/* Copyright 2014 Samsung Electronics Co., Ltd.
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

/** \addtogroup ecma ---TODO---
 * @{
 * 
 * \addtogroup ecmahelpers Helpers for operations with ECMA data types
 * @{
 */

#include "ecma-alloc.h"
#include "ecma-gc.h"
#include "ecma-globals.h"
#include "ecma-helpers.h"
#include "globals.h"

/**
 * Check if the value is empty.
 *
 * @return true - if the value contains implementation-defined empty simple value,
 *         false - otherwise.
 */
bool
ecma_is_value_empty( ecma_value_t value) /**< ecma-value */
{
  return ( value.value_type == ECMA_TYPE_SIMPLE && value.value == ECMA_SIMPLE_VALUE_EMPTY );
} /* ecma_is_value_empty */

/**
 * Check if the value is undefined.
 *
 * @return true - if the value contains ecma-undefined simple value,
 *         false - otherwise.
 */
bool
ecma_is_value_undefined( ecma_value_t value) /**< ecma-value */
{
  return ( value.value_type == ECMA_TYPE_SIMPLE && value.value == ECMA_SIMPLE_VALUE_UNDEFINED );
} /* ecma_is_value_undefined */

/**
 * Check if the value is null.
 *
 * @return true - if the value contains ecma-null simple value,
 *         false - otherwise.
 */
bool
ecma_is_value_null( ecma_value_t value) /**< ecma-value */
{
  return ( value.value_type == ECMA_TYPE_SIMPLE && value.value == ECMA_SIMPLE_VALUE_NULL );
} /* ecma_is_value_null */

/**
 * Check if the value is boolean.
 *
 * @return true - if the value contains ecma-true or ecma-false simple values,
 *         false - otherwise.
 */
bool
ecma_is_value_boolean( ecma_value_t value) /**< ecma-value */
{
  return ( ( value.value_type == ECMA_TYPE_SIMPLE && value.value == ECMA_SIMPLE_VALUE_FALSE )
           || ( value.value_type == ECMA_TYPE_SIMPLE && value.value == ECMA_SIMPLE_VALUE_TRUE ) );
} /* ecma_is_value_boolean */

/**
 * Check if the value is true.
 *
 * Warning:
 *         value must be boolean
 *
 * @return true - if the value contains ecma-true simple value,
 *         false - otherwise.
 */
bool
ecma_is_value_true( ecma_value_t value) /**< ecma-value */
{
  JERRY_ASSERT( ecma_is_value_boolean( value) );

  return ( value.value_type == ECMA_TYPE_SIMPLE && value.value == ECMA_SIMPLE_VALUE_TRUE );
} /* ecma_is_value_true */

/**
 * Simple value constructor
 */
ecma_value_t
ecma_make_simple_value( ecma_simple_value_t value) /**< simple value */
{
  return (ecma_value_t) { .value_type = ECMA_TYPE_SIMPLE, .value = value };
} /* ecma_make_simple_value */

/**
 * Number value constructor
 */
ecma_value_t
ecma_make_number_value( ecma_number_t* num_p) /**< number to reference in value */
{
  JERRY_ASSERT( num_p != NULL );

  ecma_value_t number_value;

  number_value.value_type = ECMA_TYPE_NUMBER;
  ecma_set_pointer( number_value.value, num_p);

  return number_value;
} /* ecma_make_number_value */

/**
 * String value constructor
 */
ecma_value_t
ecma_make_string_value( ecma_array_first_chunk_t* ecma_string_p) /**< string to reference in value */
{
  JERRY_ASSERT( ecma_string_p != NULL );

  ecma_value_t string_value;

  string_value.value_type = ECMA_TYPE_STRING;
  ecma_set_pointer( string_value.value, ecma_string_p);

  return string_value;
} /* ecma_make_string_value */

/**
 * object value constructor
 */
ecma_value_t
ecma_make_object_value( ecma_object_t* object_p) /**< object to reference in value */
{
  JERRY_ASSERT( object_p != NULL );

  ecma_value_t object_value;

  object_value.value_type = ECMA_TYPE_OBJECT;
  ecma_set_pointer( object_value.value, object_p);

  return object_value;
} /* ecma_make_object_value */

/**
 * Copy ecma-value.
 *
 * Note:
 *  Operation algorithm.
 *   switch (valuetype)
 *    case simple:
 *      simply return the value as it was passed;
 *    case number/string:
 *      copy the number/string
 *      and return new ecma-value
 *      pointing to copy of the number/string;
 *    case object;
 *      increase reference counter of the object
 *      and return the value as it was passed.
 *
 * TODO:
 *      reference counter in strings
 *
 * @return See note.
 */
ecma_value_t
ecma_copy_value( const ecma_value_t value) /**< ecma-value */
{
  ecma_value_t value_copy;

  switch ( (ecma_type_t)value.value_type )
  {
    case ECMA_TYPE_SIMPLE:
      {
        value_copy = value;

        break;
      }
    case ECMA_TYPE_NUMBER:
      {
        ecma_number_t *num_p = ecma_get_pointer( value.value);
        JERRY_ASSERT( num_p != NULL );

        ecma_number_t *number_copy_p = ecma_alloc_number();
        *number_copy_p = *num_p;

        value_copy = (ecma_value_t) { .value_type = ECMA_TYPE_NUMBER };
        ecma_set_pointer( value_copy.value, number_copy_p);

        break;
      }
    case ECMA_TYPE_STRING:
      {
        ecma_array_first_chunk_t *string_p = ecma_get_pointer( value.value);
        JERRY_ASSERT( string_p != NULL );

        ecma_array_first_chunk_t *string_copy_p = ecma_duplicate_ecma_string( string_p);

        value_copy = (ecma_value_t) { .value_type = ECMA_TYPE_STRING };
        ecma_set_pointer( value_copy.value, string_copy_p);

        break;
      }
    case ECMA_TYPE_OBJECT:
      {
        ecma_object_t *obj_p = ecma_get_pointer( value.value);
        JERRY_ASSERT( obj_p != NULL );

        ecma_ref_object( obj_p);

        value_copy = value;

        break;
      }
    case ECMA_TYPE__COUNT:
      {
        JERRY_UNREACHABLE();
      }
  }

  return value_copy;
} /* ecma_copy_value */

/**
 * Free the ecma-value
 */
void
ecma_free_value( ecma_value_t value) /**< value description */
{
  switch ( (ecma_type_t) value.value_type )
  {
    case ECMA_TYPE_SIMPLE:
      {
        /* doesn't hold additional memory */
        break;
      }

    case ECMA_TYPE_NUMBER:
      {
        ecma_number_t *number_p = ecma_get_pointer( value.value);
        ecma_dealloc_number( number_p);
        break;
      }

    case ECMA_TYPE_STRING:
      {
        ecma_array_first_chunk_t *string_p = ecma_get_pointer( value.value);
        ecma_free_array( string_p);
        break;
      }

    case ECMA_TYPE_OBJECT:
      {
        ecma_deref_object( ecma_get_pointer( value.value));
        break;
      }

    case ECMA_TYPE__COUNT:
      {
        JERRY_UNREACHABLE();
      }
  }
} /* ecma_free_value */

/**
 * Completion value constructor
 *
 * @return completion value
 */
ecma_completion_value_t
ecma_make_completion_value(ecma_completion_type_t type, /**< type */
                         ecma_value_t value, /**< value */
                         uint8_t target) /**< target */
{
  return (ecma_completion_value_t) { .type = type, .value = value, .target = target };
} /* ecma_make_completion_value */

/**
 * Simple normal completion value constructor
 *
 * @return completion value
 */
ecma_completion_value_t
ecma_make_simple_completion_value( ecma_simple_value_t simple_value) /**< simple ecma-value */
{
  JERRY_ASSERT( simple_value == ECMA_SIMPLE_VALUE_UNDEFINED
                || simple_value == ECMA_SIMPLE_VALUE_NULL
                || simple_value == ECMA_SIMPLE_VALUE_FALSE
                || simple_value == ECMA_SIMPLE_VALUE_TRUE );

  return ecma_make_completion_value( ECMA_COMPLETION_TYPE_NORMAL,
                                     ecma_make_simple_value( simple_value),
                                     ECMA_TARGET_ID_RESERVED);
} /* ecma_make_simple_completion_value */

/**
 * Throw completion value constructor.
 *
 * @return 'throw' completion value
 */
ecma_completion_value_t
ecma_make_throw_value( ecma_object_t *exception_p) /**< an object */
{
  JERRY_ASSERT( exception_p != NULL && !exception_p->is_lexical_environment );

  ecma_value_t exception = ecma_make_object_value( exception_p);

  return ecma_make_completion_value(ECMA_COMPLETION_TYPE_THROW,
                                  exception,
                                  ECMA_TARGET_ID_RESERVED);                                  
} /* ecma_make_throw_value */

/**
 * Empty completion value constructor.
 *
 * @return (normal, empty, reserved) completion value.
 */
ecma_completion_value_t
ecma_make_empty_completion_value( void)
{
  return ecma_make_completion_value( ECMA_COMPLETION_TYPE_NORMAL,
                                     ecma_make_simple_value( ECMA_SIMPLE_VALUE_EMPTY),
                                     ECMA_TARGET_ID_RESERVED);
} /* ecma_make_empty_completion_value */

/**
 * Copy ecma-completion value.
 *
 * @return (source.type, ecma_copy_value( source.value), source.target).
 */
ecma_completion_value_t
ecma_copy_completion_value( ecma_completion_value_t value) /**< completion value */
{
  return ecma_make_completion_value( value.type,
                                     ecma_copy_value( value.value),
                                     value.target);
} /* ecma_copy_completion_value */

/**
 * Free the completion value.
 */
void
ecma_free_completion_value( ecma_completion_value_t completion_value) /**< completion value */
{
  switch ( completion_value.type )
    {
    case ECMA_COMPLETION_TYPE_NORMAL:
    case ECMA_COMPLETION_TYPE_THROW:
    case ECMA_COMPLETION_TYPE_RETURN:
      ecma_free_value( completion_value.value);
      break;
    case ECMA_COMPLETION_TYPE_CONTINUE:
    case ECMA_COMPLETION_TYPE_BREAK:
    case ECMA_COMPLETION_TYPE_EXIT:
      JERRY_ASSERT( completion_value.value.value_type == ECMA_TYPE_SIMPLE );
      break;
    }
} /* ecma_free_completion_value */

/**
 * Check if the completion value is normal value.
 *
 * @return true - if the completion type is normal,
 *         false - otherwise.
 */
bool
ecma_is_completion_value_normal( ecma_completion_value_t value) /**< completion value */
{
  return ( value.type == ECMA_COMPLETION_TYPE_NORMAL );
} /* ecma_is_completion_value_normal */

/**
 * Check if the completion value is throw value.
 *
 * @return true - if the completion type is throw,
 *         false - otherwise.
 */
bool
ecma_is_completion_value_throw( ecma_completion_value_t value) /**< completion value */
{
  return ( value.type == ECMA_COMPLETION_TYPE_THROW );
} /* ecma_is_completion_value_throw */

/**
 * Check if the completion value is specified normal simple value.
 *
 * @return true - if the completion type is normal and
 *                value contains specified simple ecma-value,
 *         false - otherwise.
 */
bool
ecma_is_completion_value_normal_simple_value(ecma_completion_value_t value, /**< completion value */
                                             ecma_simple_value_t simple_value) /**< simple value to check for equality with */
{
  return ( value.type == ECMA_COMPLETION_TYPE_NORMAL
           && value.value.value_type == ECMA_TYPE_SIMPLE
           && value.value.value == simple_value );
} /* ecma_is_completion_value_normal_simple_value */

/**
 * Check if the completion value is normal true.
 *
 * @return true - if the completion type is normal and
 *                value contains ecma-true simple value,
 *         false - otherwise.
 */
bool
ecma_is_completion_value_normal_true( ecma_completion_value_t value) /**< completion value */
{
  return ecma_is_completion_value_normal_simple_value( value, ECMA_SIMPLE_VALUE_TRUE);
} /* ecma_is_completion_value_normal_true */

/**
 * Check if the completion value is normal false.
 *
 * @return true - if the completion type is normal and
 *                value contains ecma-false simple value,
 *         false - otherwise.
 */
bool
ecma_is_completion_value_normal_false( ecma_completion_value_t value) /**< completion value */
{
  return ecma_is_completion_value_normal_simple_value( value, ECMA_SIMPLE_VALUE_FALSE);
} /* ecma_is_completion_value_normal_false */

/**
 * Check if the completion value is normal empty value.
 *
 * @return true - if the completion type is normal and
 *                value contains empty simple value,
 *         false - otherwise.
 */
bool
ecma_is_empty_completion_value( ecma_completion_value_t value) /**< completion value */
{
  return ( ecma_is_completion_value_normal( value)
           && ecma_is_value_empty( value.value) );
} /* ecma_is_empty_completion_value */

/**
 * @}
 * @}
 */