#!/usr/bin/env python3

import sys

import json

import re

from packaging import version

def read_declared_pkgs(package_json_path):

    with open(package_json_path) as f:

        package_json = json.load(f)

        return list(package_json['dependencies'].keys()) + list(package_json['devDependencies'].keys())

def read_installed_pkgs(yarn_lock_path):

    with open(yarn_lock_path) as 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(npm({declared_pkg})) = {oldest_version}"

if __name__ == "__main__":

    if len(sys.argv) != 2:

        print(f"usage: {sys.argv[0]} package-X.Y.Z/", file=sys.stdout)

        sys.exit(1)

    package_dir = sys.argv[1]

    declared_pkgs = read_declared_pkgs(f"{package_dir}/package.json")

    installed_pkgs = read_installed_pkgs(f"{package_dir}/yarn.lock")

    provides = list_provides(declared_pkgs, installed_pkgs)

    for provide in sorted(provides):

        print(provide)