# Copyright 2012-2015 Amazon.com, Inc. or its affiliates. All Rights Reserved.

#

# Licensed under the Apache License, Version 2.0 (the "License"). You

# may not use this file except in compliance with the License. A copy of

# the License is located at

#

# http://aws.amazon.com/apache2.0/

#

# or in the "license" file accompanying this file. This file 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.

import logging

import os

import sys

import platform

import shlex

from subprocess import Popen, PIPE

from docutils.core import publish_string

from docutils.writers import manpage

from awscli.clidocs import ProviderDocumentEventHandler

from awscli.clidocs import ServiceDocumentEventHandler

from awscli.clidocs import OperationDocumentEventHandler

from awscli.clidocs import TopicListerDocumentEventHandler

from awscli.clidocs import TopicDocumentEventHandler

from awscli.bcdoc import docevents

from awscli.bcdoc.restdoc import ReSTDocument

from awscli.bcdoc.textwriter import TextWriter

from awscli.argprocess import ParamShorthandParser

from awscli.argparser import ArgTableArgParser

from awscli.topictags import TopicTagDB

from awscli.utils import ignore_ctrl_c

LOG = logging.getLogger('awscli.help')

class ExecutableNotFoundError(Exception):

def __init__(self, executable_name):

super(ExecutableNotFoundError, self).__init__(

'Could not find executable named "%s"' % executable_name)

def get_renderer():

"""

Return the appropriate HelpRenderer implementation for the

current platform.

"""

if platform.system() == 'Windows':

return WindowsHelpRenderer()

else:

return PosixHelpRenderer()

class PagingHelpRenderer(object):

"""

Interface for a help renderer.

The renderer is responsible for displaying the help content on

a particular platform.

"""

def __init__(self, output_stream=sys.stdout):

self.output_stream = output_stream

PAGER = None

def get_pager_cmdline(self):

pager = self.PAGER

if 'MANPAGER' in os.environ:

pager = os.environ['MANPAGER']

elif 'PAGER' in os.environ:

pager = os.environ['PAGER']

return shlex.split(pager)

def render(self, contents):

"""

Each implementation of HelpRenderer must implement this

render method.

"""

converted_content = self._convert_doc_content(contents)

self._send_output_to_pager(converted_content)

def _send_output_to_pager(self, output):

cmdline = self.get_pager_cmdline()

LOG.debug("Running command: %s", cmdline)

p = self._popen(cmdline, stdin=PIPE)

p.communicate(input=output)

def _popen(self, *args, **kwargs):

return Popen(*args, **kwargs)

def _convert_doc_content(self, contents):

return contents

class PosixHelpRenderer(PagingHelpRenderer):

"""

Render help content on a Posix-like system. This includes

Linux and MacOS X.

"""

PAGER = 'less -R'

def _convert_doc_content(self, contents):

man_contents = publish_string(contents, writer=manpage.Writer())

if self._exists_on_path('groff'):

cmdline = ['groff', '-m', 'man', '-T', 'ascii']

elif self._exists_on_path('mandoc'):

cmdline = ['mandoc', '-T', 'ascii']

else:

raise ExecutableNotFoundError('groff or mandoc')

LOG.debug("Running command: %s", cmdline)

p3 = self._popen(cmdline, stdin=PIPE, stdout=PIPE, stderr=PIPE)

output = p3.communicate(input=man_contents)[0]

return output

def _send_output_to_pager(self, output):

cmdline = self.get_pager_cmdline()

if not self._exists_on_path(cmdline[0]):

LOG.debug("Pager '%s' not found in PATH, printing raw help." %

cmdline[0])

self.output_stream.write(output.decode('utf-8') + "\n")

self.output_stream.flush()

return

LOG.debug("Running command: %s", cmdline)

with ignore_ctrl_c():

# We can't rely on the KeyboardInterrupt from

# the CLIDriver being caught because when we

# send the output to a pager it will use various

# control characters that need to be cleaned

# up gracefully. Otherwise if we simply catch

# the Ctrl-C and exit, it will likely leave the

# users terminals in a bad state and they'll need

# to manually run ``reset`` to fix this issue.

# Ignoring Ctrl-C solves this issue. It's also

# the default behavior of less (you can't ctrl-c

# out of a manpage).

p = self._popen(cmdline, stdin=PIPE)

p.communicate(input=output)

def _exists_on_path(self, name):

# Since we're only dealing with POSIX systems, we can

# ignore things like PATHEXT.

return any([os.path.exists(os.path.join(p, name))

for p in os.environ.get('PATH', '').split(os.pathsep)])

class WindowsHelpRenderer(PagingHelpRenderer):

"""Render help content on a Windows platform."""

PAGER = 'more'

def _convert_doc_content(self, contents):

text_output = publish_string(contents,

writer=TextWriter())

return text_output

def _popen(self, *args, **kwargs):

# Also set the shell value to True. To get any of the

# piping to a pager to work, we need to use shell=True.

kwargs['shell'] = True

return Popen(*args, **kwargs)

class HelpCommand(object):

"""

HelpCommand Interface

---------------------

A HelpCommand object acts as the interface between objects in the

CLI (e.g. Providers, Services, Operations, etc.) and the documentation

system (bcdoc).

A HelpCommand object wraps the object from the CLI space and provides

a consistent interface to critical information needed by the

documentation pipeline such as the object's name, description, etc.

The HelpCommand object is passed to the component of the

documentation pipeline that fires documentation events. It is

then passed on to each document event handler that has registered

for the events.

All HelpCommand objects contain the following attributes:

+ ``session`` - A ``botocore`` ``Session`` object.

+ ``obj`` - The object that is being documented.

+ ``command_table`` - A dict mapping command names to

callable objects.

+ ``arg_table`` - A dict mapping argument names to callable objects.

+ ``doc`` - A ``Document`` object that is used to collect the

generated documentation.

In addition, please note the `properties` defined below which are

required to allow the object to be used in the document pipeline.

Implementations of HelpCommand are provided here for Provider,

Service and Operation objects. Other implementations for other

types of objects might be needed for customization in plugins.

As long as the implementations conform to this basic interface

it should be possible to pass them to the documentation system

and generate interactive and static help files.

"""

EventHandlerClass = None

"""

Each subclass should define this class variable to point to the

EventHandler class used by this HelpCommand.

"""

def __init__(self, session, obj, command_table, arg_table):

self.session = session

self.obj = obj

if command_table is None:

command_table = {}

self.command_table = command_table

if arg_table is None:

arg_table = {}

self.arg_table = arg_table

self._subcommand_table = {}

self._related_items = []

self.renderer = get_renderer()

self.doc = ReSTDocument(target='man')

@property

def event_class(self):

"""

Return the ``event_class`` for this object.

The ``event_class`` is used by the documentation pipeline

when generating documentation events. For the event below::

doc-title.<event_class>.<name>

The document pipeline would use this property to determine

the ``event_class`` value.

"""

pass

@property

def name(self):

"""

Return the name of the wrapped object.

This would be called by the document pipeline to determine

the ``name`` to be inserted into the event, as shown above.

"""

pass

@property

def subcommand_table(self):

"""These are the commands that may follow after the help command"""

return self._subcommand_table

@property

def related_items(self):

"""This is list of items that are related to the help command"""

return self._related_items

def __call__(self, args, parsed_globals):

if args:

subcommand_parser = ArgTableArgParser({}, self.subcommand_table)

parsed, remaining = subcommand_parser.parse_known_args(args)

if getattr(parsed, 'subcommand', None) is not None:

return self.subcommand_table[parsed.subcommand](remaining,

parsed_globals)

# Create an event handler for a Provider Document

instance = self.EventHandlerClass(self)

# Now generate all of the events for a Provider document.

# We pass ourselves along so that we can, in turn, get passed

# to all event handlers.

docevents.generate_events(self.session, self)

self.renderer.render(self.doc.getvalue())

instance.unregister()

class ProviderHelpCommand(HelpCommand):

"""Implements top level help command.

This is what is called when ``aws help`` is run.

"""

EventHandlerClass = ProviderDocumentEventHandler

def __init__(self, session, command_table, arg_table,

description, synopsis, usage):

HelpCommand.__init__(self, session, None,

command_table, arg_table)

self.description = description

self.synopsis = synopsis

self.help_usage = usage

self._subcommand_table = None

self._topic_tag_db = None

self._related_items = ['aws help topics']

@property

def event_class(self):

return 'aws'

@property

def name(self):

return 'aws'

@property

def subcommand_table(self):

if self._subcommand_table is None:

if self._topic_tag_db is None:

self._topic_tag_db = TopicTagDB()

self._topic_tag_db.load_json_index()

self._subcommand_table = self._create_subcommand_table()

return self._subcommand_table

def _create_subcommand_table(self):

subcommand_table = {}

# Add the ``aws help topics`` command to the ``topic_table``

topic_lister_command = TopicListerCommand(self.session)

subcommand_table['topics'] = topic_lister_command

topic_names = self._topic_tag_db.get_all_topic_names()

# Add all of the possible topics to the ``topic_table``

for topic_name in topic_names:

topic_help_command = TopicHelpCommand(self.session, topic_name)

subcommand_table[topic_name] = topic_help_command

return subcommand_table

class ServiceHelpCommand(HelpCommand):

"""Implements service level help.

This is the object invoked whenever a service command

help is implemented, e.g. ``aws ec2 help``.

"""

EventHandlerClass = ServiceDocumentEventHandler

def __init__(self, session, obj, command_table, arg_table, name,

event_class):

super(ServiceHelpCommand, self).__init__(session, obj, command_table,

arg_table)

self._name = name

self._event_class = event_class

@property

def event_class(self):

return self._event_class

@property

def name(self):

return self._name

class OperationHelpCommand(HelpCommand):

"""Implements operation level help.

This is the object invoked whenever help for a service is requested,

e.g. ``aws ec2 describe-instances help``.

"""

EventHandlerClass = OperationDocumentEventHandler

def __init__(self, session, operation_model, arg_table, name,

event_class):

HelpCommand.__init__(self, session, operation_model, None, arg_table)

self.param_shorthand = ParamShorthandParser()

self._name = name

self._event_class = event_class

@property

def event_class(self):

return self._event_class

@property

def name(self):

return self._name

class TopicListerCommand(HelpCommand):

EventHandlerClass = TopicListerDocumentEventHandler

def __init__(self, session):

super(TopicListerCommand, self).__init__(session, None, {}, {})

@property

def event_class(self):

return 'topics'

@property

def name(self):

return 'topics'

class TopicHelpCommand(HelpCommand):

EventHandlerClass = TopicDocumentEventHandler

def __init__(self, session, topic_name):

super(TopicHelpCommand, self).__init__(session, None, {}, {})

self._topic_name = topic_name

@property

def event_class(self):

return 'topics.' + self.name

@property

def name(self):

return self._topic_name