// Copyright 2020 The Tint Authors.
//
// 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.

#ifndef SRC_TRANSFORM_MANAGER_H_
#define SRC_TRANSFORM_MANAGER_H_

#include <memory>
#include <utility>
#include <vector>

#include "src/transform/transform.h"

namespace tint {
namespace transform {

/// A collection of Transforms that act as a single Transform.
/// The inner transforms will execute in the appended order.
/// If any inner transform fails the manager will return immediately and
/// the error can be retrieved with the Output's diagnostics.
class Manager : public Castable<Manager, Transform> {
 public:
  /// Constructor
  Manager();
  ~Manager() override;

  /// Add pass to the manager
  /// @param transform the transform to append
  void append(std::unique_ptr<Transform> transform) {
    transforms_.push_back(std::move(transform));
  }

  /// Add pass to the manager of type `T`, constructed with the provided
  /// arguments.
  /// @param args the arguments to forward to the `T` constructor
  template <typename T, typename... ARGS>
  void Add(ARGS&&... args) {
    transforms_.emplace_back(std::make_unique<T>(std::forward<ARGS>(args)...));
  }

  /// Runs the transforms on `program`, returning the transformation result.
  /// @param program the source program to transform
  /// @param data optional extra transform-specific input data
  /// @returns the transformed program and diagnostics
  Output Run(const Program* program, const DataMap& data = {}) override;

 private:
  std::vector<std::unique_ptr<Transform>> transforms_;
};

}  // namespace transform
}  // namespace tint

#endif  // SRC_TRANSFORM_MANAGER_H_