Allow indexing by tile

[ianhi]

Nice to provide indexing as if you input mercator tiles into https://dudewheresmytile.mattnucc.com/?tab=tile then did .sel on the bbox returned from there.

e.g. with below code you can do:

ds.tile("314/547/10")

and it will sel the correct bbox for you.

from typing import overload

import mercantile
import xarray as xr


@xr.register_dataset_accessor("tile")
@xr.register_dataarray_accessor("tile")
class TileAccessor:
    def __init__(self, xarray_obj):
        self._ds = xarray_obj

    def mbbox(self, bbox: mercantile.LngLatBbox) -> xr.Dataset:
        return self._ds.sel(
            {
                ds.cf["longitude"].name: slice(bbox.west, bbox.east),
                ds.cf["latitude"].name: slice(bbox.south, bbox.north),
            }
        )

    @overload
    def __call__(self, tile: str) -> xr.Dataset: ...

    def __call__(self, X: int, Y: int = None, zoom: int = None) -> xr.Dataset:
        """
        Slice the bbox associated with the tile.
        Valid inputs:
        "lat/lon/zoom"
        "lat,lon,zoom"
        lat, lon, zoom (as integers)
        not sure how to do params properly for this overload.
        """
        # no safety checks! be good plz :)

        if isinstance(X, str):
            bbox = mercantile.bounds(tuple(map(int, X.replace(",", "/").split("/"))))
        else:
            bbox = mercantile.bounds(X, Y, zoom)
        return self.mbbox(bbox)