// 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.

#include "src/transform/manager.h"

/// If set to 1 then the transform::Manager will dump the WGSL of the program
/// before and after each transform. Helpful for debugging bad output.
#define PRINT_PROGRAM_FOR_EACH_TRANSFORM 0

#if PRINT_PROGRAM_FOR_EACH_TRANSFORM
#define IF_PRINT_PROGRAM(x) x
#else  // PRINT_PROGRAM_FOR_EACH_TRANSFORM
#define IF_PRINT_PROGRAM(x)
#endif  // PRINT_PROGRAM_FOR_EACH_TRANSFORM

TINT_INSTANTIATE_TYPEINFO(tint::transform::Manager);

namespace tint {
namespace transform {

Manager::Manager() = default;
Manager::~Manager() = default;

Output Manager::Run(const Program* program, const DataMap& data) {
#if PRINT_PROGRAM_FOR_EACH_TRANSFORM
  auto print_program = [&](const char* msg, const Transform* transform) {
    auto wgsl = Program::printer(program);
    std::cout << "---------------------------------------------------------"
              << std::endl;
    std::cout << "-- " << msg << " " << transform->TypeInfo().name << ":"
              << std::endl;
    std::cout << "---------------------------------------------------------"
              << std::endl;
    std::cout << wgsl << std::endl;
    std::cout << "---------------------------------------------------------"
              << std::endl
              << std::endl;
  };
#endif

  Output out;
  if (!transforms_.empty()) {
    for (const auto& transform : transforms_) {
      IF_PRINT_PROGRAM(print_program("Input to", transform.get()));

      auto res = transform->Run(program, data);
      out.program = std::move(res.program);
      out.data.Add(std::move(res.data));
      program = &out.program;
      if (!program->IsValid()) {
        IF_PRINT_PROGRAM(print_program("Invalid output of", transform.get()));
        return out;
      }

      if (transform == transforms_.back()) {
        IF_PRINT_PROGRAM(print_program("Output of", transform.get()));
      }
    }
  } else {
    out.program = program->Clone();
  }

  return out;
}

}  // namespace transform
}  // namespace tint