/***********************************************************************
 *               Copyright (C) 1995 Joe English
 *                   Freely redistributable
 ***********************************************************************
 *
 * subst.c,v 1.6 1998/11/10 00:07:00 jenglish Exp
 *
 * Author: 	Joe English
 * Created:	11 Apr 1995
 * Description: Fixed-string substitutions
 *
 */

#include <stdlib.h>
#include <string.h>
#include "tcl.h"

#include "project.h"
#include "ctrie.h"

#include "esis.h"
#include "tclcost.h"

/* SubstProc -- substitution command implementation procedure
 */
static int SubstProc(ClientData clientData, Tcl_Interp *interp,
			int argc, char *argv[])
{
    CTrie subst = (CTrie)(clientData);
    Tcl_DString result;
    char *startp, *endp, *matchp;
    CTrieNode curnode, matchnode, nextnode;

    CHECKNARGS(1, "string");

    Tcl_DStringInit(&result);

    startp = endp = argv[1]; matchp = 0;
    curnode = ctrie_root(subst); matchnode = 0;

    /* %%% verify that this works */
    while (*startp)
    {
	nextnode = *endp ? ctrie_findch(curnode, *endp) : 0;
	if (nextnode)
	{
	    curnode = nextnode;
	    if (ctrie_hasvalue(curnode))
	    {
		matchnode = curnode;
		matchp = endp;
	    }
	    ++endp;
	}
	else /* flush */
	{
	    if (matchnode)
	    {
		ASSERT(matchp != 0, "Out of sync 1");
		Tcl_DStringAppend(&result, ctrie_getvalue(matchnode), -1);
		startp = matchp + 1;
	    }
	    else
	    {
		ASSERT(matchp == 0, "Out of sync 2");
		Tcl_DStringAppend(&result, startp, 1);
		++startp;
	    }
	    endp = startp;
	    curnode = ctrie_root(subst);
	    matchp = 0;
	    matchnode = 0;
	}
    }

    Tcl_DStringResult(interp, &result);
    return TCL_OK;
}

/*
 * Destructor
 */

/*ARGSUSED*/
static void ctnfreeproc(CTrieNode ctn, void *closure)
{
    if (ctrie_hasvalue(ctn))
	free(ctrie_getvalue(ctn));
}
static void SubstDtor(ClientData clientData)
{
    CTrie subst = (CTrie)clientData;
    ctrie_foreach(subst, ctnfreeproc, 0);
    ctrie_destroy(subst);
}

	/*ARGSUSED*/
int DefineSubstProc(ClientData clientData, Tcl_Interp *interp,
			int argc, char *argv[])
{
    char *cmdName;
    char **pairs;
    int npairs, i;
    CTrie subst;

    CHECKNARGS(2,"name subst-pairs");

    cmdName = argv[1];
    if (TCL_ERROR == Tcl_SplitList(interp, argv[2], &npairs, &pairs))
	return TCL_ERROR;

    if (npairs % 2 != 0) {
	Tcl_AppendResult(interp, argv[0], ": odd number of pairs");
	Tcl_FreeSplitList(pairs);
	return TCL_ERROR;
    }

    subst = ctrie_create();
    for (i=0; i<npairs; i += 2) {
	char *p = malloc(strlen(pairs[i+1]) + 1);
	strcpy(p,pairs[i+1]);
	ctrie_set(subst, pairs[i], p);
    }
    Tcl_FreeSplitList(pairs);

    Tcl_CreateCommand(interp,cmdName,SubstProc,(ClientData)subst,SubstDtor);

    return TCL_OK;
}