#!/usr/bin/env python
#
# Authors:
# rafael@postgresql.org.es / http://www.postgresql.org.es/
#
# Copyright (c) 2014 USIT-University of Oslo

import sys
import os
import time
import json
import urllib2
import xml.etree.ElementTree as ET

# ############################################
# Method: get_temperature_box_info()
#
# Parameters: Text = temperature box hostname, deviceID
# Returns: List data estructure with temperature 
# box information
#
# device_info[0] = TempC actual value 
# device_info[1] = TempC max value
# device_info[2] = TempC min value
# device_info[3] = TempC alarm max (-255 if not defined)
# device_info[4] = TempC alarm min (-255 if not defined)
#
# ############################################

def get_device_info(temperature_box,device_id):

    device_info = []

    try:
        minutes_since_last_update = 0
        temp_file = '/tmp/' + temperature_box + '_temperature_data.xml'
        
        if os.path.exists(temp_file) == True:
            minutes_since_last_update = (time.time() - os.path.getmtime(temp_file)) / 60
        
        #
        # Get the XML data from
        # http://<temperature_box_hostname>/data.xml only if the local
        # temp file with the XML code does not exist or if the file is
        # older that 5 minutes.
        # 

        if os.path.exists(temp_file) == False or minutes_since_last_update > 5:
            
            req = urllib2.Request('http://' + temperature_box + '/data.xml')
            response = urllib2.urlopen(req,timeout=5)
            the_page = response.read()

            with open (temp_file,'w') as xmlfile:
                xmlfile.write(the_page)

        tree = ET.parse(temp_file)
        root = tree.getroot()

    except Exception as e:
        print e
        sys.exit(1)

    try:

        #
        # Generate a list with the information we get from a device 
        #

        #
        # Device information
        #
        for child in root.findall("./devices/device"):
            
            if child.attrib['id'] == device_id:
                for field in child.findall("field"):                                                                                                                                        
                    if field.attrib['key'] == 'TempC':
                        device_info.append(field.attrib['value'])
                        device_info.append(field.attrib['max'])
                        device_info.append(field.attrib['min'])
        
        if len(device_info) > 0: 

            #
            # Alarm information 
            #
            if len(root.findall("./alarms/alarm")) == 0:
                device_info.append('-255')
                device_info.append('-255')
                        
            else:    
                for child in root.findall("./alarms/alarm"):
                    if child.attrib['device-id'] == device_id and child.attrib['field'] == 'TempC':
                        device_info.append(child.attrib['max'])
                        device_info.append(child.attrib['min'])
                
        else:
            device_info = []
                    
        return device_info

    except Exception as e:
        print e
        sys.exit(1)

# ###################################################
# Method: get_filsystem_item
#
# Parameters: Text = temperature box hostname, deviceID, item
# Returns: item value
#
# device_info[0] = TempC actual value 
# device_info[1] = TempC max value
# device_info[2] = TempC min value
# device_info[3] = TempC alarm max (-255 if not defined)
# device_info[4] = TempC alarm min (-255 if not defined)
#
# ###################################################

def get_device_item(temperature_box,device_id,item):

    device_info_list = get_device_info(temperature_box,device_id)

    try:
        
        if len(device_info_list) > 0:
            if item == 'tempc':
                return float(device_info_list[0])
            
            elif item == 'tempc_max':
                return float(device_info_list[1])
            
            elif item == 'tempc_min':
                return float(device_info_list[2])

            elif item == 'tempc_alarm_max':
                return float(device_info_list[3])

            elif item == 'tempc_alarm_min':
                return float(device_info_list[4])

            else:
                return -255

        else:
            sys.exit(1)

    except Exception as e:
        print e
        sys.exit(1)




# ############################################
# MAIN
# ############################################

if __name__ == '__main__':

    try:
        if len(sys.argv) == 4:
            temperature_box = sys.argv[1].lower()
            device_id = sys.argv[2]
            item = sys.argv[3].lower()
            
            print get_device_item(temperature_box,device_id,item)
            
        else:
            print "Error: Wrong number of parameters"
            print 'Format: ' + sys.argv[0] + ' <temperature box hostname> <deviceID> <item>'        
            sys.exit(1)

    except Exception as e:
        print e
        sys.exit(1)