//===----------------------------------------------------------------------===//
//
//                         BusTub
//
// nlj_as_hash_join.cpp
//
// Identification: src/optimizer/nlj_as_hash_join.cpp
//
// Copyright (c) 2015-2025, Carnegie Mellon University Database Group
//
//===----------------------------------------------------------------------===//

#include <algorithm>
#include <memory>
#include "catalog/column.h"
#include "catalog/schema.h"
#include "common/exception.h"
#include "common/macros.h"
#include "execution/expressions/column_value_expression.h"
#include "execution/expressions/comparison_expression.h"
#include "execution/expressions/constant_value_expression.h"
#include "execution/plans/abstract_plan.h"
#include "execution/plans/filter_plan.h"
#include "execution/plans/hash_join_plan.h"
#include "execution/plans/nested_loop_join_plan.h"
#include "execution/plans/projection_plan.h"
#include "optimizer/optimizer.h"
#include "type/type_id.h"

namespace bustub {

/**
 * @brief optimize nested loop join into hash join.
 * In the starter code, we will check NLJs with exactly one equal condition. You can further support optimizing joins
 * with multiple eq conditions.
 */
auto Optimizer::OptimizeNLJAsHashJoin(const AbstractPlanNodeRef &plan) -> AbstractPlanNodeRef {
  // TODO(student): implement NestedLoopJoin -> HashJoin optimizer rule
  // Note for Spring 2025: You should support join keys of any number of conjunction of equi-conditions:
  // E.g. <column expr> = <column expr> AND <column expr> = <column expr> AND ...
  return plan;
}

}  // namespace bustub