// 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/ap/include/axpr/constants.h"
#include "paddle/ap/include/axpr/method_class.h"
#include "paddle/ap/include/axpr/pointer_value.h"

namespace ap::axpr {

template <typename ValueT>
struct PointerValueMethodClass {
  using This = PointerValueMethodClass;
  using Self = PointerValue;

  adt::Result<ValueT> ToString(const Self& self) {
    return self.Match([](const auto* impl) -> std::string {
      std::ostringstream ss;
      ss << impl;
      return ss.str();
    });
  }

  adt::Result<ValueT> Hash(const Self& self) {
    return self.Match([](const auto* impl) -> int64_t {
      return reinterpret_cast<int64_t>(impl);
    });
  }

  template <typename BuiltinUnarySymbol>
  static BuiltinUnaryFunc<ValueT> GetBuiltinUnaryFunc() {
    return adt::Nothing{};
  }

  template <typename BuiltinBinarySymbol>
  static BuiltinBinaryFunc<ValueT> GetBuiltinBinaryFunc() {
    if constexpr (std::is_same_v<BuiltinBinarySymbol, builtin_symbol::EQ>) {
      return &This::EQ;
    } else if constexpr (std::is_same_v<BuiltinBinarySymbol,  // NOLINT
                                        builtin_symbol::NE>) {
      return &This::NE;
    } else {
      return adt::Nothing{};
    }
  }

  static Result<ValueT> EQ(const ValueT& lhs_val, const ValueT& rhs_val) {
    const auto& opt_lhs = lhs_val.template TryGet<PointerValue>();
    ADT_RETURN_IF_ERR(opt_lhs);
    const auto& lhs = opt_lhs.GetOkValue();
    const auto& opt_rhs = rhs_val.template TryGet<PointerValue>();
    ADT_RETURN_IF_ERR(opt_rhs);
    const auto& rhs = opt_rhs.GetOkValue();
    const auto& pattern_match =
        ::common::Overloaded{[](auto lhs, auto rhs) -> ValueT {
          if constexpr (std::is_same_v<decltype(lhs), decltype(rhs)>) {
            return lhs == rhs;
          } else {
            return false;
          }
        }};
    return std::visit(pattern_match, lhs.variant(), rhs.variant());
  }

  static Result<ValueT> NE(const ValueT& lhs_val, const ValueT& rhs_val) {
    const auto& opt_lhs = lhs_val.template TryGet<PointerValue>();
    ADT_RETURN_IF_ERR(opt_lhs);
    const auto& lhs = opt_lhs.GetOkValue();
    const auto& opt_rhs = rhs_val.template TryGet<PointerValue>();
    ADT_RETURN_IF_ERR(opt_rhs);
    const auto& rhs = opt_rhs.GetOkValue();
    const auto& pattern_match =
        ::common::Overloaded{[](auto lhs, auto rhs) -> ValueT {
          if constexpr (std::is_same_v<decltype(lhs), decltype(rhs)>) {
            return lhs != rhs;
          } else {
            return true;
          }
        }};
    return std::visit(pattern_match, lhs.variant(), rhs.variant());
  }
};

template <typename ValueT>
struct MethodClassImpl<ValueT, PointerValue>
    : public PointerValueMethodClass<ValueT> {};

template <typename ValueT>
struct MethodClassImpl<ValueT, TypeImpl<PointerValue>>
    : public EmptyMethodClass<ValueT> {};

}  // namespace ap::axpr