use crate::Local;
use crate::Value;

extern "C" {
  fn v8__Value__IsUndefined(this: &Value) -> bool;
  fn v8__Value__IsNull(this: &Value) -> bool;
  fn v8__Value__IsNullOrUndefined(this: &Value) -> bool;
  fn v8__Value__IsString(this: &Value) -> bool;
  fn v8__Value__IsNumber(this: &Value) -> bool;
  fn v8__Value__IsArray(this: &Value) -> bool;
  fn v8__Value__IsFunction(this: &Value) -> bool;
  fn v8__Value__IsObject(this: &Value) -> bool;
  fn v8__Value__StrictEquals(this: &Value, that: &Value) -> bool;
  fn v8__Value__SameValue(this: &Value, that: &Value) -> bool;
}

impl Value {
  /// Returns true if this value is the undefined value.  See ECMA-262 4.3.10.
  pub fn is_undefined(&self) -> bool {
    unsafe { v8__Value__IsUndefined(self) }
  }

  /// Returns true if this value is the null value.  See ECMA-262 4.3.11.
  pub fn is_null(&self) -> bool {
    unsafe { v8__Value__IsNull(self) }
  }

  /// Returns true if this value is either the null or the undefined value.
  /// See ECMA-262 4.3.11. and 4.3.12
  pub fn is_null_or_undefined(&self) -> bool {
    unsafe { v8__Value__IsNullOrUndefined(self) }
  }

  /// Returns true if this value is an instance of the String type.
  /// See ECMA-262 8.4.
  pub fn is_string(&self) -> bool {
    unsafe { v8__Value__IsString(self) }
  }

  /// Returns true if this value is an array. Note that it will return false for
  /// an Proxy for an array.
  pub fn is_array(&self) -> bool {
    unsafe { v8__Value__IsArray(self) }
  }

  /// Returns true if this value is a function.
  pub fn is_function(&self) -> bool {
    unsafe { v8__Value__IsFunction(self) }
  }

  /// Returns true if this value is an object.
  pub fn is_object(&self) -> bool {
    unsafe { v8__Value__IsObject(self) }
  }

  /// Returns true if this value is a number.
  pub fn is_number(&self) -> bool {
    unsafe { v8__Value__IsNumber(self) }
  }

  pub fn strict_equals<'sc>(&self, that: Local<'sc, Value>) -> bool {
    unsafe { v8__Value__StrictEquals(self, &that) }
  }

  pub fn same_value<'sc>(&self, that: Local<'sc, Value>) -> bool {
    unsafe { v8__Value__SameValue(self, &that) }
  }
}