# -*- coding: utf-8 -*-

# Copyright (C) 2016-2017 RhodeCode GmbH
#
# This program is free software: you can redistribute it and/or modify
# it under the terms of the GNU Affero General Public License, version 3
# (only), as published by the Free Software Foundation.
#
# 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 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/>.
#
# This program is dual-licensed. If you wish to learn more about the
# RhodeCode Enterprise Edition, including its added features, Support services,
# and proprietary license terms, please see https://rhodecode.com/licenses/

import os
import re
import logging
import datetime
import ConfigParser

from rhodecode.model.db import Session, User, UserSshKeys
from rhodecode.model.scm import ScmModel

from .hg import MercurialServer
from .git import GitServer
from .svn import SubversionServer
log = logging.getLogger(__name__)


class SshWrapper(object):

    def __init__(self, command, connection_info, mode,
                 user, user_id, key_id, shell, ini_path, env):
        self.command = command
        self.connection_info = connection_info
        self.mode = mode
        self.user = user
        self.user_id = user_id
        self.key_id = key_id
        self.shell = shell
        self.ini_path = ini_path
        self.env = env

        self.config = self.parse_config(ini_path)
        self.server_impl = None

    def parse_config(self, config_path):
        parser = ConfigParser.ConfigParser()
        parser.read(config_path)
        return parser

    def update_key_access_time(self, key_id):
        key = UserSshKeys().query().filter(
            UserSshKeys.ssh_key_id == key_id).scalar()
        if key:
            key.accessed_on = datetime.datetime.utcnow()
            Session().add(key)
            Session().commit()
            log.debug('Update key `%s` access time', key_id)

    def get_connection_info(self):
        """
        connection_info

        Identifies the client and server ends of the connection.
        The variable contains four space-separated values: client IP address,
        client port number, server IP address, and server port number.
        """
        conn = dict(
            client_ip=None,
            client_port=None,
            server_ip=None,
            server_port=None,
        )

        info = self.connection_info.split(' ')
        if len(info) == 4:
            conn['client_ip'] = info[0]
            conn['client_port'] = info[1]
            conn['server_ip'] = info[2]
            conn['server_port'] = info[3]

        return conn

    def get_repo_details(self, mode):
        vcs_type = mode if mode in ['svn', 'hg', 'git'] else None
        mode = mode
        repo_name = None

        hg_pattern = r'^hg\s+\-R\s+(\S+)\s+serve\s+\-\-stdio$'
        hg_match = re.match(hg_pattern, self.command)
        if hg_match is not None:
            vcs_type = 'hg'
            repo_name = hg_match.group(1).strip('/')
            return vcs_type, repo_name, mode

        git_pattern = (
            r'^git-(receive-pack|upload-pack)\s\'[/]?(\S+?)(|\.git)\'$')
        git_match = re.match(git_pattern, self.command)
        if git_match is not None:
            vcs_type = 'git'
            repo_name = git_match.group(2).strip('/')
            mode = git_match.group(1)
            return vcs_type, repo_name, mode

        svn_pattern = r'^svnserve -t'
        svn_match = re.match(svn_pattern, self.command)

        if svn_match is not None:
            vcs_type = 'svn'
            # Repo name should be extracted from the input stream
            return vcs_type, repo_name, mode

        return vcs_type, repo_name, mode

    def serve(self, vcs, repo, mode, user, permissions):
        store = ScmModel().repos_path

        log.debug(
            'VCS detected:`%s` mode: `%s` repo_name: %s', vcs, mode, repo)

        if vcs == 'hg':
            server = MercurialServer(
                store=store, ini_path=self.ini_path,
                repo_name=repo, user=user,
                user_permissions=permissions, config=self.config, env=self.env)
            self.server_impl = server
            return server.run()

        elif vcs == 'git':
            server = GitServer(
                store=store, ini_path=self.ini_path,
                repo_name=repo, repo_mode=mode, user=user,
                user_permissions=permissions, config=self.config, env=self.env)
            self.server_impl = server
            return server.run()

        elif vcs == 'svn':
            server = SubversionServer(
                store=store, ini_path=self.ini_path,
                repo_name=None, user=user,
                user_permissions=permissions, config=self.config, env=self.env)
            self.server_impl = server
            return server.run()

        else:
            raise Exception('Unrecognised VCS: {}'.format(vcs))

    def wrap(self):
        mode = self.mode
        user = self.user
        user_id = self.user_id
        key_id = self.key_id
        shell = self.shell

        scm_detected, scm_repo, scm_mode = self.get_repo_details(mode)

        log.debug(
            'Mode: `%s` User: `%s:%s` Shell: `%s` SSH Command: `\"%s\"` '
            'SCM_DETECTED: `%s` SCM Mode: `%s` SCM Repo: `%s`',
            mode, user, user_id, shell, self.command,
            scm_detected, scm_mode, scm_repo)

        # update last access time for this key
        self.update_key_access_time(key_id)

        log.debug('SSH Connection info %s', self.get_connection_info())

        if shell and self.command is None:
            log.info(
                'Dropping to shell, no command given and shell is allowed')
            os.execl('/bin/bash', '-l')
            exit_code = 1

        elif scm_detected:
            user = User.get(user_id)
            auth_user = user.AuthUser()
            permissions = auth_user.permissions['repositories']

            try:
                exit_code, is_updated = self.serve(
                    scm_detected, scm_repo, scm_mode, user, permissions)
            except Exception:
                log.exception('Error occurred during execution of SshWrapper')
                exit_code = -1

        elif self.command is None and shell is False:
            log.error('No Command given.')
            exit_code = -1

        else:
            log.error(
                'Unhandled Command: "%s" Aborting.', self.command)
            exit_code = -1

        return exit_code