box.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 <cstdlib>
#include <memory>
#include <ostream>
#include <type_traits>
#include <typeinfo>
#include <utility>
#include <vector>
 
#include "../core/csexc.h"
#include "../text/repr.h"
#include "../text/strpp.h"
 
namespace console {
    class Item {
    private:
        struct Base {
            virtual ~Base() {}
            virtual Base                 *clone() const                = 0;
            virtual void                  print(std::ostream &) const  = 0;
            virtual void                  print(std::wostream &) const = 0;
            virtual std::string           str() const                  = 0;
            virtual std::wstring          wstr() const                 = 0;
            virtual const std::type_info &type() const                 = 0;
        };

        template <typename T>
        struct Derived : Base {
            T value; 

            Derived(const T &v) : value(v) {}

            Derived(T &&v) : value(std::move(v)) {}

            Base *clone() const override { return new Derived(value); }

            void print(std::ostream &os) const override { repr(value, os); }
            void print(std::wostream &os) const override {
                auto s = str();
                os << std::wstring(s.begin(), s.end());
            }

            std::string str() const override {
                std::ostringstream oss;
                repr(value, oss);
                return oss.str();
            }
 
            std::wstring wstr() const override {
                auto s = str();
                return std::wstring(s.begin(), s.end());
            }

            const std::type_info &type() const override { return typeid(T); }
        };
 
        Base *ptr; 
 
    public:
        Item() : ptr(nullptr) {}

        template <class T,
            class = typename std::enable_if<
                !std::is_same<typename std::decay<T>::type, Item>::value>::type>
        Item(T &&value) :
            ptr(new Derived<typename std::decay<T>::type>(
                std::forward<T>(value))) {}

        Item(const Item &other) :
            ptr(other.ptr ? other.ptr->clone() : nullptr) {}

        Item(Item &&other) noexcept : ptr(other.ptr) { other.ptr = nullptr; }

        template <class T>
        T &get() {
            if (ptr == nullptr) throw TypeError("empty item");
            if (typeid(T) != ptr->type())
                throw TypeError(std::string("type mismatch: ")
                                + tiname(typeid(T)) + " and "
                                + tiname(ptr->type()));
            return ((Derived<T> *)ptr)->value;
        }

        template <class T>
        T &unsafe_get() {
            return ((Derived<T> *)ptr)->value;
        }

        template <class T>
        const T &get() const {
            if (ptr == nullptr) throw TypeError("empty item");
            if (typeid(T) != ptr->type())
                throw TypeError(std::string("type mismatch: ")
                                + typeid(T).name() + " and "
                                + ptr->type().name());
            return ((Derived<T> *)ptr)->value;
        }

        template <class T>
        const T &unsafe_get() const {
            return ((Derived<T> *)ptr)->value;
        }

        const Item &operator=(const Item &other) {
            if (this != &other) {
                Base *new_ptr = other.ptr ? other.ptr->clone() : nullptr;
                delete ptr;
                ptr = new_ptr;
            }
            return *this;
        }

        const Item &operator=(Item &&other) noexcept {
            if (this != &other) {
                delete ptr;
                ptr       = other.ptr;
                other.ptr = nullptr;
            }
            return *this;
        }

        friend std::ostream &operator<<(std::ostream &os, const Item &item) {
            item.ptr->print(os);
            return os;
        }

        friend std::wostream &operator<<(std::wostream &os, const Item &item) {
            item.ptr->print(os);
            return os;
        }

        std::string  str() const { return ptr->str(); }
        std::wstring wstr() const { return ptr->wstr(); }

        ~Item() { delete ptr; }
    };

    class Box : public std::vector<Item> {
    public:
        template <class... Args>
        explicit Box(Args &&...args) {
            int _[] = {0, (emplace_back(std::forward<Args>(args)), 0)...};
            (void)_;
        }

        template <class T>
        T &get(size_t index) {
            if (index >= size()) throw IndexError("index out of range");
            return std::vector<Item>::operator[](index).get<T>();
        }

        template <class T>
        const T &get(size_t index) const {
            if (index >= size()) throw IndexError("index out of range");
            return std::vector<Item>::operator[](index).get<T>();
        }

        template <class T>
        T &unsafe_get(size_t index) {
            return std::vector<Item>::operator[](index).unsafe_get<T>();
        }

        template <class T>
        const T &unsafe_get(size_t index) const {
            return std::vector<Item>::operator[](index).unsafe_get<T>();
        }

        template <class... Args>
        void unpack(Args &...args) const {
            if (sizeof...(Args) != size())
                throw TypeError("unpack: argument count mismatch");
            size_t i   = 0;
            int    _[] = {0, ((args = get<Args>(i++)), 0)...};
            (void)_;
        }

        template <class... Args>
        void unsafe_unpack(Args &...args) const {
            size_t i   = 0;
            int    _[] = {0, ((args = unsafe_get<Args>(i++)), 0)...};
            (void)_;
        }

        friend std::ostream &operator<<(std::ostream &os, const Box &box) {
            if (box.empty()) return os << "()";
            auto it = box.begin();
            os << '(' << *it;
            while (++it != box.end()) os << ", " << *it;
            return os << ')';
        }

        friend std::wostream &operator<<(std::wostream &os, const Box &box) {
            if (box.empty()) return os << L"()";
            auto it = box.begin();
            os << L'(' << *it;
            while (++it != box.end()) os << L", " << *it;
            return os << L')';
        }
    };
}