"""Check if missing chunks transferred from gcp-zarr are related to dask."""
import os
import numpy as np
import xarray as xr
from fsspec import get_mapper
from dask.distributed import Client

OUTDIR = "/tmp"
TIME = "2012-01-01 00:00:00"

ZARRFILE = "gs://oceanum-era5/wind_10m.zarr"

NTRIES = 20
NCPU = 1


class TestXarrayDistributed:

    @classmethod
    def setup_class(self):
        self.client = None
        self.iter = 0
        self.success = []
        self.failure = []

    @classmethod
    def teardown_class(self):
        fname = "failure_{}-cpu_{}-tries_{}".format(NCPU, NTRIES, TIME)
        if self.failure:
            dset = xr.concat(self.failure, dim="iter")
            dset.to_netcdf(os.path.join(OUTDIR, fname+".nc"))
        else:
            with open(os.path.join(OUTDIR, fname+".txt"), "w") as stream:
                stream.write("NO FAILURES")

        fname = "success_{}-cpu_{}-tries_{}".format(NCPU, NTRIES, TIME)
        if self.success:
            dset = xr.concat(self.success, dim="iter")
            dset.to_netcdf(os.path.join(OUTDIR, fname+".nc"))
        else:
            with open(os.path.join(OUTDIR, fname+".txt"), "w") as stream:
                stream.write("NO SUCCESSES")

    def start_cluster(self):
        if NCPU > 1:
            print("Starting distributed with {} cpus".format(NCPU))
            self.client = Client()
            self.client.cluster.scale(NCPU)

    def close_cluster(self):
        if self.client is not None:
            self.client.close()

    def open_dataset(self):
        print("Opening zarr dataset: {}".format(ZARRFILE))
        fsmap = get_mapper(ZARRFILE)
        self.dset = xr.open_zarr(fsmap, consolidated=True)

    def close_dataset(self):
        if self.dset is not None:
            print("Closing zarr dataset")
            self.dset.close()

    def load_timestamp(self):
        ds = self.dset.sel(time=TIME).load()
        try:
            dvar = np.sqrt(ds.u10**2 + ds.v10**2)
        except:
            dvar = ds.hs
        return dvar

    def append_result(self):
        dvar = self.load_timestamp()
        if dvar.isnull().any():
            self.failure.append(dvar)
        else:
            self.success.append(dvar)
        self.iter += 1

    def test_transfer(self):
        self.start_cluster()
        self.open_dataset()
        for i in range(NTRIES):
            print("\n{}\nIterating: {}\n{}".format(88*"=", i, 88*"="))
            self.append_result()
        self.close_dataset()
        self.close_cluster()