/**
 * Copyright 2021 Huawei Technologies Co., Ltd
 *
 * 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 "graph/passes/branch_logical_remove_pass.h"
#include "graph/utils/node_utils.h"

namespace ge {
Status BranchLogicalRemovePass::Run(ComputeGraphPtr graph) {
  BranchExecCondCalculator calculator(graph);
  if (calculator.Calculate() != GRAPH_SUCCESS) {
    GELOGE(FAILED, "Calculate branch exec cond for removing logical dead branch failed.");
    return FAILED;
  }
  const auto &node_exec_cond = calculator.GetBranchExecCond();
  if (node_exec_cond.empty()) {
    GELOGI("No branch in graph %s, skip.", graph->GetName().c_str());
    return SUCCESS;
  }

  for (const auto &node : graph->GetDirectNode()) {
    const std::string &type = NodeUtils::GetNodeType(node);
    if ((type == SWITCH) || (type == REFSWITCH)) {
      if (RemoveRedundantSwitch(node_exec_cond, node) != SUCCESS) {
        GELOGE(FAILED, "Remove redundant switch %s failed.", node->GetName().c_str());
        return FAILED;
      }
    } else if ((type == MERGE) || (type == REFMERGE)) {
      if (RemoveDeadInputForMerge(node_exec_cond, node) != SUCCESS) {
        GELOGE(FAILED, "Remove dead input for merge %s failed.", node->GetName().c_str());
        return FAILED;
      }
    }
  }

  return SUCCESS;
}

Status BranchLogicalRemovePass::RemoveRedundantSwitch(const std::map<NodePtr, LogicOperatorItem> &node_exec_cond,
                                                      const NodePtr &switch_node) {
  const auto &iter = node_exec_cond.find(switch_node);
  if (iter == node_exec_cond.end()) {
    GELOGE(FAILED, "Find for exec cond for node %s.", switch_node->GetName().c_str());
    return FAILED;
  }
  if (!iter->second.IsValid()) {
    return SUCCESS;
  }
  for (const auto &pair : switch_node->GetOutDataNodesAndAnchors()) {
    const auto &out_node = pair.first;
    const auto &out_iter = node_exec_cond.find(out_node);
    if (out_iter == node_exec_cond.end()) {
      GELOGE(FAILED, "Find for exec cond for node %s.", out_node->GetName().c_str());
      return FAILED;
    }
    if (!out_iter->second.IsValid()) {
      GELOGI("Remove data edge %s:%d->%s:%d.", switch_node->GetName().c_str(),
             pair.second->GetPeerOutAnchor()->GetIdx(), out_node->GetName().c_str(), pair.second->GetIdx());
      if (GraphUtils::RemoveEdge(pair.second->GetPeerOutAnchor(), pair.second) != GRAPH_SUCCESS) {
        GELOGE(FAILED, "Remove data edge %s:%d->%s:%d failed.", switch_node->GetName().c_str(),
               pair.second->GetPeerOutAnchor()->GetIdx(), out_node->GetName().c_str(), pair.second->GetIdx());
        return FAILED;
      }
    } else if (iter->second.String() == out_iter->second.String()) {
      GELOGI("Remove data edge %s:%d->%s:%d.", switch_node->GetName().c_str(),
             pair.second->GetPeerOutAnchor()->GetIdx(), out_node->GetName().c_str(), pair.second->GetIdx());
      if (GraphUtils::RemoveEdge(pair.second->GetPeerOutAnchor(), pair.second) != GRAPH_SUCCESS) {
        GELOGE(FAILED, "Remove data edge %s:%d->%s:%d failed.", switch_node->GetName().c_str(),
               pair.second->GetPeerOutAnchor()->GetIdx(), out_node->GetName().c_str(), pair.second->GetIdx());
        return FAILED;
      }

      const auto data_input_anchor = switch_node->GetInDataAnchor(SWITCH_DATA_INPUT);
      GE_CHECK_NOTNULL(data_input_anchor);
      const auto &peer_out_anchor = data_input_anchor->GetPeerOutAnchor();
      GE_CHECK_NOTNULL(peer_out_anchor);
      GELOGI("Add data edge %s:%d->%s:%d.", peer_out_anchor->GetOwnerNode()->GetName().c_str(),
             pair.second->GetPeerOutAnchor()->GetIdx(), out_node->GetName().c_str(), pair.second->GetIdx());
      if (GraphUtils::AddEdge(peer_out_anchor, pair.second) != GRAPH_SUCCESS) {
        GELOGE(FAILED, "Add data edge %s:%d->%s:%d failed.", peer_out_anchor->GetOwnerNode()->GetName().c_str(),
               pair.second->GetPeerOutAnchor()->GetIdx(), out_node->GetName().c_str(), pair.second->GetIdx());
        return FAILED;
      }
    }
  }

  return SUCCESS;
}

Status BranchLogicalRemovePass::RemoveDeadInputForMerge(const std::map<NodePtr, LogicOperatorItem> &node_exec_cond,
                                                        const NodePtr &merge_node) {
  const auto &iter = node_exec_cond.find(merge_node);
  if (iter == node_exec_cond.end()) {
    GELOGE(FAILED, "Find for exec cond for node %s.", merge_node->GetName().c_str());
    return FAILED;
  }
  if (!iter->second.IsValid()) {
    return SUCCESS;
  }
  for (const auto &in_data_anchor : merge_node->GetAllInDataAnchors()) {
    const auto &peer_out_anchor = in_data_anchor->GetPeerOutAnchor();
    if (peer_out_anchor == nullptr) { continue; }
    const auto &in_node = peer_out_anchor->GetOwnerNode();
    const auto &in_iter = node_exec_cond.find(in_node);
    if (in_iter == node_exec_cond.end()) {
      GELOGE(FAILED, "Find for exec cond for node %s.", in_node->GetName().c_str());
      return FAILED;
    }
    if (!in_iter->second.IsValid()) {
      GELOGI("Remove data edge %s:%d->%s:%d.", in_node->GetName().c_str(), peer_out_anchor->GetIdx(),
             merge_node->GetName().c_str(), in_data_anchor->GetIdx());
      if (GraphUtils::RemoveEdge(peer_out_anchor, in_data_anchor) != GRAPH_SUCCESS) {
        GELOGE(FAILED, "Remove data edge %s:%d->%s:%d failed.", in_node->GetName().c_str(), peer_out_anchor->GetIdx(),
               merge_node->GetName().c_str(), in_data_anchor->GetIdx());
        return FAILED;
      }
    }
  }
  return SUCCESS;
}
}  // namespace ge