# 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 platform

import shlex

from subprocess import Popen, PIPE

from docutils.core import publish_string

from docutils.writers import manpage

import bcdoc.docevents

from bcdoc.restdoc import ReSTDocument

from bcdoc.textwriter import TextWriter

from awscli.clidocs import ProviderDocumentEventHandler

from awscli.clidocs import ServiceDocumentEventHandler

from awscli.clidocs import OperationDocumentEventHandler

from awscli.argprocess import ParamShorthand

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.

"""

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 not self._exists_on_path('groff'):

raise ExecutableNotFoundError('groff')

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

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

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

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

return groff_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.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

def __call__(self, args, 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.

bcdoc.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, session.provider,

command_table, arg_table)

self.description = description

self.synopsis = synopsis

self.help_usage = usage

@property

def event_class(self):

return 'aws'

@property

def name(self):

return self.obj.name

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 = ParamShorthand()

self._name = name

self._event_class = event_class

@property

def event_class(self):

return self._event_class

@property

def name(self):

return self._name