//
// Created by trotfunky on 04/11/2020.
//

#ifndef MISC_NEGBIN_H
#define MISC_NEGBIN_H

#include <cmath>
#include <bitset>

/// Bitset the size of a long, for convenience
typedef std::bitset<sizeof(long)*8> longBitField;

/***
 * Represents a number in base negative two.
 * For ex. : 0b1 is 1, 0b10 is -2, 0b1010 is 6.
 */
class NegBin {
public:
    NegBin() = default;

    /// Create a NegBin with a specific binary representation
    explicit NegBin(longBitField binaryRepresentation);
    /// Converts from long to NegBin. For ex 3 would set value to 0b111
    explicit NegBin(long number);

    NegBin& operator+=(const NegBin& rhs);
    // Uses += and ~ to do a subtraction
    NegBin& operator-=(const NegBin& rhs);
    NegBin& operator*=(const int& rhs);
    /// Used to obtain the binary representation of value's opposite
    NegBin operator~() const;

    /// Shifts the underlying binary representation
    NegBin operator>>(const int& rhs);
    NegBin operator<<(const int& rhs);

    friend NegBin operator+(NegBin lhs, const NegBin& rhs);
    friend NegBin operator-(NegBin lhs, const NegBin& rhs);
    // Doubled, for symmetry
    friend NegBin operator*(NegBin lhs, const int& rhs);
    friend NegBin operator*(const int& lhs, NegBin rhs);

    /// Converts from NegBin to signed long, converting to unsigned would not make sense
    explicit operator long() const;

private:
    /// Binary description of the number.
    unsigned long value; // TODO : Maybe use bitset everywhere ?
};

/// Define literal to create NegBin numbers. Calls the NegBin::NegBin(longBitField) constructor
NegBin operator "" _nb(unsigned long long);

std::ostream& operator<<(std::ostream& ostream, const NegBin& number);

#endif //MISC_NEGBIN_H