# vim: tabstop=4 shiftwidth=4 softtabstop=4

# Copyright 2012 Red Hat, Inc.
#
#    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.

r"""
A simple script to update openstack-common modules which have been copied
into other projects. See:

  http://wiki.openstack.org/CommonLibrary#Incubation

The script can be called the following ways:

  $> python update.py ../myproj
  $> python update.py --config-file ../myproj/openstack-common.conf

Where ../myproj is a project directory containing openstack-common.conf which
might look like:

  [DEFAULT]
  modules = wsgi,utils
  base = myproj

Or:

  $> python update.py ../myproj/myconf.conf
  $> python update.py --config-file ../myproj/myconf.conf

Where ../myproj is a project directory which contains a differently named
configuration file, or:

  $> python update.py --config-file ../myproj/myproj/openstack/common.conf
                      --dest-dir ../myproj

Where ../myproject is a project directory, but the configuration file is
stored in a sub-directory, or:

  $> python update.py --modules wsgi,utils --base myproj ../myproj
  $> python update.py --modules wsgi,utils --base myproj --dest-dir ../myproj

Where ../myproject is a project directory, but we explicitly specify
the modules to copy and the base destination module

Obviously, the first way is the easiest!
"""

from __future__ import print_function

import functools
import glob
import os
import os.path
import re
import shutil
import sys

from oslo.config import cfg

opts = [
    cfg.ListOpt('modules',
                default=[],
                help='The list of modules to copy from oslo-incubator '
                     '(deprecated in favor of --module)'),
    cfg.MultiStrOpt('module',
                    default=[],
                    help='The list of modules to copy from oslo-incubator'),
    cfg.StrOpt('base',
               default=None,
               help='The base module to hold the copy of openstack.common'),
    cfg.StrOpt('dest-dir',
               default=None,
               help='Destination project directory'),
    cfg.StrOpt('configfile_or_destdir',
               default=None,
               help='A config file or destination project directory',
               positional=True),
    cfg.BoolOpt('nodeps',
                default=False,
                help='Discard dependencies of configured modules'),
]


def _parse_args(argv):
    conf = cfg.ConfigOpts()
    conf.register_cli_opts(opts)
    conf(argv, usage='Usage: %(prog)s [config-file|dest-dir]')

    if conf.configfile_or_destdir:
        def def_config_file(dest_dir):
            return os.path.join(dest_dir, 'openstack-common.conf')

        config_file = None
        if os.path.isfile(conf.configfile_or_destdir):
            config_file = conf.configfile_or_destdir
        elif (os.path.isdir(conf.configfile_or_destdir)
              and os.path.isfile(def_config_file(conf.configfile_or_destdir))):
            config_file = def_config_file(conf.configfile_or_destdir)

        if config_file:
            conf(argv + ['--config-file', config_file])

    return conf


def _mod_to_path(mod):
    return os.path.join(*mod.split('.'))


def _dest_path(path, base, dest_dir):
    return os.path.join(dest_dir, _mod_to_path(base), path)


def _replace(path, pattern, replacement):
    with open(path, "rb+") as f:
        lines = f.readlines()
        f.seek(0)
        f.truncate()
        for line in lines:
            f.write(re.sub(pattern, replacement, line))


def _make_dirs(path):
    if not os.path.isdir(os.path.dirname(path)):
        os.makedirs(os.path.dirname(path))


def _copy_file(path, dest, base):
    _make_dirs(dest)
    if not os.path.isdir(os.path.dirname(dest)):
        os.makedirs(os.path.dirname(dest))

    shutil.copy2(path, dest)

    if 'rpc/' not in dest:
        _replace(dest, 'oslo', base)

    # Restore the imports for modules that are part of the oslo
    # namespace package. We can't just do something like 'oslo\..+'
    # because there are default configuration settings like
    # "oslo.sqlite" that we want to have changed to "nova.sqlite" by
    # the above call.
    for oslo_module in ['config']:
        _replace(dest, base + '.' + oslo_module,
                 'oslo.' + oslo_module)

    _replace(dest,
             '^( *)from openstack.common',
             r'\1from ' + base + '.openstack.common')

    _replace(dest,
             '\'openstack\.common',
             '\'' + base + '.openstack.common')

    _replace(dest,
             '\"openstack\.common',
             '\"' + base + '.openstack.common')

    _replace(dest,
             'possible_topdir, "oslo",$',
             'possible_topdir, "' + base + '",')


def _copy_pyfile(path, base, dest_dir):
    _copy_file(path, _dest_path(path, base, dest_dir), base)


def _copy_module(mod, base, dest_dir):
    print("Copying %s under the %s module in %s" % (mod, base, dest_dir))

    copy_pyfile = functools.partial(_copy_pyfile,
                                    base=base, dest_dir=dest_dir)

    if '.' in mod:
        path = _mod_to_path('openstack.common')
        for d in mod.split('.')[:-1]:
            path = os.path.join(path, d)
            if os.path.isdir(path):
                copy_pyfile(os.path.join(path, '__init__.py'))

    mod_path = _mod_to_path('openstack.common.%s' % mod)
    mod_file = '%s.py' % mod_path
    if os.path.isfile(mod_file):
        copy_pyfile(mod_file)
    elif os.path.isdir(mod_path):
        dest = os.path.join(dest_dir, _mod_to_path(base),
                            'openstack', 'common', mod)
        _make_dirs(dest)
        sources = filter(lambda x: x[-3:] == '.py', os.listdir(mod_path))
        for s in sources:
            copy_pyfile(os.path.join(mod_path, s))

    globs_to_copy = [
        os.path.join('tools', mod + '*'),
        os.path.join('etc', 'oslo', mod + '*.conf'),
        os.path.join('contrib', mod + '*'),
    ]

    for matches in [glob.glob(g) for g in globs_to_copy]:
        for match in matches:
            dest = os.path.join(dest_dir, match.replace('oslo', base))
            print("Copying %s to %s" % (match, dest))
            _copy_file(match, dest, base)


def _create_module_init(base, dest_dir, *sub_paths):
    """Create module __init__ files."""
    init_path = _dest_path('openstack', base, dest_dir)

    if sub_paths:
        init_path = os.path.join(init_path, *sub_paths)

    init_path = os.path.join(init_path, '__init__.py')

    if not os.path.exists(init_path):
        _make_dirs(init_path)
        open(init_path, 'w').close()


def _find_import_modules(srcfile):
    oslo_import_pattern = re.compile(r"\s*from\sopenstack\.common"
                                     "(\simport\s|\.)(\w+)($|.+)")
    with open(srcfile, 'r') as f:
        for line in f:
            result = oslo_import_pattern.match(line)
            if result:
                yield result.group(2)


def _build_dependency_tree():
    dep_tree = {}
    base_path = os.path.join('openstack', 'common')
    for dirpath, _, filenames in os.walk(base_path):
        for filename in [x for x in filenames if x.endswith('.py')]:
            if dirpath == base_path:
                mod_name = filename.split('.')[0]
            else:
                mod_name = dirpath.split(os.sep)[2]
            if mod_name == '__init__':
                continue
            filepath = os.path.join(dirpath, filename)
            dep_list = dep_tree.setdefault(mod_name, [])
            dep_list.extend([x for x in _find_import_modules(filepath)
                             if x != mod_name and x not in dep_list])
    return dep_tree


def _dfs_dependency_tree(dep_tree, mod_name, mod_list=[]):
    mod_list.append(mod_name)
    for mod in dep_tree.get(mod_name, []):
        if mod not in mod_list:
            mod_list = _dfs_dependency_tree(dep_tree, mod, mod_list)
    return mod_list


def _complete_module_list(mod_list, nodeps):
    if nodeps:
        return mod_list
    addons = []
    dep_tree = _build_dependency_tree()
    for mod in mod_list:
        addons.extend([x for x in _dfs_dependency_tree(dep_tree, mod)
                       if x not in mod_list and x not in addons])
    mod_list.extend(addons)
    return mod_list


def main(argv):
    conf = _parse_args(argv)

    dest_dir = conf.dest_dir
    if not dest_dir and conf.config_file:
        dest_dir = os.path.dirname(conf.config_file[-1])

    if not dest_dir or not os.path.isdir(dest_dir):
        print("A valid destination dir is required", file=sys.stderr)
        sys.exit(1)

    if not conf.module and not conf.modules:
        print("A list of modules to copy is required", file=sys.stderr)
        sys.exit(1)

    if not conf.base:
        print("A destination base module is required", file=sys.stderr)
        sys.exit(1)

    _create_module_init(conf.base, dest_dir)
    _create_module_init(conf.base, dest_dir, 'common')

    for mod in _complete_module_list(conf.module + conf.modules, conf.nodeps):
        _copy_module(mod, conf.base, dest_dir)


if __name__ == "__main__":
    main(sys.argv[1:])