IntervalQuality.h

#ifndef MCC_INTERVAL_INTERVAL_QUALITY_H
#define MCC_INTERVAL_INTERVAL_QUALITY_H
 
#include <MCC_BuildSettings.h>
 
#include <stdint.h>
 
namespace MCC {

enum class IntervalQualityKind : uint8_t {
    Diminished = 0,
    Minor = 1,
    Perfect = 2,
    Major = 3,
    Augmented = 4
};

class IntervalQuality {
public:
    static constexpr uint8_t MaximumCount = 4;
 
private:
    static constexpr uint8_t InvalidValue = 0xFF;
 
    // Kind in the high bits, repetition count (1 for P/M/m) in the low bits.
    uint8_t _value;
 
    constexpr IntervalQuality(IntervalQualityKind kind, int32_t count) noexcept
        : _value((count >= 1 && count <= MaximumCount)
              ? static_cast<uint8_t>(
                    (static_cast<uint8_t>(kind) << 3) | static_cast<uint8_t>(count))
              : InvalidValue) {}
 
public:
    constexpr IntervalQuality() noexcept : _value(InvalidValue) {}

    static constexpr IntervalQuality Invalid() noexcept { return IntervalQuality(); }

    static constexpr IntervalQuality Perfect() noexcept {
        return IntervalQuality(IntervalQualityKind::Perfect, 1);
    }

    static constexpr IntervalQuality Major() noexcept {
        return IntervalQuality(IntervalQualityKind::Major, 1);
    }

    static constexpr IntervalQuality Minor() noexcept {
        return IntervalQuality(IntervalQualityKind::Minor, 1);
    }

    static constexpr IntervalQuality Augmented(int32_t count = 1) noexcept {
        return IntervalQuality(IntervalQualityKind::Augmented, count);
    }

    static constexpr IntervalQuality Diminished(int32_t count = 1) noexcept {
        return IntervalQuality(IntervalQualityKind::Diminished, count);
    }

    constexpr bool IsValid() const noexcept { return _value != InvalidValue; }

    constexpr IntervalQualityKind Kind() const noexcept {
        return IsValid()
            ? static_cast<IntervalQualityKind>(_value >> 3)
            : IntervalQualityKind::Perfect;
    }

    constexpr uint8_t Count() const noexcept {
        return IsValid() ? static_cast<uint8_t>(_value & 0x07) : 0;
    }

    MCC_CONSTEXPR14 IntervalQuality Inverted() const noexcept {
        if (!IsValid()) {
            return Invalid();
        }
        switch (Kind()) {
            case IntervalQualityKind::Major:
                return Minor();
            case IntervalQualityKind::Minor:
                return Major();
            case IntervalQualityKind::Augmented:
                return Diminished(Count());
            case IntervalQualityKind::Diminished:
                return Augmented(Count());
            case IntervalQualityKind::Perfect:
                break;
        }
        return Perfect();
    }

    friend constexpr bool operator==(IntervalQuality a, IntervalQuality b) noexcept {
        return a._value == b._value;
    }
 
    friend constexpr bool operator!=(IntervalQuality a, IntervalQuality b) noexcept {
        return !(a == b);
    }
};
 
} // namespace MCC
 
#endif // MCC_INTERVAL_INTERVAL_QUALITY_H