// Licensed to the Apache Software Foundation (ASF) under one

// or more contributor license agreements.  See the NOTICE file

// distributed with this work for additional information

// regarding copyright ownership.  The ASF licenses this file

// to you 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 <gen_cpp/Descriptors_types.h>

#include <parallel_hashmap/phmap.h>

#include <cstddef>

#include <cstdint>

#include <map>

#include <set>

#include <string>

#include <string_view>

#include <unordered_map>

#include <utility>

#include <vector>

#include "common/status.h"

#include "core/column/column.h"

#include "core/data_type/data_type.h"

#include "core/field.h"

#include "core/string_ref.h"

#include "core/types.h"

#include "exprs/aggregate/aggregate_function.h"

#include "storage/segment/variant/variant_compaction_paths.h"

#include "storage/tablet/tablet_fwd.h"

#include "storage/tablet/tablet_schema.h"

namespace doris {

class TabletSchema;

enum class FieldType;

namespace segment_v2 {

struct VariantStatisticsPB;

} // namespace segment_v2

class Block;

class IColumn;

using MutableColumnPtr = IColumn::MutablePtr;

struct ColumnWithTypeAndName;

enum class ExtractType;

template <typename T>

class ColumnStr;

using ColumnString = ColumnStr<UInt32>;

} // namespace doris

const std::string SPARSE_COLUMN_PATH = "__DORIS_VARIANT_SPARSE__";

const std::string DOC_VALUE_COLUMN_PATH = "__DORIS_VARIANT_DOC_VALUE__";

namespace doris::variant_util {

using PathToNoneNullValues = std::unordered_map<std::string, int64_t>;

using PathToDataTypes = std::unordered_map<PathInData, std::vector<DataTypePtr>, PathInData::Hash>;

inline bool should_record_variant_path_stats(const TabletColumn& column) {

    return !column.variant_enable_nested_group();

}

inline bool should_write_variant_binary_columns(const TabletColumn& column) {

    return !column.variant_enable_nested_group();

}

inline bool should_check_variant_path_stats(const TabletColumn& column) {

    return !column.variant_enable_nested_group();

}

struct VariantExtendedInfo {

    PathToNoneNullValues path_to_none_null_values; // key: path, value: number of none null values

    std::unordered_set<std::string> sparse_paths;  // sparse paths in this variant column

    std::unordered_set<std::string> typed_paths;   // typed paths in this variant column

    std::unordered_set<PathInData, PathInData::Hash>

            nested_paths;               // nested paths in this variant column

    PathToDataTypes path_to_data_types; // key: path, value: data types

    bool has_nested_group = false;      // whether this variant column has nested group

};

/// Returns number of dimensions in Array type. 0 if type is not array.

size_t get_number_of_dimensions(const IDataType& type);

/// Returns number of dimensions in Array column. 0 if column is not array.

size_t get_number_of_dimensions(const IColumn& column);

/// Returns type of scalars of Array of arbitrary dimensions.

DataTypePtr get_base_type_of_array(const DataTypePtr& type);

// Cast column to dst type

Status cast_column(const ColumnWithTypeAndName& arg, const DataTypePtr& type, ColumnPtr* result);

struct ExtraInfo {

    // -1 indicates it's not a Frontend generated column

    int32_t unique_id = -1;

    int32_t parent_unique_id = -1;

    PathInData path_info {};

};

TabletColumn get_column_by_type(const DataTypePtr& data_type, const std::string& name,

                                const ExtraInfo& ext_info);

// check if the tuple_paths has ambiguous paths

// situation:

// throw exception if there exists a prefix with matched names, but not matched structure (is Nested, number of dimensions).

Status check_variant_has_no_ambiguous_paths(const std::vector<PathInData>& paths);

// Pick the tablet schema with the highest schema version as the reference.

// Then update all variant columns to there least common types.

// Return the final merged schema as common schema.

// If base_schema == nullptr then, max schema version tablet schema will be picked as base schema

Status get_least_common_schema(const std::vector<TabletSchemaSPtr>& schemas,

                               const TabletSchemaSPtr& base_schema, TabletSchemaSPtr& result,

                               bool check_schema_size = false);

// Get least common types for extracted columns which has Path info,

// with a speicified variant column's unique id

Status update_least_common_schema(const std::vector<TabletSchemaSPtr>& schemas,

                                  TabletSchemaSPtr& common_schema, int32_t variant_col_unique_id,

                                  std::set<PathInData>* path_set);

// inherit attributes like index/agg info from it's parent column

void inherit_column_attributes(TabletSchemaSPtr& schema);

// source: variant column

// target: extracted column from variant column

void inherit_column_attributes(const TabletColumn& source, TabletColumn& target,

                               TabletSchemaSPtr* target_schema = nullptr);

// Align variant subcolumn BF inheritance with FE BF-supported types.

bool is_bf_supported_by_fe_for_variant_subcolumn(FieldType type);

bool has_schema_index_diff(const TabletSchema* new_schema, const TabletSchema* old_schema,

                           int32_t new_col_idx, int32_t old_col_idx);

// create engine-side ColumnMap<String, String> for variant sparse/doc storage payloads.

MutableColumnPtr create_variant_binary_column();

// create TabletColumn Map<String, String> for sparse storage

TabletColumn create_sparse_column(const TabletColumn& variant);

// Create one bucket sparse column: name = variant.name_lower_case() + "." + SPARSE_COLUMN_PATH + ".b{index}"

TabletColumn create_sparse_shard_column(const TabletColumn& variant, int bucket_index);

// Physical doc bucket stored as MAP<STRING, STRING>.

TabletColumn create_doc_value_column(const TabletColumn& variant, int bucket_index);

// Decoded doc bucket used in compaction blocks, nullable with a SQL NULL default for old segments.

TabletColumn create_doc_value_compaction_column(const TabletColumn& variant, int bucket_index);

// Compute bucket id for given path string using SipHash64(path) % bucket_num.

uint32_t variant_binary_shard_of(const StringRef& path, uint32_t bucket_num);

void get_field_info(const Field& field, FieldInfo* info);

// inherit index from parent column

bool inherit_index(const std::vector<const TabletIndex*>& parent_indexes,

                   TabletIndexes& sub_column_indexes, FieldType column_type,

                   const std::string& suffix_path, bool is_array_nested_type = false);

bool inherit_index(const std::vector<const TabletIndex*>& parent_indexes,

                   TabletIndexes& sub_column_indexes, const TabletColumn& column);

bool inherit_index(const std::vector<const TabletIndex*>& parent_indexes,

                   TabletIndexes& sub_column_indexes, const segment_v2::ColumnMetaPB& column_pb);

Status update_least_schema_internal(const std::map<PathInData, DataTypes>& subcolumns_types,

                                    TabletSchemaSPtr& common_schema, int32_t variant_col_unique_id,

                                    const std::map<std::string, TabletColumnPtr>& typed_columns,

                                    std::set<PathInData>* path_set = nullptr);

bool generate_sub_column_info(const TabletSchema& schema, int32_t col_unique_id,

                              const std::string& path,

                              TabletSchema::SubColumnInfo* sub_column_info);

class VariantCompactionUtil {

public:

    static bool has_values_index(const TabletSchema& schema);

    static Status plan_values_index_compaction(

            const std::vector<RowsetSharedPtr>& rowsets, bool expand_subcolumns,

            const std::set<std::pair<int32_t, int64_t>>& native_indexes, TabletSchemaSPtr& schema,

            VariantCompactionPathsSPtr* paths);

    // get the subpaths and sparse paths for the variant column

    static void get_subpaths(int32_t max_subcolumns_count, const PathToNoneNullValues& path_stats,

                             VariantCompactionPaths& paths_set_info);

    // collect extended info from the variant column

    static Status aggregate_variant_extended_info(

            const RowsetSharedPtr& rs,

            std::unordered_map<int32_t, VariantExtendedInfo>* uid_to_variant_extended_info);

    // collect path stats from the variant column

    static Status aggregate_path_to_stats(

            const RowsetSharedPtr& rs,

            std::unordered_map<int32_t, PathToNoneNullValues>* uid_to_path_stats);

    // Build the temporary schema for compaction, this will reduce the memory usage of compacting

    // variant columns. `paths` receives that schema's variant path layout.

    static Status get_extended_compaction_schema(const std::vector<RowsetSharedPtr>& rowsets,

                                                 TabletSchemaSPtr& target,

                                                 VariantCompactionPathsMap& paths,

                                                 const std::set<int32_t>& skip_roots = {});

    // Used to collect all the subcolumns types of variant column from rowsets

    static TabletSchemaSPtr calculate_variant_extended_schema(

            const std::vector<RowsetSharedPtr>& rowsets, const TabletSchemaSPtr& base_schema);

    // Check if the path stats are consistent between inputs rowsets and output rowset.

    // Used to check the correctness of compaction.

    static Status check_path_stats(const std::vector<RowsetSharedPtr>& intputs,

                                   RowsetSharedPtr output, BaseTabletSPtr tablet);

    // Calculate statistics about variant data paths from the encoded sparse column

    static void calculate_variant_stats(const IColumn& encoded_sparse_column,

                                        segment_v2::VariantStatisticsPB* stats,

                                        size_t max_sparse_column_statistics_size, size_t row_pos,

                                        size_t num_rows);

    static void get_compaction_subcolumns_from_subpaths(

            VariantCompactionPaths& paths_set_info, const TabletColumnPtr parent_column,

            const TabletSchemaSPtr& target, const PathToDataTypes& path_to_data_types,

            const std::unordered_set<std::string>& sparse_paths, TabletSchemaSPtr& output_schema);

    static void get_compaction_subcolumns_from_data_types(VariantCompactionPaths& paths_set_info,

                                                          const TabletColumnPtr parent_column,

                                                          const TabletSchemaSPtr& target,

                                                          const PathToDataTypes& path_to_data_types,

                                                          TabletSchemaSPtr& output_schema);

    static Status get_compaction_typed_columns(const TabletSchemaSPtr& target,

                                               const std::unordered_set<std::string>& typed_paths,

                                               const TabletColumnPtr parent_column,

                                               TabletSchemaSPtr& output_schema,

                                               VariantCompactionPaths& paths_set_info);

    static Status get_compaction_nested_columns(

            const std::unordered_set<PathInData, PathInData::Hash>& nested_paths,

            const PathToDataTypes& path_to_data_types, const TabletColumnPtr parent_column,

            TabletSchemaSPtr& output_schema, VariantCompactionPaths& paths_set_info);

};

} // namespace  doris::variant_util