#include <iostream>
#include <typeinfo>
#include <typeindex>
#include <functional>
#include <memory>
#include <unordered_map>

class AbstractTest
{
public:
    virtual void yeah()
    {
        std::cout << "I'm AbstractTest! " << typeid(AbstractTest).name() << std::endl;
    }
};

class Test : public AbstractTest
{
public:
    void yeah() override
    {
        log();
    }

    void log()
    {
        std::cout << "I'm Test! " << typeid(Test).name() << std::endl;
    }
};

class Test2 : public AbstractTest
{
public:
    void log()
    {
        std::cout << "I'm Test2! " << typeid(Test).name() << std::endl;
    }
};

namespace ioc
{
    class Container
    {
    public:
        class AbstractInstance
        {
        public:
            virtual ~AbstractInstance() {}
        };

        template<typename T>
        class Instance : public AbstractInstance
        {
        public:
            Instance(T *ptr) : ptr(ptr) {}
            std::shared_ptr<T> ptr;
        };

        template<typename T>
        void registerType(std::function<T * ()> callback)
        {
            m_callbacks[std::type_index(typeid(T))] = callback;
        }

        template<typename T>
        std::shared_ptr<T> make()
        {
            auto type = std::type_index(typeid(T));

            auto search = m_instances.find(type);
            if (search != m_instances.end()) {
                auto instance = std::static_pointer_cast<Instance<T>>(search->second);
                return instance->ptr;
            }

            void *ptr = m_callbacks[type]();
            auto instance = std::make_shared<Instance<T>>(static_cast<T *>(ptr));
            m_instances[type] = instance;
            return instance->ptr;
        }

    protected:
        std::unordered_map<std::type_index, std::function<void * ()>> m_callbacks;
        std::unordered_map<std::type_index, std::shared_ptr<AbstractInstance>> m_instances;
    };
}

int main()
{
    ioc::Container container;
    container.registerType<AbstractTest>([]() {
        return new Test();
    });
    // container.registerType<Test2>([]() {
    //     return new Test2();
    // });

    auto test = container.make<AbstractTest>();
    // test->log();
    test->yeah();

    // auto test2 = container.make<Test>();
    // std::cout << (test == test2) << std::endl;

    return 0;
}