public class PreorderPresenter implements PreorderContract.Presenter {

    @Nullable
    private PreorderContract.View preorderView;

    @NonNull
    private final MenuLoaderInteractor menuLoaderInteractor;

    @NonNull
    private final MenuAvailabilityInteractor menuAvailabilityInteractor;

    private int currentCategoryPosition;

    @Inject
    PreorderPresenter(@NonNull MenuLoaderInteractor menuLoaderInteractor, @NonNull MenuAvailabilityInteractor menuAvailabilityInteractor) {
        this.menuLoaderInteractor = menuLoaderInteractor;
        this.menuAvailabilityInteractor = menuAvailabilityInteractor;
    }

    @Override
    public void takeView(PreorderContract.View view) {
        preorderView = view;

        if (preorderView != null) {
            preorderView.enableProgressBar(true);
        }

        getCategories();

    }

    private void getCategories() {
        menuLoaderInteractor.loadCategories(new MenuLoaderInteractor.CategoriesDownloadListener() {
            @Override
            public void onCategoriesDownloadedSuccess(List<Category> categories) {
                if (preorderView != null) {
                    preorderView.enableProgressBar(false);

                    if (categories != null) {
                        currentCategoryPosition = findSelectedCategory(categories);

                        preorderView.fillCategoryList(categories, currentCategoryPosition);
                        preorderView.fillProductList(categories.get(currentCategoryPosition).getProducts(),
                                categories.get(currentCategoryPosition).getTitle());

                        changePreOrderOnOffButton();
                    }

                }
            }

            @Override
            public void onDownloadedFailure(int errorCode) {
                if (preorderView != null) {
                    preorderView.enableProgressBar(false);
                    handleErrorsFromServer(errorCode);
                    changePreOrderOnOffButton();

                }
            }

            @Override
            public void noInternet() {
                if (preorderView != null) {
                    preorderView.enableProgressBar(false);
                    preorderView.showError(R.string.no_internet);

                    changePreOrderOnOffButton();

                }
            }
        });
    }

    private int findSelectedCategory(List<Category> categories) {
        String selectedId = menuLoaderInteractor.getSelectedCategoryId();
        int selectedPosition = 0;

        if (selectedId != null) {
            for (int i = 0; i < categories.size(); i++) {
                if (categories.get(i).getId().equals(selectedId)) {
                    selectedPosition = i;
                    break;
                }
            }
        }
        return selectedPosition;
    }

    private void handleErrorsFromServer(int errorCode) {
        switch (errorCode) {
            case ERROR_CODE_SERVER_ERROR:
                assert preorderView != null;
                preorderView.showError(R.string.server_error_msg);
                break;
            case ERROR_CODE_UNAUTHORIZED:
            case ERROR_CODE_FORBIDDEN:
                assert preorderView != null;
                preorderView.showError(R.string.error_msg_pos_info_incorrect);
                break;
        }
    }


    @Override
    public void dropView() {
        if (preorderView == null) {
            return;
        }
        preorderView.enableProgressBar(false);
        preorderView = null;
    }

    @Override
    public void onSwitchClickCategory(int position, boolean isChecked, OnUndoSwitchListener onUndoSwitchListener) {
        if (preorderView == null) {
            return;
        }
        preorderView.enableProgressBar(true);

        Category category = menuLoaderInteractor.getCachedCategories().get(position);

        menuAvailabilityInteractor.markCategoryAvailability(category.getId(), isChecked, new RemoteRepository.MarkAvailableListener() {
            @Override
            public void onMarkAvailable(boolean success, String errorMessage) {

                if (success) {
                    category.setAvailable(isChecked);

                    getCategories();
                } else {
                    if (preorderView != null) {
                        preorderView.enableProgressBar(false);
                        preorderView.showToast(errorMessage);
                    }

                    onUndoSwitchListener.undoSwitch();
                }
            }

            @Override
            public void onMarkAvailable(boolean success, int errorMessageRes) {

            }
        });

    }

    @Override
    public void onSwitchClickProduct(int position, boolean isChecked, OnUndoSwitchListener onUndoSwitchListener) {
        if (preorderView == null) {
            return;
        }
        preorderView.enableProgressBar(true);

        CategoryProduct product = menuLoaderInteractor.getCachedCategories().get(currentCategoryPosition).getProducts().get(position);

        menuAvailabilityInteractor.markProductAvailability(currentCategoryPosition,
                menuLoaderInteractor.getCachedCategories().get(currentCategoryPosition).getId(),
                product.getId(), isChecked, new RemoteRepository.MarkAvailableListener() {
                    @Override
                    public void onMarkAvailable(boolean success, String errorMessage) {

                        if (success) {
                            product.setAvailable(isChecked);

                            getCategories();
                        } else {

                            if (preorderView != null) {
                                preorderView.enableProgressBar(false);
                                preorderView.showToast(errorMessage);
                            }
                            onUndoSwitchListener.undoSwitch();
                        }
                    }

                    @Override
                    public void onMarkAvailable(boolean success, int errorMessageRes) {
                        if (preorderView != null) {
                            preorderView.enableProgressBar(false);
                        }
                        if (success) {
                            product.setAvailable(isChecked);
                        } else {
                            preorderView.showToast(errorMessageRes);
                            onUndoSwitchListener.undoSwitch();
                        }
                    }

        });
    }

    @Override
    public void onItemClickCategory(int position) {

        currentCategoryPosition = position;

        String selectedId = menuLoaderInteractor.getCachedCategories().get(position).getId();
        menuLoaderInteractor.saveSelectedCategory(selectedId);
        if (preorderView != null) {
            preorderView.fillProductList(menuLoaderInteractor.getCachedCategories().get(position).getProducts(),
                    menuLoaderInteractor.getCachedCategories().get(position).getTitle());
        }
    }

    @Override
    public void onMenuOnOffClick() {
        if (preorderView == null) {
            return;
        }

        preorderView.enableProgressBar(true);

        boolean menuAvailable = menuAvailabilityInteractor.isMenuAvailable();

        menuAvailabilityInteractor.markAllCategoryAvailability(!menuAvailable, new RemoteRepository.MarkAvailableListener() {
            @Override
            public void onMarkAvailable(boolean success, String errorMessage) {

                if (success) {
                    getCategories();

                } else {
                    if (preorderView != null) {
                        preorderView.enableProgressBar(false);
                    }
                    preorderView.showToast(errorMessage);
                }
            }

            @Override
            public void onMarkAvailable(boolean success, int errorMessageRes) {

            }
        });


    }

    private void changePreOrderOnOffButton() {
        if (preorderView == null) {
            return;
        }

        if (menuAvailabilityInteractor.isMenuAvailable()) {
            preorderView.onMenuChange(R.string.preorder_on, R.drawable.ic_preorder_on);
        } else {
            preorderView.onMenuChange(R.string.preorder_off, R.drawable.ic_preorder_off);
        }
    }

    public interface OnUndoSwitchListener {
        void undoSwitch();
    }
}