beacon.py

#! /usr/bin/env python
import json
import os
import sys
import time
import urllib
import urllib2

MASTER = "http://localhost:8000/beacons/"
RC_FILE = os.path.expanduser("~/.beaconrc")
LOG_FILE = os.path.expanduser("~/beacon_log")
TIMEOUT = 5*60  # 5 minutes


def init_beacon():
    """
    Check if beacon is already set up.
    Ask for beacon name.
    Register beacon via API.
    Put beacon ID into .beaconrc
    Quit.
    """
    try:
        with open(RC_FILE, "r") as beaconrc:
            config = json.loads(beaconrc.read())
            if "name" in config and "beacon_id" in config:
                print("Beacon already configured: ")
                print(" Name: {}".format(config["name"]))
                print(" ID: {}".format(config["beacon_id"]))
                if not confirm("Do you want to re-configure beacon [Y/N]? "):
                    print("Done. ID: {}".format(config["beacon_id"]))
                    return
    except IOError:
        pass

    name = raw_input("Please enter name for this beacon: ")
    print("* Initializing: {}".format(name))

    data = urllib.urlencode({"name": name})
    req = urllib2.Request(MASTER, data)
    try:
        response = urllib2.urlopen(req)
    except urllib2.HTTPError as e:
        print("Failed to register beacon! {}".format(e.read()))
    else:
        the_page = response.read()
        try:
            beacon_id = json.loads(the_page)["id"]
        except Exception:
            print("Failed to read Master response: {}".format(the_page))
        else:
            with open(RC_FILE, "w") as beaconrc:
                beaconrc.write(json.dumps(dict(
                    name=name,
                    beacon_id=beacon_id
                )))
            print("Done. ID: {}".format(beacon_id))


def ping():
    """
    Get beacon details or bail out.
    Ping master.
    Sleep for 5 minutes.
    """
    beacon_id = None
    try:
        with open(RC_FILE, "r") as beaconrc:
            config = json.loads(beaconrc.read())
            beacon_id = config["beacon_id"]
    except Exception as e:
        with open(LOG_FILE, "a+") as log:
            log.write("Failed to open config. {}\r\n".format(e))
            return

    data = urllib.urlencode({"test": "1"})
    req = urllib2.Request("{}{}/".format(MASTER, beacon_id), data)
    try:
        urllib2.urlopen(req)
    except urllib2.HTTPError as e:
        with open(LOG_FILE, "a+") as log:
            log.write("Failed to ping master. {}\r\n".format(e))

    time.sleep(TIMEOUT)
    ping()


def confirm(message):
    """
    Ask user to enter Y or N (case-insensitive).
    :return: True if the answer is Y.
    :rtype: bool
    """
    answer = ""
    while answer not in ["y", "n"]:
        answer = raw_input(message).lower()
    return answer == "y"


if __name__ == '__main__':
    if "--init" in sys.argv:
        init_beacon()
    else:
        ping()