#
#
#
import numpy as np
import os, sys
import pickle
from mpi4py import MPI
import gc
#
import matplotlib as mpl
mpl.use('Agg')
from matplotlib.backends.backend_pdf import PdfPages
import matplotlib.pyplot as plt
import time
#
# Gert the information from the configuration file.
#
import configparser
config=configparser.ConfigParser({'SaveWeights':'true', "DiagLon":"0.0, 0.0", "DiagLat":"0.0, 0.0", "numop" : 100})
config.read("run.def")
saveweights=config.get("OverAll", "SaveWeights")
nbasmax=int(config.getfloat("OverAll", "nbasmax"))
numop=int(config.getfloat("OverAll", "numop"))
OutGraphFile=config.get("OverAll","GraphFile")
lonint=np.array(config.get("OverAll", "DiagLon").split(","),dtype=float)
latint=np.array(config.get("OverAll", "DiagLat").split(","),dtype=float)
#
EarthRadius=config.getfloat("OverAll", "EarthRadius")
#
import ModelGrid as MG
import Partition as PA
import RPPtools as RPP
import HydroGrid as HG
import diagplots as DP
import Interface as IF
from Truncate import trunc as TR
from spherical_geometry import vector
#
# Logging in MPI : https://groups.google.com/forum/#!topic/mpi4py/SaNzc8bdj6U
#
import getargs
log_master, log_world = getargs.getLogger()
INFO, DEBUG, ERROR = log_master.info, log_master.debug, log_world.error
INFO_ALL, DEBUG_ALL = log_world.info, log_world.debug
#
# Read full grid and partition the domain.
#
gg = MG.GlobalGrid()
#
comm = MPI.COMM_WORLD
szhalo=1
nbcore=comm.Get_size()
rank=comm.Get_rank()
#
# Verify directories
#
wdir="Weights"
if rank == 0 :
    if not os.path.exists(wdir) :
        os.mkdir(wdir)
comm.Barrier()
#
# Region of grid to be treated
#
part = PA.partition(gg.ni, gg.nj, gg.land, comm, nbcore, szhalo, rank)
#
# Weight file to be created
#
wfile=os.path.basename(config.get("OverAll", "ModelGridFile").replace(".","_"))+"_i"+str(part.istart).zfill(4)+"di"+str(part.ni).zfill(4)+"j"+str(part.jstart).zfill(4)+"dj"+str(part.nj).zfill(4)
#
#
modelgrid=MG.ModelGrid(part.ihstart+gg.igstart,part.nih,part.jhstart+gg.jgstart,part.njh)
INFO("Longitude interval on proc "+str(rank)+" = "+str(modelgrid.box_land[0][0])+" : "+str(modelgrid.box_land[0][1]))
INFO("Latitude interval on proc "+str(rank)+" = "+str(modelgrid.box_land[1][0])+" : "+str(modelgrid.box_land[1][1]))

print("modelgrid.box_land",modelgrid.box_land)
hydrogrid=HG.HydroGrid(modelgrid.box_land)

icell = 0
sub_index = []
sub_area = []
sub_lon = []
sub_lat = []
#
# Only compute the weights if the file does not exist.
#

if not os.path.exists(wdir+"/"+wfile) :
    INFO("Computing weights")
    for cell, center, radius, area in zip(modelgrid.polylist, modelgrid.centers, modelgrid.radius, modelgrid.area) :
        llinside=vector.vector_to_lonlat(cell.polygons[0].inside[0],cell.polygons[0].inside[1],cell.polygons[0].inside[2])
        area_in=np.zeros((hydrogrid.jjm,hydrogrid.iim), dtype=float)

        selected = hydrogrid.select(center, radius)
        INFO(str(icell)+" Number of HydroCells selected : "+str(len(selected))+ " out of "+str(len(hydrogrid.index)))
        for isel in selected :
            hydrocell = hydrogrid.polylist[isel]
            index = hydrogrid.index[isel]
            if cell.intersects_poly(hydrocell):
                inter = cell.intersection(hydrocell)
                # Another strange behaviour of SphericalHarmonics. There should be an overlap but the intersection polygone is empty.
                if len(inter.polygons) > 0 :
                    inside = inter.polygons[0]._inside
                    if hydrocell.contains_point(inside) and cell.contains_point(inside):
                        area_in[index[0],index[1]] = inter.area()*(EarthRadius**2)
                    else:
                        area_in[index[0],index[1]] = (4*np.pi-inter.area())*(EarthRadius**2)
        
        ##############
        # Output of Overlap areas for each grid point
        #
        #ncfile="Area_"+str("%.2f"%llinside[0])+"_"+str("%.2f"%llinside[1])+"_"+str(rank+1)+"of"+str(nbcore)+".nc"
        #RPP.dumpfield(area_in, hydrogrid.lon, hydrogrid.lat, ncfile, "Intersect area")
        #

        INFO(str(icell)+" Sum of overlap "+str(np.sum(area_in)/area)+
             " Nb of Hydro grid overlaping : "+str(np.count_nonzero(area_in)))
        sub_index.append(np.where(area_in > 0.0))
        sub_area.append(np.extract(area_in > 0.0, area_in))
        sub_lon.append(np.extract(area_in > 0.0, hydrogrid.lon))
        sub_lat.append(np.extract(area_in > 0.0, hydrogrid.lat))
        icell = icell + 1
    #
    # Save the weights to a dedicated file for future use
    #
    if ( saveweights.lower() == 'true' ) :
        with open(wdir+"/"+wfile, 'wb') as fp:
            pickle.dump(sub_index, fp)
            pickle.dump(sub_area, fp)
            pickle.dump(sub_lon, fp)
            pickle.dump(sub_lat, fp)
        fp.close()
else :
    #
    # Extract the weights from the file if it exists
    #
    INFO("Reading weights")
    with open (wdir+"/"+wfile, 'rb') as fp:
        sub_index = pickle.load(fp)
        sub_area = pickle.load(fp)
        sub_lon = pickle.load(fp)
        sub_lat = pickle.load(fp)
    fp.close()
#
#
#
nbpt = len(sub_index)
sub_pts = np.array(list(len(sub_index[i][0]) for i in range(len(sub_index))))
nbvmax = part.domainmax(max(sub_pts))
print("nbpt : ", nbpt)
print("nbvmax : ", nbvmax)
print("nbasmax : ", nbasmax)
#
# Extract hydo data from file
#
INFO("hydrodata")
hydrodata = HG.HydroData(hydrogrid.ncfile, hydrogrid.box, sub_index)

INFO("initiatmgrid")
IF.initatmgrid(rank, nbcore, nbpt, modelgrid)

INFO("hoverlap")
hoverlap = IF.HydroOverlap(nbpt, nbvmax, sub_pts, sub_index, sub_area, sub_lon, sub_lat, part, modelgrid, hydrodata)

#
# Do some memory management and synchronize procs.
#
comm.Barrier()
del sub_index
del sub_area
del sub_lon
del sub_lat
gc.collect()

if rank ==0 :
    if lonint[0] != lonint[1] and latint[0] != latint[1] :
        DP.MAPPLOT("MapHydroGrid", lonint, latint, hoverlap, hoverlap.hierarchy_bx, modelgrid.polyll, title="Distance to ocean")

hsuper = IF.HydroSuper(nbvmax, hydrodata, hoverlap, nbasmax)
#
# Plot the hydrological supermesh
#
if rank == 0 :
    if lonint[0] != lonint[1] and latint[0] != latint[1] :
        DP.SUPERMESHPLOT("MapSuperGrid_Beforelinkup", lonint, latint, hoverlap, hsuper, modelgrid.polyll)

print("=================== LINKUP ====================")
hsuper.linkup(hydrodata)
if rank ==0 :
    if lonint[0] != lonint[1] and latint[0] != latint[1] :
        DP.SUPERMESHPLOT("MapSuperGrid_Afterlinkup", lonint, latint, hoverlap, hsuper, modelgrid.polyll)
#
# Do some memory management and synchronize procs.
#
 
comm.Barrier()
del hoverlap
gc.collect()

print("=================== Compute fetch ====================")
t = time.time()
hsuper.fetch(part)
comm.Barrier()
t1 = time.time()
print("Time for fetch: {:0.2f} s.".format(t1-t)) 
comm.Barrier()

hsuper.dumpnetcdf(OutGraphFile.replace(".nc","_HydroSuper.nc"), gg, modelgrid, part)

print("Rank : {0} - Basin_count Before Truncate : ".format(part.rank), hsuper.basin_count)
hs = TR(hsuper, part, comm, modelgrid, numop = numop)
print("Rank : {0} - Basin_count After Truncate : ".format(part.rank), hsuper.basin_count)

hgraph = IF.HydroGraph(nbasmax, hsuper, part, modelgrid)
hgraph.dumpnetcdf(OutGraphFile, gg, modelgrid, part)

IF.closeinterface(comm)