/* Copyright (c) 2018 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 <map>
#include <memory>
#include <string>
#include <vector>

#include "paddle/fluid/framework/ir/node.h"
#include "paddle/fluid/framework/program_desc.h"
#include "paddle/fluid/platform/enforce.h"
#include "paddle/fluid/platform/variant.h"

namespace paddle {
namespace framework {
namespace ir {

class Graph {
 public:
  explicit Graph(const ProgramDesc &program);

  virtual ~Graph() {
    for (auto &attr : attrs_) {
      attr_dels_[attr.first]();
    }
    attrs_.clear();
    attr_dels_.clear();
  }

  template <typename AttrType>
  AttrType &Get(const std::string &attr_name) const {
    return *boost::any_cast<AttrType *>(attrs_.at(attr_name));
  }

  template <typename AttrType>
  void Set(const std::string &attr_name, AttrType *attr) {
    PADDLE_ENFORCE(attrs_.count(attr_name) == 0);
    attrs_[attr_name] = attr;
    attr_dels_[attr_name] = [attr, attr_name]() {
      VLOG(3) << "deleting " << attr_name;
      delete attr;
    };
  }

  const std::unordered_set<ir::Node *> &Nodes() const { return node_set_; }

  ir::Node *CreateVarNode(VarDesc *var_desc) {
    return AddNode(new ir::Node(var_desc));
  }

  ir::Node *CreateOpNode(OpDesc *op_desc) {
    return AddNode(new ir::Node(op_desc));
  }

  ir::Node *CreateControlDepVar() {
    // TODO(panyx0718): control var name should be unique.
    const std::string name = string::Sprintf(
        "%s@%llu", ir::Node::kControlDepVarName, node_set_.size());
    return AddNode(new ir::Node(name, ir::Node::Type::kVariable));
  }

  ir::Node *CreateEmptyNode(const std::string &name, ir::Node::Type type) {
    return AddNode(new ir::Node(name, type));
  }

  std::vector<std::unique_ptr<ir::Node>> ReleaseNodes() {
    std::vector<std::unique_ptr<ir::Node>> ret;
    for (auto &n : nodes_) {
      ret.emplace_back(n.second.release());
    }
    nodes_.clear();
    node_set_.clear();
    return ret;
  }

 private:
  // This method takes ownership of `node`.
  ir::Node *AddNode(ir::Node *node) {
    PADDLE_ENFORCE(node_set_.find(node) == node_set_.end());
    nodes_[node].reset(node);
    node_set_.insert(node);
    return node;
  }

  void RemoveNode(ir::Node *node) {
    PADDLE_ENFORCE(node_set_.find(node) != node_set_.end());
    node_set_.erase(node);
    nodes_.erase(node);
  }

  // NOTE: program_ shouldn't be exposed to user.
  const ProgramDesc &program_;
  std::map<std::string, boost::any> attrs_;
  std::map<std::string, std::function<void(void)>> attr_dels_;
  std::map<ir::Node *, std::unique_ptr<ir::Node>> nodes_;
  std::unordered_set<ir::Node *> node_set_;
};
}  // namespace ir
}  // namespace framework
}  // namespace paddle