package event

import (
	"errors"
	"time"
)

type Service struct {
	repo *Repository
}

func NewService() *Service {
	return &Service{repo: NewRepository()}
}

func (s *Service) CreateEvent(userID uint, name string, eventDate time.Time, eventType, priority, location, notes, url string, distance float64) (*Event, error) {
	if name == "" {
		return nil, errors.New("name is required")
	}
	if eventDate.IsZero() {
		return nil, errors.New("event_date is required")
	}
	if !isValidEventType(eventType) {
		return nil, errors.New("invalid event_type")
	}
	if !isValidPriority(priority) {
		priority = "C"
	}

	event := &Event{
		UserID:    userID,
		Name:      name,
		EventDate: eventDate,
		EventType: eventType,
		Distance:  distance,
		Priority:  priority,
		Location:  location,
		Notes:     notes,
		URL:       url,
	}

	if err := s.repo.CreateEvent(event); err != nil {
		return nil, err
	}
	return event, nil
}

func (s *Service) GetUserEvents(userID uint) ([]Event, error) {
	return s.repo.GetUserEvents(userID)
}

func (s *Service) GetUpcomingEvents(userID uint, limit int) ([]Event, error) {
	return s.repo.GetUpcomingEvents(userID, limit)
}

func (s *Service) UpdateEvent(id, userID uint, name string, eventDate time.Time, eventType, priority, location, notes, url string, distance float64) (*Event, error) {
	event, err := s.repo.GetEventByID(id, userID)
	if err != nil {
		return nil, err
	}

	if name != "" {
		event.Name = name
	}
	if !eventDate.IsZero() {
		event.EventDate = eventDate
	}
	if eventType != "" {
		if !isValidEventType(eventType) {
			return nil, errors.New("invalid event_type")
		}
		event.EventType = eventType
	}
	if priority != "" {
		if !isValidPriority(priority) {
			return nil, errors.New("invalid priority")
		}
		event.Priority = priority
	}
	event.Location = location
	event.Notes = notes
	event.URL = url
	event.Distance = distance

	if err := s.repo.UpdateEvent(event); err != nil {
		return nil, err
	}
	return event, nil
}

func (s *Service) DeleteEvent(id, userID uint) error {
	return s.repo.DeleteEvent(id, userID)
}

func isValidEventType(t string) bool {
	valid := map[string]bool{
		"race": true, "gran_fondo": true, "group_ride": true,
		"time_trial": true, "century": true,
	}
	return valid[t]
}

func isValidPriority(p string) bool {
	return p == "A" || p == "B" || p == "C"
}