"""
PRISM uncertainty module.
"""

import random

from env.models import Task


def apply_uncertainty(task: Task, rng: random.Random) -> float:
    noise = rng.gauss(0, task.uncertainty * 0.3)
    return max(0.0, min(1.0, task.risk + noise))


class PRISM:
    """
    Probabilistic risk and inference shaping module.
    """

    def __init__(self, seed: int = 42):
        self.rng = random.Random(seed)

    def apply_uncertainty(self, task: Task) -> float:
        return apply_uncertainty(task, self.rng)

    def execution_succeeds(self, task: Task) -> bool:
        effective_risk = self.apply_uncertainty(task)
        return self.rng.random() > effective_risk