"""Chase animation — a lit segment moves along the strip."""
from lightsync.animations.base import AnimationBase


class ChaseAnimation(AnimationBase):
    """Moving lit segment(s) chasing along the strip.

    At speed=1.0, the segment moves at 60 pixels/second.
    Pattern repeats every (size + spacing) pixels.
    """

    def __init__(
        self,
        color: tuple[int, int, int] = (255, 255, 255),
        bg_color: tuple[int, int, int] = (0, 0, 0),
        speed: float = 0.5,
        size: int = 3,
        spacing: int = 7,
        reverse: bool = False,
        white: int = 0,
    ) -> None:
        self.color = tuple(color)  # type: ignore[arg-type]
        self.bg_color = tuple(bg_color)  # type: ignore[arg-type]
        self.speed = speed
        self.size = size
        self.spacing = spacing
        self.reverse = reverse
        self.white = white

    def render(self, t: float, led_count: int) -> list[tuple]:
        period = self.size + self.spacing
        offset = int(t * self.speed * 60)  # pixels/sec at speed=1.0 is 60

        pixels = []
        for i in range(led_count):
            if self.reverse:
                pos = (i + offset) % period
            else:
                pos = (i - offset) % period

            if pos < self.size:
                pixels.append(self.color)
            else:
                pixels.append(self.bg_color)

        return pixels

    @classmethod
    def from_params(cls, params: dict) -> "ChaseAnimation":
        return cls(
            color=tuple(params.get("color", [255, 255, 255])),  # type: ignore[arg-type]
            bg_color=tuple(params.get("bg_color", [0, 0, 0])),  # type: ignore[arg-type]
            speed=params.get("speed", 0.5),
            size=params.get("size", 3),
            spacing=params.get("spacing", 7),
            reverse=params.get("reverse", False),
            white=params.get("white", 0),
        )