"""Plot construction and color tables shared by radar views."""

import numpy as np
import pyqtgraph as pg


def create_plot(title: str = "") -> pg.PlotWidget:
    plot = pg.PlotWidget(background="#0f141c", enableMenu=False, title=title)
    plot.showGrid(x=True, y=True, alpha=0.2)
    return plot


def build_lut(stops: list[str], *, size: int = 256) -> np.ndarray:
    """Interpolate hex color stops into 8-bit RGB LUT array."""
    stop_positions = np.linspace(0.0, 1.0, num=len(stops), dtype=np.float32)
    sample_positions = np.linspace(0.0, 1.0, num=size, dtype=np.float32)
    stop_colors = np.asarray([pg.mkColor(value).getRgb()[:3] for value in stops], dtype=np.float32)

    lut = np.empty((size, 3), dtype=np.uint8)
    for channel in range(3):
        lut[:, channel] = np.interp(sample_positions, stop_positions, stop_colors[:, channel]).astype(np.uint8)
    return lut