#!/usr/bin/env python
# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2010 United States Government as represented by the
# Administrator of the National Aeronautics and Space Administration.
# All Rights Reserved.
#
#    Licensed under the Apache License, Version 2.0 (the "License"); you may
#    not use this file except in compliance with the License. You may obtain
#    a copy of the License at
#
#         http://www.apache.org/licenses/LICENSE-2.0
#
#    Unless required by applicable law or agreed to in writing, software
#    distributed under the License is distributed on an "AS IS" BASIS, WITHOUT
#    WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. See the
#    License for the specific language governing permissions and limitations
#    under the License.

"""
  Download images from Canonical Image Store
"""

import json
import os
import tempfile
import shutil
import subprocess
import sys
import urllib2

from nova import flags
from nova import utils
from nova.objectstore import image

FLAGS = flags.FLAGS

api_url = 'https://imagestore.canonical.com/api/dashboard'

image_cache = None
def images():
    global image_cache
    if not image_cache:
        try:
            images = json.load(urllib2.urlopen(api_url))['images']
            image_cache = [i for i in images if i['title'].find('amd64') > -1]
        except Exception:
            print 'unable to download canonical image list'
            sys.exit(1)
    return image_cache

# FIXME(ja): add checksum/signature checks
def download(img):
    tempdir = tempfile.mkdtemp(prefix='cis-')

    kernel_id = None
    ramdisk_id = None

    for f in img['files']:
        if f['kind'] == 'kernel':
            dest = os.path.join(tempdir, 'kernel')
            subprocess.call(['curl', f['url'], '-o', dest])
            kernel_id = image.Image.add(dest,
                description='kernel/' + img['title'], kernel=True)

    for f in img['files']:
        if f['kind'] == 'ramdisk':
            dest = os.path.join(tempdir, 'ramdisk')
            subprocess.call(['curl', f['url'], '-o', dest])
            ramdisk_id = image.Image.add(dest,
                description='ramdisk/' + img['title'], ramdisk=True)

    for f in img['files']:
        if f['kind'] == 'image':
            dest = os.path.join(tempdir, 'image')
            subprocess.call(['curl', f['url'], '-o', dest])
            ramdisk_id = image.Image.add(dest,
                description=img['title'], kernel=kernel_id, ramdisk=ramdisk_id)

    shutil.rmtree(tempdir)

def main():
    utils.default_flagfile()
    argv = FLAGS(sys.argv)

    if len(argv) == 2:
        for img in images():
            if argv[1] == 'all' or argv[1] == img['title']:
                download(img)
    else:
        print 'usage: %s (title|all)'
        print 'available images:'
        for image in images():
            print image['title']

if __name__ == '__main__':
    main()