#ifndef MATADOR_OBJECT_GENERATOR_HPP
#define MATADOR_OBJECT_GENERATOR_HPP

#include "matador/object/basic_repository.hpp"
#include "matador/object/object.hpp"

#include "matador/utils/access.hpp"
#include "matador/utils/primary_key_attribute.hpp"

#include <memory>

namespace matador::object {
class pk_type_determinator {
private:
    pk_type_determinator() = default;

public:
    template<class Type>
    static utils::basic_type determine() {
        pk_type_determinator determinator;
        Type t;

        access::process(determinator, t);
        return determinator.type_;
    }

    template<typename ValueType>
    void on_primary_key(const char *, ValueType &/*pk*/, const utils::primary_key_attribute& attr = utils::default_pk_attributes) {
        type_ = utils::data_type_traits<ValueType>::type(attr.size());
    }
    static void on_revision(const char * /*id*/, uint64_t &/*rev*/) {}
    template < class Type >
    static void on_attribute(const char * /*id*/, Type &/*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
    static void on_attribute(const char * /*id*/, char * /*x*/, const utils::field_attributes &/*attr*/ = utils::null_attributes) {}
    template<class Pointer>
    static void on_belongs_to(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
    template<class Pointer>
    static void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}
    template<class ContainerType>
    static void on_has_many(const char * /*id*/, ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
    template<class ContainerType>
    static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const char * /*join_column*/, const char * /*inverse_join_column*/, const utils::foreign_attributes &/*attr*/) {}
    template<class ContainerType>
    static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const utils::foreign_attributes &/*attr*/) {}

private:
    utils::basic_type type_{};
};

class object_generator {
private:
    explicit object_generator(basic_repository& repo, const std::shared_ptr<object> &object);

public:
    template < class Type >
    static std::shared_ptr<object> generate(basic_repository &repo, const std::string &name) {
        return generate(std::make_unique<Type>(), repo, name);
    }

    template < class Type >
    static std::shared_ptr<object> generate(std::unique_ptr<Type>&& t, basic_repository &repo, const std::string &name) {
        const std::type_index ti(typeid(Type));
        if (repo.has_object_for_type(ti)) {
            auto obj = repo.object_for_type(ti);
            repo.remove_object_for_type(ti);
            obj->update_name(name);
            return obj;
        }

        auto obj = std::make_shared<object>(name);
        std::ignore = repo.provide_object_in_advance(ti, obj);
        object_generator gen(repo, obj);
        access::process(gen, *t);
        return obj;
    }

    template < class Type >
    void on_primary_key(const char *, Type &x, const utils::primary_key_attribute& attr = utils::default_pk_attributes);
    void on_revision(const char *id, uint64_t &rev);

    template<typename Type>
    void on_attribute(const char *id, Type &x, const utils::field_attributes &attr = utils::null_attributes);

    template<typename Type>
    void on_attribute(const char *id, std::optional<Type> &x, const utils::field_attributes &attr = utils::null_attributes);

    template<class Pointer>
    void on_belongs_to(const char *id, Pointer &x, const utils::foreign_attributes &/*attr*/) {
      on_foreign_key(id, x);
      create_fk_constraint<typename Pointer::value_type>(id);
    }
    template<class Pointer>
    static void on_has_one(const char * /*id*/, Pointer &/*x*/, const utils::foreign_attributes &/*attr*/) {}

    template <class Pointer>
    void on_foreign_key(const char *id, Pointer &/*x*/) {
        const auto type = pk_type_determinator::determine<typename Pointer::value_type>();
        auto &ref = object_->attributes_.emplace_back(id, type, utils::constraints::ForeignKey, null_option_type::NotNull);
        ref.owner_ = object_;
    }
    template<class ContainerType>
    static void on_has_many(const char * /*id*/, ContainerType &, const char *, const utils::foreign_attributes &/*attr*/) {}
    template<class ContainerType>
    static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const char * /*join_column*/, const char * /*inverse_join_column*/, const utils::foreign_attributes &/*attr*/) {}
    template<class ContainerType>
    static void on_has_many_to_many(const char * /*id*/, ContainerType & /*cont*/, const utils::foreign_attributes &/*attr*/) {}

private:
    template<typename ValueType>
    attribute &emplace_attribute(const char *id, const utils::field_attributes& attr, null_option_type null_option) {
        auto &ref = object_->attributes_.emplace_back(id, utils::data_type_traits<ValueType>::type(attr.size()), attr, null_option);
        ref.owner_ = object_;
        return ref;
    }

    void create_pk_constraint(const std::string& name) const;
    template<typename Type>
    void create_fk_constraint(const std::string& name) const;
    void create_unique_constraint(const std::string& name) const;

    [[nodiscard]] std::list<attribute>::iterator find_attribute_by_name(const std::string &name) const;

    void prepare_primary_key(attribute &ref, utils::identifier &&pk) const;

    template<typename Type>
    [[nodiscard]] std::shared_ptr<object> fk_object() const;

    static std::shared_ptr<object> acquire_object(basic_repository &repo, const std::type_index &ti, const std::string& name);
private:
    basic_repository &repo_;
    std::shared_ptr<object> object_;
};

template<typename ValueType>
void object_generator::on_primary_key(const char *id, ValueType &x, const utils::primary_key_attribute& attr) {
    auto &ref = emplace_attribute<ValueType>(id, { attr.size(), utils::constraints::PrimaryKey }, null_option_type::NotNull);
    prepare_primary_key(ref, utils::identifier(x));
}

template<typename Type>
void object_generator::on_attribute(const char *id, Type &/*x*/, const utils::field_attributes &attr) {
    std::ignore = emplace_attribute<Type>(id, attr, null_option_type::NotNull);
}

template<typename Type>
void object_generator::on_attribute(const char *id, std::optional<Type> & /*x*/, const utils::field_attributes &attr) {
    std::ignore = emplace_attribute<Type>(id, attr, null_option_type::Nullable);
}

template<typename Type>
void object_generator::create_fk_constraint(const std::string& name) const {
    const auto pk_attr = find_attribute_by_name(name);
    if (pk_attr == std::end(object_->attributes_)) {
        return;
    }
    const auto obj = fk_object<Type>();
    restriction pk_constraint(*pk_attr);
    pk_constraint.options_ |= utils::constraints::ForeignKey;
    pk_constraint.owner_ = object_;
    pk_constraint.reference_ = obj;
    object_->constraints_.emplace_back(std::move(pk_constraint));
}

template<typename Type>
std::shared_ptr<object> object_generator::fk_object() const {
    const auto ti = std::type_index(typeid(Type));
    if (const auto result = repo_.basic_info(ti)) {
        return result->get().object();
    }

    if (repo_.has_object_for_type(ti)) {
        return repo_.object_for_type(ti);
    }
    const auto obj = repo_.provide_object_in_advance(ti, std::make_shared<object>(""));
    object_generator gen(repo_, obj);
    Type t;
    access::process(gen, t);
    return obj;
}

}
#endif //MATADOR_OBJECT_GENERATOR_HPP