#!/usr/bin/python
# -*- coding: utf-8 -*-

# (c) 2012-2013, Timothy Appnel <tim@appnel.com>
#
# Ansible is free software: you can redistribute it and/or modify
# it under the terms of the GNU General Public License as published by
# the Free Software Foundation, either version 3 of the License, or
# (at your option) any later version.
#
# Ansible 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 General Public License
# along with Ansible.  If not, see <http://www.gnu.org/licenses/>.
from __future__ import (absolute_import, division, print_function)
__metaclass__ = type

import os.path

from ansible.plugins.action import ActionBase
from ansible.plugins import connection_loader
from ansible.utils.boolean import boolean
from ansible import constants as C


class ActionModule(ActionBase):

    def _get_absolute_path(self, path):
        if self._task._role is not None:
            original_path = path

            if self._task._role is not None:
                path = self._loader.path_dwim_relative(self._task._role._role_path, 'files', path)
            else:
                path = self._loader.path_dwim_relative(self._loader.get_basedir(), 'files', path)

            if original_path and original_path[-1] == '/' and path[-1] != '/':
                # make sure the dwim'd path ends in a trailing "/"
                # if the original path did
                path += '/'

        return path

    def _host_is_ipv6_address(self, host):
        return ':' in host

    def _format_rsync_rsh_target(self, host, path, user):
        ''' formats rsync rsh target, escaping ipv6 addresses if needed '''

        user_prefix = ''
        if user:
            user_prefix = '%s@' % (user, )

        if self._host_is_ipv6_address(host):
            return '[%s%s]:%s' % (user_prefix, host, path)
        else:
            return '%s%s:%s' % (user_prefix, host, path)

    def _process_origin(self, host, path, user):

        if host not in C.LOCALHOST:
            return self._format_rsync_rsh_target(host, path, user)

        if ':' not in path and not path.startswith('/'):
            path = self._get_absolute_path(path=path)
        return path

    def _process_remote(self, host, path, user):
        transport = self._play_context.connection
        if host not in C.LOCALHOST or transport != "local":
            if host in C.LOCALHOST:
                self._task.args['_substitute_controller'] = True
            return self._format_rsync_rsh_target(host, path, user)

        if ':' not in path and not path.startswith('/'):
            path = self._get_absolute_path(path=path)
        return path

    def _override_module_replaced_vars(self, task_vars):
        """ Some vars are substituted into the modules.  Have to make sure
        that those are correct for localhost when synchronize creates its own
        connection to localhost."""

        # Clear the current definition of these variables as they came from the
        # connection to the remote host
        if 'ansible_syslog_facility' in task_vars:
            del task_vars['ansible_syslog_facility']
        for key in task_vars.keys():
            if key.startswith("ansible_") and key.endswith("_interpreter"):
                del task_vars[key]

        # Add the definitions from localhost
        for host in C.LOCALHOST:
            if host in task_vars['hostvars']:
                localhost = task_vars['hostvars'][host]
                break
        if 'ansible_syslog_facility' in localhost:
            task_vars['ansible_syslog_facility'] = localhost['ansible_syslog_facility']
        for key in localhost:
            if key.startswith("ansible_") and key.endswith("_interpreter"):
                task_vars[key] = localhost[key]

    def run(self, tmp=None, task_vars=None):
        ''' generates params and passes them on to the rsync module '''
        # When modifying this function be aware of the tricky convolutions
        # your thoughts have to go through:
        #
        # In normal ansible, we connect from controller to inventory_hostname
        # (playbook's hosts: field) or controller to delegate_to host and run
        # a module on one of those hosts.
        #
        # So things that are directly related to the core of ansible are in
        # terms of that sort of connection that always originate on the
        # controller.
        #
        # In synchronize we use ansible to connect to either the controller or
        # to the delegate_to host and then run rsync which makes its own
        # connection from controller to inventory_hostname or delegate_to to
        # inventory_hostname.
        #
        # That means synchronize needs to have some knowledge of the
        # controller to inventory_host/delegate host that ansible typically
        # establishes and use those to construct a command line for rsync to
        # connect from the inventory_host to the controller/delegate.  The
        # challenge for coders is remembering which leg of the trip is
        # associated with the conditions that you're checking at any one time.
        if task_vars is None:
            task_vars = dict()

        result = super(ActionModule, self).run(tmp, task_vars)

        # self._play_context.connection accounts for delegate_to so
        # remote_transport is the transport ansible thought it would need
        # between the controller and the delegate_to host or the controller
        # and the remote_host if delegate_to isn't set.

        remote_transport = False
        if self._play_context.connection != 'local':
            remote_transport = True

        try:
            delegate_to = self._task.delegate_to
        except (AttributeError, KeyError):
            delegate_to = None

        use_ssh_args = self._task.args.pop('use_ssh_args', None)

        # Parameter name needed by the ansible module
        self._task.args['_local_rsync_path'] = task_vars.get('ansible_rsync_path') or 'rsync'

        # rsync thinks that one end of the connection is localhost and the
        # other is the host we're running the task for  (Note: We use
        # ansible's delegate_to mechanism to determine which host rsync is
        # running on so localhost could be a non-controller machine if
        # delegate_to is used)
        src_host = '127.0.0.1'
        inventory_hostname = task_vars.get('inventory_hostname')
        dest_host_inventory_vars = task_vars['hostvars'].get(inventory_hostname)
        try:
            dest_host = dest_host_inventory_vars['ansible_host']
        except KeyError:
            dest_host = dest_host_inventory_vars.get('ansible_ssh_host', inventory_hostname)

        # dest_is_local tells us if the host rsync runs on is the same as the
        # host rsync puts the files on.  This is about *rsync's connection*,
        # not about the ansible connection to run the module.
        dest_is_local = False
        if not delegate_to and remote_transport is False:
            dest_is_local = True
        elif delegate_to and delegate_to == dest_host:
            dest_is_local = True

        # CHECK FOR NON-DEFAULT SSH PORT
        if self._task.args.get('dest_port', None) is None:
            inv_port = task_vars.get('ansible_ssh_port', None) or C.DEFAULT_REMOTE_PORT
            if inv_port is not None:
                self._task.args['dest_port'] = inv_port

        # Set use_delegate if we are going to run rsync on a delegated host
        # instead of localhost
        use_delegate = False
        if dest_host == delegate_to:
            # edge case: explicit delegate and dest_host are the same
            # so we run rsync on the remote machine targeting its localhost
            # (itself)
            dest_host = '127.0.0.1'
            use_delegate = True
        elif delegate_to is not None and remote_transport:
            # If we're delegating to a remote host then we need to use the
            # delegate_to settings
            use_delegate = True

        # Delegate to localhost as the source of the rsync unless we've been
        # told (via delegate_to) that a different host is the source of the
        # rsync
        if not use_delegate and remote_transport:
            # Create a connection to localhost to run rsync on
            new_stdin = self._connection._new_stdin
            new_connection = connection_loader.get('local', self._play_context, new_stdin)
            self._connection = new_connection
            self._override_module_replaced_vars(task_vars)

        # SWITCH SRC AND DEST HOST PER MODE
        if self._task.args.get('mode', 'push') == 'pull':
            (dest_host, src_host) = (src_host, dest_host)

        # MUNGE SRC AND DEST PER REMOTE_HOST INFO
        src = self._task.args.get('src', None)
        dest = self._task.args.get('dest', None)
        if not dest_is_local:
            # Private key handling
            if use_delegate:
                private_key = task_vars.get('ansible_ssh_private_key_file') or self._play_context.private_key_file
            else:
                private_key = task_vars.get('ansible_ssh_private_key_file') or self._play_context.private_key_file

            if private_key is not None:
                private_key = os.path.expanduser(private_key)
                self._task.args['private_key'] = private_key

            # Src and dest rsync "path" handling
            # Determine if we need a user@
            user = None
            if boolean(self._task.args.get('set_remote_user', 'yes')):
                if use_delegate:
                    user = task_vars.get('ansible_delegated_vars', dict()).get('ansible_ssh_user', None)
                    if not user:
                        user = C.DEFAULT_REMOTE_USER

                else:
                    user = task_vars.get('ansible_ssh_user') or self._play_context.remote_user

            # use the mode to define src and dest's url
            if self._task.args.get('mode', 'push') == 'pull':
                # src is a remote path: <user>@<host>, dest is a local path
                src = self._process_remote(src_host, src, user)
                dest = self._process_origin(dest_host, dest, user)
            else:
                # src is a local path, dest is a remote path: <user>@<host>
                src = self._process_origin(src_host, src, user)
                dest = self._process_remote(dest_host, dest, user)
        else:
            # Still need to munge paths (to account for roles) even if we aren't
            # copying files between hosts
            if not src.startswith('/'):
                src = self._get_absolute_path(path=src)
            if not dest.startswith('/'):
                dest = self._get_absolute_path(path=dest)

        self._task.args['src'] = src
        self._task.args['dest'] = dest

        # Allow custom rsync path argument
        rsync_path = self._task.args.get('rsync_path', None)

        if not dest_is_local:
            if self._play_context.become and not rsync_path:
                # If no rsync_path is set, become was originally set, and dest is
                # remote then add privilege escalation here.
                if self._play_context.become_method == 'sudo':
                    rsync_path = 'sudo rsync'
                # TODO: have to add in the rest of the become methods here

            # We cannot use privilege escalation on the machine running the
            # module.  Instead we run it on the machine rsync is connecting
            # to.
            self._play_context.become = False

        # make sure rsync path is quoted.
        if rsync_path:
            self._task.args['rsync_path'] = '"%s"' % rsync_path

        if use_ssh_args:
            self._task.args['ssh_args'] = C.ANSIBLE_SSH_ARGS

        # run the module and store the result
        result.update(self._execute_module('synchronize', task_vars=task_vars))

        if 'SyntaxError' in result.get('exception', result.get('msg', '')):
            # Emit a warning about using python3 because synchronize is
            # somewhat unique in running on localhost
            result['traceback'] = result['msg']
            result['msg'] = 'SyntaxError parsing module.  Perhaps invoking "python" on your local (or delegate_to) machine invokes python3.  You can set ansible_python_interpreter for localhost (or the delegate_to machine) to the location of python2 to fix this'
        return result