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#ifndef RFL_PARSING_VIEWREADERWITHDEFAULT_HPP_
#define RFL_PARSING_VIEWREADERWITHDEFAULT_HPP_
#include <array>
#include <sstream>
#include <string_view>
#include <type_traits>
#include <utility>
#include <vector>
#include "../Result.hpp"
#include "../Tuple.hpp"
#include "../internal/is_array.hpp"
namespace rfl::parsing {
template <class R, class W, class ViewType, class ProcessorsType>
class ViewReaderWithDefault {
private:
using InputVarType = typename R::InputVarType;
static constexpr size_t size_ = ViewType::size();
public:
ViewReaderWithDefault(const R* _r, ViewType* _view,
std::vector<Error>* _errors)
: r_(_r), view_(_view), errors_(_errors) {
found_->fill(false);
}
~ViewReaderWithDefault() = default;
/// Assigns the parsed version of _var to the field signified by _name, if
/// such a field exists in the underlying view.
void read(const std::string_view& _name, const InputVarType& _var) const {
assign_to_matching_field(*r_, _name, _var, view_, errors_, found_.get(),
std::make_integer_sequence<int, size_>());
}
private:
template <int i>
static void assign_if_field_matches(const R& _r,
const std::string_view& _current_name,
const auto& _var, auto* _view,
auto* _errors, auto* _found,
bool* _already_assigned) {
using FieldType = tuple_element_t<i, typename ViewType::Fields>;
using OriginalType = typename FieldType::Type;
using T =
std::remove_cvref_t<std::remove_pointer_t<typename FieldType::Type>>;
constexpr auto name = FieldType::name();
if (!(*_already_assigned) && !std::get<i>(*_found) &&
_current_name == name) {
std::get<i>(*_found) = true;
*_already_assigned = true;
auto res = Parser<R, W, T, ProcessorsType>::read(_r, _var);
if (!res) {
std::stringstream stream;
stream << "Failed to parse field '" << std::string(name)
<< "': " << res.error().what();
_errors->emplace_back(Error(stream.str()));
return;
}
if constexpr (std::is_pointer_v<OriginalType>) {
move_to(rfl::get<i>(*_view), &(*res));
} else {
rfl::get<i>(*_view) = std::move(*res);
}
}
}
template <int _pos>
static void assign_to_extra_fields(const R& _r,
const std::string_view& _current_name,
const auto& _var, auto* _view,
auto* _errors) {
auto* extra_fields = _view->template get<_pos>();
using ExtraFieldsType =
std::remove_cvref_t<std::remove_pointer_t<decltype(extra_fields)>>;
using T = std::remove_cvref_t<
std::remove_pointer_t<typename ExtraFieldsType::Type>>;
auto res = Parser<R, W, T, ProcessorsType>::read(_r, _var);
if (!res) {
std::stringstream stream;
stream << "Failed to parse field '" << _current_name
<< "': " << res.error().what();
_errors->emplace_back(Error(stream.str()));
return;
}
extra_fields->emplace(std::string(_current_name), std::move(*res));
}
template <int... is>
static void assign_to_matching_field(const R& _r,
const std::string_view& _current_name,
const auto& _var, auto* _view,
auto* _errors, auto* _found,
std::integer_sequence<int, is...>) {
bool already_assigned = false;
(assign_if_field_matches<is>(_r, _current_name, _var, _view, _errors,
_found, &already_assigned),
...);
if constexpr (ViewType::pos_extra_fields() != -1) {
constexpr int pos = ViewType::pos_extra_fields();
if (!already_assigned) {
assign_to_extra_fields<pos>(_r, _current_name, _var, _view, _errors);
}
} else if constexpr (ProcessorsType::no_extra_fields_) {
if (!already_assigned) {
std::stringstream stream;
stream << "Value named '" << std::string(_current_name)
<< "' not used. Remove the rfl::NoExtraFields processor or add "
"rfl::ExtraFields to avoid this error message.";
_errors->emplace_back(Error(stream.str()));
}
}
}
template <class Target, class Source>
static void move_to(Target* _t, Source* _s) {
if constexpr (std::is_const_v<Target>) {
return move_to(const_cast<std::remove_const_t<Target>*>(_t), _s);
} else if constexpr (!rfl::internal::is_array_v<Source> &&
!std::is_array_v<Target>) {
*_t = Target(std::move(*_s));
} else if constexpr (rfl::internal::is_array_v<Source>) {
static_assert(std::is_array_v<Target>,
"Expected target to be a c-array.");
for (size_t i = 0; i < _s->arr_.size(); ++i) {
move_to(&((*_t)[i]), &(_s->arr_[i]));
}
} else {
for (size_t i = 0; i < _s->size(); ++i) {
move_to(&((*_t)[i]), &((*_s)[i]));
}
}
}
private:
/// The underlying reader.
const R* r_;
/// The underlying view.
ViewType* view_;
/// Indicates that a certain field has been found.
rfl::Ref<std::array<bool, size_>> found_;
/// Collects any errors we may have come across.
std::vector<Error>* errors_;
};
} // namespace rfl::parsing
#endif
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