"""AnimationBase ABC — all animations implement render() and from_params()."""
from abc import ABC, abstractmethod


class AnimationBase(ABC):
    """Pure animation renderer — no I/O, stateless or state-per-instance.

    Each animation computes pixel data from time t and strip length.
    No networking, no disk I/O — just math.
    """

    @abstractmethod
    def render(self, t: float, led_count: int) -> list[tuple]:
        """Render frame at time t (seconds since animation started).

        Returns list of (R, G, B) tuples, length == led_count.
        All channel values in range 0-255.
        """
        ...

    @classmethod
    @abstractmethod
    def from_params(cls, params: dict) -> "AnimationBase":
        """Construct from CueModel.params dict.

        Missing keys use animation-specific defaults.
        """
        ...