"""Generate 128×128 union impact thumbnail for WhatsApp mockup attachment label."""
from pathlib import Path

import geopandas as gpd
import matplotlib.pyplot as plt

from src.config import DECK_SEVERITY_COLORS, PROCESSED_UNIONS


def generate_micro_map(union_name: str, severity: str, out_dir: Path) -> Path:
    out_dir.mkdir(parents=True, exist_ok=True)
    out = out_dir / f"micro_{union_name.replace(' ', '_')}.png"
    if out.exists():
        return out
    gdf = gpd.read_file(PROCESSED_UNIONS)
    row = gdf[gdf["union_name"] == union_name]
    if row.empty:
        return out
    fig, ax = plt.subplots(figsize=(1.28, 1.28), dpi=100)
    color = DECK_SEVERITY_COLORS.get(severity, [128, 128, 128, 255])
    row.plot(ax=ax, color=[c / 255 for c in color[:3]], edgecolor="white", linewidth=0.5)
    ax.axis("off")
    fig.savefig(out, bbox_inches="tight", pad_inches=0, facecolor="#0B141A")
    plt.close(fig)
    return out