// 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 <stddef.h>

#include <stdint.h>

#include <algorithm>

#include <cstdint>

#include <memory>

#include <string>

#include <vector>

#include "common/consts.h"

#include "core/column/column.h"

#include "exprs/aggregate/aggregate_function.h"

#include "io/io_common.h"

#include "runtime/thread_context.h"

#include "storage/olap_common.h"

#include "storage/tablet/tablet_schema.h"

#include "storage/utils.h"

namespace doris {

// The class is used to represent row's format in memory.  Each row contains

// multiple columns, some of which are key-columns (the rest are value-columns).

// NOTE: If both key-columns and value-columns exist, then the key-columns

// must be placed before value-columns.

//

// To compare two rows whose schemas are different, but they are from the same origin

// we store all column schema maybe accessed here. And default access through column id

class Schema;

using SchemaSPtr = std::shared_ptr<const Schema>;

class Schema {

public:

    Schema(TabletSchemaSPtr tablet_schema) {

        size_t num_columns = tablet_schema->num_columns();

        // ignore this column

        if (tablet_schema->columns().back()->name() == BeConsts::ROW_STORE_COL) {

            --num_columns;

        }

        std::vector<ColumnId> col_ids(num_columns);

        _unique_ids.resize(num_columns);

        std::vector<TabletColumnPtr> columns;

        columns.reserve(num_columns);

        size_t num_key_columns = 0;

        for (uint32_t cid = 0; cid < num_columns; ++cid) {

            col_ids[cid] = cid;

            const TabletColumn& column = tablet_schema->column(cid);

            _unique_ids[cid] = column.unique_id();

            if (column.is_key()) {

                ++num_key_columns;

            }

            if (column.name() == BeConsts::ROWID_COL ||

                column.name().starts_with(BeConsts::GLOBAL_ROWID_COL)) {

                _rowid_col_idx = cid;

            }

            if (column.name() == VERSION_COL) {

                _version_col_idx = cid;

            }

            columns.push_back(std::make_shared<TabletColumn>(column));

        }

        _delete_sign_idx = tablet_schema->delete_sign_idx();

        if (tablet_schema->has_sequence_col() || tablet_schema->has_seq_map()) {

            _has_sequence_col = true;

        }

        _init(columns, col_ids, num_key_columns);

    }

    // All the columns of one table may exist in the columns param, but col_ids is only a subset.

    Schema(const std::vector<TabletColumnPtr>& columns, const std::vector<ColumnId>& col_ids) {

        size_t num_key_columns = 0;

        _unique_ids.resize(columns.size());

        for (int i = 0; i < columns.size(); ++i) {

            if (columns[i]->is_key()) {

                ++num_key_columns;

            }

            if (columns[i]->name() == DELETE_SIGN) {

                _delete_sign_idx = i;

            }

            if (columns[i]->name() == BeConsts::ROWID_COL ||

                columns[i]->name().starts_with(BeConsts::GLOBAL_ROWID_COL)) {

                _rowid_col_idx = i;

            }

            if (columns[i]->name() == VERSION_COL) {

                _version_col_idx = i;

            }

            _unique_ids[i] = columns[i]->unique_id();

        }

        _init(columns, col_ids, num_key_columns);

    }

    // Only for UT

    Schema(const std::vector<TabletColumnPtr>& columns, size_t num_key_columns) {

        std::vector<ColumnId> col_ids(columns.size());

        _unique_ids.resize(columns.size());

        for (uint32_t cid = 0; cid < columns.size(); ++cid) {

            col_ids[cid] = cid;

            _unique_ids[cid] = columns[cid]->unique_id();

        }

        _init(columns, col_ids, num_key_columns);

    }

    Schema(const Schema&);

    Schema& operator=(const Schema& other);

    ~Schema();

    static DataTypePtr get_data_type_ptr(const TabletColumn& column);

    static IColumn::MutablePtr get_predicate_column_ptr(const FieldType& type, bool is_nullable,

                                                        const ReaderType reader_type);

    const std::vector<TabletColumnPtr>& columns() const { return _cols; }

    const TabletColumn* column(ColumnId cid) const { return _cols[cid].get(); }

    size_t num_key_columns() const { return _num_key_columns; }

    size_t num_columns() const { return _cols.size(); }

    size_t num_column_ids() const { return _col_ids.size(); }

    const std::vector<ColumnId>& column_ids() const { return _col_ids; }

    ColumnId column_id(size_t index) const { return _col_ids[index]; }

    int32_t unique_id(size_t index) const { return _unique_ids[index]; }

    int32_t delete_sign_idx() const { return _delete_sign_idx; }

    bool has_sequence_col() const { return _has_sequence_col; }

    int32_t rowid_col_idx() const { return _rowid_col_idx; }

    int32_t version_col_idx() const { return _version_col_idx; }

    // Don't use.

    // TODO: memory size of Schema cannot be accurately tracked.

    // In some places, temporarily use num_columns() as Schema size.

    int64_t mem_size() const { return _mem_size; }

private:

    void _init(const std::vector<TabletColumnPtr>& cols, const std::vector<ColumnId>& col_ids,

               size_t num_key_columns);

    void _copy_from(const Schema& other);

    // NOTE: The ColumnId here represents the sequential index number (starting from 0) of

    // a column in current row, not the unique id-identifier of each column

    std::vector<ColumnId> _col_ids;

    std::vector<int32_t> _unique_ids;

    // NOTE: _cols[cid] can only be accessed when the cid is

    // contained in _col_ids

    std::vector<TabletColumnPtr> _cols;

    size_t _num_key_columns;

    int32_t _delete_sign_idx = -1;

    bool _has_sequence_col = false;

    int32_t _rowid_col_idx = -1;

    int32_t _version_col_idx = -1;

    int64_t _mem_size = 0;

};

} // namespace doris