### Python script to use SNAP as InSAR processor compatible with StaMPS PSI processing
# Author Jose Manuel Delgado Blasco
# Date: 21/06/2018
# Version: 1.0

# Step 1 : preparing slaves in folder structure
# Step 2 : TOPSAR Splitting (Assembling) and Apply Orbit
# Step 3 : Coregistration and Interferogram generation
# Step 4 : StaMPS export

# Added option for CACHE and CPU specification by user
# Planned support for DEM selection and ORBIT type selection 


import os
from pathlib import Path
import sys
import glob
import subprocess
import shlex
import time
inputfile = sys.argv[1]

bar_message='\n#####################################################################\n'

# Getting configuration variables from inputfile
try:
        in_file = open(inputfile, 'r')

        for line in in_file.readlines():
                if "PROJECTFOLDER" in line:
                        PROJECT = line.split('=')[1].strip()
                        print (PROJECT)
                if "IW1" in line:
                        IW = line.split('=')[1].strip()
                        print (IW)
                if "MASTER" in line:
                        MASTER = line.split('=')[1].strip()
                        print (MASTER)
                if "GRAPHSFOLDER" in line:
                        GRAPH = line.split('=')[1].strip()
                        print (GRAPH)
                if "GPTBIN_PATH" in line:
                        GPT = line.split('=')[1].strip()
                        print (GPT)
                if "LONMIN" in line:
                        LONMIN = line.split('=')[1].strip()
                if "LATMIN" in line:
                        LATMIN = line.split('=')[1].strip()
                if "LONMAX" in line:
                        LONMAX = line.split('=')[1].strip()
                if "LATMAX" in line:
                        LATMAX = line.split('=')[1].strip()
                if "CACHE" in line:
                        CACHE = line.split('=')[1].strip()
                if "CPU" in line:
                        CPU = line.split('=')[1].strip()
finally:
        in_file.close()

polygon='POLYGON (('+LONMIN+' '+LATMIN+','+LONMAX+' '+LATMIN+','+LONMAX+' '+LATMAX+','+LONMIN+' '+LATMAX+','+LONMIN+' '+LATMIN+'))'

######################################################################################
## TOPSAR Coregistration and Interferogram formation ##
######################################################################################
slavesplittedfolder=PROJECT+'/split'
outputcoregfolder=PROJECT+'/coreg'
outputifgfolder=PROJECT+'/ifg'
logfolder=PROJECT+'/logs'
if not os.path.exists(outputcoregfolder):
                os.makedirs(outputcoregfolder)
if not os.path.exists(outputifgfolder):
                os.makedirs(outputifgfolder)
if not os.path.exists(logfolder):
                os.makedirs(logfolder)

outlog=logfolder+'/coreg_ifg_proc_stdout.log'

graphxml=GRAPH+'/coreg_ifg_computation_subset.xml'
print (graphxml)
graph2run=GRAPH+'/coreg_ifg2run.xml'

out_file = open(outlog, 'a')
err_file=out_file

print (bar_message)
out_file.write(bar_message)
message='## Coregistration and Interferogram computation started:\n'
print (message)
out_file.write(message)
print (bar_message) 
out_file.write(bar_message)
k=0
for dimfile in glob.iglob(slavesplittedfolder + '/*/*'+IW+'.dim'):
    print (dimfile)
    k=k+1
    head, tail = os.path.split(os.path.join(slavesplittedfolder, dimfile))
    message='['+str(k)+'] Processing slave file :'+tail+'\n'
    print (message)
    out_file.write(message)
    head , tailm = os.path.split(MASTER)
    outputname=tailm[17:25]+'_'+tail[0:8]+'_'+IW+'.dim'
    with open(graphxml, 'r') as file :
       filedata = file.read()
    # Replace the target string
    filedata = filedata.replace('MASTER',MASTER)
    filedata = filedata.replace('SLAVE', dimfile)
    filedata = filedata.replace('OUTPUTCOREGFOLDER',outputcoregfolder)
    filedata = filedata.replace('OUTPUTIFGFOLDER', outputifgfolder)
    filedata = filedata.replace('OUTPUTFILE',outputname)
    filedata = filedata.replace('POLYGON',polygon)
    # Write the file out again
    with open(graph2run, 'w') as file:
       file.write(filedata)
    args = [ GPT, graph2run, '-c', CACHE, '-q', CPU]
    # Launch the processing
    process = subprocess.Popen(args, stdout=subprocess.PIPE,stderr=subprocess.STDOUT)
    timeStarted = time.time()
    stdout = process.communicate()[0]
    print ('SNAP STDOUT:{}'.format(stdout))
    timeDelta = time.time() - timeStarted                     # Get execution time.
    print('['+str(k)+'] Finished process in '+str(timeDelta)+' seconds.')
    out_file.write('['+str(k)+'] Finished process in '+str(timeDelta)+' seconds.\n')
    if process.returncode != 0 :
        message='Error computing with coregistration and interferogram generation of splitted slave '+str(dimfile)
        err_file.write(message+'\n')
    else:
        message='Coregistration and Interferogram computation for data '+str(tail)+' successfully completed.\n'
        print (message)
        out_file.write(message)
    print (bar_message)
    out_file.write(bar_message)
out_file.close()