use crate::isolate::Isolate;
use crate::support::int;
use crate::support::MapFnTo;
use crate::support::MaybeBool;
use crate::AccessorNameGetterCallback;
use crate::AccessorNameSetterCallback;
use crate::Array;
use crate::Context;
use crate::HandleScope;
use crate::Local;
use crate::Map;
use crate::Name;
use crate::Object;
use crate::Private;
use crate::PropertyAttribute;
use crate::Value;
use std::convert::TryFrom;

extern "C" {
  fn v8__Object__New(isolate: *mut Isolate) -> *const Object;
  fn v8__Object__New__with_prototype_and_properties(
    isolate: *mut Isolate,
    prototype_or_null: *const Value,
    names: *const *const Name,
    values: *const *const Value,
    length: usize,
  ) -> *const Object;
  fn v8__Object__SetAccessor(
    this: *const Object,
    context: *const Context,
    key: *const Name,
    getter: AccessorNameGetterCallback,
  ) -> MaybeBool;
  fn v8__Object__SetAccessorWithSetter(
    this: *const Object,
    context: *const Context,
    key: *const Name,
    getter: AccessorNameGetterCallback,
    setter: AccessorNameSetterCallback,
  ) -> MaybeBool;
  fn v8__Object__Get(
    this: *const Object,
    context: *const Context,
    key: *const Value,
  ) -> *const Value;
  fn v8__Object__GetIndex(
    this: *const Object,
    context: *const Context,
    index: u32,
  ) -> *const Value;
  fn v8__Object__GetPrototype(this: *const Object) -> *const Value;
  fn v8__Object__Set(
    this: *const Object,
    context: *const Context,
    key: *const Value,
    value: *const Value,
  ) -> MaybeBool;
  fn v8__Object__SetIndex(
    this: *const Object,
    context: *const Context,
    index: u32,
    value: *const Value,
  ) -> MaybeBool;
  fn v8__Object__SetPrototype(
    this: *const Object,
    context: *const Context,
    prototype: *const Value,
  ) -> MaybeBool;
  fn v8__Object__CreateDataProperty(
    this: *const Object,
    context: *const Context,
    key: *const Name,
    value: *const Value,
  ) -> MaybeBool;
  fn v8__Object__DefineOwnProperty(
    this: *const Object,
    context: *const Context,
    key: *const Name,
    value: *const Value,
    attr: PropertyAttribute,
  ) -> MaybeBool;
  fn v8__Object__GetIdentityHash(this: *const Object) -> int;
  fn v8__Object__CreationContext(this: *const Object) -> *const Context;
  fn v8__Object__GetOwnPropertyNames(
    this: *const Object,
    context: *const Context,
  ) -> *const Array;
  fn v8__Object__GetPropertyNames(
    this: *const Object,
    context: *const Context,
  ) -> *const Array;
  fn v8__Object__Has(
    this: *const Object,
    context: *const Context,
    key: *const Value,
  ) -> MaybeBool;
  fn v8__Object__HasIndex(
    this: *const Object,
    context: *const Context,
    index: u32,
  ) -> MaybeBool;
  fn v8__Object__Delete(
    this: *const Object,
    context: *const Context,
    key: *const Value,
  ) -> MaybeBool;
  fn v8__Object__DeleteIndex(
    this: *const Object,
    context: *const Context,
    index: u32,
  ) -> MaybeBool;
  fn v8__Object__InternalFieldCount(this: *const Object) -> int;
  fn v8__Object__GetInternalField(
    this: *const Object,
    index: int,
  ) -> *const Value;
  fn v8__Object__SetInternalField(
    this: *const Object,
    index: int,
    value: *const Value,
  );
  fn v8__Object__GetPrivate(
    this: *const Object,
    context: *const Context,
    key: *const Private,
  ) -> *const Value;
  fn v8__Object__SetPrivate(
    this: *const Object,
    context: *const Context,
    key: *const Private,
    value: *const Value,
  ) -> MaybeBool;
  fn v8__Object__DeletePrivate(
    this: *const Object,
    context: *const Context,
    key: *const Private,
  ) -> MaybeBool;
  fn v8__Object__HasPrivate(
    this: *const Object,
    context: *const Context,
    key: *const Private,
  ) -> MaybeBool;

  fn v8__Array__New(isolate: *mut Isolate, length: int) -> *const Array;
  fn v8__Array__New_with_elements(
    isolate: *mut Isolate,
    elements: *const *const Value,
    length: usize,
  ) -> *const Array;
  fn v8__Array__Length(array: *const Array) -> u32;
  fn v8__Map__Size(map: *const Map) -> usize;
  fn v8__Map__As__Array(this: *const Map) -> *const Array;
}

impl Object {
  /// Creates an empty object.
  pub fn new<'s>(scope: &mut HandleScope<'s>) -> Local<'s, Object> {
    unsafe { scope.cast_local(|sd| v8__Object__New(sd.get_isolate_ptr())) }
      .unwrap()
  }

  /// Creates a JavaScript object with the given properties, and the given
  /// prototype_or_null (which can be any JavaScript value, and if it's null,
  /// the newly created object won't have a prototype at all). This is similar
  /// to Object.create(). All properties will be created as enumerable,
  /// configurable and writable properties.
  pub fn with_prototype_and_properties<'s>(
    scope: &mut HandleScope<'s>,
    prototype_or_null: Local<'s, Value>,
    names: &[Local<Name>],
    values: &[Local<Value>],
  ) -> Local<'s, Object> {
    assert_eq!(names.len(), values.len());
    let names = Local::slice_into_raw(names);
    let values = Local::slice_into_raw(values);
    unsafe {
      scope.cast_local(|sd| {
        v8__Object__New__with_prototype_and_properties(
          sd.get_isolate_ptr(),
          &*prototype_or_null,
          names.as_ptr(),
          values.as_ptr(),
          names.len(),
        )
      })
    }
    .unwrap()
  }

  /// Set only return Just(true) or Empty(), so if it should never fail, use
  /// result.Check().
  pub fn set(
    &self,
    scope: &mut HandleScope,
    key: Local<Value>,
    value: Local<Value>,
  ) -> Option<bool> {
    unsafe {
      v8__Object__Set(self, &*scope.get_current_context(), &*key, &*value)
    }
    .into()
  }

  /// Set only return Just(true) or Empty(), so if it should never fail, use
  /// result.Check().
  pub fn set_index(
    &self,
    scope: &mut HandleScope,
    index: u32,
    value: Local<Value>,
  ) -> Option<bool> {
    unsafe {
      v8__Object__SetIndex(self, &*scope.get_current_context(), index, &*value)
    }
    .into()
  }

  /// Set the prototype object. This does not skip objects marked to be
  /// skipped by proto and it does not consult the security handler.
  pub fn set_prototype(
    &self,
    scope: &mut HandleScope,
    prototype: Local<Value>,
  ) -> Option<bool> {
    unsafe {
      v8__Object__SetPrototype(self, &*scope.get_current_context(), &*prototype)
    }
    .into()
  }

  /// Implements CreateDataProperty (ECMA-262, 7.3.4).
  ///
  /// Defines a configurable, writable, enumerable property with the given value
  /// on the object unless the property already exists and is not configurable
  /// or the object is not extensible.
  ///
  /// Returns true on success.
  pub fn create_data_property(
    &self,
    scope: &mut HandleScope,
    key: Local<Name>,
    value: Local<Value>,
  ) -> Option<bool> {
    unsafe {
      v8__Object__CreateDataProperty(
        self,
        &*scope.get_current_context(),
        &*key,
        &*value,
      )
    }
    .into()
  }

  /// Implements DefineOwnProperty.
  ///
  /// In general, CreateDataProperty will be faster, however, does not allow
  /// for specifying attributes.
  ///
  /// Returns true on success.
  pub fn define_own_property(
    &self,
    scope: &mut HandleScope,
    key: Local<Name>,
    value: Local<Value>,
    attr: PropertyAttribute,
  ) -> Option<bool> {
    unsafe {
      v8__Object__DefineOwnProperty(
        self,
        &*scope.get_current_context(),
        &*key,
        &*value,
        attr,
      )
    }
    .into()
  }

  pub fn get<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    key: Local<Value>,
  ) -> Option<Local<'s, Value>> {
    unsafe {
      scope
        .cast_local(|sd| v8__Object__Get(self, sd.get_current_context(), &*key))
    }
  }

  pub fn get_index<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    index: u32,
  ) -> Option<Local<'s, Value>> {
    unsafe {
      scope.cast_local(|sd| {
        v8__Object__GetIndex(self, sd.get_current_context(), index)
      })
    }
  }

  /// Get the prototype object. This does not skip objects marked to be
  /// skipped by proto and it does not consult the security handler.
  pub fn get_prototype<'s>(
    &self,
    scope: &mut HandleScope<'s>,
  ) -> Option<Local<'s, Value>> {
    unsafe { scope.cast_local(|_| v8__Object__GetPrototype(self)) }
  }

  /// Note: SideEffectType affects the getter only, not the setter.
  pub fn set_accessor(
    &self,
    scope: &mut HandleScope,
    name: Local<Name>,
    getter: impl for<'s> MapFnTo<AccessorNameGetterCallback<'s>>,
  ) -> Option<bool> {
    unsafe {
      v8__Object__SetAccessor(
        self,
        &*scope.get_current_context(),
        &*name,
        getter.map_fn_to(),
      )
    }
    .into()
  }

  pub fn set_accessor_with_setter(
    &self,
    scope: &mut HandleScope,
    name: Local<Name>,
    getter: impl for<'s> MapFnTo<AccessorNameGetterCallback<'s>>,
    setter: impl for<'s> MapFnTo<AccessorNameSetterCallback<'s>>,
  ) -> Option<bool> {
    unsafe {
      v8__Object__SetAccessorWithSetter(
        self,
        &*scope.get_current_context(),
        &*name,
        getter.map_fn_to(),
        setter.map_fn_to(),
      )
    }
    .into()
  }

  /// The `Object` specific equivalent of `Data::get_hash()`.
  /// This function is kept around for testing purposes only.
  #[doc(hidden)]
  pub fn get_identity_hash(&self) -> int {
    unsafe { v8__Object__GetIdentityHash(self) }
  }

  /// Returns the context in which the object was created.
  pub fn creation_context<'s>(
    &self,
    scope: &mut HandleScope<'s>,
  ) -> Local<'s, Context> {
    unsafe { scope.cast_local(|_| v8__Object__CreationContext(self)) }.unwrap()
  }

  /// This function has the same functionality as GetPropertyNames but the
  /// returned array doesn't contain the names of properties from prototype
  /// objects.
  pub fn get_own_property_names<'s>(
    &self,
    scope: &mut HandleScope<'s>,
  ) -> Option<Local<'s, Array>> {
    unsafe {
      scope.cast_local(|sd| {
        v8__Object__GetOwnPropertyNames(self, sd.get_current_context())
      })
    }
  }

  /// Returns an array containing the names of the filtered properties of this
  /// object, including properties from prototype objects. The array returned by
  /// this method contains the same values as would be enumerated by a for-in
  /// statement over this object.
  pub fn get_property_names<'s>(
    &self,
    scope: &mut HandleScope<'s>,
  ) -> Option<Local<'s, Array>> {
    unsafe {
      scope.cast_local(|sd| {
        v8__Object__GetPropertyNames(self, sd.get_current_context())
      })
    }
  }

  // Calls the abstract operation HasProperty(O, P) described in ECMA-262,
  // 7.3.10. Returns true, if the object has the property, either own or on the
  // prototype chain. Interceptors, i.e., PropertyQueryCallbacks, are called if
  // present.
  //
  // This function has the same side effects as JavaScript's variable in object.
  // For example, calling this on a revoked proxy will throw an exception.
  //
  // Note: This function converts the key to a name, which possibly calls back
  // into JavaScript.
  pub fn has<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    key: Local<Value>,
  ) -> Option<bool> {
    unsafe { v8__Object__Has(self, &*scope.get_current_context(), &*key) }
      .into()
  }

  pub fn has_index<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    index: u32,
  ) -> Option<bool> {
    unsafe { v8__Object__HasIndex(self, &*scope.get_current_context(), index) }
      .into()
  }

  pub fn delete<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    key: Local<Value>,
  ) -> Option<bool> {
    unsafe { v8__Object__Delete(self, &*scope.get_current_context(), &*key) }
      .into()
  }

  pub fn delete_index<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    index: u32,
  ) -> Option<bool> {
    unsafe {
      v8__Object__DeleteIndex(self, &*scope.get_current_context(), index)
    }
    .into()
  }

  /// Gets the number of internal fields for this Object.
  pub fn internal_field_count(&self) -> usize {
    let count = unsafe { v8__Object__InternalFieldCount(self) };
    usize::try_from(count).expect("bad internal field count") // Can't happen.
  }

  /// Gets the value from an internal field.
  pub fn get_internal_field<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    index: usize,
  ) -> Option<Local<'s, Value>> {
    // Trying to access out-of-bounds internal fields makes V8 abort
    // in debug mode and access out-of-bounds memory in release mode.
    // The C++ API takes an i32 but doesn't check for indexes < 0, which
    // results in an out-of-bounds access in both debug and release mode.
    if index < self.internal_field_count() {
      if let Ok(index) = int::try_from(index) {
        return unsafe {
          scope.cast_local(|_| v8__Object__GetInternalField(self, index))
        };
      }
    }
    None
  }

  /// Sets the value in an internal field. Returns false when the index
  /// is out of bounds, true otherwise.
  pub fn set_internal_field(&self, index: usize, value: Local<Value>) -> bool {
    // Trying to access out-of-bounds internal fields makes V8 abort
    // in debug mode and access out-of-bounds memory in release mode.
    // The C++ API takes an i32 but doesn't check for indexes < 0, which
    // results in an out-of-bounds access in both debug and release mode.
    if index < self.internal_field_count() {
      if let Ok(index) = int::try_from(index) {
        unsafe { v8__Object__SetInternalField(self, index, &*value) };
        return true;
      }
    }
    false
  }

  /// Functionality for private properties.
  /// This is an experimental feature, use at your own risk.
  /// Note: Private properties are not inherited. Do not rely on this, since it
  /// may change.
  pub fn get_private<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    key: Local<Private>,
  ) -> Option<Local<'s, Value>> {
    unsafe {
      scope.cast_local(|sd| {
        v8__Object__GetPrivate(self, sd.get_current_context(), &*key)
      })
    }
  }

  /// Functionality for private properties.
  /// This is an experimental feature, use at your own risk.
  /// Note: Private properties are not inherited. Do not rely on this, since it
  /// may change.
  pub fn set_private<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    key: Local<Private>,
    value: Local<Value>,
  ) -> Option<bool> {
    unsafe {
      v8__Object__SetPrivate(
        self,
        &*scope.get_current_context(),
        &*key,
        &*value,
      )
    }
    .into()
  }

  /// Functionality for private properties.
  /// This is an experimental feature, use at your own risk.
  /// Note: Private properties are not inherited. Do not rely on this, since it
  /// may change.
  pub fn delete_private<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    key: Local<Private>,
  ) -> Option<bool> {
    unsafe {
      v8__Object__DeletePrivate(self, &*scope.get_current_context(), &*key)
    }
    .into()
  }

  /// Functionality for private properties.
  /// This is an experimental feature, use at your own risk.
  /// Note: Private properties are not inherited. Do not rely on this, since it
  /// may change.
  pub fn has_private<'s>(
    &self,
    scope: &mut HandleScope<'s>,
    key: Local<Private>,
  ) -> Option<bool> {
    unsafe {
      v8__Object__HasPrivate(self, &*scope.get_current_context(), &*key)
    }
    .into()
  }
}

impl Array {
  /// Creates a JavaScript array with the given length. If the length
  /// is negative the returned array will have length 0.
  pub fn new<'s>(scope: &mut HandleScope<'s>, length: i32) -> Local<'s, Array> {
    unsafe {
      scope.cast_local(|sd| v8__Array__New(sd.get_isolate_ptr(), length))
    }
    .unwrap()
  }

  /// Creates a JavaScript array out of a Local<Value> array with a known
  /// length.
  pub fn new_with_elements<'s>(
    scope: &mut HandleScope<'s>,
    elements: &[Local<Value>],
  ) -> Local<'s, Array> {
    if elements.is_empty() {
      return Self::new(scope, 0);
    }
    let elements = Local::slice_into_raw(elements);
    unsafe {
      scope.cast_local(|sd| {
        v8__Array__New_with_elements(
          sd.get_isolate_ptr(),
          elements.as_ptr(),
          elements.len(),
        )
      })
    }
    .unwrap()
  }

  pub fn length(&self) -> u32 {
    unsafe { v8__Array__Length(self) }
  }
}

impl Map {
  pub fn size(&self) -> usize {
    unsafe { v8__Map__Size(self) }
  }
  /// Returns an array of length size() * 2, where index N is the Nth key and
  /// index N + 1 is the Nth value.
  pub fn as_array<'s>(&self, scope: &mut HandleScope<'s>) -> Local<'s, Array> {
    unsafe { scope.cast_local(|_| v8__Map__As__Array(self)) }.unwrap()
  }
}