#!/usr/bin/python3

"""
Convert JSON data to human-readable form.

Usage:
  fmtjson.py inputFile [inputFile2...]
  or
  fmtjson.py <input >output

  -n		Dry run mode.
"""

import sys
import json

def main(args):
  problem = False
  if len(args) and args[0] == '-n':
    files = args[1:]
    readonly = True
  else:
    files = args
    readonly = False

  if not files:
    if readonly:
      json.loads(sys.stdin.read())
    else:
      print(
              json.dumps(
                  json.loads(sys.stdin.read()),
                  sort_keys=True,
                  indent=2,
                  separators=(',', ': ')
                  )
              )
  else:
    for filename in files:
      orig = {}
      with open(filename, 'r') as f:
        try:
          orig_data = f.read()
          orig = json.loads(orig_data)
        except ValueError as e:
          print('Reformatting: %s' % filename)
          print('ERROR:', str(e))
          problem = True
      if (not problem) and (not readonly):
        fixed_data = json.dumps(orig,
            sort_keys=True, indent=2, separators=(',', ': ')) + '\n'
        if orig_data != fixed_data:
          print('Reformatting: %s' % filename)
          with open(filename, 'w') as f:
            f.write(fixed_data)
  return problem

def usage():
  print(__doc__)


if __name__ == "__main__":
  sys.exit(main(sys.argv[1:]))