#!/usr/bin/env python

# Transforms a map spreadsheet to use a different root

import csv

import os.path

import re

import sys

sys.path.append(os.path.dirname(__file__)+"/../lib")

import opts

def main():

    # Get config from env vars

    env_names = []

    print_usage_ref = [False]

    def on_unset(e): print_usage_ref[0] = True

    configs = [opts.get_env_vars(['in_root', 'out_root'], col, env_names,

        on_unset) for col in ['left', 'right']]

    if print_usage_ref[0]: raise SystemExit(

        'Usage: '+opts.env_usage(env_names)+' '+sys.argv[0]+' <in_map >out_map')

    # Transform map

    reader = csv.reader(sys.stdin)

    writer = csv.writer(sys.stdout)

    cols = reader.next()

    for i in xrange(len(configs)):

        config = configs[i]

        label, sep, config['root'] = cols[i].partition(':')

        cols[i] = label+sep+config['out_root']

        config['in_root_re'] = r'^'+re.escape(config['in_root'])+r'(?=\b|\W|$)'

    writer.writerow(cols)

    for row in reader:

        def sub(i):

            row[i], n = re.subn(configs[i]['in_root_re'], r'',

                configs[i]['root']+row[i])

            return n > 0

        if row[0] != '' and sub(0):

            if row[1] != '' and not sub(1): raise SystemExit('Map error: Root "'

                +configs[1]['in_root']+'" is not contained in output mapping: '

                +row[1])

            writer.writerow(row)

main()