#!/usr/bin/env python3
#
# init.py - part of the FDroid server tools
# Copyright (C) 2010-2013, Ciaran Gultnieks, ciaran@ciarang.com
# Copyright (C) 2013-2014 Daniel Martí <mvdan@mvdan.cc>
# Copyright (C) 2013 Hans-Christoph Steiner <hans@eds.org>
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# This program 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 Affero General Public License for more details.
#
# You should have received a copy of the GNU Affero General Public License
# along with this program.  If not, see <http://www.gnu.org/licenses/>.

import glob
import os
import re
import shutil
import socket
import sys
from argparse import ArgumentParser
import logging

from . import _
from . import common
from .exception import FDroidException

config = {}
options = None


def disable_in_config(key, value):
    """Write a key/value to the local config.yml, then comment it out."""
    import yaml

    with open('config.yml') as f:
        data = f.read()
    pattern = r'\n[\s#]*' + key + r':.*'
    repl = '\n#' + yaml.dump({key: value}, default_flow_style=False)
    data = re.sub(pattern, repl, data)
    with open('config.yml', 'w') as f:
        f.writelines(data)


def main():

    global options, config

    # Parse command line...
    parser = ArgumentParser()
    common.setup_global_opts(parser)
    parser.add_argument(
        "-d",
        "--distinguished-name",
        default=None,
        help=_("X.509 'Distinguished Name' used when generating keys"),
    )
    parser.add_argument(
        "--keystore",
        default=None,
        help=_("Path to the keystore for the repo signing key"),
    )
    parser.add_argument(
        "--repo-keyalias",
        default=None,
        help=_("Alias of the repo signing key in the keystore"),
    )
    parser.add_argument(
        "--android-home",
        default=None,
        help=_("Path to the Android SDK (sometimes set in ANDROID_HOME)"),
    )
    parser.add_argument(
        "--no-prompt",
        action="store_true",
        default=False,
        help=_("Do not prompt for Android SDK path, just fail"),
    )
    options = parser.parse_args()

    fdroiddir = os.getcwd()
    test_config = dict()
    examplesdir = common.get_examples_dir()
    common.fill_config_defaults(test_config)

    # track down where the Android SDK is, the default is to use the path set
    # in ANDROID_HOME if that exists, otherwise None
    if options.android_home is not None:
        test_config['sdk_path'] = options.android_home
    elif not common.test_sdk_exists(test_config):
        # if neither --android-home nor the default sdk_path
        # exist, prompt the user using platform-specific default
        # and if the user leaves it blank, ignore and move on.
        default_sdk_path = ''
        if sys.platform in ('win32', 'cygwin'):
            p = os.path.join(
                os.getenv('USERPROFILE'), 'AppData', 'Local', 'Android', 'android-sdk'
            )
        elif sys.platform == 'darwin':
            # on OSX, Homebrew is common and has an easy path to detect
            p = '/usr/local/opt/android-sdk'
        elif os.path.isdir('/usr/lib/android-sdk'):
            # if the Debian packages are installed, suggest them
            p = '/usr/lib/android-sdk'
        else:
            p = '/opt/android-sdk'
        if os.path.exists(p):
            default_sdk_path = p
            test_config['sdk_path'] = default_sdk_path

        if not common.test_sdk_exists(test_config):
            del (test_config['sdk_path'])
            while not options.no_prompt:
                try:
                    s = input(
                        _('Enter the path to the Android SDK (%s) here:\n> ')
                        % default_sdk_path
                    )
                except KeyboardInterrupt:
                    print('')
                    sys.exit(1)
                if re.match(r'^\s*$', s) is not None:
                    test_config['sdk_path'] = default_sdk_path
                else:
                    test_config['sdk_path'] = s
                if common.test_sdk_exists(test_config):
                    break
                default_sdk_path = ''

    if test_config.get('sdk_path') and not common.test_sdk_exists(test_config):
        raise FDroidException(
            _("Android SDK not found at {path}!").format(path=test_config['sdk_path'])
        )

    if not os.path.exists('config.yml') and not os.path.exists('config.py'):
        # 'metadata' and 'tmp' are created in fdroid
        if not os.path.exists('repo'):
            os.mkdir('repo')
        example_config_yml = os.path.join(examplesdir, 'config.yml')
        if os.path.exists(example_config_yml):
            shutil.copyfile(example_config_yml, 'config.yml')
        else:
            from pkg_resources import get_distribution

            versionstr = get_distribution('fdroidserver').version
            if not versionstr:
                versionstr = 'master'
            with open('config.yml', 'w') as fp:
                fp.write('# see https://gitlab.com/fdroid/fdroidserver/blob/')
                fp.write(versionstr)
                fp.write('/examples/config.yml\n')
        os.chmod('config.yml', 0o0600)
        # If android_home is None, test_config['sdk_path'] will be used and
        # "$ANDROID_HOME" may be used if the env var is set up correctly.
        # If android_home is not None, the path given from the command line
        # will be directly written in the config.
        if 'sdk_path' in test_config:
            common.write_to_config(test_config, 'sdk_path', options.android_home)
    else:
        logging.warning(
            'Looks like this is already an F-Droid repo, cowardly refusing to overwrite it...'
        )
        logging.info('Try running `fdroid init` in an empty directory.')
        raise FDroidException('Repository already exists.')

    # now that we have a local config.yml, read configuration...
    config = common.read_config(options)

    # the NDK is optional and there may be multiple versions of it, so it's
    # left for the user to configure

    # find or generate the keystore for the repo signing key. First try the
    # path written in the default config.yml.  Then check if the user has
    # specified a path from the command line, which will trump all others.
    # Otherwise, create ~/.local/share/fdroidserver and stick it in there.  If
    # keystore is set to NONE, that means that Java will look for keys in a
    # Hardware Security Module aka Smartcard.
    keystore = config['keystore']
    if options.keystore:
        keystore = os.path.abspath(options.keystore)
        if options.keystore == 'NONE':
            keystore = options.keystore
        else:
            keystore = os.path.abspath(options.keystore)
            if not os.path.exists(keystore):
                logging.info(
                    '"' + keystore + '" does not exist, creating a new keystore there.'
                )
    common.write_to_config(test_config, 'keystore', keystore)
    repo_keyalias = None
    keydname = None
    if options.repo_keyalias:
        repo_keyalias = options.repo_keyalias
        common.write_to_config(test_config, 'repo_keyalias', repo_keyalias)
    if options.distinguished_name:
        keydname = options.distinguished_name
        common.write_to_config(test_config, 'keydname', keydname)
    if keystore == 'NONE':  # we're using a smartcard
        common.write_to_config(
            test_config, 'repo_keyalias', '1'
        )  # seems to be the default
        disable_in_config('keypass', 'never used with smartcard')
        common.write_to_config(
            test_config,
            'smartcardoptions',
            (
                '-storetype PKCS11 '
                + '-providerClass sun.security.pkcs11.SunPKCS11 '
                + '-providerArg opensc-fdroid.cfg'
            ),
        )
        # find opensc-pkcs11.so
        if not os.path.exists('opensc-fdroid.cfg'):
            if os.path.exists('/usr/lib/opensc-pkcs11.so'):
                opensc_so = '/usr/lib/opensc-pkcs11.so'
            elif os.path.exists('/usr/lib64/opensc-pkcs11.so'):
                opensc_so = '/usr/lib64/opensc-pkcs11.so'
            else:
                files = glob.glob(
                    '/usr/lib/' + os.uname()[4] + '-*-gnu/opensc-pkcs11.so'
                )
                if len(files) > 0:
                    opensc_so = files[0]
                else:
                    opensc_so = '/usr/lib/opensc-pkcs11.so'
                    logging.warning(
                        'No OpenSC PKCS#11 module found, '
                        + 'install OpenSC then edit "opensc-fdroid.cfg"!'
                    )
            with open('opensc-fdroid.cfg', 'w') as f:
                f.write('name = OpenSC\nlibrary = ')
                f.write(opensc_so)
                f.write('\n')
        logging.info(
            "Repo setup using a smartcard HSM. Please edit keystorepass and repo_keyalias in config.yml."
        )
        logging.info(
            "If you want to generate a new repo signing key in the HSM you can do that with 'fdroid update "
            "--create-key'."
        )
    elif os.path.exists(keystore):
        to_set = ['keystorepass', 'keypass', 'repo_keyalias', 'keydname']
        if repo_keyalias:
            to_set.remove('repo_keyalias')
        if keydname:
            to_set.remove('keydname')
        logging.warning(
            '\n'
            + _('Using existing keystore "{path}"').format(path=keystore)
            + '\n'
            + _('Now set these in config.yml:')
            + ' '
            + ', '.join(to_set)
            + '\n'
        )
    else:
        password = common.genpassword()
        c = dict(test_config)
        c['keystorepass'] = password
        c['keypass'] = password
        c['repo_keyalias'] = repo_keyalias or socket.getfqdn()
        c['keydname'] = 'CN=' + c['repo_keyalias'] + ', OU=F-Droid'
        common.write_to_config(test_config, 'keystorepass', password)
        common.write_to_config(test_config, 'keypass', password)
        common.write_to_config(test_config, 'repo_keyalias', c['repo_keyalias'])
        common.write_to_config(test_config, 'keydname', c['keydname'])
        common.genkeystore(c)

    msg = '\n'
    msg += _('Built repo based in "%s" with this config:') % fdroiddir
    msg += '\n\n  Android SDK:\t\t\t' + config['sdk_path']
    msg += '\n  ' + _('Keystore for signing key:\t') + keystore
    if repo_keyalias is not None:
        msg += '\n  Alias for key in store:\t' + repo_keyalias
    msg += '\n\n'
    msg += (
        _(
            '''To complete the setup, add your APKs to "%s"
then run "fdroid update -c; fdroid update".  You might also want to edit
"config.yml" to set the URL, repo name, and more.  You should also set up
a signing key (a temporary one might have been automatically generated).

For more info: https://f-droid.org/docs/Setup_an_F-Droid_App_Repo
and https://f-droid.org/docs/Signing_Process'''
        )
        % os.path.join(fdroiddir, 'repo')
    )
    logging.info(msg)
