package service

// NotificationSettingService provides business logic for notification settings.
// Reference: Chatwoot NotificationSettingsController — show + update

import (
	"context"

	"github.com/gochat/gochat/internal/model"
	"github.com/gochat/gochat/internal/repository"
)

// NotificationSettingService handles notification setting operations.
type NotificationSettingService struct {
	repo *repository.NotificationSettingRepo
}

// NewNotificationSettingService creates a new service instance.
func NewNotificationSettingService(repo *repository.NotificationSettingRepo) *NotificationSettingService {
	return &NotificationSettingService{repo: repo}
}

// UpdateNotificationSettingRequest is the DTO for updating notification settings.
// Reference: Chatwoot `params.require(:notification_settings).permit(selected_email_flags: [], selected_push_flags: [])`
type UpdateNotificationSettingRequest struct {
	SelectedEmailFlags []string `json:"selected_email_flags"`
	SelectedPushFlags  []string `json:"selected_push_flags"`
}

// Get retrieves the notification setting for a user in an account.
// Reference: Chatwoot show action — loads setting via find_by(account_id, user_id)
func (s *NotificationSettingService) Get(ctx context.Context, accountID, userID uint) (*model.NotificationSetting, error) {
	ns, err := s.repo.FindByAccountAndUser(accountID, userID)
	if err != nil {
		// If no setting exists, return default (all flags enabled)
		return &model.NotificationSetting{
			AccountID:  accountID,
			UserID:     userID,
			EmailFlags: model.AllEmailFlags(),
			PushFlags:  model.AllPushFlags(),
		}, nil
	}
	return ns, nil
}

// Update modifies notification settings for a user in an account.
// Reference: Chatwoot update action — updates email_flags and push_flags bitmask from selected flags
func (s *NotificationSettingService) Update(ctx context.Context, accountID, userID uint, req UpdateNotificationSettingRequest) (*model.NotificationSetting, error) {
	// Find existing or create default
	ns, err := s.repo.FindByAccountAndUser(accountID, userID)
	if err != nil {
		// Create new setting
		ns = &model.NotificationSetting{
			AccountID: accountID,
			UserID:    userID,
		}
	}

	// Update flags from request
	ns.SetEmailFlagsFromNames(req.SelectedEmailFlags)
	ns.SetPushFlagsFromNames(req.SelectedPushFlags)

	if ns.ID == 0 {
		return s.repo.Create(ns)
	}
	return s.repo.Update(ns)
}