import fractions
import functools

import generator.rhythm

@functools.cache
def library() -> generator.rhythm.Library:
  snippets = []
  for beats in (2, 3, 4, 5):
    bars = []
    for mask in range(1 << beats):
      events = tuple(generator.rhythm.Event(fractions.Fraction(i), fractions.Fraction(1), bool(mask & (1 << i)), 'quarter') for i in range(beats))
      bar = generator.rhythm.Bar(events, fractions.Fraction(beats))
      bars.append(bar)
      snippets.append(generator.rhythm.Snippet(f'{beats}_4/quarters/{mask}', f'{beats}/4', (bar,)))
    for phase in (0, 1):
      events = tuple(generator.rhythm.Event(fractions.Fraction(i, 2), fractions.Fraction(1, 2), i % 2 == phase, 'eighth') for i in range(beats * 2))
      snippets.append(generator.rhythm.Snippet(f'{beats}_4/eighths/{phase}', f'{beats}/4', (generator.rhythm.Bar(events, fractions.Fraction(beats)),)))
    snippets.append(generator.rhythm.Snippet(f'{beats}_4/pair', f'{beats}/4', (bars[1], bars[-1])))
  return generator.rhythm.Library(tuple(snippets))