#!/usr/bin/env python

#
# Copyright (c) 2011 Brian House
# 
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
# 
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.
# 
# See <http://www.gnu.org/licenses/gpl.html> for details.
# 

""" For more info / discussion:
    http://blog.brianhouse.net/post/22400908807
"""

import sys, os, json, time, datetime, urllib2

API_KEY = "XXXXXXXXXX"
FEED_ID = 52901
DATASTREAM = 'Temp'
SOURCE = "aquarium_temperature"


def main():
    t = time.time()
    start = int(t) - (28 * 6 * 60 * 60)        
    t = time.time()
    print("NOW %s (%s)" % (t, datetime.datetime.utcfromtimestamp(t).isoformat()))
    print("START %s (%s)" % (start, datetime.datetime.utcfromtimestamp(start).isoformat()))
    while float(start) < t:
        request(start)
        start += 6 * 60 * 60        # add six hours


def request(start):
    page = 1
    while True:
        try:
            start_clock = time.time()
            start_str = "start=%sZ&" % datetime.datetime.utcfromtimestamp(start).isoformat()
            url = "http://api.pachube.com/v2/feeds/%s/datastreams/%s.json?%sduration=6hours&interval=0&per_page=1000&page=%s" % (FEED_ID, DATASTREAM, start_str, page)
            print(url)
            result = net_read(url, headers={'X-PachubeApiKey': API_KEY})
            try:
                data = json.loads(result)
                if 'datapoints' not in data:
                    # print("No points, got: %s" % data)
                    break
                datapoints = data['datapoints']
                page += 1                
                for datapoint in datapoints:
                    value = datapoint['value']
                    date = datapoint['at']
                    # do something with the data here
                    print("%s: %s" % (date, value))
            except Exception as e:
                print("Parse error (%s), exiting..." % e)
                exit()
            # rate limit is 100/minute, so just make sure each request takes a second.
            elapsed = time.time() - start_clock
            if elapsed < 1:
                time.sleep(1 - elapsed)            
        except Exception as e:
            print(e)


def net_read(source, headers=None):
    request = urllib2.Request(source)
    if headers:
        for header, value in headers.items():
            request.add_header(header, value) 
    return urllib2.urlopen(request).read()    


if __name__ == "__main__":
    main()