// Copyright (C) 2017-2022 Jonathan Müller and cppast contributors
// SPDX-License-Identifier: MIT

/// \file
/// Generates enum `to_string()` code.
///
/// Given an input file, it will generate a to_string() function for all enums marked with
/// [[generate::to_string]].

#include <iostream>

#include <cppast/cpp_enum.hpp> // cpp_enum
#include <cppast/visitor.hpp>  // visit()

#include "example_parser.hpp"

void generate_to_string(const cppast::cpp_file& file)
{
    cppast::visit(
        file,
        [](const cppast::cpp_entity& e) {
            // only visit enum definitions that have the attribute set
            return (e.kind() == cppast::cpp_entity_kind::enum_t && cppast::is_definition(e)
                    && cppast::has_attribute(e, "generate::to_string"))
                   // or all namespaces
                   || e.kind() == cppast::cpp_entity_kind::namespace_t;
        },
        [](const cppast::cpp_entity& e, const cppast::visitor_info& info) {
            if (e.kind() == cppast::cpp_entity_kind::enum_t && !info.is_old_entity())
            {
                // a new enum, generate to string function
                auto& enum_ = static_cast<const cppast::cpp_enum&>(e);

                // write function header
                std::cout << "inline const char* to_string(const " << enum_.name() << "& e) {\n";

                // generate switch
                std::cout << "  switch (e) {\n";
                for (const auto& enumerator : enum_)
                {
                    std::cout << "  case " << enum_.name() << "::" << enumerator.name() << ":\n";

                    // attribute can be used to override the string
                    if (auto attr = cppast::has_attribute(enumerator, "generate::to_string"))
                        std::cout << "    return " << attr.value().arguments().value().as_string()
                                  << ";\n";
                    else
                        std::cout << "    return \"" << enumerator.name() << "\";\n";
                }
                std::cout << "  }\n";

                std::cout << "}\n\n";
            }
            else if (e.kind() == cppast::cpp_entity_kind::namespace_t)
            {
                if (info.event == cppast::visitor_info::container_entity_enter)
                    // open namespace
                    std::cout << "namespace " << e.name() << " {\n\n";
                else // if (info.event == cppast::visitor_info::container_entity_exit)
                    // close namespace
                    std::cout << "}\n";
            }
        });
}

int main(int argc, char* argv[])
{
    return example_main(argc, argv, {}, &generate_to_string);
}