Source code for workflow.scripts.plotting.plot_regions_map

#! /usr/bin/env python3
# SPDX-FileCopyrightText: 2025 Koen van Greevenbroek
#
# SPDX-License-Identifier: GPL-3.0-or-later

import logging
from pathlib import Path

import cartopy.crs as ccrs
from cartopy.mpl.ticker import LatitudeFormatter, LongitudeFormatter
import geopandas as gpd
import matplotlib

matplotlib.use("pdf")
import matplotlib.pyplot as plt
import matplotlib.ticker as mticker
import numpy as np

logger = logging.getLogger(__name__)




def plot_regions_map(regions_path: str, output_path: str) -> None:
    logger.info("Loading regions from %s", regions_path)
    gdf = gpd.read_file(regions_path)

    if gdf.crs is None:
        logger.warning("Input CRS missing; assuming EPSG:4326 (WGS84)")
        gdf = gdf.set_crs(4326, allow_override=True)
    else:
        gdf = gdf.to_crs(4326)

    # Prepare output directory
    out = Path(output_path)
    out.parent.mkdir(parents=True, exist_ok=True)

    fig, ax = plt.subplots(
        figsize=(12, 6),
        dpi=150,
        subplot_kw={"projection": ccrs.EqualEarth()},
    )
    ax.set_facecolor("#f7f9fb")
    ax.set_global()

    ax.add_geometries(
        gdf.geometry,
        crs=ccrs.PlateCarree(),
        facecolor="#cfd8dc",
        edgecolor="#444444",
        linewidth=0.4,
        zorder=1,
    )

    for name, spine in ax.spines.items():
        if name == "geo":
            spine.set_visible(True)
            spine.set_linewidth(0.5)
            spine.set_edgecolor("#555555")
            spine.set_alpha(0.7)
        else:
            spine.set_visible(False)

    gl = ax.gridlines(
        draw_labels=True,
        crs=ccrs.PlateCarree(),
        linewidth=0.35,
        color="#888888",
        alpha=0.45,
        linestyle="--",
    )
    gl.xlocator = mticker.FixedLocator(np.arange(-180, 181, 30))
    gl.ylocator = mticker.FixedLocator(np.arange(-60, 61, 15))
    gl.xformatter = LongitudeFormatter(number_format=".0f")
    gl.yformatter = LatitudeFormatter(number_format=".0f")
    gl.xlabel_style = {"size": 8, "color": "#555555"}
    gl.ylabel_style = {"size": 8, "color": "#555555"}
    gl.top_labels = False
    gl.right_labels = False

    ax.set_xlabel("Longitude", fontsize=8, color="#555555")
    ax.set_ylabel("Latitude", fontsize=8, color="#555555")

    ax.set_title("Regions", fontsize=12)
    plt.tight_layout()
    fig.savefig(out, bbox_inches="tight", dpi=300)
    plt.close(fig)

    logger.info("Saved regions map to %s", output_path)



if __name__ == "__main__":
    plot_regions_map(snakemake.input.regions, snakemake.output.pdf)