package de.ph87.homeautomation.property;

import de.ph87.homeautomation.channel.ChannelChangedEvent;
import de.ph87.homeautomation.channel.ChannelService;
import de.ph87.homeautomation.web.WebSocketService;
import lombok.RequiredArgsConstructor;
import lombok.extern.slf4j.Slf4j;
import org.springframework.stereotype.Service;
import org.springframework.transaction.annotation.Transactional;
import org.springframework.transaction.event.TransactionPhase;
import org.springframework.transaction.event.TransactionalEventListener;

import java.util.function.BiConsumer;

@Slf4j
@Service
@Transactional
@RequiredArgsConstructor
public class PropertyWriteService {

  private static final String NAME_PREFIX = "NEU ";

  private final PropertyReadService propertyReadService;

  private final ChannelService channelService;

  private final PropertyMapper propertyMapper;

  private final WebSocketService webSocketService;

  private final PropertyRepository propertyRepository;

  public void write(final String name, final double value) {
    write(propertyReadService.getByName(name), value);
  }

  public void write(final Property property, final double value) {
    channelService.write(property, value);
  }

  @TransactionalEventListener(phase = TransactionPhase.BEFORE_COMMIT)
  public void channelChangedEventListener(final ChannelChangedEvent event) {
    propertyReadService.findAllByReadChannel_Id(event.getChannelId())
      .forEach(property -> {
          property.setValue(property.getReadChannel().getValue());
          property.setTimestamp(property.getReadChannel().getValueTimestamp());
          log.debug("Updated Property from Channel: {}", property);
          webSocketService.send(propertyMapper.toDto(property), true);
        }
      );
  }

  public PropertyDto create() {
    final Property entry = new Property();
    entry.setTitle(generateUnusedName());
    return propertyMapper.toDto(propertyRepository.save(entry));
  }

  private String generateUnusedName() {
    int index = 0;
    String name = null;
    while (name == null || propertyRepository.existsByName(name)) {
      name = PropertyWriteService.NAME_PREFIX + ++index;
    }
    return name;
  }

  public <T> PropertyDto set(final long id, final BiConsumer<Property, T> setter, final T value) {
    final Property property = propertyReadService.getById(id);
    setter.accept(property, value);
    return propertyMapper.toDto(property);
  }

  public void delete(final long id) {
    propertyRepository.deleteById(id);
  }

}