hblink3/tools/migrate_obp_rules.py

#!/usr/bin/env python
#
# migrate_obp_rules.py -- one-shot migration for the OpenBridge config-model change.
#
# HBlink3 no longer configures OpenBridge (MODE: OPENBRIDGE) systems as inline
# BRIDGES members. They now live in a per-OBP table:
#
#     OBP_BRIDGES = { <obp system> : { <bridge name> : <TGID> } }   # TS 1, or (TGID, TS)
#
# This tool reads your existing hblink.cfg (to learn which systems are OPENBRIDGE)
# and your existing rules.py (old inline form), then:
#   * lifts every inline OBP member out of BRIDGES into OBP_BRIDGES,
#   * drops any bridge left with no members (OBP_BRIDGES recreates it at load),
#   * flags the two problems the new loader would reject/warn on
#       - a TGID mapped to >1 bridge on one OBP (ingress fork)  -> ERROR
#       - a bridge with different TGIDs across OBPs (renumber)   -> WARNING
#   * prints a summary of what moved, and writes a new rules file.
#
# It never overwrites your rules.py: output goes to a separate file you review
# and rename. Comments and commented-out members in the old file are NOT carried
# over (the tool works on the active, executed config), so re-add any notes by hand.
#
#   venv/bin/python tools/migrate_obp_rules.py [--config hblink.cfg] [--rules rules.py] [--out rules.py.migrated]
#
# Exit status is non-zero if an ingress-fork ERROR was found (the output still
# gets written so you can see and fix it).

import argparse
import configparser
import importlib.util
import os
import sys


def _openbridge_systems(cfg_path):
    """Section names in hblink.cfg whose MODE is OPENBRIDGE."""
    cp = configparser.ConfigParser()
    if not cp.read(cfg_path):
        sys.exit('ERROR: could not read config file: {}'.format(cfg_path))
    obp = set()
    for section in cp.sections():
        if cp.has_option(section, 'MODE') and cp.get(section, 'MODE').strip().upper() == 'OPENBRIDGE':
            obp.add(section)
    return obp


def _load_rules(rules_path):
    spec = importlib.util.spec_from_file_location('rules_old', rules_path)
    mod = importlib.util.module_from_spec(spec)
    try:
        spec.loader.exec_module(mod)
    except Exception as e:
        sys.exit('ERROR: could not import rules file {}: {}'.format(rules_path, e))
    return mod


def _fmt_member(m):
    return ("{{'SYSTEM': {!r}, 'TS': {}, 'TGID': {}, 'ACTIVE': {}, "
            "'TIMEOUT': {}, 'TO_TYPE': {!r}, 'ON': {}, 'OFF': {}, 'RESET': {}}},").format(
        m['SYSTEM'], m['TS'], m['TGID'], m['ACTIVE'],
        m.get('TIMEOUT', 2), m.get('TO_TYPE', 'NONE'),
        m.get('ON', []), m.get('OFF', []), m.get('RESET', []))


def migrate(bridges, obp_systems):
    """Return (new_bridges, obp_bridges, moved, errors, warnings)."""
    new_bridges = {}
    obp_bridges = {}                 # obp -> {bridge: tgid_or_(tgid, ts)}
    moved = []                       # (obp, bridge, tgid, ts)
    errors = []
    warnings = []
    tgid_to_bridge = {}              # (obp, tgid) -> bridge, ingress-fork check
    bridge_obp_tgid = {}             # bridge -> {obp: tgid}, renumber check

    for bridge_name, members in bridges.items():
        kept = []
        for m in members:
            if m['SYSTEM'] in obp_systems:
                tgid, ts = m['TGID'], m.get('TS', 1)
                key = (m['SYSTEM'], tgid)
                if key in tgid_to_bridge and tgid_to_bridge[key] != bridge_name:
                    errors.append('OBP "{}" TGID {} maps to more than one bridge ("{}" and "{}") -- '
                                  'ingress fork; keep only one before starting HBlink3'
                                  .format(m['SYSTEM'], tgid, tgid_to_bridge[key], bridge_name))
                tgid_to_bridge[key] = bridge_name
                obp_bridges.setdefault(m['SYSTEM'], {})[bridge_name] = tgid if ts == 1 else (tgid, ts)
                bridge_obp_tgid.setdefault(bridge_name, {})[m['SYSTEM']] = tgid
                moved.append((m['SYSTEM'], bridge_name, tgid, ts))
            else:
                kept.append(m)
        if kept:
            new_bridges[bridge_name] = kept        # drop bridges left empty (OBP_BRIDGES recreates them)

    for bridge_name, obp_tgids in bridge_obp_tgid.items():
        if len(set(obp_tgids.values())) > 1:
            detail = ', '.join('{}={}'.format(o, t) for o, t in sorted(obp_tgids.items()))
            warnings.append('bridge "{}" renumbers TGID across OpenBridges ({}) -- legal but unusual'
                            .format(bridge_name, detail))

    return new_bridges, obp_bridges, moved, errors, warnings


def render(new_bridges, obp_bridges, unit):
    L = []
    L.append('# Generated by tools/migrate_obp_rules.py -- REVIEW before use.')
    L.append('# OpenBridge members were moved from BRIDGES into OBP_BRIDGES; comments from')
    L.append('# the original rules.py were not preserved.')
    L.append('')
    L.append('BRIDGES = {')
    for bridge_name, members in new_bridges.items():
        L.append('    {!r}: ['.format(bridge_name))
        for m in members:
            L.append('        ' + _fmt_member(m))
        L.append('    ],')
    L.append('}')
    L.append('')
    L.append('OBP_BRIDGES = {')
    for obp, table in obp_bridges.items():
        L.append('    {!r}: {{'.format(obp))
        for bridge_name, val in table.items():
            L.append('        {!r}: {},'.format(bridge_name, val))
        L.append('    },')
    L.append('}')
    L.append('')
    L.append('UNIT = {!r}'.format(list(unit)))
    L.append('')
    return '\n'.join(L)


def main():
    ap = argparse.ArgumentParser(description='Migrate rules.py OpenBridge members to the OBP_BRIDGES table')
    ap.add_argument('--config', default='hblink.cfg', help='hblink.cfg to read system MODEs from')
    ap.add_argument('--rules', default='rules.py', help='existing (old-form) rules.py')
    ap.add_argument('--out', default=None, help='output file (default: <rules>.migrated)')
    args = ap.parse_args()

    out_path = args.out or (args.rules + '.migrated')
    obp_systems = _openbridge_systems(args.config)
    rules = _load_rules(args.rules)
    bridges = getattr(rules, 'BRIDGES', {})
    unit = getattr(rules, 'UNIT', [])

    if getattr(rules, 'OBP_BRIDGES', None):
        print('NOTE: {} already defines OBP_BRIDGES; this looks migrated already.'.format(args.rules))

    new_bridges, obp_bridges, moved, errors, warnings = migrate(bridges, obp_systems)

    print('OpenBridge systems found in {}: {}'.format(args.config, ', '.join(sorted(obp_systems)) or '(none)'))
    print('\n{} inline OBP member(s) moved into OBP_BRIDGES:'.format(len(moved)))
    for obp, bridge_name, tgid, ts in moved:
        print('  {:<12} {:<14} TGID {}{}'.format(obp, bridge_name, tgid, '' if ts == 1 else ' (TS {})'.format(ts)))
    dropped = [b for b in bridges if b not in new_bridges]
    if dropped:
        print('\nBridges now defined only via OBP_BRIDGES (dropped from BRIDGES): {}'.format(', '.join(dropped)))
    for w in warnings:
        print('\nWARNING: ' + w)
    for e in errors:
        print('\nERROR: ' + e)

    with open(out_path, 'w', encoding='utf-8') as f:
        f.write(render(new_bridges, obp_bridges, unit))
    print('\nWrote {}. Review it, then replace your rules.py with it.'.format(out_path))
    return 1 if errors else 0


if __name__ == '__main__':
    sys.exit(main())