/* This file is part of GCC.

GCC 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 3, or (at your option) any later
version.

GCC 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 GCC; see the file COPYING3.  If not see
<http://www.gnu.org/licenses/>.  */

#ifdef HAVE_CONFIG_H
#include "config.h"
#endif

#include <stdio.h>
#include <stdlib.h>
#include <string.h>
#include <stdbool.h>
#include <stdarg.h>

#include <gpython/gpython.h>
#include <gpython/vectors.h>
#include <gpython/objects.h>
#include <gpython/runtime.h>

gpy_object_t ** __GPY_GLOBL_RR_STACK;
gpy_vector_t * __GPY_GLOBL_CALL_STACK;
gpy_vector_t * __GPY_GLOBL_PRIMITIVES;
gpy_object_t ** __GPY_GLOBL_RETURN_ADDR;
gpy_object_t ** __GPY_GLOBL_RR_STACK_POINTER;

/*
  size
  current_length
  return addr
  .... symbols
*/

static
void gpy_rr_init_primitives (void)
{
  gpy_obj_integer_mod_init (__GPY_GLOBL_PRIMITIVES);
  gpy_obj_staticmethod_mod_init (__GPY_GLOBL_PRIMITIVES);
  gpy_obj_class_mod_init (__GPY_GLOBL_PRIMITIVES);
  gpy_obj_classmethod_mod_init (__GPY_GLOBL_PRIMITIVES);
}

static
void gpy_rr_init_runtime_stack (void)
{
  __GPY_GLOBL_PRIMITIVES = gpy_malloc (sizeof (gpy_vector_t));
  gpy_vec_init (__GPY_GLOBL_PRIMITIVES);
  gpy_rr_init_primitives ();

  __GPY_GLOBL_CALL_STACK = gpy_malloc (sizeof (gpy_vector_t));
  gpy_vec_init (__GPY_GLOBL_CALL_STACK);

  __GPY_GLOBL_RR_STACK = gpy_calloc (3, sizeof (gpy_object_t *));
  *__GPY_GLOBL_RR_STACK = gpy_rr_fold_integer (2);

  __GPY_GLOBL_RR_STACK_POINTER = __GPY_GLOBL_RR_STACK;
  __GPY_GLOBL_RR_STACK_POINTER++;

  *__GPY_GLOBL_RR_STACK_POINTER = gpy_rr_fold_integer (0);

  __GPY_GLOBL_RR_STACK_POINTER++;
  *__GPY_GLOBL_RR_STACK_POINTER = NULL;
  __GPY_GLOBL_RETURN_ADDR = __GPY_GLOBL_RR_STACK_POINTER;
}

/* remember to update the stack pointer's and the stack size */
void gpy_rr_extend_runtime_stack (int nslots)
{
  size_t size = sizeof (gpy_object_t *) * (3+nslots);
  __GPY_GLOBL_RR_STACK = gpy_realloc (__GPY_GLOBL_RR_STACK, size);
  
  __GPY_GLOBL_RR_STACK_POINTER = __GPY_GLOBL_RR_STACK;
  __GPY_GLOBL_RR_STACK_POINTER += 3 + nslots;
}

void gpy_rr_init_runtime (void)
{
  gpy_rr_init_runtime_stack ();
}

void gpy_rr_cleanup_final (void)
{
  /*
    Cleanup the runtime stack and all other object data
   */
  mpfr_free_cache ();
}

gpy_object_attrib_t * gpy_rr_fold_attribute (const unsigned char * identifier,
					     unsigned char * code_addr,
					     unsigned int offset)
{
  gpy_object_attrib_t * attrib = gpy_malloc (sizeof (gpy_object_attrib_t));
  attrib->identifier = identifier;
  if (code_addr)
    {
      gpy_object_t * f = gpy_rr_fold_classmethod_decl (identifier, code_addr);
      attrib->addr = f;
    }
  else
    attrib->addr = NULL;

  attrib->offset = offset;
  return attrib;
}

gpy_object_attrib_t ** gpy_rr_fold_attrib_list (int n, ...)
{
  gpy_object_attrib_t ** retval = NULL;
  if (n > 0)
    {
      /* +1 for the sentinal */
      retval = (gpy_object_attrib_t **)
	gpy_calloc (n+1, sizeof (gpy_object_attrib_t *));

      va_list ap;
      int idx;
      va_start (ap, n);
      for (idx = 0; idx < n; ++idx)
	{
	  gpy_object_attrib_t * i = va_arg (ap, gpy_object_attrib_t *);
	  retval[idx] = i;
	}
      /* sentinal */
      retval[idx] = NULL;
    }
  return retval;
}

gpy_object_t * gpy_rr_fold_class_decl (gpy_object_attrib_t ** attribs,
				       int size, const char * identifier)
{
  gpy_object_t * retval = NULL_OBJECT;

  gpy_object_t ** args = (gpy_object_t **)
    gpy_calloc (4, sizeof(gpy_object_t*));

  gpy_literal_t A;
  A.type = TYPE_ATTRIB_L;
  A.literal.attribs = attribs;

  gpy_literal_t i;
  i.type = TYPE_INTEGER;
  i.literal.integer = size;

  gpy_literal_t s;
  s.type = TYPE_STRING;
  s.literal.string = (char *) identifier;

  gpy_object_t a1 = { .T = TYPE_OBJECT_LIT, .o.literal = &A };
  gpy_object_t a2 = { .T = TYPE_OBJECT_LIT, .o.literal = &i };
  gpy_object_t a3 = { .T = TYPE_OBJECT_LIT, .o.literal = &s };
  gpy_object_t a4 = { .T = TYPE_NULL, .o.literal = NULL };

  args[0] = &a1;
  args[1] = &a2;
  args[2] = &a3;
  args[3] = &a4;

  gpy_typedef_t * def = __gpy_class_type_node;
  retval = def->tp_new (def, args);
  gpy_free (args);

  gpy_assert (retval->T == TYPE_OBJECT_DECL);

  return retval;
}

gpy_object_t * gpy_rr_fold_staticmethod_decl (const char * identifier,
					      unsigned char * code_addr)
{
  gpy_object_t * retval = NULL_OBJECT;

  gpy_object_t ** args = (gpy_object_t **)
    gpy_calloc (4, sizeof(gpy_object_t*));

  gpy_literal_t i;
  i.type = TYPE_STRING;
  i.literal.string = (char *)identifier;

  gpy_literal_t p;
  p.type = TYPE_ADDR;
  p.literal.addr = code_addr;

  gpy_literal_t n;
  n.type = TYPE_INTEGER;
  n.literal.integer = 0;

  gpy_object_t a1 = { .T = TYPE_OBJECT_LIT, .o.literal = &i };
  gpy_object_t a2 = { .T = TYPE_OBJECT_LIT, .o.literal = &p };
  gpy_object_t a3 = { .T = TYPE_OBJECT_LIT, .o.literal = &n };
  gpy_object_t a4 = { .T = TYPE_NULL, .o.literal = NULL };

  args[0] = &a1;
  args[1] = &a2;
  args[2] = &a3;
  args[3] = &a4;

  gpy_typedef_t * def = __gpy_staticmethod_type_node;
  retval = def->tp_new (def, args);
  gpy_free (args);

  gpy_assert (retval->T == TYPE_OBJECT_DECL);

  return retval;
}

gpy_object_t * gpy_rr_fold_classmethod_decl (const char * identifier,
					     unsigned char * code_addr)
{
  gpy_object_t * retval = NULL_OBJECT;

  gpy_object_t ** args = (gpy_object_t **)
    gpy_calloc (4, sizeof(gpy_object_t*));

  gpy_literal_t s;
  s.type = TYPE_STRING;
  s.literal.string = (char *)identifier;

  gpy_literal_t p;
  p.type = TYPE_ADDR;
  p.literal.addr = code_addr;

  gpy_literal_t n;
  n.type = TYPE_INTEGER;
  n.literal.integer = 0;

  gpy_object_t a1 = { .T = TYPE_OBJECT_LIT, .o.literal = &s };
  gpy_object_t a2 = { .T = TYPE_OBJECT_LIT, .o.literal = &p };
  gpy_object_t a3 = { .T = TYPE_OBJECT_LIT, .o.literal = &n };
  gpy_object_t a4 = { .T = TYPE_NULL, .o.literal = NULL };

  args[0] = &a1;
  args[1] = &a2;
  args[2] = &a3;
  args[3] = &a4;

  gpy_typedef_t * def = __gpy_classmethod_type_node;
  retval = def->tp_new (def, args);
  gpy_free (args);

  gpy_assert (retval->T == TYPE_OBJECT_DECL);

  return retval;
}


gpy_object_t * gpy_rr_fold_call (gpy_object_t * decl, int nargs, ...)
{
  gpy_object_t * retval = NULL_OBJECT;

  gpy_assert (decl->T == TYPE_OBJECT_DECL);
  gpy_typedef_t * type = decl->o.object_state->definition;
  
  /* + 1 for sentinal */
  gpy_object_t ** args = calloc (nargs + 1, sizeof (gpy_object_t *));
  va_list ap;
  int idx;
  va_start (ap, nargs);
  for (idx = 0; idx < nargs; ++idx)
    {
      args[idx] = va_arg (ap, gpy_object_t *);
    }
  args[idx] = NULL;

  if (type->tp_call)
    {
      retval = type->tp_call (decl, args);
    }
  else
    fatal ("name is not callable!\n");
    
  return retval;
}

unsigned char * gpy_rr_eval_attrib_reference (gpy_object_t * base,
					      const char * attrib)
{
  unsigned char * retval = NULL;
  gpy_typedef_t * type = base->o.object_state->definition;
  
  struct gpy_object_attrib_t ** members = type->members_defintion;
  gpy_object_state_t * objs = base->o.object_state;

  int idx, offset = -1;
  for (idx = 0; members[idx] != NULL; ++idx)
    {
      struct gpy_object_attrib_t * it = members[idx];
      if (!strcmp (attrib, it->identifier))
	{
	  offset = it->offset;
	  unsigned char * state = (unsigned char *)objs->state;
	  retval = state + offset;
	  break;
	}
    }
  gpy_assert (retval);
  return retval;
}

gpy_object_t * gpy_rr_fold_integer (const int x)
{
  gpy_object_t * retval = NULL_OBJECT;

  gpy_object_t ** args = (gpy_object_t **)
    gpy_calloc (2, sizeof(gpy_object_t*));

  gpy_literal_t i;
  i.type = TYPE_INTEGER;
  i.literal.integer = x;

  gpy_object_t a1 = { .T = TYPE_OBJECT_LIT, .o.literal = &i };
  gpy_object_t a2 = { .T = TYPE_NULL, .o.literal = NULL };

  args[0] = &a1;
  args[1] = &a2;

  gpy_typedef_t * Int_def = __gpy_integer_type_node;
  retval = Int_def->tp_new (Int_def, args);
  gpy_free(args);
  gpy_assert (retval->T == TYPE_OBJECT_STATE);

  return retval;
}

inline
void * gpy_rr_get_object_state (gpy_object_t * o)
{
  gpy_assert (o);
  return o->o.object_state->state;
}

/**
 * int fd: we could use bit masks to represent:
 *   stdout/stderr ...
 **/
void gpy_rr_eval_print (int fd, int count, ...)
{
  va_list vl; int idx;
  va_start (vl,count);

  gpy_object_t * it = NULL;
  for (idx = 0; idx<count; ++idx)
    {
      it = va_arg (vl, gpy_object_t *);
      struct gpy_typedef_t * definition = it->o.object_state->definition;

      switch (fd)
	{
	case 1:
	  definition->tp_print (it, stdout, false);
	  break;

	case 2:
	  definition->tp_print (it, stderr, false);
	  break;

	default:
	  fatal ("invalid print file-descriptor <%i>!\n", fd );
	  break;
	}
    }

  fprintf (stdout, "\n");
  va_end (vl);
}

inline
void gpy_rr_incr_ref_count (gpy_object_t * x1)
{
  gpy_assert (x1->T == TYPE_OBJECT_STATE);
  gpy_object_state_t * x = x1->o.object_state;

  debug ("incrementing ref count on <%p>:<%i> to <%i>!\n",
	 (void*) x, x->ref_count, (x->ref_count + 1));
  x->ref_count++;
}

inline
void gpy_rr_decr_ref_count (gpy_object_t * x1)
{
  gpy_assert (x1->T == TYPE_OBJECT_STATE);
  gpy_object_state_t * x = x1->o.object_state;

  debug ("decrementing ref count on <%p>:<%i> to <%i>!\n",
	 (void*) x, x->ref_count, (x->ref_count - 1));
  x->ref_count--;
}

gpy_object_t * gpy_rr_eval_expression (gpy_object_t * x1,
				       gpy_object_t * y1,
				       unsigned int op)
{
  char * op_str = NULL;
  gpy_object_t * retval = NULL;

  gpy_assert (x1->T == TYPE_OBJECT_STATE);
  gpy_assert (y1->T == TYPE_OBJECT_STATE);
  gpy_object_state_t * x = x1->o.object_state;
  gpy_object_state_t * y = y1->o.object_state;

  struct gpy_typedef_t * def = x1->o.object_state->definition;
  struct gpy_number_prot_t * binops = (*def).binary_protocol;
  struct gpy_number_prot_t binops_l = (*binops);

  debug ("Eval expression!\n");

  binary_op o = NULL;
  switch( op )
    {
      /* addition */
    case 1:
      o = binops_l.n_add;
      op_str = "+ ";
      break;

      /* FINISH .... */

    default:
      fatal("unhandled binary operation <%x>!\n", op );
      break;
    }

  if (o)
    {
#ifdef DEBUG
      x->definition->tp_print (x1, stdout, false);
      fprintf (stdout, "%s", op_str );
      y->definition->tp_print (y1, stdout, true);
#endif
      retval = o (x1,y1);
#ifdef DEBUG
      fprintf (stdout, "evaluated to: ");
      retval->o.object_state->definition->tp_print (retval, stdout, false);
      fprintf (stdout, "!\n");
#endif
    }
  else
    fatal ("no binary protocol!\n");
 
  return retval;
}