# HG changeset patch
# User Jeff Hammel <k0scist@gmail.com>
# Date 1435966773 25200
# Node ID 05fef8e5b8a9fbdc66c75e8220c30db83b73e66c
# Parent  e6fb1a8fe66b2a8d27c766bd0ee84fb98c596aed
example step of the conductor example

diff -r e6fb1a8fe66b -r 05fef8e5b8a9 python/example/INSTALL.py
--- /dev/null	Thu Jan 01 00:00:00 1970 +0000
+++ b/python/example/INSTALL.py	Fri Jul 03 16:39:33 2015 -0700
@@ -0,0 +1,295 @@
+#!/usr/bin/env python
+
+"""
+install and setup stuff
+"""
+
+### imports
+import argparse
+import inspect
+import os
+import subprocess
+import sys
+
+### globals
+string = (str, unicode)
+BASEDIR = os.environ.get('VIRTUAL_ENV', os.getcwd())
+
+def comment(text, comment_character='#', join=False):
+    """
+    comment some text
+
+    text -- text to comment
+    join -- whether to ``str.join`` the lines of text
+    """
+    text = text.strip()
+    if text:
+        retval = ['{} {}'.format(comment_character, line.rstrip())
+                  for line in text.splitlines()]
+    else:
+        retval = []
+    if join:
+        retval =  '\n'.join(retval)
+    return retval
+
+
+class Command(object):
+    """an individual command"""
+    def __init__(self, command):
+        self.command = command
+    def shell(self):
+        return isinstance(self.command, string)
+    def interpolate(self, **variables):
+        if self.shell():
+            return self.command.format(**variables)
+        return [i.format(**variables) for i in self.command]
+    def commandline(self, **variables):
+        command = self.interpolate(**variables)
+        if self.shell():
+            return command
+        else:
+            return subprocess.list2cmdline(command)
+    __str__ = commandline
+    def __call__(self, variables=None, **kwargs):
+        variables = variables or {}
+        commandline = self.commandline(**variables)
+        kwargs['shell'] = self.shell()
+        print (commandline)
+        code = subprocess.call(self.interpolate(**variables), **kwargs)
+        if code:
+            raise subprocess.CalledProcessError(code, commandline)
+
+
+### setup and installation steps
+
+class Step(object):
+    commands = []
+    env = {}
+    comment_character = '#'
+
+    @classmethod
+    def name(cls):
+        return cls.__name__
+    @classmethod
+    def description(cls):
+        return (getattr(cls, '__doc__', '') or '').strip()
+    @classmethod
+    def name_and_description(cls):
+        description = cls.description()
+        return '{}{}'.format(cls.name(), ': {}'.format(description if description else ''))
+    def __init__(self, **variables):
+        self.commands = self.commands[:]
+        self.variables = variables
+        for key in self.env:
+            os.environ[key] = self.env[key].format(**variables)
+    def command_objs(self):
+        return [Command(command) for command in self.commands]
+    def interpolate(self):
+        return [command.interpolate(**self.variables)
+                for command in self.command_objs()]
+    def write(self, output=sys.stdout):
+        for command in self.command_objs():
+            output.write(str(command) + '\n')
+    def __call__(self):
+        for command in self.command_objs():
+            command(variables=self.variables)
+    def script(self):
+        retval = comment(self.name(), self.comment_character)
+        description = self.description()
+        if description:
+            retval.extend(comment(description, self.comment_character))
+        for command in self.command_objs():
+            retval.append(command.commandline(**self.variables))
+        return '\n'.join(retval)
+
+class UbuntuPackages(Step):
+    commands = [['sudo', 'apt-get', '-y', 'update'],
+                ['sudo', 'apt-get', '-y', 'upgrade'],
+                ]
+    packages = []
+    def __init__(self, **kwargs):
+        Step.__init__(self, **kwargs)
+        self.commands.append(['sudo', 'apt-get', '-y', 'install'] + self.packages)
+
+class InstallXinePrerequisites(UbuntuPackages):
+    """install the prerequisites for the xine-based client"""
+    packages = ['libcurl4-gnutls-dev',
+                'g++',
+                'libx11-dev',
+                'libxext-dev',
+                'libxine1',
+                'libxine-dev',
+                'gxine',
+                ]
+
+class InstallFFMPEG(UbuntuPackages):
+    """install prerequisites for the FFMPEG-based client"""
+    packages = ['subversion',
+                'make',
+                'gcc',
+                'g++',
+                'libcurl4-gnutls-dev']
+    yasm = '1.2.0'
+    ffmpeg = '1.2'
+    def __init__(self, client=os.path.join(BASEDIR, 'linux_client')):
+        UbuntuPackages.__init__(self, client=client, yasm=self.yasm, ffmpeg=self.ffmpeg)
+
+        self.commands.extend([['mkdir', '-p', '{client}'],
+                              ['wget', 'http://www.tortall.net/projects/yasm/releases/yasm-{yasm}.tar.gz', '-O', '{client}/yasm-{yasm}.tar.gz'],
+                              ['wget', 'http://ffmpeg.org/releases/ffmpeg-{ffmpeg}.tar.gz', '-O', '{client}/ffmpeg-{ffmpeg}.tar.gz'],
+                              ['tar', 'zfvx', '{client}/yasm-{yasm}.tar.gz', '-C', '{client}'],
+                              ['tar', 'zfvx', '{client}/ffmpeg-{ffmpeg}.tar.gz', '-C', '{client}'],
+
+                              # YASM
+                              'cd {client}/yasm-{yasm} && ./configure',
+                              'cd {client}/yasm-{yasm} && make',
+                              'cd {client}/yasm-{yasm} && sudo make install',
+
+                              # FFMPEG
+                              'cd {client}/ffmpeg-{ffmpeg} && ./configure --enable-shared',
+                              'cd {client}/ffmpeg-{ffmpeg} && make',
+                              'cd {client}/ffmpeg-{ffmpeg} && sudo make install',
+                              ])
+
+
+### functionality for running multiple steps
+
+class Steps(object):
+    """run a series of steps"""
+
+    comment_character = '#'
+
+    # instance defaults
+    defaults = {}
+
+    # variable descriptions
+    descriptions = dict()
+
+    def __init__(self, *steps, **variables):
+        self.steps = steps
+        self.variables = variables
+        self.step_dict = {step.name():step for step in steps}
+
+    def parser(self, description=None):
+        """return argument parser"""
+        parser = argparse.ArgumentParser(description=description)
+        parser.add_argument('--list', dest='list_steps',
+                            action='store_true', default=False,
+                            help="list available steps and exit")
+        parser.add_argument('--commands', dest='list_commands',
+                            action='store_true', default=False,
+                            help="list commands to be run and exit")
+        return parser
+
+    def comment(self, text, join=False):
+        """
+        comment some text
+
+        text -- text to comment
+        join -- whether to ``str.join`` the lines of text
+        """
+        return comment(text, self.comment_character, join)
+
+    def script(self, steps=None, description=None, variables=None):
+        """returns a script"""
+        variables = variables or {}
+        retval = ['#!/bin/bash', '']
+        if description:
+            retval.extend(self.comment(description))
+            retval.append('') # whitespace delimiter
+        steps = self.instantiate(*steps, **variables)
+        for step in steps:
+            retval.append(step.script())
+            retval.append('') # whitespace
+
+        return '\n'.join(retval)
+
+    @staticmethod
+    def args(step):
+        args, varargs, varkw, defaults = inspect.getargspec(step.__init__)
+        return args[1:]
+
+    def all_args(self, steps=None):
+        retval = []
+        steps = steps or self.steps
+        for step in steps:
+            args = self.args(step)
+            retval.extend([arg for arg in args if arg not in retval])
+        return retval
+
+    def get_variables(self, options, steps=None):
+        """get variables from a namespace"""
+        return {i:getattr(options, i, None) or self.defaults.get(i)
+                for i in self.all_args(steps)}
+
+    def instantiate(self, *steps, **variables):
+        """instantiate a set of steps with variables"""
+        return [step(**{arg:variables.get(arg)
+                        for arg in self.args(step)})
+                for step in steps]
+
+    def parse(self, args=sys.argv[1:], description=None):
+
+        # create a parser
+        parser = self.parser(description)
+
+        # add step names as arguments
+        parser.add_argument('steps', nargs='*', metavar='step',
+                            help="steps to run; if omitted, all steps will be run")
+
+        # add step arguments
+        for arg in self.all_args():
+            variable_description = self.descriptions.get(arg)
+            default = self.defaults.get(arg)
+            if variable_description and default:
+                variable_description += ' [DEFAULT: %(default)s]'
+            parser.add_argument('--{}'.format(arg), dest=arg,
+                                default=default, help=variable_description)
+
+        # parse arguments
+        options = parser.parse_args(args)
+
+        # get steps to run
+        if options.steps:
+            missing = [i for i in options.steps if i not in self.step_dict]
+            if missing:
+                parser.error("No such step: {}".format(', '.join(missing)))
+            steps = [self.step_dict[i] for i in options.steps]
+        else:
+            steps = self.steps[:]
+
+        # get variables for execution
+        variables = self.get_variables(options)
+
+        if options.list_steps:
+            # list steps and exit
+            for step in steps:
+                print (step.name_and_description())
+                variables = self.args(step)
+                if variables:
+                    print ('Variables: {}'.format(', '.join(variables)))
+                print ('') # whitespace
+            sys.exit(0)
+
+        # instantiate steps
+        step_objs = self.instantiate(*steps, **variables)
+
+        if options.list_commands:
+            # print commands and exit
+            print (self.script(steps, description, variables))
+            sys.exit(0)
+
+        # run steps
+        for step in step_objs:
+            step()
+
+
+### main
+
+def main(args=sys.argv[1:]):
+    """CLI"""
+    Steps(*[InstallXinePrerequisites,
+            InstallFFMPEG]).parse(args=args, description=__doc__)
+
+if __name__ == '__main__':
+    main()