#!/usr/bin/env python

import argparse
import re
import sys
import os
import getpass
import platform
import json

import defaults

# argparse converts hyphens to underscores,
# so for lookups in the original options hash we have to
# convert them back
def field_to_option(s):
    return re.sub(r'_', '-', s)

def get_default_build_by():
    return "{user}@{host}".format(user= getpass.getuser(), host=platform.node())


options = {
   'architecture': ('Image target architecture (amd64 or i586)', lambda: 'amd64', lambda x: x in ['amd64', 'i586']),
   'build-by': ('Builder identifier (e.g. jrandomhacker@example.net)', get_default_build_by, None)
}

# Create the option parser
parser = argparse.ArgumentParser()
for k, v in options.items():
    parser.add_argument('--' + k, type=str, help=v[0], default=v[1]())

args = vars(parser.parse_args())

# Validate options
for k, v in args.items():
    key = field_to_option(k)
    func = options[key][2]
    if func is not None:
        if not func(v):
            print("{v} is not a valid value for --{o} option".format(o=key, v=v))
            sys.exit(1)

# Save to file
with open(defaults.BUILD_CONFIG, 'w') as f:
    json.dump(args, f)