"""Bootstrap landcover and canopy rasters for an AOI."""

from __future__ import annotations

import argparse
import math
from pathlib import Path
from urllib.error import HTTPError, URLError
from urllib.request import urlretrieve

WORLDCOVER_BASE_URL = "https://esa-worldcover.s3.eu-central-1.amazonaws.com/v200/2021/map"
WORLDCOVER_GRID_URL = (
    "https://esa-worldcover.s3.eu-central-1.amazonaws.com/v200/2021/esa_worldcover_2021_grid.geojson"
)


def parse_bbox(raw: str) -> tuple[float, float, float, float]:
    parts = [float(part.strip()) for part in raw.split(",")]
    if len(parts) != 4:
        raise argparse.ArgumentTypeError("bbox must be minlon,minlat,maxlon,maxlat")
    minlon, minlat, maxlon, maxlat = parts
    if minlon >= maxlon or minlat >= maxlat:
        raise argparse.ArgumentTypeError("bbox min values must be lower than max values")
    return minlon, minlat, maxlon, maxlat


def _tile_id(lat: int, lon: int) -> str:
    lat_prefix = "N" if lat >= 0 else "S"
    lon_prefix = "E" if lon >= 0 else "W"
    return f"{lat_prefix}{abs(lat):02d}{lon_prefix}{abs(lon):03d}"


def tiles_for_bbox(bbox: tuple[float, float, float, float]) -> list[str]:
    minlon, minlat, maxlon, maxlat = bbox
    lats = range(math.floor(minlat / 3) * 3, math.ceil(maxlat), 3)
    lons = range(math.floor(minlon / 3) * 3, math.ceil(maxlon), 3)
    return [_tile_id(lat, lon) for lat in lats for lon in lons]


def tile_url(tile: str) -> str:
    return f"{WORLDCOVER_BASE_URL}/ESA_WorldCover_10m_2021_v200_{tile}_Map.tif"


def parse_args() -> argparse.Namespace:
    parser = argparse.ArgumentParser(description="Bootstrap WorldCover/CORINE/canopy data")
    parser.add_argument("--bbox", required=True, type=parse_bbox, help="minlon,minlat,maxlon,maxlat")
    parser.add_argument("--landcover-dir", default=Path("data/landcover"), type=Path)
    parser.add_argument("--canopy-dir", default=Path("data/canopy"), type=Path)
    parser.add_argument("--overwrite", action="store_true")
    return parser.parse_args()


def main() -> None:
    args = parse_args()
    args.landcover_dir.mkdir(parents=True, exist_ok=True)
    args.canopy_dir.mkdir(parents=True, exist_ok=True)

    downloaded = 0
    skipped = 0
    failed: list[str] = []

    for tile in tiles_for_bbox(args.bbox):
        destination = args.landcover_dir / f"ESA_WorldCover_10m_2021_v200_{tile}_Map.tif"
        if destination.exists() and not args.overwrite:
            skipped += 1
            print(f"skip existing {destination}")
            continue

        url = tile_url(tile)
        print(f"download {url}")
        try:
            urlretrieve(url, destination)
        except (HTTPError, URLError) as exc:
            failed.append(f"{tile}: {exc}")
            if destination.exists():
                destination.unlink()
            continue
        downloaded += 1

    print(
        "Canopy bootstrap is not bundled with WorldCover tiles. "
        "Place canopy height GeoTIFF/COG files manually under "
        f"{args.canopy_dir} if needed."
    )
    print(f"downloaded={downloaded} skipped={skipped} failed={len(failed)}")
    if failed:
        for item in failed:
            print(f"failed {item}")
        raise SystemExit(1)


if __name__ == "__main__":
    main()