#!/usr/bin/python3
import requests
import json
from time import sleep
import uuid
import subprocess
from trisurf import trisurf
import os
import shutil
import signal
import sys
import socket
CONNECT_ADDR='http://localhost:8000'

p=None
workingdir=None



#--- SIGINT and SIGTERM HANDLING ---
def signal_handler(signal,frame):
	global p
	global wirkingdir
	if p is not None:
		p.terminate()
	if(workingdir is not None):
		removeDir(workingdir.fullpath())
	print("Process ended with signal " +str(signal))
	sys.exit(0)
signal.signal(signal.SIGINT, signal_handler)
signal.signal(signal.SIGTERM, signal_handler)
#--- END SIGINT and SIGTERM----



def get_hostname():
	return socket.gethostname()

def get_ip():
	return ((([ip for ip in socket.gethostbyname_ex(socket.gethostname())[2] if not ip.startswith("127.")] or [[(s.connect(("8.8.8.8", 53)), s.getsockname()[0], s.close()) for s in [socket.socket(socket.AF_INET, socket.SOCK_DGRAM)]][0][1]]) + ["no IP found"])[0])

def get_client_id(addr, my_ip, my_hostname):
	client_auth={'ip':my_ip,'hostname':my_hostname}
	response=requests.post(addr+"/api/register/", data=client_auth)
	if(response.status_code==200):
		client_data=json.loads(response.text)
		client_id=client_data['id']
		return client_id
	else:
		raise ValueError


def get_run(addr,cid):
	response=requests.get(addr+"/api/getrun/"+str(cid)+"/")
	if(response.status_code==200):
		client_data=json.loads(response.text)
		rid=client_data['id']
		tape=client_data['tape']
		vtu=client_data['lastVTU']
		status=client_data['status']
		return (rid,tape,vtu,status)
	else:
		print(response.text)
		raise ValueError


def ping_run(addr,cid, rid):
	client_data={'client_id':cid, 'run_id':rid}
	response=requests.post(addr+"/api/ping/", data=client_data)
	if(response.status_code==200):
		return
	else:
		raise ValueError

def send_error_report(addr,cid, rid,errcode):
	client_data={'client_id':cid, 'run_id':rid, 'error_code':errcode}
	response=requests.post(addr+"/api/reporterr/", data=client_data)
	if(response.status_code==200):
		return
	else:
		raise ValueError

def upload(addr,cid, rid, vtu, status):
	client_data={'client_id': cid, 'run_id': rid, 'lastVTU': vtu, 'status': status}
	response=requests.post(addr+"/api/upload/", data=client_data)
	if(response.status_code==200):
		return
	else:
		raise ValueError

def getNewVTU(directory):
	fset=set()
	for file in os.listdir(directory):
		if file.endswith(".vtu") and file.startswith("timestep_"):
			fset.add(file)
	return fset


def removeDir(directory):
	os.chdir('/')
	try:
		shutil.rmtree(directory)
	except:
		print("Cannot remove directory "+directory+ "\n")
	return


while(True):
	try:
		cid=get_client_id(CONNECT_ADDR, get_ip(),get_hostname())
	except:
		print("Cannot get CID.")
		sleep(10)
		continue
	print("Got CID. getting RID.")
	while(True):
		try:
			(rid,tape,vtu,status)=get_run(CONNECT_ADDR,cid)
		except:
			print("Could not get RID.")
			sleep(10)
			break
		else:
			#start separate thread with simulations.
			workingdir=trisurf.Directory('/tmp/ts_'+str(uuid.uuid4()))
			workingdir.makeifnotexist()
			workingdir.goto()
			with open(workingdir.fullpath()+"/tape", 'w') as f:
				f.write(tape)
			if(int(status)==-1):
				cmd=['trisurf', '--force-from-tape']
				print("Run id="+str(rid)+ " :: Starting from tape")
			else:
				with open(workingdir.fullpath()+"/.status",'w') as f:
					f.write(status)
				with open(workingdir.fullpath()+"/initial.vtu",'w') as f:
					f.write(vtu)
				cmd=['trisurf', '--restore-from-vtk', 'initial.vtu']
				print("Run id="+str(rid)+ " :: Restoring from vtk, last timestep "+status)
			p=subprocess.Popen(cmd, stdout=subprocess.DEVNULL)
			s=int(status)
			while(True):
				#monitor for new file. If file is present, upload it!
				newVTU=getNewVTU(workingdir.fullpath())
				if newVTU: #upload
					try:
						for nv in sorted(newVTU):
							with open(nv,'r') as f:
								fc=f.read()
							s=s+1
							print('Uploading '+nv)
							upload(CONNECT_ADDR, cid, rid, fc, s)
							os.unlink(nv)
					except:
						print("Could not upload")
						p.terminate()
						removeDir(workingdir.fullpath())
						break
					else:
						print("VTU uploaded")
				else: #ping
					try:
						ping_run(CONNECT_ADDR, cid, rid)
					except:
						print("Could not ping")
						p.terminate()
						removeDir(workingdir.fullpath())
						#stop simulations
						break
				#check if trisurf is still running. If not break the highest level loop.
				sleep(1)
				if(p.poll() is not None): # trisurf exited!
					print("Trisurf was stopped with return code {}".format(p.returncode))
					if(p.returncode!=0):
						try:
							send_error_report(CONNECT_ADDR, cid, rid, p.returncode)
						except:
							print("Server didn't accept error report")
					removeDir(workingdir.fullpath())
					break
				sleep(100)