// 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.

// This file is copied from

// https://github.com/ClickHouse/ClickHouse/blob/master/src/DataTypes/Serializations/PathInData.h

// and modified by Doris

#pragma once

#include <gen_cpp/segment_v2.pb.h>

#include <stddef.h>

#include <algorithm>

#include <memory>

#include <string>

#include <string_view>

#include <vector>

#include "core/uint128.h"

namespace doris {

/// Class that represents path in document, e.g. JSON.

class PathInData;

using PathInDataPtr = std::shared_ptr<PathInData>;

class PathInData {

public:

    struct Part {

        Part() = default;

        Part(std::string_view key_, bool is_nested_, UInt8 anonymous_array_level_)

                : key(key_), is_nested(is_nested_), anonymous_array_level(anonymous_array_level_) {}

        bool operator==(const Part& other) const {

            return this->key == other.key && this->is_nested == other.is_nested &&

                   this->anonymous_array_level == other.anonymous_array_level;

        }

        /// Name of part of path.

        std::string_view key;

        /// If this part is Nested, i.e. element

        /// related to this key is the array of objects.

        bool is_nested = false;

        /// Number of array levels between current key and previous key.

        /// E.g. in JSON {"k1": [[[{"k2": 1, "k3": 2}]]]}

        /// "k1" is nested and has anonymous_array_level = 0.

        /// "k2" and "k3" are not nested and have anonymous_array_level = 2.

        UInt8 anonymous_array_level = 0;

        /// Get the total array depth for this part.

        /// Used for NestedGroup offset indexing.

        /// If is_nested (array<object>), the depth is anonymous_array_level + 1

        /// Otherwise it's just the anonymous_array_level.

        UInt8 get_array_depth() const {

            return is_nested ? (anonymous_array_level + 1) : anonymous_array_level;

        }

    };

    using Parts = std::vector<Part>;

    PathInData() = default;

    explicit PathInData(std::string_view path_, bool is_typed_ = false);

    explicit PathInData(const Parts& parts_);

    explicit PathInData(std::string_view path_, const Parts& parts_, bool is_typed_ = false);

    explicit PathInData(const std::vector<std::string>& paths);

    explicit PathInData(const std::string& root, const std::vector<std::string>& paths);

    PathInData(const PathInData& other);

    PathInData& operator=(const PathInData& other);

    static UInt128 get_parts_hash(const Parts& parts_, bool is_typed_ = false);

    bool empty() const { return parts.empty(); }

    const String& get_path() const { return path; }

    // if path is v.a.b, then relative path will return a.b

    // make sure the parts is not empty

    std::string_view get_relative_path() const {

        if (parts.size() <= 1) {

            // return empty string

            return {};

        }

        return {path.begin() + parts[0].key.size() + 1, path.end()};

    }

    const Parts& get_parts() const { return parts; }

    bool is_nested(size_t i) const { return parts[i].is_nested; }

    bool has_nested_part() const { return has_nested; }

    bool operator==(const PathInData& other) const {

        return parts == other.parts && is_typed == other.is_typed;

    }

    bool operator!=(const PathInData& other) const { return !(*this == other); }

    PathInData get_nested_prefix_path() const;

    struct Hash {

        size_t operator()(const PathInData& value) const;

    };

    std::string to_jsonpath() const;

    PathInData copy_pop_front() const;

    PathInData copy_pop_nfront(size_t n) const;

    PathInData copy_pop_back() const;

    static bool try_strip_prefix(const std::string& name, const std::string& prefix_dot,

                                 std::string* out);

    static PathInData append(const PathInData& base, std::string_view suffix);

    void to_protobuf(segment_v2::ColumnPathInfo* pb, int32_t parent_col_unique_id) const;

    void from_protobuf(const segment_v2::ColumnPathInfo& pb);

    bool get_is_typed() const { return is_typed; }

    bool need_record_stats() const;

    bool operator<(const PathInData& rhs) const {

        return std::lexicographical_compare(

                parts.begin(), parts.end(), rhs.parts.begin(), rhs.parts.end(),

                [](const auto& a, const auto& b) { return a.key < b.key; });

    }

private:

    /// Creates full path from parts.

    void build_path(const Parts& other_parts);

    /// Creates new parts full from full path with correct string pointers.

    void build_parts(const Parts& other_parts);

    /// The full path. Parts are separated by dots.

    String path;

    /// Parts of the path. All string_view-s in parts must point to the @path.

    Parts parts;

    /// True if at least one part is nested.

    /// Cached to avoid linear complexity at 'has_nested'.

    bool has_nested = false;

    /// True if the path is typed, e.g. a.b: int

    bool is_typed = false;

};

class PathInDataBuilder {

public:

    const PathInData::Parts& get_parts() const { return parts; }

    PathInDataBuilder& append(std::string_view key, bool is_array);

    PathInDataBuilder& append(const PathInData::Parts& path, bool is_array);

    PathInDataBuilder& append(const std::vector<std::string>& parts);

    void pop_back();

    void pop_back(size_t n);

    PathInData build() { return PathInData(parts); }

private:

    PathInData::Parts parts;

    /// Number of array levels without key to which

    /// next non-empty key will be nested.

    /// Example: for JSON { "k1": [[{"k2": 1, "k3": 2}] }

    // `k2` and `k3` has anonymous_array_level = 1 in that case.

    size_t current_anonymous_array_level = 0;

};

using PathsInData = std::vector<PathInData>;

struct PathInDataRef {

    const PathInData* ref;

    struct Hash {

        size_t operator()(const PathInDataRef& value) const {

            return PathInData::Hash {}(*value.ref);

        }

    };

    PathInDataRef(const PathInData* ptr) : ref(ptr) {}

    PathInDataRef() : ref(nullptr) {}

    bool operator==(const PathInDataRef& other) const {

        return (this->ref != nullptr && other.ref != nullptr && *this->ref == *other.ref) ||

               (this->ref == nullptr && other.ref == nullptr);

    }

};

} // namespace doris

template <>

struct std::hash<doris::PathInData> {

    size_t operator()(const doris::PathInData& value) const {

        return doris::PathInData::Hash {}(value);

    }

};