/****************************************************************************
 * apps/examples/interpreters/bas/auto.c
 * BASIC file system interface.
 *
 *   Copyright (c) 1999-2014 Michael Haardt
 *
 * 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.
 *
 * Adapted to NuttX and re-released under a 3-clause BSD license:
 *
 *   Copyright (C) 2014 Gregory Nutt. All rights reserved.
 *   Authors: Alan Carvalho de Assis <Alan Carvalho de Assis>
 *            Gregory Nutt <gnutt@nuttx.org>
 *
 * Redistribution and use in source and binary forms, with or without
 * modification, are permitted provided that the following conditions
 * are met:
 *
 * 1. Redistributions of source code must retain the above copyright
 *    notice, this list of conditions and the following disclaimer.
 * 2. Redistributions in binary form must reproduce the above copyright
 *    notice, this list of conditions and the following disclaimer in
 *    the documentation and/or other materials provided with the
 *    distribution.
 * 3. Neither the name NuttX nor the names of its contributors may be
 *    used to endorse or promote products derived from this software
 *    without specific prior written permission.
 *
 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS
 * FOR A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE
 * COPYRIGHT OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT,
 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING,
 * BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS
 * OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED
 * AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN
 * ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
 * POSSIBILITY OF SUCH DAMAGE.
 *
 ****************************************************************************/

/****************************************************************************
 * Included Files
 ****************************************************************************/

#include "config.h"

#include <assert.h>
#include <ctype.h>
#include <stdlib.h>
#include <string.h>

#include "auto.h"

/****************************************************************************
 * Pre-processor Definitions
 ****************************************************************************/

#define INCREASE_STACK 16
#define _(String) String

/****************************************************************************
 * Public Functions
 ****************************************************************************/

/* interpretation methods */

struct Auto *Auto_new(struct Auto *this)
{
  this->stackPointer = 0;
  this->stackCapacity = 0;
  this->framePointer = 0;
  this->frameSize = 0;
  this->onerror.line = -1;
  this->erl = 0;
  Value_new_NIL(&this->err);
  Value_new_NIL(&this->lastdet);
  this->begindata.line = -1;
  this->slot = (union AutoSlot *)0;
  this->cur = this->all = (struct Symbol *)0;
  return this;
}

void Auto_destroy(struct Auto *this)
{
  struct Symbol *l;

  Value_destroy(&this->err);
  Value_destroy(&this->lastdet);
  if (this->stackCapacity)
    {
      free(this->slot);
    }

  for (l = this->all; l != (struct Symbol *)0;)
    {
      struct Symbol *f;

      f = l;
      l = l->next;
      free(f->name);
      free(f);
    }
}

struct Var *Auto_pushArg(struct Auto *this)
{
  if ((this->stackPointer + 1) >= this->stackCapacity)
    {
      this->slot =
        realloc(this->slot,
                sizeof(this->slot[0]) *
                (this->
                 stackCapacity ? (this->stackCapacity =
                                  this->stackPointer +
                                  INCREASE_STACK) : (this->stackCapacity =
                                                     INCREASE_STACK)));
    }

  return &this->slot[this->stackPointer++].var;
}

void Auto_pushFuncRet(struct Auto *this, int firstarg, struct Pc *pc)
{
  if (this->stackPointer + 2 >= this->stackCapacity)
    {
      this->slot =
        realloc(this->slot,
                sizeof(this->slot[0]) *
                (this->
                 stackCapacity ? (this->stackCapacity =
                                  this->stackCapacity +
                                  INCREASE_STACK) : (this->stackCapacity =
                                                     INCREASE_STACK)));
    }

  this->slot[this->stackPointer].retException.onerror = this->onerror;
  this->slot[this->stackPointer].retException.resumeable = this->resumeable;
  ++this->stackPointer;
  this->slot[this->stackPointer].retFrame.pc = *pc;
  this->slot[this->stackPointer].retFrame.framePointer = this->framePointer;
  this->slot[this->stackPointer].retFrame.frameSize = this->frameSize;
  ++this->stackPointer;
  this->framePointer = firstarg;
  this->frameSize = this->stackPointer - firstarg;
  this->onerror.line = -1;
}

void Auto_pushGosubRet(struct Auto *this, struct Pc *pc)
{
  if ((this->stackPointer + 1) >= this->stackCapacity)
    {
      this->slot =
        realloc(this->slot,
                sizeof(this->slot[0]) *
                (this->
                 stackCapacity ? (this->stackCapacity =
                                  this->stackPointer +
                                  INCREASE_STACK) : (this->stackCapacity =
                                                     INCREASE_STACK)));
    }

  this->slot[this->stackPointer].retFrame.pc = *pc;
  ++this->stackPointer;
}

struct Var *Auto_local(struct Auto *this, int l)
{
  assert(this->frameSize > (l + 2));
  return &(this->slot[this->framePointer + l].var);
}

int Auto_funcReturn(struct Auto *this, struct Pc *pc)
{
  int i, retFrame, retException;

  if (this->stackPointer == 0)
    {
      return 0;
    }

  assert(this->frameSize);
  retFrame = this->framePointer + this->frameSize - 1;
  retException = this->framePointer + this->frameSize - 2;
  assert(retException >= 0 && retFrame < this->stackPointer);
  for (i = 0; i < this->frameSize - 2; ++i)
    {
      Var_destroy(&this->slot[this->framePointer + i].var);
    }

  this->stackPointer = this->framePointer;
  if (pc != (struct Pc *)0)
    {
      *pc = this->slot[retFrame].retFrame.pc;
    }

  this->frameSize = this->slot[retFrame].retFrame.frameSize;
  this->framePointer = this->slot[retFrame].retFrame.framePointer;
  this->onerror = this->slot[retException].retException.onerror;
  return 1;
}

int Auto_gosubReturn(struct Auto *this, struct Pc *pc)
{
  if (this->stackPointer <= this->framePointer + this->frameSize)
    {
      return 0;
    }

  --this->stackPointer;
  if (pc)
    {
      *pc = this->slot[this->stackPointer].retFrame.pc;
    }

  return 1;
}

void Auto_frameToError(struct Auto *this, struct Program *program, struct Value *v)
{
  int i = this->stackPointer, framePointer, frameSize, retFrame;
  struct Pc p;

  framePointer = this->framePointer;
  frameSize = this->frameSize;
  while (i > framePointer + frameSize)
    {
      p = this->slot[--i].retFrame.pc;
      Value_errorSuffix(v, _("Called"));
      Program_PCtoError(program, &p, v);
    }

  if (i)
    {
      retFrame = framePointer + frameSize - 1;
      i = framePointer;
      p = this->slot[retFrame].retFrame.pc;
      frameSize = this->slot[retFrame].retFrame.frameSize;
      framePointer = this->slot[retFrame].retFrame.framePointer;
      Value_errorSuffix(v, _("Proc Called"));
      Program_PCtoError(program, &p, v);
    }
}

void Auto_setError(struct Auto *this, long int line, struct Pc *pc, struct Value *v)
{
  this->erpc = *pc;
  this->erl = line;
  Value_destroy(&this->err);
  Value_clone(&this->err, v);
}

/* compilation methods */
int Auto_find(struct Auto *this, struct Identifier *ident)
{
  struct Symbol *find;

  for (find = this->cur; find != (struct Symbol *)0; find = find->next)
    {
      const char *s = ident->name;
      const char *r = find->name;

      while (*s && tolower(*s) == tolower(*r))
        {
          ++s;
          ++r;
        }

      if (tolower(*s) == tolower(*r))
        {
          ident->sym = find;
          return 1;
        }
    }

  return 0;
}

int Auto_variable(struct Auto *this, const struct Identifier *ident)
{
  struct Symbol **tail;
  int offset;

  for (offset = 0, tail = &this->cur;
       *tail != (struct Symbol *)0;
       tail = &(*tail)->next, ++offset)
    {
      const char *s = ident->name;
      const char *r = (*tail)->name;

      while (*s && tolower(*s) == tolower(*r))
        {
          ++s;
          ++r;
        }

      if (tolower(*s) == tolower(*r))
        {
          return 0;
        }
    }

  (*tail) = malloc(sizeof(struct Symbol));
  (*tail)->next = (struct Symbol *)0;
  (*tail)->name = strcpy(malloc(strlen(ident->name) + 1), ident->name);
  (*tail)->type = LOCALVAR;
  (*tail)->u.local.type = ident->defaultType;

  /* the offset -1 of the V_VOID procedure return symbol is ok, it is not used */

  (*tail)->u.local.offset =
    offset - (this->cur->u.local.type == V_VOID ? 1 : 0);
  return 1;
}

enum ValueType Auto_argType(const struct Auto *this, int l)
{
  struct Symbol *find;
  int offset;

  if (this->cur->u.local.type == V_VOID)
    {
      ++l;
    }

  for (offset = 0, find = this->cur; l != offset; find = find->next, ++offset)
    {
      assert(find != (struct Symbol *)0);
    }

  assert(find != (struct Symbol *)0);
  return find->u.local.type;
}

enum ValueType Auto_varType(const struct Auto *this, struct Symbol *sym)
{
  struct Symbol *find;

  for (find = this->cur;
       find->u.local.offset != sym->u.local.offset;
       find = find->next)
    {
      assert(find != (struct Symbol *)0);
    }

  assert(find != (struct Symbol *)0);
  return find->u.local.type;
}

void Auto_funcEnd(struct Auto *this)
{
  struct Symbol **tail;

  for (tail = &this->all; *tail != (struct Symbol *)0; tail = &(*tail)->next);
  *tail = this->cur;
  this->cur = (struct Symbol *)0;
}