// repository_manager.h
#ifndef REPOSITORY_MANAGER_H
#define REPOSITORY_MANAGER_H

#include "repository_interface.h"

#include <QMap>
#include <QSqlDatabase>

// The repository manager inherits the QObject class to delete child objects
class RepositoryManager : public QObject {
  Q_OBJECT

private:
  // Database connection
  QSqlDatabase database_;

  // Map of repository names to instances
  QMap<QString, RepositoryInterface *> repositories_;

public:
  // Singleton instance accessor
  static RepositoryManager &instance();

  // Get a repository by name
  RepositoryInterface *getRepository(const QString &repositoryTableName) const;

  // Get a repository by name and type
  template <typename T>
  T *getRepositoryAs(const QString &repositoryTableName) const;

private:
  // Register a new repository
  template <typename T>
  bool registerRepository(const QString &repositoryTableName);

  // Initialize repositories
  void initialize();

  // Private constructor for singleton
  RepositoryManager();

  // Destructor to clean up resources
  ~RepositoryManager();

  // Delete copy constructor
  RepositoryManager(const RepositoryManager &) = delete;

  // Delete assignment operator
  RepositoryManager &operator=(const RepositoryManager &) = delete;
};

// NOTE: Implementation of template methods

template <typename T>
T *RepositoryManager::getRepositoryAs(
    const QString &repositoryTableName) const {
  auto *repository = dynamic_cast<T *>(getRepository(repositoryTableName));
  if (!repository) {
    qFatal() << "Failed to downcast repository for" << repositoryTableName
             << "(typeid name):" << typeid(T).name();
    return nullptr;
  }
  qInfo() << "Successfully downcast repository for" << repositoryTableName;
  return repository;
}

template <typename T>
bool RepositoryManager::registerRepository(const QString &repositoryTableName) {
  static_assert(
      std::is_constructible<T, QSqlDatabase &, QObject *>::value,
      "Repository class must have a constructor accepting QSqlDatabase& and "
      "QObject*");

  if (repositories_.contains(repositoryTableName)) {
    qInfo() << "Repository" << repositoryTableName << "is already registered";
    return true;
  }

  auto *repository = new T(database_, this); // Qt will delete the model
  repository->setObjectName(repositoryTableName);

  repositories_.insert(repositoryTableName, repository);

  qInfo() << "Repository" << repositoryTableName
          << "was registered successfully";
  return true;
}

#endif // REPOSITORY_MANAGER_H