"""One curated, deterministic composition policy; all times are quarter-note beats."""
from __future__ import annotations

import dataclasses
import hashlib
import json

@dataclasses.dataclass(frozen=True)
class Policy:
  acoustic_activity: float = 1.125
  electric_activity: float = 1.375
  active_occupancy: float = 0.75
  arrival_occupancy: float = 0.9
  weights: tuple[tuple[str, float], ...] = (('activity', 4), ('occupancy', 4), ('fidelity', 3), ('landmarks', 3), ('register', 1), ('contour', 1), ('connection', 1), ('repetition', 1), ('movement', 0.5), ('harmonic_exposure', 2), ('draft_preservation', 3), ('development', 2), ('direction', 1), ('join_coherence', 2), ('ending_integration', 2))
  beam_width: int = 64
  extensions: int = 32
  retrieval: int = 32
  alternatives: int = 4
  long_note: float = 2.0
  stopping_note: float = 1.0
  suspension_preparation: float = 0.5
  suspension_resolution: float = 1.0
  replan_attempts: int = 2
  anchor_lines: int = 8
  draft_frontier: int = 16
  phrase_alternatives: int = 8
  join_alternatives: int = 8
  revision_sweeps: int = 2
  join_window: float = 2.0

# Preserve the former default root seeds while decoupling them from policy edits.
SEED_NAMESPACE = 'a85abb240d7cfa9d054375b654bcb5c23c746201fd4aed7acf81cb3f4ee720e1'

DEFAULT = Policy()

def describe():
  values = dataclasses.asdict(DEFAULT)
  identity = hashlib.sha256(json.dumps(values, sort_keys=True).encode()).hexdigest()
  return {'fingerprint': identity, 'seed_namespace': SEED_NAMESPACE, 'parameters': values}

def stable_rank(seed, value):
  return hashlib.sha256((seed + repr(value)).encode()).hexdigest()