#!/usr/bin/python3

import argparse
from pathlib import Path
import json
import sys

import jinja2


def main():
  # Note: this is a pretty transparent interface to jinja2--there's no reason
  # this script couldn't be renamed and then used to generate any config from
  # a template.
  parser = argparse.ArgumentParser(
      description="Generates the raspberry pi configs from a template.")
  parser.add_argument("template", type=str, help="File to use for template.")
  parser.add_argument("replacements", type=json.loads, help="Dictionary of parameters to replace in the template.")
  parser.add_argument("output", type=str, help="Output file to create.")
  args = parser.parse_args(sys.argv[1:])

  with open(args.template, 'r') as input_file:
    template = jinja2.Template(input_file.read())

  output = template.render(args.replacements)
  with open(args.output, 'w') as config_file:
    config_file.write(output)

if __name__ == '__main__':
  main()