#ifndef OBJECT_PROXY_HPP
#define OBJECT_PROXY_HPP

#include "matador/object/primary_key_resolver.hpp"

#include <memory>

namespace matador::object {

class basic_object_proxy {
public:
    virtual ~basic_object_proxy() = default;

    [[nodiscard]] virtual void *get() const = 0;
};

template < typename Type >
class object_proxy;

template < typename Type >
class object_resolver {
public:
    virtual ~object_resolver() = default;

    virtual Type* resolve(const object_proxy<Type> &proxy) const = 0;
};

template < typename Type >
class static_object_resolver final : public object_resolver<Type> {
public:
    static_object_resolver() = default;
    explicit static_object_resolver(Type* obj)
    : obj_(obj) {}
    explicit static_object_resolver(std::unique_ptr<Type> obj)
    : obj_(std::move(obj)) {}

    Type* resolve(const object_proxy<Type> &/*proxy*/) const override {
        return obj_.get();
    }

private:
    std::unique_ptr<Type> obj_{};
};


template<class Type>
class object_proxy final : public basic_object_proxy {
public:
  object_proxy() = default;
  explicit object_proxy(Type* obj)
  : resolver_(std::make_unique<static_object_resolver<Type>>(obj))
  , pk_(primary_key_resolver::resolve_object(*obj).pk) {}

  [[nodiscard]] void *get() const override { return static_cast<void*>(pointer()); }

  Type* operator->() const { return pointer(); }
  Type& operator*() { return *pointer(); }
  const Type& operator*() const { return *pointer(); }

  Type* pointer() const { return resolve(); }

  Type& ref() { return *pointer(); }
  const Type& ref() const { return *pointer(); }

  void reset(Type* obj) {
    pk_ = primary_key_resolver::resolve_object(*obj).pk;
    resolver_ = std::make_unique<static_object_resolver<Type>>(obj);
  }
  void reset(std::unique_ptr<Type> obj) {
    pk_ = primary_key_resolver::resolve_object(*obj).pk;
    resolver_ = std::make_unique<static_object_resolver<Type>>(std::move(obj));
  }
  void reset(std::unique_ptr<object_resolver<Type>> &&resolver) {
    resolver_ = std::move(resolver);
  }

  [[nodiscard]] bool empty() const { return resolver_ == nullptr; }
  [[nodiscard]] bool valid() const { return !empty(); }
  [[nodiscard]] bool has_primary_key() const { return !pk_.is_null(); }
  [[nodiscard]] const utils::identifier& primary_key() const { return pk_; }
  void primary_key(const utils::identifier &pk) { pk_ = pk; }

private:
  Type* resolve() const {
    return resolver_->resolve(*this);
  }

private:
    std::unique_ptr<object_resolver<Type>> resolver_{std::make_unique<static_object_resolver<Type>>()};
    utils::identifier pk_{};
};

}
#endif //OBJECT_PROXY_HPP