#!/usr/bin/env python3

import re
from os.path import join
from subprocess import check_call, check_output
from sys import argv
from tempfile import TemporaryDirectory

TARGETS = ['', 'dev', 'docs']  # the empty string is used for the project itself


def print_packages(packages, heading):
    print(f'{heading}:')
    print('  ', end='')
    print('\n  '.join(packages))


# would  be nice if there was a cleaner way to get this, but I've not found a
# more reliable one.
with open('setup.py') as fh:
    match = re.search(r"name='(?P<pkg>[\w-]+)',", fh.read())
    if not match:
        raise Exception('failed to determine our package name')
    our_package_name = match.group('pkg')
    print(f'our_package_name: {our_package_name}')

with TemporaryDirectory() as tmpdir:
    check_call(['python3', '-m', 'venv', tmpdir])

    for target in TARGETS:
        to_install = f'.[{target}]' if target else '.'

        check_call([join(tmpdir, 'bin', 'pip'), 'install', to_install])
        frozen = check_output([join(tmpdir, 'bin', 'pip'), 'freeze'])
        frozen = set(frozen.decode('utf-8').strip().split('\n'))
        # pip installs the module itself along with deps so we need to get that out of
        # our list by finding the thing that was file installed during dev

        frozen = sorted(
            [p for p in frozen if not p.startswith(our_package_name)]
        )

        print_packages(frozen, f'{target}-frozen')

        script = argv[0]

        with open(
            f'requirements{"-" + target if target else ""}.txt', 'w'
        ) as fh:
            fh.write(
                f'# DO NOT EDIT THIS FILE DIRECTLY - use {script} to update\n'
            )
            fh.write('\n'.join(frozen))
            fh.write('\n')