#ifndef RIPPLE_SHAMAPNODE_H
#define RIPPLE_SHAMAPNODE_H

// Identifies a node in a SHA256 hash map
class SHAMapNode
{
public:
	SHAMapNode() : mDepth(0), mHash(0)	{ ; }
	SHAMapNode(int depth, uint256 const& hash);

	int getDepth() const				{ return mDepth; }
	uint256 const& getNodeID()	const	{ return mNodeID; }
	bool isValid() const 				{ return (mDepth >= 0) && (mDepth < 64); }
	bool isRoot() const					{ return mDepth == 0; }
	size_t getMHash() const				{ if (mHash == 0) setMHash(); return mHash; }

	virtual bool isPopulated() const	{ return false; }

	SHAMapNode getParentNodeID() const
	{
		assert(mDepth);
		return SHAMapNode(mDepth - 1, mNodeID);
	}

	SHAMapNode getChildNodeID(int m) const;
	int selectBranch(uint256 const& hash) const;

	bool operator<(const SHAMapNode&) const;
	bool operator>(const SHAMapNode&) const;
	bool operator<=(const SHAMapNode&) const;
	bool operator>=(const SHAMapNode&) const;

	bool operator==(const SHAMapNode& n) const	{ return (mDepth == n.mDepth) && (mNodeID == n.mNodeID); }
	bool operator==(uint256 const& n) const		{ return n == mNodeID; }
	bool operator!=(const SHAMapNode& n) const	{ return (mDepth != n.mDepth) || (mNodeID != n.mNodeID); }
	bool operator!=(uint256 const& n) const		{ return n != mNodeID; }

	virtual std::string getString() const;
	void dump() const;

	static bool ClassInit();
	static uint256 getNodeID(int depth, uint256 const& hash);

	// Convert to/from wire format (256-bit nodeID, 1-byte depth)
	void addIDRaw(Serializer &s) const;
	std::string getRawString() const;
	static int getRawIDLength(void) { return 33; }
	SHAMapNode(const void *ptr, int len);

protected:
	SHAMapNode(int depth, uint256 const& id, bool) : mNodeID(id), mDepth(depth), mHash(0) { ; }

private:
	static uint256 smMasks[65]; // AND with hash to get node id

	uint256	mNodeID;
	int		mDepth;
	mutable size_t	mHash;

	void setMHash() const;
};

extern std::size_t hash_value(const SHAMapNode& mn);

inline std::ostream& operator<<(std::ostream& out, const SHAMapNode& node) { return out << node.getString(); }

#endif