#include "ed2k.h"

namespace Multihash {
	template<class T>
	inline T min(T a, T b) {
		return (a > b) ? b : a;
	}
	
	Ed2k::Ed2k(Hash* n) : Hash(n) {
		MD4_Init(&md4_partial);
		MD4_Init(&md4_final);
		size_total = 0;
	}
	
	void Ed2k::hash_update(const char* data, int length) {
		while(length) {
			if(!(size_total % (9500 * 1024)) && size_total) {
				unsigned char digest[16];
				MD4_Final(digest, &md4_partial);
				MD4_Update(&md4_final, digest, 16);
				MD4_Init(&md4_partial);
			}
			int size = min<int>(length, (9500 * 1024) - (size_total % (9500 * 1024)));
			MD4_Update(&md4_partial, data, size);
			length -= size;
			data += size;
			size_total += size;
		};
	}
	
	std::string Ed2k::hash_digest() {
		char digest[16];
		if(size_total > (9500 * 1024)) {
			unsigned char digest_partial[16];
			MD4_Final(digest_partial, &md4_partial);
			MD4_Update(&md4_final, digest_partial, 16);
			MD4_Final((unsigned char*)digest, &md4_final);
		} else {
			MD4_Final((unsigned char*)digest, &md4_partial);
		}
		return Hex::hex(digest, 16);
	}
}