\\");
	len = 1;
	break;
    case ':':
	sprintf(obuf, ";");
	len = 1;
	break;
    case '(':
	sprintf(obuf, "{");
	len = 1;
	break;
    case ')':
	sprintf(obuf, "}");
	len = 1;
	break;
    case '<':
	if (resolveall)
	{
	    if (ibuf[1] == ':')
	    {
		sprintf(obuf, "{pd [concat ");
		len = 2;
	    }
	    else if (ibuf[1] == '|')
	    {
		sprintf(obuf, "{pd [concat %s ", sp->s_rptarget->s_name);
		len = 2;
	    }
	    else
	    {
		sprintf(obuf, "{pd [concat %s _cb ", sp->s_cbtarget->s_name);
		len = 1;
	    }
	}
	break;
    case '>':
	if (resolveall)
	{
	    sprintf(obuf, "\\;]}");
	    len = 1;
	}
	break;
    }
    return (len ? ibuf + len : 0);
}

int scriptlet_isempty(t_scriptlet *sp)
{
    return (!(sp->s_tail > sp->s_head && *sp->s_head));
}

void scriptlet_reset(t_scriptlet *sp)
{
    sp->s_cvstate = SCRIPTLET_CVUNKNOWN;
    sp->s_locked = 0;
    sp->s_separator = 0;
    strcpy(sp->s_buffer, "namespace eval ::toxy {\
 proc query {} {set ::toxy::reply [\n");
    sp->s_head = sp->s_tail = sp->s_buffer + strlen(sp->s_buffer);
}

void scriptlet_prealloc(t_scriptlet *sp, int sz, int mayshrink)
{
    if (sz < SCRIPTLET_INISIZE)
	sz = SCRIPTLET_INISIZE;
    if (sz < sp->s_size && mayshrink)
    {
	if (sp->s_buffer != sp->s_bufini)
	    freebytes(sp->s_buffer, sp->s_size * sizeof(*sp->s_buffer));
	else
	    bug("scriptlet_prealloc");
	sp->s_size = SCRIPTLET_INISIZE;
	sp->s_buffer = sp->s_bufini;
    }
    if (sz > sp->s_size)
	sp->s_buffer = grow_nodata(&sz, &sp->s_size, sp->s_buffer,
				   SCRIPTLET_INISIZE, sp->s_bufini,
				   sizeof(*sp->s_buffer));
    scriptlet_reset(sp);
}

static int scriptlet_addstring(t_scriptlet *sp, char *ibuf,
			       int resolveall, int visedonly,
			       int ac, t_atom *av, t_props *argprops)
{
    int result = 1;
    char *bp = ibuf, *ep = ibuf, *ep1;
    char dotbuf[256];  /* FIXME requires a growable per-scriptlet buffer. */
    if (!sp->s_separator)
	sp->s_separator = ' ';
    while (*ep)
    {
	if (*ep == '.'
	    && (ep1 = scriptlet_dedot(sp, ep + 1, dotbuf,
				      resolveall, visedonly, ac, av, argprops)))
	{
	    *ep = 0;
	    if (!(result = scriptlet_doappend(sp, bp)))
		break;
	    *ep = '.';
	    if (!(result = scriptlet_doappend(sp, dotbuf)))
		break;
	    bp = ep = ep1;
	}
	else ep++;
    }
    if (result)
	result = scriptlet_doappend(sp, bp);
    sp->s_separator = 0;
    return (result);
}

static int scriptlet_addfloat(t_scriptlet *sp, t_float f)
{
    char buf[64];
    if (!sp->s_separator)
	sp->s_separator = ' ';
    sprintf(buf, "%g ", f);
    return (scriptlet_doappend(sp, buf));
}

int scriptlet_add(t_scriptlet *sp,
		  int resolveall, int visedonly, int ac, t_atom *av)
{
    while (ac--)
    {
	int result = 1;
	if (av->a_type == A_SYMBOL)
	    result = scriptlet_addstring(sp, av->a_w.w_symbol->s_name,
					 resolveall, visedonly, 0, 0, 0);
	else if (av->a_type == A_FLOAT)
	    result = scriptlet_addfloat(sp, av->a_w.w_float);
	if (!result)
	    return (0);
	av++;
    }
    return (1);
}

void scriptlet_setseparator(t_scriptlet *sp, char c)
{
    sp->s_separator = c;
}

void scriptlet_push(t_scriptlet *sp)
{
    if (scriptlet_ready(sp))
    {
	char *tail = sp->s_tail;
	strcpy(tail, "\n");
	sys_gui(sp->s_head);
	*tail = 0;
    }
}

void scriptlet_qpush(t_scriptlet *sp)
{
    if (scriptlet_ready(sp))
    {
	char buf[MAXPDSTRING];
	char *tail = sp->s_tail;
	/* Could not find any other way, than to postpone processing of the
	   query, after everything which might have been glued to our tail,
	   is evaluated.  Otherwise, any command arriving later, during
	   blocking of the query (e.g. in a Tk dialog), would be evaluated
	   prior to our tail, via Tcl_DoOneEvent().  We postpone also the
	   setup step (defining the query proc), in order to be able to
	   handle several queries at once.  All this is far from ideal --
	   the sequence "query this, tot that", is swapped, unless written
	   as "query this, tot after 0 .(that.)", which is going to cause
	   much confusion...  LATER revisit.  Do not forget, that since
	   pd_readsocket() is not reentrant, sys_gui()d commands should never
	   enter event loop directly by blocking on a dialog, vwait, etc.,
	   because the pd_readsocket handler is event-driven on unix. */
	sys_gui("after 0 {\n");
	strcpy(tail, "]}}\n");
	sys_gui(sp->s_buffer);
	*tail = 0;
	sprintf(buf, "\
 if {[info tclversion] < 8.4} {\n\
  trace variable ::toxy::reply w \"::toxy::doreply %s\"\n\
 } else {\n\
  trace add variable ::toxy::reply write \"::toxy::doreply %s\"\n\
 }\n\
 ::toxy::query}\n", sp->s_rptarget->s_name, sp->s_rptarget->s_name);
	sys_gui(buf);
    }
}

/* Non-substituting -- LATER think if this is likely to cause any confusion.
   Especially, consider the widget_vis() vs. widget_update() case. */
void scriptlet_vpush(t_scriptlet *sp, char *varname)
{
    if (scriptlet_ready(sp))
    {
	char *tail = sp->s_tail;
	strcpy(tail, "}\n");
	sys_vgui("set ::toxy::%s { ", varname);
	sys_gui(sp->s_head);
	*tail = 0;
    }
}

int scriptlet_evaluate(t_scriptlet *insp, t_scriptlet *outsp, int visedonly,
		       int ac, t_atom *av, t_props *argprops)
{
    if (scriptlet_ready(insp))
    {
	t_atom *ap;
	int i;
	char *bp;
	char separator = 0;
	insp->s_ac = ac;
	for (i = 0, ap = insp->s_av; i < SCRIPTLET_MAXARGS; i++, ap++)
	{
	    if (ac)
	    {
		if (av->a_type == A_FLOAT ||
		    (av->a_type == A_SYMBOL && av->a_w.w_symbol))
		    *ap = *av;
		else
		    SETFLOAT(ap, 0);
		ac--; av++;
	    }
	    else SETFLOAT(ap, 0);
	}
	/* FIXME pregrowing of the transient scriptlet */
	scriptlet_reset(outsp);
	/* LATER abstract this into scriptlet_parse() */
	bp = insp->s_head;
	while (*bp)
	{
	    if (*bp == '\n')
		separator = '\n';
	    else if (*bp == ' ' || *bp == '\t')
	    {
		if (!separator) separator = ' ';
	    }
	    else
	    {
		int done = 1;
		char *ep = bp;
		char c = ' ';
		while (*++ep)
		{
		    if (*ep == ' ' || *bp == '\t' || *ep == '\n')
		    {
			done = 0;
			c = *ep;
			*ep = 0;
			break;
		    }
		}
		outsp->s_separator = separator;
		scriptlet_addstring(outsp, bp, 1, visedonly,
				    ac, insp->s_av, argprops);
		if (done)
		    break;
		*ep = c;
		bp = ep;
		separator = (c == '\t' ? ' ' : c);
	    }
	    bp++;
	}
	return (outsp->s_cvstate != SCRIPTLET_CVMISSING);
    }
    else return (0);
}

/* utility function to be used in a comment-parsing callback */
char *scriptlet_nextword(char *buf)
{
    while (*++buf)
    {
	if (*buf == ' ' || *buf == '\t')
	{
	    char *ptr = buf + 1;
	    while (*ptr == ' ' || *ptr == '\t') ptr++;
	    *buf = 0;
	    return (*ptr ? ptr : 0);
	}
    }
    return (0);
}

static int scriptlet_doread(t_scriptlet *sp, t_pd *caller, FILE *fp,
			    char *rc, char *builtin, t_scriptlet_cmntfn cmntfn)
{
    t_scriptlet *outsp = sp, *newsp;
    char buf[MAXPDSTRING];
    if (!caller) caller = sp->s_owner;
    while ((fp && !feof(fp) && fgets(buf, MAXPDSTRING - 1, fp))
	   || builtin)
    {
	char *ptr;
	if (builtin)
	{
	    int i;
	    for (i = 0, ptr = buf; i < MAXPDSTRING - 1; i++, ptr++)
	    {
		if ((*ptr = (*builtin ? *builtin : '\n')) == '\n')
		{
		    ptr[1] = 0;
		    if (*builtin) builtin++;
		    if (!*builtin) builtin = 0;
		    break;
		}
		else builtin++;
	    }
	}
	ptr = buf;
	while (*ptr == ' ' || *ptr == '\t') ptr++;
	if (*ptr == '#')
	{
	    if (cmntfn)
	    {
		char sel = *++ptr;
		if (sel && sel != '\n')
		{
		    ptr++;
		    while (*ptr == ' ' || *ptr == '\t') ptr++;
		    if (*ptr == '\n')
			*ptr = 0;
		    if (*ptr)
		    {
			char *ep = ptr + strlen(ptr) - 1;
			while (*ep == ' ' || *ep == '\t' || *ep == '\n')
			    ep--;
			ep[1] = 0;
		    }
		    newsp = cmntfn(caller, rc, sel, ptr);
		    if (newsp == SCRIPTLET_UNLOCK)
			outsp->s_locked = 0;
		    else if (newsp == SCRIPTLET_LOCK)
			outsp->s_locked = 1;
		    else if (newsp != outsp)
		    {
			outsp->s_locked = 0;
			scriptlet_reset(outsp = newsp);
		    }
		}
	    }
	}
	else if (*ptr && *ptr != '\n')
	    scriptlet_doappend(outsp, buf);
    }
    outsp->s_locked = 0;
    return (SCRIPTLET_OK);
}

/* Load particular section(s) from buffer (skip up to an unlocking comment,
   keep appending up to a locking comment, repeat). */
int scriptlet_rcparse(t_scriptlet *sp, t_pd *caller, char *rc, char *contents,
		      t_scriptlet_cmntfn cmntfn)
{
    int result;
    sp->s_locked = 1;  /* see scriptlet_doread() above for unlocking scheme */
    result = scriptlet_doread(sp, caller, 0, rc, contents, cmntfn);
    return (result);
}

int scriptlet_rcload(t_scriptlet *sp, t_pd *caller, char *rc, char *ext,
		     char *builtin, t_scriptlet_cmntfn cmntfn)
{
    int result;
    char filename[MAXPDSTRING], buf[MAXPDSTRING], *nameptr, *dir;
    int fd;
    if (sp->s_glist)
	dir = canvas_getdir(sp->s_glist)->s_name;
    else
	dir = "";  /* which means pwd, usually the same as at Pd startup... */
    if ((fd = open_via_path(dir, rc, ext, buf, &nameptr, MAXPDSTRING, 0)) < 0)
    {
	result = SCRIPTLET_NOFILE;
    }
    else
    {
	FILE *fp;
    	close(fd);
	if (nameptr != buf)
	{
	    strcpy(filename, buf);
	    strcat(filename, "/");
	    strcat(filename, nameptr);
	    sys_bashfilename(filename, filename);
	}
	else sys_bashfilename(nameptr, filename);
	if (fp = fopen(filename, "r"))
	{
	    result = scriptlet_doread(sp, caller, fp, rc, 0, cmntfn);
	    fclose(fp);
	}
	else
	{
	    bug("scriptlet_rcload");
	    result = SCRIPTLET_NOFILE;
	}
    }
    if (result != SCRIPTLET_OK)
    {
	scriptlet_doread(sp, caller, 0, rc, builtin, cmntfn);
    }
    return (result);
}

int scriptlet_read(t_scriptlet *sp, t_symbol *fn)
{
    int result;
    FILE *fp;
    char buf[MAXPDSTRING];
    post("loading scriptlet file \"%s\"", fn->s_name);
    if (sp->s_glist)
	canvas_makefilename(sp->s_glist, fn->s_name, buf, MAXPDSTRING);
    else
	strncpy(buf, fn->s_name, MAXPDSTRING);
    sys_bashfilename(buf, buf);
    if (fp = fopen(buf, "r"))
    {
	scriptlet_reset(sp);
	result = scriptlet_doread(sp, 0, fp, 0, 0, 0);
	fclose(fp);
    }
    else
    {
	loud_error(sp->s_owner, "error while loading file \"%s\"", fn->s_name);
    	result = SCRIPTLET_NOFILE;
    }
    return (result);
}

int scriptlet_write(t_scriptlet *sp, t_symbol *fn)
{
    int size = sp->s_tail - sp->s_head;
    if (size > 0 && *sp->s_head)
    {
	FILE *fp;
	char buf[MAXPDSTRING];
	post("saving scriptlet file \"%s\"", fn->s_name);
	if (sp->s_glist)
	    canvas_makefilename(sp->s_glist, fn->s_name, buf, MAXPDSTRING);
	else
	    strncpy(buf, fn->s_name, MAXPDSTRING);
	sys_bashfilename(buf, buf);
	if (fp = fopen(buf, "w"))
	{
	    int result = fwrite(sp->s_head, 1, size, fp);
	    fclose(fp);
	    if (result == size)
		return (SCRIPTLET_OK);
	}
	loud_error(sp->s_owner, "error while saving file \"%s\"", fn->s_name);
	return (fp ? SCRIPTLET_BADFILE : SCRIPTLET_NOFILE);
    }
    else
    {
	loud_warning(sp->s_owner, "scriptlet", "empty scriptlet not written");
	return (SCRIPTLET_IGNORED);
    }
}

char *scriptlet_getcontents(t_scriptlet *sp, int *lenp)
{
    *lenp = sp->s_tail - sp->s_head;
    return (sp->s_head);
}

char *scriptlet_getbuffer(t_scriptlet *sp, int *sizep)
{
    *sizep = sp->s_size;
    return (sp->s_buffer);
}

void scriptlet_setowner(t_scriptlet *sp, t_pd *owner)
{
    sp->s_owner = owner;
}

void scriptlet_clone(t_scriptlet *to, t_scriptlet *from)
{
    scriptlet_reset(to);
    to->s_separator = ' ';
    /* LATER add a flag to optionally use from's buffer with refcount */
    scriptlet_doappend(to, from->s_head);
}

void scriptlet_append(t_scriptlet *to, t_scriptlet *from)
{
    to->s_separator = ' ';
    scriptlet_doappend(to, from->s_head);
}

void scriptlet_free(t_scriptlet *sp)
{
    if (sp)
    {
	if (sp->s_buffer != sp->s_bufini)
	    freebytes(sp->s_buffer, sp->s_size * sizeof(*sp->s_buffer));
	freebytes(sp, sizeof(*sp));
    }
}

/* The parameter 'gl' (null accepted) is necessary, because the 's_glist'
   field, if implicitly set, would be dangerous (after a glist is gone)
   and confusing (current directory used for i/o of a global scriptlet). */
t_scriptlet *scriptlet_new(t_pd *owner, t_symbol *rptarget, t_symbol *cbtarget,
			   t_symbol *item, t_glist *gl, t_scriptlet_cvfn cvfn)
{
    t_scriptlet *sp = getbytes(sizeof(*sp));
    if (sp)
    {
	static int configured = 0;
	if (!configured)
	{
	    sys_gui("image create bitmap ::toxy::img::empty -data {}\n");
	    sys_gui("proc ::toxy::doreply {target vname vndx op} {\n");
	    sys_gui(" pd [concat $target _rp $::toxy::reply \\;]\n");
	    sys_gui(" unset ::toxy::reply\n");
	    sys_gui("}\n");
	}
	sp->s_owner = owner;
	sp->s_glist = gl;
	sp->s_rptarget = rptarget;
	sp->s_cbtarget = cbtarget;
	sp->s_item = item;
	sp->s_cvfn = cvfn;
	sp->s_size = SCRIPTLET_INISIZE;
	sp->s_buffer = sp->s_bufini;
	scriptlet_reset(sp);
    }
    return (sp);
}