package it.cavallium.dbengine.database.collections;

import io.netty.buffer.ByteBufAllocator;
import io.netty.buffer.PooledByteBufAllocator;
import io.netty.buffer.Unpooled;
import io.netty.buffer.api.BufferAllocator;
import io.netty.buffer.api.pool.PooledBufferAllocator;
import it.cavallium.dbengine.database.LLUtils;
import java.util.Arrays;
import org.junit.jupiter.api.AfterAll;
import org.junit.jupiter.api.Assertions;
import org.junit.jupiter.api.BeforeAll;
import org.junit.jupiter.api.Test;
import static io.netty.buffer.Unpooled.*;

public class TestRanges {

	private static BufferAllocator alloc;

	@BeforeAll
	public static void beforeAll() {
		alloc = BufferAllocator.offHeapPooled();
	}

	@AfterAll
	public static void afterAll() {
		alloc = BufferAllocator.offHeapPooled();
	}

	@Test
	public void testDirectBuffer() {
		Assertions.assertTrue(wrappedBuffer(Unpooled.directBuffer(10, 10), Unpooled.buffer(10, 10)).isDirect());
	}

	@Test
	public void testNextRangeKey() {
		testNextRangeKey(new byte[] {0x00, 0x00, 0x00});
		testNextRangeKey(new byte[] {0x00, 0x00, 0x01});
		testNextRangeKey(new byte[] {0x00, 0x00, 0x02});
		testNextRangeKey(new byte[] {0x00, 0x01, 0x02});
		testNextRangeKey(new byte[] {0x00, 0x00, (byte) 0xFF});
		testNextRangeKey(new byte[] {0x00, 0x01, (byte) 0xFF});
		testNextRangeKey(new byte[] {0x00, (byte) 0xFF, (byte) 0xFF});
	}

	@Test
	public void testNextRangeKey2() {
		testNextRangeKey(new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF});
		testNextRangeKey(new byte[] {(byte) 0xFF, (byte) 0, (byte) 0xFF});
		testNextRangeKey(new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0});
	}

	public void testNextRangeKey(byte[] prefixKey) {
		byte[] firstRangeKey;
		try (var firstRangeKeyBuf = DatabaseMapDictionaryDeep.firstRangeKey(alloc,
				alloc.allocate(prefixKey.length).writeBytes(prefixKey).send(),
				prefixKey.length, 7, 3).receive()) {
			firstRangeKey = LLUtils.toArray(firstRangeKeyBuf);
		}
		byte[] nextRangeKey;
		try (var nextRangeKeyBuf = DatabaseMapDictionaryDeep.nextRangeKey(alloc,
				alloc.allocate(prefixKey.length).writeBytes(prefixKey).send(),
				prefixKey.length,
				7,
				3
		).receive()) {
			nextRangeKey = LLUtils.toArray(nextRangeKeyBuf);
		}

		if (Arrays.equals(prefixKey, new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF})) {
			Assertions.assertArrayEquals(new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, 0}, nextRangeKey);
		} else {
			long biPrefix = 0;
			var s = 0;
			for (int i = prefixKey.length - 1; i >= 0; i--) {
				biPrefix += ((long) (prefixKey[i] & 0xFF)) << s;
				s += Byte.SIZE;
			}
			var nrPrefix = Arrays.copyOf(nextRangeKey, prefixKey.length);

			long biNextPrefix = 0;
			s = 0;
			for (int i = prefixKey.length - 1; i >= 0; i--) {
				biNextPrefix += ((long) (nrPrefix[i] & 0xFF)) << s;
				s += Byte.SIZE;
			}
			Assertions.assertEquals(biPrefix + 1, biNextPrefix);
			Assertions.assertArrayEquals(
					new byte[7 + 3],
					Arrays.copyOfRange(nextRangeKey, prefixKey.length, prefixKey.length + 7 + 3)
			);
		}
	}
	@Test
	public void testNextRangeKeyWithSuffix() {
		testNextRangeKeyWithSuffix(new byte[] {0x00, 0x01, (byte) 0xFF}, new byte[] {0x00, 0x00, 0x00});
		testNextRangeKeyWithSuffix(new byte[] {0x00, 0x00, 0x01}, new byte[] {0x00, 0x00, 0x01});
		testNextRangeKeyWithSuffix(new byte[] {0x00, 0x00, 0x02}, new byte[] {0x00, 0x00, 0x02});
		testNextRangeKeyWithSuffix(new byte[] {0x00, 0x01, 0x02}, new byte[] {0x00, 0x01, 0x02});
		testNextRangeKeyWithSuffix(new byte[] {0x00, 0x00, (byte) 0xFF}, new byte[] {0x00, 0x00, (byte) 0xFF});
		testNextRangeKeyWithSuffix(new byte[] {0x00, 0x01, (byte) 0xFF}, new byte[] {0x00, 0x01, (byte) 0xFF});
		testNextRangeKeyWithSuffix(new byte[] {0x00, (byte) 0xFF, (byte) 0xFF}, new byte[] {0x00, (byte) 0xFF, (byte) 0xFF});
	}
	@Test
	public void testNextRangeKeyWithSuffix2() {
		testNextRangeKeyWithSuffix(new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF}, new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF});
		testNextRangeKeyWithSuffix(new byte[] {(byte) 0xFF, (byte) 0, (byte) 0xFF}, new byte[] {(byte) 0xFF, (byte) 0, (byte) 0xFF});
		testNextRangeKeyWithSuffix(new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0}, new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0});
	}

	public void testNextRangeKeyWithSuffix(byte[] prefixKey, byte[] suffixKey) {

		byte[] firstRangeKey;
		try (var firstRangeKeyBuf = DatabaseMapDictionaryDeep.firstRangeKey(alloc,
				alloc.allocate(prefixKey.length).writeBytes(prefixKey).send(),
				alloc.allocate(suffixKey.length).writeBytes(suffixKey).send(),
				prefixKey.length,
				3,
				7
		).receive()) {
			firstRangeKey = LLUtils.toArray(firstRangeKeyBuf);
		}
		try (var nextRangeKeyBuf = DatabaseMapDictionaryDeep.nextRangeKey(alloc,
				alloc.allocate(prefixKey.length).writeBytes(prefixKey).send(),
				alloc.allocate(suffixKey.length).writeBytes(suffixKey).send(),
				prefixKey.length,
				3,
				7
		).receive()) {
			byte[] nextRangeKey = LLUtils.toArray(nextRangeKeyBuf);

			if (Arrays.equals(prefixKey, new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF}) && Arrays.equals(suffixKey, new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF})) {
				Assertions.assertArrayEquals(new byte[] {(byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, (byte) 0xFF, 0}, nextRangeKey);
			} else {
				long biPrefix = 0;
				var s = 0;
				for (int i = (suffixKey.length) - 1; i >= 0; i--) {
					biPrefix += ((long) (suffixKey[i] & 0xFF)) << s;
					s += Byte.SIZE;
				}
				for (int i = (prefixKey.length) - 1; i >= 0; i--) {
					biPrefix += ((long) (prefixKey[i] & 0xFF)) << s;
					s += Byte.SIZE;
				}
				var nrPrefix = Arrays.copyOf(nextRangeKey, prefixKey.length + suffixKey.length);

				long biNextPrefix = 0;
				s = 0;
				for (int i = (prefixKey.length + suffixKey.length) - 1; i >= 0; i--) {
					biNextPrefix += ((long) (nrPrefix[i] & 0xFF)) << s;
					s += Byte.SIZE;
				}
				Assertions.assertEquals(biPrefix + 1, biNextPrefix);
				Assertions.assertArrayEquals(
						new byte[7],
						Arrays.copyOfRange(nextRangeKey, prefixKey.length + suffixKey.length, prefixKey.length + suffixKey.length + 7)
				);
			}
		}
	}
}