1class Tone:
  2    def __init__(self, tone_name):
  3        self.tone_name = tone_name
  4    
  5    def __str__(self):
  6        return str(self.tone_name)
  7    
  8    @property
  9    def name(self):
 10        return self.tone_name
 11    
 12    def __add__(self, other):
 13        if isinstance(other, Tone):
 14            return Chord(self, other)
 15        elif isinstance(other, Interval):
 16            tone_index = Chord.index_of_tone(self)
 17            dist = other.number_of_semitones
 18            result_index = (tone_index + dist) % 12
 19            return Tone(Chord.get_tone_by_index(result_index))
 20    
 21    def __sub__(self, other):
 22        if isinstance(other, Tone):
 23            return Interval(Chord.index_of_tone(self) - Chord.index_of_tone(other))
 24        elif isinstance(other, Interval):
 25            tone_index = Chord.index_of_tone(self)
 26            dist = other.number_of_semitones
 27            res_index = (tone_index - dist) % 12
 28            return Tone(Chord.get_tone_by_index(res_index))
 29
 30
 31class Interval:
 32    NAMED_INTERVALS = ("unison", "minor 2nd", "major 2nd", "minor 3rd", "major 3rd",
 33                       "perfect 4th", "diminished 5th", "perfect 5th", "minor 6th",
 34                       "major 6th", "minor 7th", "major 7th")
 35     
 36    def __init__(self, number_of_semitones):
 37        self.number_of_semitones = number_of_semitones % 12
 38    
 39    def __str__(self):
 40        return self.NAMED_INTERVALS[self.number_of_semitones]
 41    
 42    def get_index(self):
 43        return self.NAMED_INTERVALS.index(str(self))
 44    
 45    def __add__(self, other):
 46        return Interval(self.get_index() + other.get_index())
 47    
 48    def __neg__(self):
 49        return Interval(-self.number_of_semitones)
 50    
 51
 52class Chord:
 53    ALL_TONES = ("C", "C#", "D", "D#", "E", "F", "F#", "G", "G#", "A", "A#", "B")
 54    
 55    def __init__(self, root, *tones):
 56        self.root = root
 57        tones_names = [curr_tone_name.name for curr_tone_name in tones]
 58        tones_names = set(tones_names)
 59        self.unique_tones_names = {root.name} | tones_names
 60        self.tones_unique = [Tone(tone_name) for tone_name in self.unique_tones_names]
 61        if len(self.tones_unique) == 1:
 62            raise TypeError("Cannot have a chord made of only 1 unique tone")
 63        self.create_right_orderd_list()
 64
 65    def create_right_orderd_list(self):
 66        root_index = self.ALL_TONES.index(self.root.name)
 67        right_order_seq = self.ALL_TONES[root_index:] + self.ALL_TONES[:root_index]
 68        self.tones_unique = [Tone(tone) for tone in right_order_seq if tone in self.unique_tones_names]
 69        self.unique_tones_names = [str(tone) for tone in self.tones_unique]
 70    
 71    def __str__(self):
 72        return "-".join(str(tone) for tone in self.tones_unique)
 73
 74    @classmethod
 75    def index_of_tone(cls, tone):
 76        return cls.ALL_TONES.index(tone.name)
 77    
 78    @classmethod
 79    def get_tone_by_index(cls, index):
 80        return cls.ALL_TONES[index]
 81    
 82    def is_major(self):
 83        MAJOR_STRING = "major 3rd"
 84
 85        for curr_tone in self.tones_unique:
 86            curr_dist = self.index_of_tone(curr_tone) - self.index_of_tone(self.root)
 87            if str(Interval(curr_dist)) == MAJOR_STRING:
 88                return True
 89        return False
 90    
 91    def is_minor(self):
 92        MINOR_STRING = "minor 3rd"
 93
 94        for curr_tone in self.tones_unique:
 95            curr_dist = self.index_of_tone(curr_tone) - self.index_of_tone(self.root)
 96            if str(Interval(curr_dist)) == MINOR_STRING:
 97                return True
 98        return False
 99    
100    def is_power_chord(self):
101        return not self.is_minor() and not self.is_major()
102
103    def __add__(self, other):
104        if isinstance(other, Tone):
105            return Chord(self.root, *(self.tones_unique + [other]))
106        elif isinstance(other, Chord):
107            return Chord(self.root, *(self.tones_unique + other.tones_unique))
108
109    def __sub__(self, other):
110         if isinstance(other, Tone):
111            if other.name not in self.unique_tones_names:
112                raise TypeError(f"Cannot remove tone {other} from chord {self}")
113            chord_tones = tuple(tone for tone in self.tones_unique if tone.name != other.name)
114            return Chord(self.root, *chord_tones)
115            
116    def transposed(self, interval):
117        transposed_chord = [curr_tone + interval for curr_tone in self.tones_unique]
118        return Chord(*transposed_chord)
119