/*
 *  R : A Computer Langage for Statistical Data Analysis
 *  Copyright (C) 1995, 1996  Robert Gentleman and Ross Ihaka
 *
 *  This program is free software; you can redistribute it and/or modify
 *  it under the terms of the GNU General Public License as published by
 *  the Free Software Foundation; either version 2 of the License, or
 *  (at your option) any later version.
 *
 *  This program is distributed in the hope that it will be useful,
 *  but WITHOUT ANY WARRANTY; without even the implied warranty of
 *  MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 *  GNU General Public License for more details.
 *
 *  You should have received a copy of the GNU General Public License
 *  along with this program; if not, write to the Free Software
 *  Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
 */

#ifdef HAVE_CONFIG_H
#include <Rconfig.h>
#endif

#include "Defn.h"

/*  duplicate  -  object duplication  */

/*  Because we try to maintain the illusion of call by
 *  value, we often need to duplicate entire data
 *  objects.  There are a couple of points to note.
 *  First, duplication of list-like objects is done
 *  iteratively to prevent growth of the pointer
 *  protection stack, and second, the duplication of
 *  promises requires that the promises be forced and
 *  the value duplicated.  */

SEXP duplicate(SEXP s)
{
    SEXP h, t,  sp;
    int i, n;

    switch (TYPEOF(s)) {
    case NILSXP:
    case SYMSXP:
    case ENVSXP:
    case SPECIALSXP:
    case BUILTINSXP:
	return s;
    case CLOSXP:
	PROTECT(s);
	PROTECT(t = allocSExp(CLOSXP));
	FORMALS(t) = FORMALS(s);
	BODY(t) = BODY(s);
	CLOENV(t) = CLOENV(s);
	ATTRIB(t) = duplicate(ATTRIB(s));
	UNPROTECT(2);
	break;
    case LISTSXP:
	PROTECT(sp = s);
	PROTECT(h = t = CONS(R_NilValue, R_NilValue));
	while(sp != R_NilValue) {
	    CDR(t) = CONS(duplicate(CAR(sp)), R_NilValue);
	    t = CDR(t);
	    TAG(t) = TAG(sp);
	    ATTRIB(t) = duplicate(ATTRIB(sp));
	    sp = CDR(sp);
	}
	t = CDR(h);
	UNPROTECT(2);
	break;
    case LANGSXP:
	PROTECT(sp = s);
	PROTECT(h = t = CONS(R_NilValue, R_NilValue));
	while(sp != R_NilValue) {
	    CDR(t) = CONS(duplicate(CAR(sp)), R_NilValue);
	    t = CDR(t);
	    TAG(t) = TAG(sp);
	    ATTRIB(t) = duplicate(ATTRIB(sp));
	    sp = CDR(sp);
	}
	t = CDR(h);
	TYPEOF(t) = LANGSXP;
	ATTRIB(t) = duplicate(ATTRIB(s));
	UNPROTECT(2);
	break;
    case CHARSXP:
	PROTECT(s);
	PROTECT(t = allocString(strlen(CHAR(s))));
	strcpy(CHAR(t), CHAR(s));
	ATTRIB(t) = duplicate(ATTRIB(s));
	UNPROTECT(2);
	break;
    case EXPRSXP:
    case VECSXP:
	n = length(s);
	PROTECT(s);
	PROTECT(t = allocVector(TYPEOF(s), LENGTH(s)));
	for(i = 0 ; i < n ; i++)
	    VECTOR(t)[i] = duplicate(VECTOR(s)[i]);
	ATTRIB(t) = duplicate(ATTRIB(s));
	TRUELENGTH(t) = TRUELENGTH(s);
	UNPROTECT(2);
	break;
    case STRSXP:
    case LGLSXP:
    case INTSXP:
    case REALSXP:
    case CPLXSXP:
	PROTECT(s);
	t = allocVector(TYPEOF(s), LENGTH(s));
	copyVector(t, s);
	PROTECT(t);
	ATTRIB(t) = duplicate(ATTRIB(s));
	UNPROTECT(2);
	TRUELENGTH(t) = TRUELENGTH(s);
	break;
    case PROMSXP: /* duplication requires that we evaluate the promise */
#ifdef OLD
	if (PRVALUE(s) == R_UnboundValue) {
	    t = eval(PREXPR(s), PRENV(s));
	    PRVALUE(s) = t;
	}
	t = duplicate(PRVALUE(s));
#endif
	return s;
	break;
    default:
	UNIMPLEMENTED("duplicate");
	t = s;/* for -Wall */
    }
    if(TYPEOF(t) == TYPEOF(s) ) /* surely it only makes sense in this case*/
	OBJECT(t) = OBJECT(s);
    return t;
}

void copyVector(SEXP s, SEXP t)
{
    int i, ns, nt;

    nt = LENGTH(t);
    ns = LENGTH(s);
    switch (TYPEOF(s)) {
    case STRSXP:
    case EXPRSXP:
	for (i = 0; i < ns; i++)
	    VECTOR(s)[i] = VECTOR(t)[i % nt];
	break;
    case LGLSXP:
	for (i = 0; i < ns; i++)
	    LOGICAL(s)[i] = LOGICAL(t)[i % nt];
	break;
    case INTSXP:
	for (i = 0; i < ns; i++)
	    INTEGER(s)[i] = INTEGER(t)[i % nt];
	break;
    case REALSXP:
	for (i = 0; i < ns; i++)
	    REAL(s)[i] = REAL(t)[i % nt];
	break;
    case CPLXSXP:
	for (i = 0; i < ns; i++)
	    COMPLEX(s)[i] = COMPLEX(t)[i % nt];
	break;
    default:
	UNIMPLEMENTED("copyVector");
    }
}

void copyListMatrix(SEXP s, SEXP t, int byrow)
{
    SEXP pt, tmp;
    int i, j, nr, nc, ns;

    nr = nrows(s);
    nc = ncols(s);
    ns = nr*nc;
    pt = t;
    if(byrow) {
	PROTECT(tmp = allocVector(STRSXP, nr*nc));
	for (i = 0; i < nr; i++)
	    for (j = 0; j < nc; j++) {
		STRING(tmp)[i + j * nr] = duplicate(CAR(pt));
		pt = CDR(pt);
		if(pt == R_NilValue) pt = t;
	    }
	for (i = 0; i < ns; i++) {
	    CAR(s) = STRING(tmp)[i++];
	    s = CDR(s);
	}
	UNPROTECT(1);
    }
    else {
	for (i = 0; i < ns; i++) {
	    CAR(s) = duplicate(CAR(pt));
	    s = CDR(s);
	    pt = CDR(pt);
	    if(pt == R_NilValue) pt = t;
	}
    }
}

void copyMatrix(SEXP s, SEXP t, int byrow)
{
    int i, j, k, nr, nc, nt;

    nr = nrows(s);
    nc = ncols(s);
    nt = LENGTH(t);
    k = 0;

    if (byrow) {
	switch (TYPEOF(s)) {
	case STRSXP:
	    for (i = 0; i < nr; i++)
		for (j = 0; j < nc; j++)
		    STRING(s)[i + j * nr] = STRING(t)[k++ % nt];
	    break;
	case LGLSXP:
	    for (i = 0; i < nr; i++)
		for (j = 0; j < nc; j++)
		    LOGICAL(s)[i + j * nr] = LOGICAL(t)[k++ % nt];
	    break;
	case INTSXP:
	    for (i = 0; i < nr; i++)
		for (j = 0; j < nc; j++)
		    INTEGER(s)[i + j * nr] = INTEGER(t)[k++ % nt];
	    break;
	case REALSXP:
	    for (i = 0; i < nr; i++)
		for (j = 0; j < nc; j++)
		    REAL(s)[i + j * nr] = REAL(t)[k++ % nt];
	    break;
	case CPLXSXP:
	    for (i = 0; i < nr; i++)
		for (j = 0; j < nc; j++)
		    COMPLEX(s)[i + j * nr] = COMPLEX(t)[k++ % nt];
	    break;
	default:
	    UNIMPLEMENTED("copyMatrix");
	}
    }
    else
	copyVector(s, t);
}