#pragma once

#include <Processors/QueryPlan/IQueryPlanStep.h>
#include <Processors/QueryPlan/ITransformingStep.h>
#include <Core/Joins.h>

namespace DB
{

class IJoin;
using JoinPtr = std::shared_ptr<IJoin>;

/// Join two data streams.
class JoinStep : public IQueryPlanStep
{
public:
    JoinStep(
        const Header & left_header_,
        const Header & right_header_,
        JoinPtr join_,
        size_t max_block_size_,
        size_t max_streams_,
        NameSet required_output_,
        bool keep_left_read_in_order_,
        bool use_new_analyzer_);

    String getName() const override { return "Join"; }

    QueryPipelineBuilderPtr updatePipeline(QueryPipelineBuilders pipelines, const BuildQueryPipelineSettings &) override;

    void describePipeline(FormatSettings & settings) const override;

    void describeActions(JSONBuilder::JSONMap & map) const override;
    void describeActions(FormatSettings & settings) const override;

    const JoinPtr & getJoin() const { return join; }
    void setJoin(JoinPtr join_, bool swap_streams_ = false);
    bool allowPushDownToRight() const;

    JoinInnerTableSelectionMode inner_table_selection_mode = JoinInnerTableSelectionMode::Right;

private:
    void updateOutputHeader() override;

    /// Header that expected to be returned from IJoin
    Block join_algorithm_header;

    JoinPtr join;
    size_t max_block_size;
    size_t max_streams;

    const NameSet required_output;
    std::set<size_t> columns_to_remove;
    bool keep_left_read_in_order;
    bool use_new_analyzer = false;
    bool swap_streams = false;
};

/// Special step for the case when Join is already filled.
/// For StorageJoin and Dictionary.
class FilledJoinStep : public ITransformingStep
{
public:
    FilledJoinStep(const Header & input_header_, JoinPtr join_, size_t max_block_size_);

    String getName() const override { return "FilledJoin"; }
    void transformPipeline(QueryPipelineBuilder & pipeline, const BuildQueryPipelineSettings &) override;

    void describeActions(JSONBuilder::JSONMap & map) const override;
    void describeActions(FormatSettings & settings) const override;

    const JoinPtr & getJoin() const { return join; }

private:
    void updateOutputHeader() override;

    JoinPtr join;
    size_t max_block_size;
};

}