/*
 * t4parse.cpp --
 *
 *	This file contains procedures to parse vertex and insert-order
 *	specifications.
 *
 *	Authors: Jacob Levy and Jean-Claude Wippler.
 *		 jyl@best.com	jcw@equi4.com
 *
 * Copyright (c) 2000-2003, JYL Software Inc.
 * 
 * Permission is hereby granted, free of charge, to any person obtaining
 * a copy of this software and associated documentation files (the
 * "Software"), to deal in the Software without restriction, including
 * without limitation the rights to use, copy, modify, merge, publish,
 * distribute, sublicense, and/or sell copies of the Software, and to
 * permit persons to whom the Software is furnished to do so, subject to
 * the following conditions:
 * 
 * The above copyright notice and this permission notice shall be
 * included in all copies or substantial portions of the Software.
 * 
 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND,
 * EXPRESS OR IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF
 * MERCHANTABILITY, FITNESS FOR A PARTICULAR PURPOSE AND
 * NONINFRINGEMENT. IN NO EVENT SHALL THE AUTHORS OR COPYRIGHT HOLDERS BE
 * LIABLE FOR ANY CLAIM, DAMAGES OR OTHER LIABILITY, WHETHER IN AN ACTION
 * OF CONTRACT, TORT OR OTHERWISE, ARISING FROM, OUT OF OR IN CONNECTION
 * WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE SOFTWARE, EVEN IF
 * JYL SOFTWARE INC. IS MADE AWARE OF THE POSSIBILITY OF SUCH DAMAGE.
 */

#include "t4graphrep.h"

/*
 * This pattern is used to split appart vertex specifications into their
 * elements.
 */

static char *splitpattern = (char *) "split {%s} ()";
static int splitpatternlen = 9;

/*
 * These are the names of the insert orders in Tcl:
 */

static CONST84 char *ionames[] = {
    (char *) "none",
    (char *) "at",
    (char *) "first",
    (char *) "last",
    (char *) "before",
    (char *) "after",
    NULL
};

int
T4Graph_ParseVertexName(Tcl_Interp *interp,
			char *specstr,
			char **fnpp,
			int *indexp,
			T4VertexNameKinds *vnkp)
{
    int iv, len;
    char *cmdbuf;
    Tcl_Obj **objv;
    Tcl_DString ds;

    /*
     * If the spec is of the form "a(b)" or "(b)" then split it up.
     * Use the part before the open-paren as the name of a vertex and
     * the part inside the parens as an index. Thus, "foo(3)" means the
     * third vertex named "foo".
     */

    if (Tcl_StringMatch(specstr, "*(*)") == 1) {
	Tcl_DStringInit(&ds);
	Tcl_DStringAppend(&ds, "split {", -1);
	Tcl_DStringAppend(&ds, specstr, -1);

	cmdbuf = Tcl_DStringAppend(&ds, "} ()", -1);
	if (Tcl_Eval(interp, cmdbuf) == TCL_ERROR) {
	    Tcl_DStringFree(&ds);
	    return TCL_ERROR;
	}
	Tcl_DStringFree(&ds);
	if (Tcl_ListObjGetElements(interp, Tcl_GetObjResult(interp), &len,
				   &objv) == TCL_ERROR) {
	    return TCL_ERROR;
	}
	if (len != 3) {
	    Tcl_ResetResult(interp);
	    Tcl_AppendResult(interp, "\"", specstr, 
			     "\": badly formed vertex spec", NULL);
	    return TCL_ERROR;
	}
	specstr = Tcl_GetString(objv[0]);
	if (Tcl_GetIntFromObj(interp, objv[1], &iv) == TCL_ERROR) {
	    iv = 1;
	}

	/*
	 * Interpreter result should not be reset because it would smash
	 * specstr. Only reset it after use, in the caller of ParseVertexName.
	 */

	*fnpp = specstr;
	*indexp = iv;
	*vnkp = T4VNK_INDEX;

	return TCL_OK;
    }

    /*
     * See if it is an integer. If so, use that as a rank.
     */

    Tcl_SetStringObj(Tcl_GetObjResult(interp), specstr, -1);
    if (Tcl_GetIntFromObj(interp, Tcl_GetObjResult(interp), &iv) == TCL_OK) {
        Tcl_ResetResult(interp);
	*fnpp = NULL;
	*indexp = iv;
	*vnkp = T4VNK_RANK;

	return TCL_OK;
    }
    
    /*
     * Simple form. Use it as the name of a field.
     */

    Tcl_ResetResult(interp);
    *fnpp = specstr;
    *indexp = 1;
    *vnkp = T4VNK_INDEX;

    return TCL_OK;
}

/*
 * T4Graph_ParseInsertOrder --
 *
 *	This procedure parses a string that denotes an insert order as
 *	defined by enum e4_InsertOrder in <root>/main/include/e4common.h.
 *
 * Results:
 *	A standard Tcl result. Upon success the output parameter iop is
 *	set to one of the values defined by enum e4_InsertOrder.
 *
 * Side effects:
 *	None.
 */

int
T4Graph_ParseInsertOrder(Tcl_Interp *interp,
			 Tcl_Obj *spec,
			 e4_InsertOrder *iop)
{
    return Tcl_GetIndexFromObj(interp, spec,
			       (CONST84 char **) ionames, 
			       (char *) "insert order", 0,
			       (int *) iop);
}