# Script for automatically downloading UCAC4 catalogue
# Last revision: Jan 08, 2015
# Author: Denis Vida, denis.vida@gmail.com

# This file is part of the Astrometry.net suite.
# Copyright 2014 Denis Vida.
# The Astrometry.net suite 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, version 2.
# The Astrometry.net suite 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 the GNU
# General Public License for more details.
# You should have received a copy of the GNU General Public License
# along with the Astrometry.net suite ; if not, write to the Free Software
# Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
from __future__ import print_function


# Start dectination (in degrees, e.g. +50.0)
start_dec = +90.0

# End declination (in degrees, e.g. -30.0)
end_dec = -90.0

try:
    from urllib.request import URLopener
except ImportError:
    from urllib import URLopener
import os
from shutil import copyfileobj
import bz2

# Retry failed downloads (how many times?)
No_retries = 5

# The URL prefix to the FTP repository
prefix = 'http://cdsarc.u-strasbg.fr/viz-bin/ftp-index?/ftp/cats/aliases/U/UCAC4/UCAC4/u4b/'

def Convert_Dec_to_Znum(start_dec, end_dec):
    """ Convert declination range to UCAC4 file number range. """
    z_file_constatnt = 180.0/900

    if start_dec < end_dec:
        temp = start_dec
        start_dec = end_dec
        end_dec = start_dec

    if start_dec > +90.0:
        start_dec = +90.0

    if end_dec < -90.0:
        end_dec = -90.0

    start_z = int(-(start_dec-90)/z_file_constatnt) + 1
    end_z = int(-(end_dec-90)/z_file_constatnt)

    return start_z, end_z

def Download_File(name):
    """ Download UCAC4 file. """

    url_name = prefix+name
    ucac_file = URLopener()
    ucac_file.retrieve(url_name, name)

    inp = open(name, 'rb')
    bz2_file = bz2.BZ2File(name+'.bz2', 'wb', compresslevel=1)
    copyfileobj(inp, bz2_file)
    inp.close()
    bz2_file.close()

    os.remove(name)

    return 0

start_z, end_z = Convert_Dec_to_Znum(start_dec, end_dec)

# Downloading the catalogue
fail_list = []
successes = 0
for i in range(start_z, end_z+1):
    name = 'z'+str(i).zfill(3)

    print('Downloading: '+name)
    try:
        Download_File(name)

        successes += 1
    except:
        fail_list.append(name)
        print('ERROR downloading file: ', name)

# Retry failed downloads
for i in range(No_retries):
    for name in fail_list:
        print('Retrying:', name)
        try:
            Download_File(name)
            successes += 1
            fail_list.pop(fail_list.index(name))
        except:
            print('Will retry', name, 'again...')


if len(fail_list) == 0:
    print('SUCCESS! All files downloaded successfully!')
elif successes > 0:
    print('WARNING! PARTIAL SUCCESS:')
    print(successes, 'files downloaded successfully,', len(fail_list), 'failed!')
    print('These files were NOT downloaded:', fail_list)
else:
    print('ERROR! ALL FILES FAILED TO DOWNLOAD!')
    print('Check your internet connection or try downloading later...')