package io.github.magwas.inez.query;
   
   import static io.github.magwas.runtime.LogUtil.debug;
   
   import java.util.List;
   import java.util.Map;
   import java.util.Set;
   import java.util.function.Function;
   import java.util.stream.Stream;
  
  import org.springframework.beans.factory.annotation.Autowired;
  import org.springframework.stereotype.Service;
  
  import io.github.magwas.inez.Bridi;
  import io.github.magwas.inez.parse.IdUtil;
  import io.github.magwas.inez.parse.ParserOutput;
  import io.github.magwas.inez.storage.model.Sumti;
  import io.github.magwas.inez.storage.repository.SumtiRepository;
  
  @Service
  public class CreateBridisFromParserOutputService implements Function<ParserOutput, Stream<Bridi>> {
  
  	@Autowired
  	SumtiRepository sumtiRepository;
  
  	@Override
  	public Stream<Bridi> apply(final ParserOutput parserOutput) {
  		String top = parserOutput.top();
  		Map<String, List<String>> refMap = parserOutput.referenceMap();
  		return apply(top, refMap);
  	}
  
  	private Stream<Bridi> apply(final String top, final Map<String, List<String>> refMap) {
  		debug("apply(", top, refMap);
  		if (!refMap.containsKey(top)) {
  			Bridi bridi = new Bridi(getIdOrRepr(top), top, List.of());
  			debug("bridi->", bridi);
  			return Stream.of(bridi);
  		}
  		List<String> partList = refMap.get(top);
  		return Stream.of(new Bridi(
  						getIdOrRepr(top),
  						top,
  						partList.stream().map(this::getIdOrRepr).toList()))
  				.mapMulti((topBridi, consumer) -> {
  					consumer.accept(topBridi);
  					partList.stream().map(x -> apply(x, refMap)).flatMap(x -> x).forEach(consumer::accept);
  				});
  	}
  
  	private String getIdOrRepr(final String top) {
  		Set<Sumti> candidates = sumtiRepository.findAllByRepresentation(top);
  		if (candidates.isEmpty()) return IdUtil.createID(top);
  		if (candidates.size() > 1) System.err.println("multiple candidates for " + top + ":" + candidates);
  		return candidates.iterator().next().id();
  	}
  }