import java.math.BigInteger;
import java.util.ArrayList;
import java.util.Arrays;
import java.util.List;

import tester.Tester;

// Ported by Derek Young from the C version (specifically the endian-neutral
// version) from:
//   http://murmurhash.googlepages.com/
//
// released to the public domain - dmy999@gmail.com
public class MurmurHash2 {
	
	public static List<Integer> hashCodes(Object o, Integer k, Integer m) {
		List<Integer> result = new ArrayList<Integer>();
		byte[] codes = BigInteger.valueOf(o.hashCode()).toByteArray();
		
		/* hash using previous hash as seed with
		 * initial seed as hashCode */
		result.add(Math.abs(hash(codes, o.hashCode())) % m);
		for (int i = 1; i < k; i++) {
			result.add(Math.abs(hash(codes, result.get(i - 1))) % m);
		}
		
		return result;
	}

    @SuppressWarnings("fallthrough")
        public static int hash(byte[] data, int seed) {
        // 'm' and 'r' are mixing constants generated offline.
        // They're not really 'magic', they just happen to work well.
        int m = 0x5bd1e995;
        int r = 24;

        // Initialize the hash to a 'random' value
        int len = data.length;
        int h = seed ^ len;

        int i = 0;
        while (len  >= 4) {
            int k = data[i + 0] & 0xFF;
            k |= (data[i + 1] & 0xFF) << 8;
            k |= (data[i + 2] & 0xFF) << 16;
            k |= (data[i + 3] & 0xFF) << 24;

            k *= m;
            k ^= k >>> r;
            k *= m;

            h *= m;
            h ^= k;

            i += 4;
            len -= 4;
        }

        switch (len) {
        case 3: h ^= (data[i + 2] & 0xFF) << 16;
        case 2: h ^= (data[i + 1] & 0xFF) << 8;
        case 1: h ^= (data[i + 0] & 0xFF);
                h *= m;
        }

        h ^= h >>> 13;
        h *= m;
        h ^= h >>> 15;

        return h;
    }
}

class MurmurExamples {
	
	public Boolean testHashCodes(Tester t) {
		List<Integer> codes = MurmurHash2.hashCodes(new Integer(5), 5, 10);
		List<Integer> codes2 = MurmurHash2.hashCodes(new Integer(7), 5, 10);
		System.out.println(codes);
		System.out.println(codes2);
		
		return t.checkExpect(codes.size(), 5);
	}
}