// Copyright 2015 The Chromium Authors. All rights reserved.
// Use of this source code is governed by a BSD-style license that can be
// found in the LICENSE file.

#ifndef MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_PTR_INFO_H_
#define MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_PTR_INFO_H_

#include <stdint.h>
#include <utility>

#include "base/macros.h"
#include "mojo/public/cpp/bindings/scoped_interface_endpoint_handle.h"

namespace mojo {

// AssociatedInterfacePtrInfo stores necessary information to construct an
// associated interface pointer. It is similar to InterfacePtrInfo except that
// it doesn't own a message pipe handle.
template <typename Interface>
class AssociatedInterfacePtrInfo {
 public:
  AssociatedInterfacePtrInfo() : version_(0u) {}
  AssociatedInterfacePtrInfo(std::nullptr_t) : version_(0u) {}

  AssociatedInterfacePtrInfo(AssociatedInterfacePtrInfo&& other)
      : handle_(std::move(other.handle_)), version_(other.version_) {
    other.version_ = 0u;
  }

  AssociatedInterfacePtrInfo(ScopedInterfaceEndpointHandle handle,
                             uint32_t version)
      : handle_(std::move(handle)), version_(version) {}

  ~AssociatedInterfacePtrInfo() {}

  AssociatedInterfacePtrInfo& operator=(AssociatedInterfacePtrInfo&& other) {
    if (this != &other) {
      handle_ = std::move(other.handle_);
      version_ = other.version_;
      other.version_ = 0u;
    }

    return *this;
  }

  bool is_valid() const { return handle_.is_valid(); }

  explicit operator bool() const { return handle_.is_valid(); }

  ScopedInterfaceEndpointHandle PassHandle() {
    return std::move(handle_);
  }
  const ScopedInterfaceEndpointHandle& handle() const { return handle_; }
  void set_handle(ScopedInterfaceEndpointHandle handle) {
    handle_ = std::move(handle);
  }

  uint32_t version() const { return version_; }
  void set_version(uint32_t version) { version_ = version; }

  bool Equals(const AssociatedInterfacePtrInfo& other) const {
    if (this == &other)
      return true;

    // Now that the two refer to different objects, they are equivalent if
    // and only if they are both invalid.
    return !is_valid() && !other.is_valid();
  }

 private:
  ScopedInterfaceEndpointHandle handle_;
  uint32_t version_;

  DISALLOW_COPY_AND_ASSIGN(AssociatedInterfacePtrInfo);
};

}  // namespace mojo

#endif  // MOJO_PUBLIC_CPP_BINDINGS_ASSOCIATED_INTERFACE_PTR_INFO_H_