// Copyright 2005-2024 Google LLC
//
// 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.
//
// See www.openfst.org for extensive documentation on this weighted
// finite-state transducer library.

#ifndef FST_SCRIPT_CONCAT_H_
#define FST_SCRIPT_CONCAT_H_

#include <utility>
#include <vector>

#include <fst/concat.h>
#include <fst/fst.h>
#include <fst/mutable-fst.h>
#include <fst/script/fst-class.h>

namespace fst {
namespace script {

using FstConcatArgs1 = std::pair<MutableFstClass*, const FstClass&>;

template <class Arc>
void Concat(FstConcatArgs1* args) {
  MutableFst<Arc>* fst1 = std::get<0>(*args)->GetMutableFst<Arc>();
  const Fst<Arc>& fst2 = *std::get<1>(*args).GetFst<Arc>();
  Concat(fst1, fst2);
}

using FstConcatArgs2 = std::pair<const FstClass&, MutableFstClass*>;

template <class Arc>
void Concat(FstConcatArgs2* args) {
  const Fst<Arc>& fst1 = *std::get<0>(*args).GetFst<Arc>();
  MutableFst<Arc>* fst2 = std::get<1>(*args)->GetMutableFst<Arc>();
  Concat(fst1, fst2);
}

using FstConcatArgs3 =
    std::pair<const std::vector<FstClass*>&, MutableFstClass*>;

template <class Arc>
void Concat(FstConcatArgs3* args) {
  const auto& untyped_fsts1 = std::get<0>(*args);
  std::vector<const Fst<Arc>*> typed_fsts1;
  typed_fsts1.reserve(untyped_fsts1.size());
  for (const auto& untyped_fst1 : untyped_fsts1) {
    typed_fsts1.emplace_back(untyped_fst1->GetFst<Arc>());
  }
  MutableFst<Arc>* fst2 = std::get<1>(*args)->GetMutableFst<Arc>();
  Concat(typed_fsts1, fst2);
}

void Concat(MutableFstClass* fst1, const FstClass& fst2);

void Concat(const FstClass& fst1, MutableFstClass* fst2);

void Concat(const std::vector<FstClass*>& fsts1, MutableFstClass* fst2);

}  // namespace script
}  // namespace fst

#endif  // FST_SCRIPT_CONCAT_H_
