#! /usr/bin/python2.5

# Copyright 2009 the Melange authors.

#

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

# you may not use this file except in compliance with the License.

# You may obtain a copy of the License at

#

#   http://www.apache.org/licenses/LICENSE-2.0

#

# Unless required by applicable law or agreed to in writing, software

# distributed under the License 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.

"""A script to generate the app.yaml from the template with an application

name filled in.

Usage:

  gen_app_yaml.py [-f] APPLICATION_NAME

Arguments:

  APPLICATION_NAME: the name to use for the application (no underscores)

Flags:

  -f:  overwrite an existing app.yaml (default=false)

"""

from __future__ import with_statement

__authors__ = [

    # alphabetical order by last name, please

    '"Dan Bentley" <dbentley@google.com>',

    ]

import os

import sys

def generateAppYaml(application_name, force=False):

  """Generate the app.yaml file.

  Args:

    application_name: str, the name to write into the application filed

    force: bool, whether to overwrite an existing app.yaml

  """

  scripts_directory = os.path.dirname(__file__)

  app_dir = os.path.abspath(os.path.join(scripts_directory, '../app'))

  template_path = os.path.join(app_dir, 'app.yaml.template')

  app_yaml_path = os.path.join(app_dir, 'app.yaml')

  if not os.path.exists(template_path):

    sys.exit("Template file %s non-existent. Corrupt client?" % template_path)

  if os.path.exists(app_yaml_path):

    if not force:

      sys.exit("%s exists; exiting. To overwrite, pass -f on the command-line"

               % app_yaml_path)

  with open(template_path) as infile:

    template_contents = infile.read()

  app_yaml_contents = template_contents.replace(

      '# application: FIXME',

      'application: '+ application_name)

  with open(app_yaml_path, 'w') as outfile:

    outfile.write(app_yaml_contents)

  # TODO(dbentley): should this be done via logging?

  print "Wrote application name %s to %s." % (application_name, app_yaml_path)

def usage(msg):

  """Print an error message and the usage of the program; then quit.

  """

  sys.exit('Error: %s\n\n%s' % (msg, __doc__))

def main(args):

  args = args[1:] # strip off the binary name

  if not args:

    usage("No arguments supplied.")

  if args[0] == '-f':

    force = True

    args = args[1:]

  else:

    force = False

  if len(args) != 1:

    usage("No application name supplied.")

  application_name = args[0]

  generateAppYaml(application_name, force=force)

if __name__ == '__main__':

  main(sys.argv)