#!/usr/bin/env python3
import sys
import os.path
import tarfile
from io import TextIOWrapper
import json
import re
from packaging import version


def read_declared_pkgs(f):
    package_json = json.load(f)
    return list(package_json['devDependencies'].keys()) + list(package_json['dependencies'].keys())


def read_installed_pkgs(f):
    lockfile = f.read()
    return re.findall(r'^"?'  # can start with a "
                      r'(.+?)@.+(?:,.*)?:\n'  # characters up to @
                      r'  version "(.+)"',  # and the version
                      lockfile, re.MULTILINE)


def list_provides(declared_pkgs, installed_pkgs):
    for declared_pkg in declared_pkgs:
        # there can be multiple versions installed of one package (transitive dependencies)
        # but rpm doesn't support Provides: with a single package and multiple versions
        # so let's declare the oldest version here
        versions = [version.parse(pkg_version)
                    for pkg_name, pkg_version in installed_pkgs if pkg_name == declared_pkg]
        oldest_version = sorted(versions)[0]
        yield f"Provides: bundled(nodejs-{declared_pkg}) = {oldest_version}"


if __name__ == "__main__":
    if len(sys.argv) != 2:
        print(f"usage: {sys.argv[0]} grafana-pcp-X.Y.Z.tar.gz", file=sys.stdout)
        sys.exit(1)

    source_archive_path = sys.argv[1]
    root_dir = os.path.basename(source_archive_path)[:-len('.tar.gz')]
    with tarfile.open(source_archive_path) as tar:
        package_json = TextIOWrapper(tar.extractfile(f'{root_dir}/package.json'))
        declared_pkgs = read_declared_pkgs(package_json)

        yarn_lock = TextIOWrapper(tar.extractfile(f'{root_dir}/yarn.lock'))
        installed_pkgs = read_installed_pkgs(yarn_lock)

    provides = list_provides(declared_pkgs, installed_pkgs)
    for provide in sorted(provides):
        print(provide)