#!/usr/bin/python3
import subprocess
import json
import sys
import datetime
import os
import xmlrpc.client
import ssl
import sys
import time

class UpdateLTSPImage:
	def __init__(self, identifier, datetime_delay):

		self.identifier = identifier
		self.datetime = datetime.datetime.strptime(datetime_delay, '%d-%m-%Y %H:%M')
		self.TODAY = datetime.datetime.now()
		self.ID_DATE_STRING = self.TODAY.strftime("%Y%m%d")
		self.new_identifier = "{identifier}_{date_string}".format(identifier=self.identifier, date_string=self.ID_DATE_STRING)

		self.CHROOT_BASE = '/opt/ltsp'
		self.LMD_CONFIG_BASE = '/etc/ltsp/images'
		context = ssl._create_unverified_context()
		self.n4d = xmlrpc.client.ServerProxy('https://localhost:9779',context=context)
		command = "ltsp-chroot -a {chroot} dpkg-architecture | grep DEB_BUILD_ARCH_CPU | awk -F'[/=]' {{'print $2'}}".format(chroot=self.identifier)
		p = subprocess.Popen([command],shell=True,stdout=subprocess.PIPE)
		self.arch = p.communicate()[0].strip().decode('utf-8')

	def get_unique_identifier(self):
		'''
			Set self.new_identifier unique identifier. 
			This identifier is non exists folder on /opt/ltsp with identifier value 
			and date on name
		'''
		counter = 1
		while os.path.exists(os.path.join(self.CHROOT_BASE,'images',self.new_identifier) + ".img") or os.path.exists(os.path.join(self.CHROOT_BASE,self.new_identifier)) or os.path.exists(os.path.join(self.LMD_CONFIG_BASE,self.new_identifier + ".json")) :
			self.new_identifier = "{identifier}_{date_string}_{counter}".format(
																identifier=self.identifier,
																date_string=self.ID_DATE_STRING,
																counter=str(counter))
			counter+=1
		return self.new_identifier

	def build_lmd_conf_file(self):
		'''
			Create file on /etc/ltsp/images/ with new identifier based on original identifier.
			On file change id and name.
		'''
		with open(os.path.join(self.LMD_CONFIG_BASE, self.identifier + ".json"), 'r') as data_file:
			lmd_config = json.load(data_file)
		lmd_config['id'] = self.new_identifier
		lmd_config['name'] = "{name} ({date_string})".format(name=lmd_config['name'], date_string=self.TODAY.strftime("%d-%m-%Y %H:%M"))
		lmd_config['status'] = "enabled-non-editable"
		with open(os.path.join(self.LMD_CONFIG_BASE, self.new_identifier + ".json"), 'w') as data_file:
			json.dump(lmd_config, data_file, indent=4)
		print("Created config for Lmd")

	def ltsp_update_image(self):
		arch_build = 'linux32'
		if self.arch == 'amd64':
			arch_build = 'linux64'
		options = {
			"original_chroot" : os.path.join(self.CHROOT_BASE,self.identifier),
			"new_chroot": os.path.join(self.CHROOT_BASE,self.new_identifier),
			"new_identifier" : self.new_identifier,
			"arch" : arch_build
		}
		command = "mount --bind {original_chroot} {new_chroot} && {arch} ltsp-update-image {new_identifier}".format(**options)
		process = subprocess.Popen(command, shell=True, stdout=subprocess.PIPE)
		while True:
			output = os.read(process.stdout.fileno(),1024).decode('utf-8')
			if output.strip() == '' and process.poll() is not None:
				break
			if output:
				print(output.strip())
				sys.stdout.flush()
			time.sleep(1)
		command = "umount -l {new_chroot}".format(**options)
		subprocess.Popen([command],shell=True).communicate()


	def run(self):
		# Get unique identifier
		self.get_unique_identifier()

		# Create temp folder to mount original chroot
		os.mkdir(os.path.join(self.CHROOT_BASE, self.new_identifier))
		print("Created temp folder to chroot")

		self.build_lmd_conf_file()
		self.ltsp_update_image()
		os.rmdir(os.path.join(self.CHROOT_BASE, self.new_identifier))
		masterkey = ''
		with open('/etc/n4d/key') as file_data:
			masterkey = file_data.readlines()[0].strip()
		self.n4d.pushToBootList(masterkey,'LlxBootManager', "ltsp_label{new_identifier}".format(new_identifier=self.new_identifier))
		
		self.n4d.write_tasks(masterkey,'SchedulerServer','local',{'PromoteImg':
			{
				'0':{
					'dom':str(self.datetime.day),
					'mon':str(self.datetime.month),
					'h':str(self.datetime.hour),
					'm':str(self.datetime.minute),
					'cmd':'lmd-promote-image {new_identifier} {identifier}'.format(new_identifier=self.new_identifier,identifier=self.identifier),
					'dow':'*',
					'kind':'fixed',
					'autoremove':True,
					'name':'Promote image {new_identifier} to {identifier}'.format(new_identifier=self.new_identifier, identifier=self.identifier)
					 }
				}}
		)
		print("Finish update image. New image available")

def main():
	if len(sys.argv) >= 3:
		p = UpdateLTSPImage(sys.argv[1], sys.argv[2])
		p.run()
	else:
		print("!!! Error on arguments")
		sys.exit(1)

if __name__ == '__main__':
	main()