// Copyright (c) 2024 PaddlePaddle Authors. All Rights Reserved.
//
// 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.

#pragma once
#include "paddle/cinn/hlir/framework/pir/trivial_op_impl.h"

namespace cinn::fusion {

using TrivialOp = cinn::hlir::framework::pir::trivial_fusion_detail::TrivialOp;
using ReduceOp = cinn::hlir::framework::pir::trivial_fusion_detail::ReduceOp;
using FusibleOp = cinn::hlir::framework::pir::trivial_fusion_detail::FusibleOp;

struct FusibleOp2Expr {
  std::vector<ir::Expr> operator()(const TrivialOp& op) {
    return {op.GetFuncBody()};
  }
  std::vector<ir::Expr> operator()(const ReduceOp& op) {
    return {op.GetFuncBody()};
  }
};

struct ApplyAxisTransform {
  explicit ApplyAxisTransform(const ir::Expr& expr) : expr_(expr) {}
  ir::Expr operator()(const IdentityTransformPtr& trans) { return expr_; }
  ir::Expr operator()(const TransposeTransformPtr& trans);
  ir::Expr operator()(const AppendAxisTransformPtr& trans);
  ir::Expr operator()(const DeleteAxisTransformPtr& trans);
  ir::Expr operator()(const ReshapeTransformPtr& trans);
  ir::Expr operator()(const UnsupportedTransformPtr& trans) {
    PADDLE_THROW(
        ::common::errors::Unavailable("Cannot apply UnsupportedTransform!"));
  }

 private:
  ir::Expr expr_;
};

std::vector<ir::Expr> GetFusibleOpsExpr(std::vector<FusibleOp> fusion_ops);

std::vector<ir::Expr> TopoSort(const std::vector<ir::Expr>& op_exprs);

std::vector<ir::Tensor> GetOutputTensors(const ir::Expr& op_expr);

}  // namespace cinn::fusion