path: root/src/openvic-dataloader/csv/Parser.cpp

#include <iostream>
#include <optional>
#include <type_traits>
#include <vector>

#include <openvic-dataloader/Error.hpp>
#include <openvic-dataloader/NodeLocation.hpp>
#include <openvic-dataloader/csv/LineObject.hpp>
#include <openvic-dataloader/csv/Parser.hpp>
#include <openvic-dataloader/detail/Encoding.hpp>
#include <openvic-dataloader/detail/OStreamOutputIterator.hpp>
#include <openvic-dataloader/detail/Utility.hpp>

#include <lexy/action/parse.hpp>
#include <lexy/encoding.hpp>
#include <lexy/input/buffer.hpp>
#include <lexy/input/file.hpp>

#include <dryad/node.hpp>

#include "CsvGrammar.hpp"
#include "CsvParseState.hpp"
#include "detail/NullBuff.hpp"
#include "detail/ParseHandler.hpp"

using namespace ovdl;
using namespace ovdl::csv;

///   ParseHandler ///

struct Parser::ParseHandler final : detail::BasicFileParseHandler<CsvParseState> {
   template<typename Node>
   std::optional<DiagnosticLogger::error_range> parse() {
      auto result = [&] {
         switch (parse_state().encoding()) {
            using enum detail::Encoding;
            case Ascii:
            case Utf8:
               return lexy::parse<Node>(buffer<lexy::utf8_char_encoding>(), parse_state(), parse_state().logger().error_callback());
            case Unknown:
            case Windows1251:
            case Windows1252:
               return lexy::parse<Node>(buffer<lexy::default_encoding>(), parse_state(), parse_state().logger().error_callback());
            default:
               ovdl::detail::unreachable();
         }
      }();
      if (!result) {
         return this->parse_state().logger().get_errors();
      }
      _lines = LEXY_MOV(result).value();
      return std::nullopt;
   }

   std::vector<csv::LineObject>& get_lines() {
      return _lines;
   }

   Parser::error_range get_errors() {
      using iterator = typename decltype(std::declval<const error::Root*>()->children())::iterator;
      if (!is_valid())
         return dryad::make_node_range<error::Error>(iterator::from_ptr(nullptr), iterator::from_ptr(nullptr));
      return parse_state().logger().get_errors();
   }

private:
   std::vector<csv::LineObject> _lines;
};

///   ParserHandler ///

Parser::Parser()
   : _parse_handler(std::make_unique<ParseHandler>()) {
   set_error_log_to_null();
}

Parser::Parser(std::basic_ostream<char>& error_stream)
   : _parse_handler(std::make_unique<ParseHandler>()) {
   set_error_log_to(error_stream);
}

Parser::Parser(Parser&&) = default;
Parser& Parser::operator=(Parser&&) = default;
Parser::~Parser() = default;

Parser Parser::from_buffer(const char* data, std::size_t size, std::optional<detail::Encoding> encoding_fallback) {
   Parser result;
   return std::move(result.load_from_buffer(data, size, encoding_fallback));
}

Parser Parser::from_buffer(const char* start, const char* end, std::optional<detail::Encoding> encoding_fallback) {
   Parser result;
   return std::move(result.load_from_buffer(start, end, encoding_fallback));
}

Parser Parser::from_string(const std::string_view string, std::optional<detail::Encoding> encoding_fallback) {
   Parser result;
   return std::move(result.load_from_string(string, encoding_fallback));
}

Parser Parser::from_file(const char* path, std::optional<detail::Encoding> encoding_fallback) {
   Parser result;
   return std::move(result.load_from_file(path, encoding_fallback));
}

Parser Parser::from_file(const std::filesystem::path& path, std::optional<detail::Encoding> encoding_fallback) {
   Parser result;
   return std::move(result.load_from_file(path, encoding_fallback));
}

///
/// @brief Executes a function on _buffer_handler that is expected to load a buffer
///
/// Expected Use:
/// @code {.cpp}
///   _run_load_func(&BufferHandler::<load_function>, <arguments>);
/// @endcode
///
/// @tparam Type
/// @tparam Args
/// @param func
/// @param args
///
template<typename... Args>
constexpr void Parser::_run_load_func(detail::LoadCallback<ParseHandler, Args...> auto func, Args... args) {
   _has_fatal_error = false;
   auto error = func(_parse_handler.get(), std::forward<Args>(args)...);
   auto error_message = _parse_handler->make_error_from(error);
   if (!error_message.empty()) {
      _has_error = true;
      _has_fatal_error = true;
      _parse_handler->parse_state().logger().template create_log<error::BufferError>(DiagnosticLogger::DiagnosticKind::error, fmt::runtime(error_message));
   }
   if (has_error() && &_error_stream.get() != &detail::cnull) {
      print_errors_to(_error_stream.get());
   }
}

Parser& Parser::load_from_buffer(const char* data, std::size_t size, std::optional<detail::Encoding> encoding_fallback) {
   // Type can't be deduced?
   _run_load_func(std::mem_fn(&ParseHandler::load_buffer_size), data, size, encoding_fallback);
   return *this;
}

Parser& Parser::load_from_buffer(const char* start, const char* end, std::optional<detail::Encoding> encoding_fallback) {
   // Type can't be deduced?
   _run_load_func(std::mem_fn(&ParseHandler::load_buffer), start, end, encoding_fallback);
   return *this;
}

Parser& Parser::load_from_string(const std::string_view string, std::optional<detail::Encoding> encoding_fallback) {
   return load_from_buffer(string.data(), string.size(), encoding_fallback);
}

Parser& Parser::load_from_file(const char* path, std::optional<detail::Encoding> encoding_fallback) {
   set_file_path(path);
   // Type can be deduced??
   _run_load_func(std::mem_fn(&ParseHandler::load_file), get_file_path().data(), encoding_fallback);
   return *this;
}

Parser& Parser::load_from_file(const std::filesystem::path& path, std::optional<detail::Encoding> encoding_fallback) {
   return load_from_file(path.string().c_str(), encoding_fallback);
}

bool Parser::parse_csv(bool handle_strings) {
   if (!_parse_handler->is_valid()) {
      return false;
   }

   std::optional<Parser::error_range> errors = [&] {
      if (handle_strings)
         return _parse_handler->template parse<csv::grammar::strings::SemiColonFile>();
      else
         return _parse_handler->template parse<csv::grammar::SemiColonFile>();
   }();
   _has_error = _parse_handler->parse_state().logger().errored();
   _has_warning = _parse_handler->parse_state().logger().warned();
   if (errors && !errors->empty()) {
      _has_error = true;
      _has_fatal_error = true;
      if (&_error_stream.get() != &detail::cnull) {
         print_errors_to(_error_stream);
      }
      return false;
   }
   return true;
}

const std::vector<csv::LineObject>& Parser::get_lines() const {
   return _parse_handler->get_lines();
}

typename Parser::error_range Parser::get_errors() const {
   return _parse_handler->get_errors();
}

const FilePosition Parser::get_error_position(const error::Error* error) const {
   if (!error || !error->is_linked_in_tree()) {
      return {};
   }
   auto err_location = _parse_handler->parse_state().logger().location_of(error);
   if (err_location.is_synthesized()) {
      return {};
   }

// TODO: Remove reinterpret_cast
// WARNING: This almost certainly breaks on utf16 and utf32 encodings, luckily we don't parse in that format
// This is purely to silence the node_location errors because char8_t is useless
#define REINTERPRET_IT(IT) reinterpret_cast<const std::decay_t<decltype(buffer)>::encoding::char_type*>((IT))

   return _parse_handler->parse_state().file().visit_buffer(
      [&](auto&& buffer) -> FilePosition {
         auto loc_begin = lexy::get_input_location(buffer, REINTERPRET_IT(err_location.begin()));
         FilePosition result { loc_begin.line_nr(), loc_begin.line_nr(), loc_begin.column_nr(), loc_begin.column_nr() };
         if (err_location.begin() < err_location.end()) {
            auto loc_end = lexy::get_input_location(buffer, REINTERPRET_IT(err_location.end()), loc_begin.anchor());
            result.end_line = loc_end.line_nr();
            result.end_column = loc_end.column_nr();
         }
         return result;
      });

#undef REINTERPRET_IT
}

void Parser::print_errors_to(std::basic_ostream<char>& stream) const {
   auto errors = get_errors();
   if (errors.empty()) return;
   for (const auto error : errors) {
      dryad::visit_tree(
         error,
         [&](const error::BufferError* buffer_error) {
            stream << "buffer error: " << buffer_error->message() << '\n';
         },
         [&](dryad::child_visitor<error::ErrorKind> visitor, const error::AnnotatedError* annotated_error) {
            stream << annotated_error->message() << '\n';
            auto annotations = annotated_error->annotations();
            for (auto annotation : annotations) {
               visitor(annotation);
            }
         },
         [&](const error::PrimaryAnnotation* primary) {
            stream << primary->message() << '\n';
         },
         [&](const error::SecondaryAnnotation* secondary) {
            stream << secondary->message() << '\n';
         });
   }
}