#!/usr/local/sci/bin/python2.7

# NOTE - you will need to point this script to where your Python2.7 installation lives

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#
# British Crown Copyright (c) 2018, the Met Office All rights reserved.
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#########################################################

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#
# AUTHOR - Robert Dunn
# DATE - 24th September 2018
#
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# import libraries
import urllib2
import os
import numpy as np

# set fixed variables
VERSION = "2.0.2.2017f"
REMOTE_LOCATION = "/hadobs/hadisd/v202_2017f/data/"

diagnostics = True

#*********************************************
def http(host, remote_loc, filename, local_loc, diagnostics = False):
    """
    Using urllib2 http access

    :param str host: HTTP hostename
    :param str remote_loc: remote directory
    :param str filename: remote filename
    :param str local_loc: local directory
    :param bool diagnostics: extra output
    """

    if diagnostics:
        print "{}/{}/{}".format(host, remote_loc, filename)
    
    req = urllib2.Request("{}/{}/{}".format(host, remote_loc, filename), headers={'User-Agent' : "Magic Browser"}) 
    remote_file = urllib2.urlopen(req)
        
    local_file = open(os.path.join(local_loc, filename), "w")
    local_file.write(remote_file.read())
    local_file.close()
    if diagnostics:
        print "     Downloaded"

    return # http

#***************************************

# read the station listing and extract the IDs
station_info = np.genfromtxt("hadisd_station_info_v202.txt", dtype=(str))
station_ids = station_info[:, 0]

# spin through the ids, building up the link required for each download
for station in station_ids:

    print station
    # files are at:
    #   https://www.metoffice.gov.uk/hadobs/hadisd/v202_2017f/data/hadisd.2.0.2.2017f_19310101-20171231_010010-99999.nc.gz
    # so build up the link

    http("http://www.metoffice.gov.uk/", REMOTE_LOCATION, "hadisd.{}_19310101-20171231_{}.nc.gz".format(VERSION, station), ".", diagnostics = diagnostics)

    # escape loop after single download - remove this to run through all stations.
    break

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# END
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