collide.h

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/*
Copyright (c) 2026 MrXie1109
 
Permission is hereby granted, free of charge, to any person obtaining a copy
of this software and associated documentation files (the "Software"), to deal
in the Software without restriction, including without limitation the rights
to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
copies of the Software, and to permit persons to whom the Software is
furnished to do so, subject to the following conditions:
 
The above copyright notice and this permission notice shall be included in all
copies or substantial portions of the Software.
 
THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
SOFTWARE.
*/
 
#pragma once
#include <functional>
#include <memory>
#include <string>
#include <typeindex>
#include <unordered_map>
#include <utility>
 
#include "../core/csexc.h"
#ifdef __GNUG__
#include <cxxabi.h>
#endif
 
namespace console {
    struct PairHash {
        template <typename T1, typename T2>
        std::size_t operator()(std::pair<T1, T2> p) const {
            auto h1 = std::hash<T1>{}(p.first);
            auto h2 = std::hash<T2>{}(p.second);
            return h1 ^ (h2 << 1);
        }
    };

    template <class T, class F = std::function<void(T &, T &)>>
    class Table {
    public:
        typedef std::pair<std::type_index, std::type_index> KeyType;
        typedef F FunctionType;

        Table(FunctionType default_handler = FunctionType{}) :
            default_handler(default_handler) {}

        void add(const std::type_index &type1,
            const std::type_index      &type2,
            FunctionType                func) {
            table[{type1, type2}] = func;
        }

        void add_symmetric(const std::type_info &type1,
            const std::type_info                &type2,
            FunctionType                         func) {
            add(type1, type2, func);
            add(type2, type1, func);
        }

        FunctionType operator()(
            const std::type_index &type1, const std::type_index &type2) const {
            auto it = table.find({type1, type2});
            if (it != table.end())
                return it->second;
            else if (default_handler)
                return default_handler;
            else {
                static auto get_name
                    = [](const std::type_index &ti) -> std::string {
#ifdef _MSC_VER
                    return ti.name();
#elif defined(__GNUG__)
                    int                                     status = 0;
                    std::unique_ptr<char, void (*)(void *)> result(
                        abi::__cxa_demangle(
                            ti.name(), nullptr, nullptr, &status),
                        std::free);
                    return (status == 0) ? result.get() : ti.name();
#else
                    return ti.name();
#endif
                };
                throw TypeError("Bad Collide Type: <" + get_name(type1)
                                + "> & <" + get_name(type2) + ">");
            }
        }

        void call(T &a, T &b) const { (*this)(typeid(a), typeid(b))(a, b); }

        bool
        has(const std::type_index &type1, const std::type_index &type2) const {
            return table.find({type1, type2}) != table.end();
        }

        bool has_default() const { return static_cast<bool>(default_handler); }

        bool callable(
            const std::type_index &type1, const std::type_index &type2) const {
            return has(type1, type2) || static_cast<bool>(default_handler);
        }

        void set_default(FunctionType func = FunctionType{}) {
            default_handler = func;
        }

        void
        remove(const std::type_index &type1, const std::type_index &type2) {
            table.erase({type1, type2});
        }

        void clear() { table.clear(); }
 
    private:
        std::unordered_map<KeyType, FunctionType, PairHash> table;

        FunctionType default_handler;
    };
}