#!/usr/bin/env python
#    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.

"""Generate and install requirements from stub file and source files."""

import argparse
import subprocess
import sys

import pip

parser = argparse.ArgumentParser(description='Sync requirements.')
parser.add_argument('--stub', metavar='STUBFILE',
                    required=True,
                    help="File with requirements stubs.")
parser.add_argument('--source', metavar='SOURCE',
                    required=True, action='append',
                    help="Source file to sync requirements from. "
                    "May be supplied several times.")
parser.add_argument('-t', '--target', metavar='TARGET',
                    required=True,
                    help="Target file to write synced requirements to.")
parser.add_argument('pipopts', metavar='PIP OPTIONS',
                    nargs=argparse.REMAINDER,
                    help='Options to pass to "pip install".')

args = parser.parse_args()

sources = {}
for requirements_file in args.source:
    rqs = pip.req.req_file.parse_requirements(requirements_file,
                                              session=False)
    sources.update({s.name: s for s in rqs})
stubs = list(pip.req.req_file.parse_requirements(args.stub,
                                                 session=False))
reqs = []
for r in stubs:
    if r.name in sources:
        # safe-guard for future additions to stub file
        if r.specifier:
            sys.exit("ERROR: package '%(pkg)s' in stub file %(stub)s "
                     "has version specified but is also present "
                     "in provided sources requirements. "
                     "Please remove version from the stub file." % {
                         'pkg': r.name, 'stub': args.stub})
        reqs.append(sources[r.name])
    else:
        reqs.append(r)

with open(args.target, 'w') as target:
    target.write('\n'.join([str(r.req) for r in reqs]))

pip_install = ['pip', 'install', '-r', args.target]
pip_install.extend(args.pipopts)

sys.exit(subprocess.call(pip_install))