#!/usr/bin/python3

import os
import sys

from subprocess import check_output

droot = 'debian'
if len(sys.argv) > 1:
    droot = sys.argv[1]

debian = 'debian.master'
if len(sys.argv) > 2:
    debian = sys.argv[2]

rules = os.path.join(droot, 'rules')
changelog = os.path.join(debian, 'changelog')
changelog_new = os.path.join(debian, 'changelog.new')

# Generate the list of new changes
changes = check_output(['make', '-s', '-f', rules, 'printchanges']).decode('UTF-8')

# Insert the new changes into the changelog
with open(changelog) as orig, open(changelog_new, 'w') as new:
    printed = False
    skip_newline = False
    for line in orig:
        if line.startswith('  CHANGELOG: '):
            if not printed:
                printed = True
                if changes == '':
                    skip_newline = True
                    continue
                new.write(changes)
        else:
            if skip_newline and line.strip() == '':
                skip_newline = False
                continue
            new.write(line)

# Replace the original changelog with the new one
os.rename(changelog_new, changelog)