package it.cavallium.dbengine.database.disk;

import io.net5.buffer.api.Drop;
import io.net5.buffer.api.Owned;
import io.net5.buffer.api.internal.ResourceSupport;
import java.io.IOException;
import org.apache.lucene.index.IndexReader;
import org.apache.lucene.search.IndexSearcher;
import org.apache.lucene.search.SearcherManager;
import org.jetbrains.annotations.Nullable;
import org.slf4j.Logger;
import org.slf4j.LoggerFactory;

public class LLIndexSearcher extends ResourceSupport<LLIndexSearcher, LLIndexSearcher> {

	private IndexSearcher indexSearcher;

	public LLIndexSearcher(IndexSearcher indexSearcher, Drop<LLIndexSearcher> drop) {
		super(new LLIndexSearcher.CloseOnDrop(drop));
		this.indexSearcher = indexSearcher;
	}

	public IndexReader getIndexReader() {
		if (!isOwned()) {
			throw attachTrace(new IllegalStateException("LLIndexSearcher must be owned to be used"));
		}
		return indexSearcher.getIndexReader();
	}

	public IndexSearcher getIndexSearcher() {
		if (!isOwned()) {
			throw attachTrace(new IllegalStateException("LLIndexSearcher must be owned to be used"));
		}
		return indexSearcher;
	}

	@Override
	protected RuntimeException createResourceClosedException() {
		return new IllegalStateException("Closed");
	}

	@Override
	protected Owned<LLIndexSearcher> prepareSend() {
		var indexSearcher = this.indexSearcher;
		makeInaccessible();
		return drop -> new LLIndexSearcher(indexSearcher, drop);
	}

	private void makeInaccessible() {
		this.indexSearcher = null;
	}

	private static class CloseOnDrop implements Drop<LLIndexSearcher> {

		private final Drop<LLIndexSearcher> delegate;

		public CloseOnDrop(Drop<LLIndexSearcher> drop) {
			this.delegate = drop;
		}

		@Override
		public void drop(LLIndexSearcher obj) {
			try {
				delegate.drop(obj);
			} finally {
				obj.makeInaccessible();
			}
		}
	}
}