#!/usr/bin/env python
import numpy as np
import xarray as xr
import os

from climdata import run_shell

# country name and lon/lat ranges
cntry_name = 'Thailand'
cntry_sname = cntry_name.replace(' ', '')


# IO files
ifile = f'erai.tas.p75.{cntry_sname}.nc'
ofile = ifile.replace('p75', 'p05')
xname = 'lon'
yname = 'lat'

# get the lon/lat values
ds = xr.open_dataset(ifile)
x = ds[xname].values
y = ds[yname].values

# set the new grid
ysign = 1 if y[-1] > y[0] else -1 # 1 if y increases; -1 if y decreases
dx, dy = 0.05, 0.05 * ysign
xsize, ysize = round( (x[-1] - x[0]) / dx ) + 1, round( (y[-1] - y[0]) /dy + 1 )

with open('newgrid', 'w') as f:
    f.write('gridtype = lonlat \n')
    f.write(f'xfirst = {x[0]} \n')
    f.write(f'xinc = {dx} \n')
    f.write(f'xsize = {int(xsize)} \n')
    f.write(f'yfirst = {y[0]} \n')
    f.write(f'yinc = {dy} \n')
    f.write(f'ysize = {int(ysize)} \n')
    
run_shell(f'cdo remapbil,newgrid {ifile} {ofile}')