import fractions
import generator.score
import generator.model
import generator.arrange.form

def regions(document):
  result, first, start = {}, 0, fractions.Fraction()
  source = generator.score.source_staff(document)['measures']
  for section in generator.arrange.form.full_arrangement_sections(source, 'acoustic'):
    length = sum((generator.model.fraction(m['duration']) for m in source[section.source_measure_index:section.source_measure_index + section.measure_count]), fractions.Fraction())
    result[section.section_index] = (first, section.measure_count, start, length)
    first += section.measure_count
    start += length
  return result