"""Complete generated rhythm groups, indexed once, independent of source rhythms."""
from fractions import Fraction as F
from generator import vocabulary
from generator.solo import groups, policy

class Rhythms:
  def __init__(self, library, tempo):
    self.groups=[]; limits=vocabulary.data('roles')['difficulty']
    for item in vocabulary.data('solo')['groups']:
      difficulty=item.get('difficulty')
      if difficulty and tempo>limits[difficulty+'_max_bpm']:continue
      cursor=F();pattern=[]
      for value in item['values']:
        duration=F(value.removeprefix('r:'))
        if not value.startswith('r:'):pattern.append((cursor,cursor+duration))
        cursor+=duration
      self.groups.append((item['id'],tuple(pattern),cursor,tuple(item['purpose'])))
    for cell in vocabulary.rhythm_cells(tempo):
      # Imported authored cells remain whole. They are never sliced to fit.
      if groups.valid(cell.pattern):self.groups.append((cell.id,cell.pattern,cell.duration,('develop','answer') if cell.purpose=='answer' else ('arpeggio','scalar','develop','neighbor')))
    # Meter-indexed catalog representatives: file counts do not set style frequency.
    self.catalog={}
    for meter,items in library.snippets.items():
      representatives={}
      for item in items:
        for bar in item.bars:
          pattern=tuple((e.onset,e.onset+e.duration) for e in bar.events if e.sounding)
          if any(e.continuation for e in bar.events) or not pattern or not groups.valid(pattern):continue
          if any(b-a<F(1,2) for a,b in pattern):continue
          descriptor=(len(pattern),pattern[0][0]>0,any(a[1]<b[0] for a,b in zip(pattern,pattern[1:])),len(set(b-a for a,b in pattern)))
          representatives.setdefault(descriptor,(item.id,pattern,bar.length,('develop','answer')))
      self.catalog[meter]=tuple(representatives.values())
    self.cache={}

  def realize(self,start,end,purpose,seed,meter):
    key=(start,end,purpose,seed,meter)
    if key in self.cache:return self.cache[key]
    cursor=start;notes=[];sources=[];chosen=[];home=None;uses=0
    while cursor<end:
      available=[g for g in self.groups if purpose in g[3] and g[2]<=end-cursor]
      # Catalog is a separate family, not thousands of duplicate votes.
      if purpose in ('develop','answer'):
        available += sorted((g for g in self.catalog.get(meter,()) if g[2]<=end-cursor),key=lambda g:policy.stable_rank(seed,('catalog',cursor,g[0])))[:1]
      available=[g for g in available if ((end-cursor-g[2])*2).denominator==1]
      if not available:return (),(),()
      # Prefer complete multi-event groups; single values finish an exact remainder.
      large=[g for g in available if g[2]>=1]
      if home is not None and uses<2 and home in available:
        selected=home
      else:
        # Establish one rhythmic idea before reshaping it. A complete phrase
        # is not a fresh unrelated catalog draw at every short boundary.
        selected=min(large or available,key=lambda g:policy.stable_rank(seed,('rhythm',len(chosen)//4,g[0])))
        home=selected;uses=0
      uses+=1
      name,pattern,length,_=selected
      events=tuple((cursor+a,cursor+b) for a,b in pattern)
      notes.extend(events);sources.append(name)
      chosen.extend(groups.describe(pattern,origin=cursor,source=name))
      cursor+=length
    result=(tuple(notes),tuple(chosen),tuple(sources));self.cache[key]=result
    return result