#pragma once

#include "sql/sql_class.h"

#include "../coders/protocol_fwd.h"
#include "../coders/command_delegate.h"

#include "protocol.h"
#include "meta.h"

namespace rpc_executor {
using KeyPartMap = ::key_part_map;
using KeyRange = ::key_range;
using KeyFlag = enum ha_rkey_function;

class PlanNode;

class Executor {
public:
  static Executor &instance() {
    static Executor executor;
    return executor;
  }

  int execute(const Polarx::ExecPlan::ExecPlan &plan_wrapper,
              polarx_rpc::CcommandDelegate &resultset,
              THD *thd);
  int execute(const Polarx::ExecPlan::AnyPlan &plan,
              const ParamsList &params,
              polarx_rpc::CcommandDelegate &resultset,
              THD *thd);

private:
  int build_and_execute(const Polarx::ExecPlan::AnyPlan &plan_msg,
                        polarx_rpc::CcommandDelegate &resultset,
                        THD *thd);

  int execute_get(const Polarx::ExecPlan::GetPlan &get_plan,
                  polarx_rpc::CcommandDelegate &resultset,
                  THD *thd);
  int execute_batch_get(const Polarx::ExecPlan::GetPlan &batch_get_plan,
                        polarx_rpc::CcommandDelegate &resultset,
                        THD *thd);
  int execute_key_only_scan(
                  const Polarx::ExecPlan::KeyOnlyRangeScan &key_only_scan_plan,
      polarx_rpc::CcommandDelegate &resultset,
                  THD *thd);
  int execute_scan(const Polarx::ExecPlan::RangeScan &scan_plan,
                   polarx_rpc::CcommandDelegate &resultset,
                   THD *thd);
  int execute_project(const Polarx::ExecPlan::TableProject &project,
                      polarx_rpc::CcommandDelegate &resultset,
                      THD *thd);
};

class PlanBuilder {
public:
  static PlanBuilder &instance() {
    static PlanBuilder plan_builder;
    return plan_builder;
  }

  int create_plan_tree(const Polarx::ExecPlan::AnyPlan &plan_msg,
                       polarx_rpc::CcommandDelegate &resultset,
                       InternalDataSet &dataset,
                       THD *thd,
                       std::unique_ptr<PlanNode> &plan);
  int create_project_tree(const Polarx::ExecPlan::TableProject &project_msg,
                          InternalDataSet &dataset,
                          THD *thd,
                          std::unique_ptr<PlanNode> &plan);
  int create_project_tree(const Polarx::ExecPlan::Project &project_msg,
                          InternalDataSet &dataset,
                          THD *thd,
                          std::unique_ptr<PlanNode> &plan);
  int create_filter_tree(const Polarx::ExecPlan::Filter &filter_msg,
                         InternalDataSet &dataset,
                         THD *thd,
                         std::unique_ptr<PlanNode> &plan);
  int create_get_tree(const Polarx::ExecPlan::GetPlan &get_message,
                      InternalDataSet &dataset,
                      THD *thd,
                      std::unique_ptr<PlanNode> &plan);
  int create_scan_tree(const Polarx::ExecPlan::RangeScan &scan_message,
                       InternalDataSet &dataset,
                       THD *thd,
                       std::unique_ptr<PlanNode> &plan);
  int create_scan_tree(const Polarx::ExecPlan::TableScanPlan &scan_message,
                       InternalDataSet &dataset,
                       THD *thd,
                       std::unique_ptr<PlanNode> &plan);

  int create_aggr_tree(const Polarx::ExecPlan::Aggr &aggr_msg,
                       InternalDataSet &dataset, THD *thd,
                       std::unique_ptr<PlanNode> &plan);

private:
  int create(const Polarx::ExecPlan::AnyPlan &plan_message,
             InternalDataSet &dataset,
             THD *thd,
             std::unique_ptr<PlanNode> &plan);
};

class PlanNode {
public:
  virtual ~PlanNode() {}
  virtual int next(InternalDataSet &result) = 0;
  virtual int finish(int ret) = 0;
  std::unique_ptr<PlanNode> left_tree_;
  std::unique_ptr<PlanNode> right_tree_;
  std::unique_ptr<PlanNode> project_info_node_;
};

class ResponseNode : public PlanNode {
public:
  int init(polarx_rpc::CcommandDelegate &resultset,
           InternalDataSet &dataset);
  virtual int next(InternalDataSet &dataset) override;
  virtual int finish(int ret) override;
private:
  std::unique_ptr<Protocol> protocol_;
};

class ProjectNode : public PlanNode {
public:
  int init(const Polarx::ExecPlan::TableProject &project_message,
           InternalDataSet &dataset);
  int init(const Polarx::ExecPlan::Project &project_msg,
           InternalDataSet &dataset);
  virtual int next(InternalDataSet &dataset) override;
  virtual int finish(int ret) override;
private:
  ProjectInfo project_exprs_;
};

class AggrNode : public PlanNode {
public:
  int init(const Polarx::ExecPlan::Aggr &aggr_msg, InternalDataSet &dataset);
  int init_aggr_expr(Polarx::ExecPlan::Aggr::AggrType type, ExprItem *item);
  virtual int next(InternalDataSet &dataset) override;
  virtual int finish(int ret) override;

  bool is_type_valid(Polarx::ExecPlan::Aggr::AggrType type);
  int calculate(InternalDataSet &dataset);

private:
  Polarx::ExecPlan::Aggr::AggrType type_;

  POS pos_;  // just for placeholder
  std::string aggr_name_;
  Item_sum *aggr_expr_;
};

class FilterNode : public PlanNode {
public:
  int init(const ::Polarx::ExecPlan::Filter &filter_msg,
           InternalDataSet &dataset);
  virtual int next(InternalDataSet &dataset) override;
  virtual int finish(int ret) override;
private:
  ExprItem* condition_expr_;
};

class GetNode : public PlanNode {
public:
  int init(const Polarx::ExecPlan::GetPlan &get_msg,
           InternalDataSet &dataset,
           THD *thd);
  virtual int next(InternalDataSet &dataset) override;
  virtual int finish(int ret) override;
private:
  THD *thd_;
  std::unique_ptr<char[]> table_name_ptr_;
  std::unique_ptr<char[]> schema_name_ptr_;
  ExecTable *table_;
  ExecKeyMeta *key_meta_;
  SearchKey search_key_;
  int table_status_ = HA_ERR_INTERNAL_ERROR;
  bool first_next_ = true;
};

class InlineScanNode {
public:
  int init(const Polarx::ExecPlan::RangeScan &scan_msg,
           InternalDataSet &dataset,
           THD *thd);
  int init(const Polarx::ExecPlan::KeyOnlyRangeScan &scan_msg,
           InternalDataSet &dataset,
           THD *thd);
  int init(const Polarx::ExecPlan::TableScanPlan &scan_msg,
           InternalDataSet &dataset,
           THD *thd);
  int seek(InternalDataSet &dataset);
  int next(InternalDataSet &dataset);

  int index_first(InternalDataSet &dataset);
  int index_next(InternalDataSet &dataset);
  int finish(int ret);
private:

  int init(const Polarx::ExecPlan::TableInfo &table_info,
           const char *index_name,
           const RangeInfo &range_info,
           InternalDataSet &dataset,
           THD *thd);

  THD *thd_;
  std::unique_ptr<char[]> table_name_ptr_;
  std::unique_ptr<char[]> schema_name_ptr_;
  ExecTable *table_;
  ExecKeyMeta *key_meta_;
  RangeSearchKey range_key_;
  int64_t flags_;
  int table_status_ = HA_ERR_INTERNAL_ERROR;
  bool key_only_ = false;
};

class ScanNode : public PlanNode {
public:
  int init(const Polarx::ExecPlan::RangeScan &scan_msg,
           InternalDataSet &dataset,
           THD *thd);
  virtual int next(InternalDataSet &dataset) override;
  virtual int finish(int ret) override;
private:
  InlineScanNode inline_scan_node_;
  bool first_next_;
};

class TableScanNode : public PlanNode {
public:
  int init(const Polarx::ExecPlan::TableScanPlan &table_scan_msg,
          InternalDataSet &dataset,
          THD *thd);
  virtual int next(InternalDataSet &dataset) override;
  virtual int finish(int ret) override;
private:
  InlineScanNode inline_scan_node_;
  bool first_next_;
};

class KeyScanNode : public PlanNode {
public:
  int init(const Polarx::ExecPlan::RangeScan &scan_msg,
           InternalDataSet &dataset,
           THD *thd);
  virtual int next(InternalDataSet &dataset) override;
  virtual int finish(int ret) override;
private:
  InlineScanNode inline_scan_node_;
  bool first_next_;
};

} // namespace executor