ArrayView.hpp

//------------------------------------------------------------------------------
/*
    This file is part of clio: https://github.com/XRPLF/clio
    Copyright (c) 2024, the clio developers.
 
    Permission to use, copy, modify, and distribute this software for any
    purpose with or without fee is hereby granted, provided that the above
    copyright notice and this permission notice appear in all copies.
 
    THE  SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
    WITH  REGARD  TO  THIS  SOFTWARE  INCLUDING  ALL  IMPLIED  WARRANTIES  OF
    MERCHANTABILITY  AND  FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
    ANY  SPECIAL,  DIRECT,  INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
    WHATSOEVER  RESULTING  FROM  LOSS  OF USE, DATA OR PROFITS, WHETHER IN AN
    ACTION  OF  CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
    OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
*/
//==============================================================================
 
#pragma once
 
#include "util/Assert.hpp"
#include "util/config/ConfigDefinition.hpp"
#include "util/config/ObjectView.hpp"
#include "util/config/ValueView.hpp"
 
#include <cstddef>
#include <functional>
#include <iterator>
#include <string>
#include <string_view>
 
namespace util::config {

class ArrayView {
public:
    template <typename T>
    struct ArrayIterator {
        using iterator_category = std::forward_iterator_tag;
        using pointer = T const*;
        using reference = T const&;
        using value_type = T;

        ArrayIterator(ArrayView const& arr, std::size_t index) : arr_{arr}, index_{index}
        {
            if (arr_.clioConfig_.get().contains(arr_.prefix_)) {
                ASSERT((std::is_same_v<T, ValueView>), "Array iterator must be ValueView");
            } else {
                ASSERT((std::is_same_v<T, ObjectView>), "Array iterator must be ObjectView");
            }
        }

        ArrayIterator&
        operator++()
        {
            if (index_ < arr_.size())
                ++index_;
            return *this;
        }

        ArrayIterator
        operator++(int)
        {
            ArrayIterator temp = *this;
            if (index_ < arr_.size())
                ++index_;
            return temp;
        }

        T
        operator*()
        {
            if constexpr (std::is_same_v<T, ObjectView>) {
                return ObjectView{arr_.prefix_, index_, arr_.clioConfig_.get()};
            } else {
                return arr_.clioConfig_.get().getValueInArray(arr_.prefix_, index_);
            }
        }

        bool
        operator==(ArrayIterator const& other) const
        {
            return &arr_ == &(other.arr_) && index_ == other.index_;
        }

        bool
        operator!=(ArrayIterator const& other) const
        {
            return &arr_ != &(other.arr_) || index_ != other.index_;
        }
 
    private:
        ArrayView const& arr_;
        std::size_t index_ = 0;
    };

    template <typename T>
    [[nodiscard]] auto
    begin() const
    {
        return ArrayIterator<T>(*this, 0);
    }

    template <typename T>
    [[nodiscard]] auto
    end() const
    {
        return ArrayIterator<T>(*this, this->size());
    }

    ArrayView(std::string_view prefix, ClioConfigDefinition const& configDef);

    [[nodiscard]] ObjectView
    objectAt(std::size_t idx) const;

    [[nodiscard]] ValueView
    valueAt(std::size_t idx) const;

    [[nodiscard]] size_t
    size() const;
 
private:
    std::string prefix_;
    std::reference_wrapper<ClioConfigDefinition const> clioConfig_;
};
 
}  // namespace util::config