package org.warp.jcwdb;

import it.unimi.dsi.fastutil.ints.IntArrayList;
import it.unimi.dsi.fastutil.longs.LongArrayList;

public class DBLightBigListParser<T> extends DBTypeParserImpl<LightBigList<T>> {
	private final JCWDatabase db;

	public DBLightBigListParser(JCWDatabase db) {
		this.db = db;
	}

	public DBReader<LightBigList<T>> getReader() {
		return (i, size) -> {
			LongArrayList chunks = new LongArrayList();
			IntArrayList chunkSizes = new IntArrayList();
			long max = size / (Long.BYTES + Integer.BYTES);
			for (int item = 0; item < max; item++) {
				long itm = i.readLong();
				int itm2 = i.readInt();
				chunks.add(itm);
				chunkSizes.add(itm2);
			}
			return new LightBigList<>(db, chunks, chunkSizes);
		};
	}

	public DBDataOutput<LightBigList<T>> getWriter(final LightBigList<T> value) {
		final int elementsCount = value.chunksCount();
		return DBDataOutput.create((o) -> {
			LongArrayList list = value.chunks;
			IntArrayList list2 = value.chunkSizes;
			for (int i = 0; i < elementsCount; i++) {
				o.writeLong(list.getLong(i));
				o.writeInt(list2.getInt(i));
			}
		}, DBStandardTypes.LIGHT_LIST_BIG, elementsCount * (Long.BYTES + Integer.BYTES), calculateHash(value));
	}

	@Override
	public long calculateHash(LightBigList<T> value) {
		return (((long)value.chunks.hashCode()) << 32) | (value.chunkSizes.hashCode() & 0xffffffffL);
	}
}