#!/usr/bin/python3

# Update the module information used to generate related device IDs

import json
import os.path
import subprocess
import sys


def iter_modules(base_dir):
    def onerror(e):
        raise e
    for root, dirs, files in \
        os.walk(os.path.join(base_dir, 'kernel'), onerror=onerror):
        for name in files:
            if name.endswith('.ko'):
                yield name[:-3], os.path.join(root, name)


def get_module_info(filename, attr_name):
    output = subprocess.check_output(['modinfo', '-F', attr_name, filename],
                                     text=True)
    if output == '':
        return []
    return output.rstrip('\n').split('\n')


def main(kernel_id=None):
    if kernel_id is None:
        kernel_dir = '/lib/modules/' + os.uname().release
    elif '/' not in kernel_id:
        kernel_dir = '/lib/modules/' + kernel_id
    else:
        kernel_dir = kernel_id

    modinfo = {}
    for name, filename in iter_modules(kernel_dir):
        # We only care about modules that might request firmware
        firmware = get_module_info(filename, 'firmware')
        if not firmware:
            continue

        # We only care about aliases generated from device IDs, which
        # start with <type> ":"
        aliases = [alias
                   for alias in get_module_info(filename, 'alias')
                   if ':' in alias]

        modinfo[name] = {
            'alias': aliases,
            'firmware': firmware,
        }

    with open('debian/modinfo.json', 'w') as f:
        json.dump(modinfo, f, indent=2, sort_keys=True)


if __name__ == '__main__':
    main(*sys.argv[1:])