#!/usr/bin/env python3

import os
import pprint
import http.server as SimpleHTTPServer
import socketserver as SocketServer
from huawei_lte_api.Client import Client
from huawei_lte_api.AuthorizedConnection import AuthorizedConnection
from huawei_lte_api.Connection import Connection

def prom_exporter():
	MANDATORY_ENV_VARS = ["ROUTER_ADDRESS", "ROUTER_USER", "ROUTER_PASS", "PROM_PORT"]
	for var in MANDATORY_ENV_VARS:
	    if var not in os.environ:
	        raise EnvironmentError("Failed because {} is not set.".format(var))

	# Auth to router
	conn ='http://'+os.environ.get('ROUTER_USER')+':'+os.environ.get('ROUTER_PASS')+'@'+os.environ.get('ROUTER_ADDRESS')+'/'
	connection = AuthorizedConnection(conn)

	# Initiatise client
	client = Client(connection)

	if os.environ.get('VERBOSE') is not None:
		pprint.pprint(client.device.signal())  # Can be accessed without authorization
		pprint.pprint(client.device.information())  # Needs valid authorization, will throw exception if invalid credentials are passed in URL

	# Set common response attributes
	band = client.device.signal().get('band')
	device = 'deviceName="'+ client.device.information().get('DeviceName')+'",iccid="'+client.device.information().get('Iccid')+'"'
	deviceband = device
	if band is not None:
		devband = device+',band="'+band+'"'

	# Retrieve attributes
	signal = {	'band': { 'help': 'The signal band the LTE connection is using', 'type': 'gauge', 'device': device, 'value': band},
				'rsrp': { 'help': 'The average power received from a single Reference signal in dBm', 'type': 'gauge', 'device': deviceband, 'value': client.device.signal().get('rsrp')},
				'rsrq': { 'help': 'Indicates quality of the received signal in db', 'type': 'gauge', 'device': deviceband, 'value': client.device.signal().get('rsrq')},
				'rssi': { 'help': 'Represents the entire received power including the wanted power from the serving cell as well as all co-channel power and other sources of noise in dBm', 'type': 'gauge', 'device': deviceband, 'value': client.device.signal().get('rssi')},
				'rscp': { 'help': 'Denotes the power measured by a receiver on a particular physical communication channel in dBm', 'type': 'gauge', 'device': deviceband, 'value': client.device.signal().get('rscp')},
				'sinr': { 'help': 'The signal-to-noise ratio of the given signal in dB', 'type': 'gauge', 'device': deviceband, 'value': client.device.signal().get('sinr')},
				'ecio': { 'help': 'The EC/IO is a measure of the quality/cleanliness of the signal from the tower to the modem and indicates the signal-to noise ratio in dB', 'type': 'gauge', 'device': deviceband, 'value': client.device.signal().get('ecio')}
			 }
	if os.environ.get('VERBOSE') is not None:
		pprint.pprint(signal)	
	# Cleanse data
	for attribute, info in signal.items():
		if info['value'] is not None:
			info['value'] = info['value'].replace("dBm", "")
			info['value'] = info['value'].replace("dB", "")
	# Populate response
	response=[]
	for attribute, info in signal.items():
		if attribute is not None and info['value'] is not None:
			response.append('#HELP '+attribute+' '+info['help'])
			response.append('#TYPE '+attribute+' '+info['type'])
			response.append(attribute+'{'+info['device']+'} '+info['value'])

	return '\n'.join(response)


class GetHandler(SimpleHTTPServer.SimpleHTTPRequestHandler):
	
    timeout=5
    def do_GET(self):
        self.send_response(200)
        self.end_headers()
        self.wfile.write(prom_exporter().encode())

Handler = GetHandler
httpd = SocketServer.TCPServer(("", int(os.environ.get('PROM_PORT'))), Handler)

httpd.serve_forever()