import logging

# External libs
import xarray as xr

# Optional libs
try:
    import salem
except ImportError:
    pass

# Locals
from oggm import utils
from oggm import entity_task

# Module logger
log = logging.getLogger(__name__)

LMR_SERVER = 'https://cluster.klima.uni-bremen.de/~fmaussion/runs/lmr_2025/data/unstacked/'


@entity_task(log, writes=['climate_historical'])
def process_mira_data(gdir, output_filesuffix=None, nat_forcing=False):
    """Processes and writes the baseline climate data for this glacier.

    Extracts the nearest timeseries and writes everything to a NetCDF file.

    Parameters
    ----------
    output_filesuffix : str
        this add a suffix to the output file (useful to avoid overwriting
        previous experiments)
    """

    # Use xarray to read the data
    lon = gdir.cenlon
    lat = gdir.cenlat

    # Files
    if nat_forcing:
        f_temp = utils.file_downloader(LMR_SERVER + 'tp_nat_monthly.nc')
    else:
        f_temp = utils.file_downloader(LMR_SERVER + 'tp_monthly.nc')
    f_pcp = utils.file_downloader(LMR_SERVER + 'p_monthly.nc')
    f_h = utils.file_downloader(LMR_SERVER + 'elev.nc')

    with xr.open_dataset(f_temp, use_cftime=True) as ds:
        yrs = ds['time.year'].data
        y0 = yrs[0]
        y1 = yrs[-1]
        ds = ds.sel(lon=lon, lat=lat, method='nearest')
        temp = ds['tas'].data - 273.15
        time = ds.time.data
        ref_lon = float(ds['lon'])
        ref_lon = ref_lon - 360 if ref_lon > 180 else ref_lon
        ref_lat = float(ds['lat'])
    with xr.open_dataset(f_pcp, use_cftime=True) as ds:
        ds = ds.sel(time=slice(f'{y0:04d}-01-01', f'{y1:04d}-12-01'))
        ds = ds.sel(lon=lon, lat=lat, method='nearest')
        # 'kg m-2 s-1' to 'kg m-2 month'
        prcp = ds['pr'].data * ds['time.daysinmonth'] * 24 * 60 * 60
    with xr.open_dataset(f_h) as ds:
        ds = ds.sel(lon=lon, lat=lat, method='nearest')
        hgt = ds['elevation'].data

    # OK, ready to write
    gdir.write_monthly_climate_file(time, prcp, temp, hgt, ref_lon, ref_lat,
                                    filesuffix=output_filesuffix,
                                    source='lmr_mira')