/*
 * Copyright (c) 2010 Stephen Williams (steve@icarus.com)
 *
 *    This source code is free software; you can redistribute it
 *    and/or modify it in source code form 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
 */

# include "vpi_config.h"
# include "sv_vpi_user.h"
# include  <stdlib.h>
# include  <assert.h>

static void missing_arguments(vpiHandle sys)
{
      vpi_printf("%s:%d: error: Invalid/missing arguments next/prev method\n",
		 vpi_get_str(vpiFile, sys), vpi_get(vpiLineNo,sys));
      vpi_control(vpiFinish, 1);
}

static PLI_INT32 ivl_method_next_prev_compiletf(ICARUS_VPI_CONST PLI_BYTE8*data)
{
      vpiHandle sys = vpi_handle(vpiSysTfCall, 0);
      vpiHandle argv = vpi_iterate(vpiArgument, sys);
      vpiHandle arg_enum, arg_item, arg_extra;

      if (argv == 0) {
	    missing_arguments(sys);
	    return 0;
      }

      arg_enum = vpi_scan(argv);
      if (arg_enum == 0) {
	    missing_arguments(sys);
	    return 0;
      }

      arg_item = vpi_scan(argv);
      if (arg_item == 0) {
	    missing_arguments(sys);
	    return 0;
      }

	/* Make sure there are no excess arguments */
      arg_extra = vpi_scan(argv);
      if (arg_extra != 0) {
	    missing_arguments(sys);
	    vpi_free_object(argv);
	    return 0;
      }

	/* The first argument must be an enum typespec */
      if (vpi_get(vpiType, arg_enum) != vpiEnumTypespec) {
	    missing_arguments(sys);
	    return 0;
      }

	/* The return value and input value must be the same size */
      if (vpi_get(vpiSize,sys) != vpi_get(vpiSize,arg_item)) {
	    missing_arguments(sys);
	    return 0;
      }
      return 0;
}

static int compare_value_eequal(s_vpi_value*ref1, s_vpi_value*ref2, long wid)
{
      if (ref1->format == vpiIntVal && ref2->format == vpiIntVal)
	    return ref1->value.integer == ref2->value.integer;

      if (ref1->format == vpiVectorVal && ref2->format == vpiVectorVal) {
	    int words = (wid-1)/32 + 1;
	    int idx;

	    for (idx = 0 ; idx < words ; idx += 1) {
		  if (ref1->value.vector[idx].aval != ref2->value.vector[idx].aval)
			return 0;
		  if (ref1->value.vector[idx].bval != ref2->value.vector[idx].bval)
			return 0;
	    }
	    return 1;
      }

      if (ref1->format == vpiVectorVal && ref2->format == vpiIntVal) {
	    s_vpi_value*tmp = ref1;
	    ref1 = ref2;
	    ref2 = tmp;
      }

      if (ref1->format == vpiIntVal && ref2->format == vpiVectorVal) {
	    int use_aval = ref1->value.integer;
	    int words = (wid-1)/32 + 1;
	    int idx;

	    for (idx = 0 ; idx < words ; idx += 1) {
		  if (use_aval != ref2->value.vector[idx].aval)
			return 0;
		  if (0        != ref2->value.vector[idx].bval)
			return 0;

		  use_aval = 0;
	    }
	    return 1;
      }

      vpi_printf("XXXX formats are: %d vs %d\n", ref1->format, ref2->format);
      assert(0);
      return 0;
}

static PLI_INT32 ivl_method_next_calltf(PLI_BYTE8*data)
{
      vpiHandle sys = vpi_handle(vpiSysTfCall, 0);
      vpiHandle argv = vpi_iterate(vpiArgument, sys);
      vpiHandle arg_enum = vpi_scan(argv);
      vpiHandle arg_item = vpi_scan(argv);
      vpiHandle arg_extra = vpi_scan(argv);

      vpiHandle enum_list = 0;
      vpiHandle memb = 0, first_memb = 0;
      long use_width = 0;
      long item_width = vpi_get(vpiSize, arg_item);

      s_vpi_value memb_value, item_value;

      assert(arg_extra == 0);

      item_value.format = vpiObjTypeVal;
      vpi_get_value(arg_item, &item_value);

	/* If this value is a vector value, then make a safe copy of
	   the vector so that other vpi functions don't trash it. */
      if (item_value.format == vpiVectorVal) {
	    unsigned idx;
	    unsigned hwid = (item_width - 1)/32 + 1;
	    s_vpi_vecval*op = calloc(hwid, sizeof(s_vpi_vecval));
	    for (idx = 0 ; idx < hwid ; idx += 1) {
		  op[idx].aval = item_value.value.vector[idx].aval;
		  op[idx].bval = item_value.value.vector[idx].bval;
	    }
	    item_value.value.vector = op;
      }

      enum_list = vpi_iterate(vpiMember, arg_enum);
      assert(enum_list);

	/* Search for the current value in the member list. */
      do {
	    memb = vpi_scan(enum_list);
	    if (first_memb == 0) {
		  first_memb = memb;
		  use_width = vpi_get(vpiSize, first_memb);
		  assert(use_width == vpi_get(vpiSize, arg_item));
	    }
	    if (memb == 0) break;

	    memb_value.format = vpiObjTypeVal;
	    vpi_get_value(memb, &memb_value);

      } while (! compare_value_eequal(&item_value, &memb_value, use_width));

      if (memb != 0)
	    memb = vpi_scan(enum_list);

      if (memb != 0)
	    vpi_free_object(enum_list);

      if (memb == 0) {
	    memb = first_memb;
	    memb_value.format = vpiIntVal;
      }

	/* Free any stached copy of the vector. */
      if (item_value.format == vpiVectorVal)
	    free(item_value.value.vector);

      vpi_get_value(memb, &memb_value);
      vpi_put_value(sys, &memb_value, 0, vpiNoDelay);

      return 0;
}

static PLI_INT32 ivl_method_prev_calltf(PLI_BYTE8*data)
{
      vpiHandle sys = vpi_handle(vpiSysTfCall, 0);
      vpiHandle argv = vpi_iterate(vpiArgument, sys);
      vpiHandle arg_enum = vpi_scan(argv);
      vpiHandle arg_item = vpi_scan(argv);
      vpiHandle arg_extra = vpi_scan(argv);

      vpiHandle enum_list = 0;
      vpiHandle memb = 0, prev = 0, last_memb = 0;
      int use_wid = 0;

      s_vpi_value memb_value, item_value;

      assert(arg_extra == 0);

      item_value.format = vpiIntVal;
      vpi_get_value(arg_item, &item_value);

      enum_list = vpi_iterate(vpiMember, arg_enum);
      assert(enum_list);

	/* Search for the current value in the member list. */
      do {
	    prev = memb;
	    memb = vpi_scan(enum_list);
	    if (memb == 0) break;
	    if (use_wid == 0)
		  use_wid = vpi_get(vpiSize, memb);

	    last_memb = memb;
	    memb_value.format = vpiIntVal;
	    vpi_get_value(memb, &memb_value);
      } while (! compare_value_eequal(&memb_value, &item_value, use_wid));

      while (memb) {
	    last_memb = memb;
	    memb = vpi_scan(enum_list);
      }

      if (prev == 0)
	    prev = last_memb;

      vpi_get_value(prev, &memb_value);
      vpi_put_value(sys, &memb_value, 0, vpiNoDelay);

      return 0;
}

void v2009_enum_register(void)
{
      s_vpi_systf_data tf_data;

      tf_data.type        = vpiSysFunc;
      tf_data.calltf      = ivl_method_next_calltf;
      tf_data.compiletf   = ivl_method_next_prev_compiletf;
      tf_data.sizetf      = 0;
      tf_data.tfname      = "$ivl_method$next";
      tf_data.user_data   = "$ivl_method$next";
      vpi_register_systf(&tf_data);

      tf_data.type        = vpiSysFunc;
      tf_data.calltf      = ivl_method_prev_calltf;
      tf_data.compiletf   = 0;
      tf_data.sizetf      = 0;
      tf_data.tfname      = "$ivl_method$prev";
      tf_data.user_data   = "$ivl_method$prev";
      vpi_register_systf(&tf_data);
}