"""Count-checked optional bridge installation. Default CHECK ONLY, no service action.
Only dedicated V4 GUI files are added. app.js/index.html/styles.css stay untouched.
Every changed legacy source is backed up with hashes. Concurrent changes abort.
"""
from pathlib import Path
from datetime import datetime,timezone
import argparse,ast,hashlib,json,os,tempfile
ROOT=Path(__file__).resolve().parent
SERVICES=Path('/home/agent/services')

def once(text,old,new):
    if text.count(old)!=1:raise ValueError('Source anchor changed/ambiguous; review before updating')
    return text.replace(old,new,1)

def patch_forecast(text):
    if '# ENELIX_V4_SHADOW_BRIDGE' in text:return text
    text='from netplan_v4_publisher import publish_forecasts as _v4_publish_forecasts\n'+text
    anchor='                p_3 = v3.predict(data_obj, p_1, p_2)'
    text=once(text,anchor,'                # ENELIX_V4_SHADOW_BRIDGE\n                _v4_publish_forecasts(config, [(3,p_1,p_2),(13,p_10,p_11),(23,p_21,p_22)])\n\n'+anchor)
    text=once(text,'            d[key] = float(d.get(key) or default)','            raw_value = d.get(key)\n            d[key] = float(default if raw_value is None or raw_value == "" else raw_value)')
    ast.parse(text);return text

def patch_api(text):
    if '# ENELIX_V4_SHADOW_BRIDGE' in text:return text
    text='from netplan_v4_publisher import publish_tariffs as _v4_publish_tariffs\n'+text
    anchor='    _portal_store_configuration(anlagen_id, configuration)\n'
    text=once(text,anchor,anchor+'    # ENELIX_V4_SHADOW_BRIDGE\n    _v4_publish_tariffs(anlagen_id, configuration)\n')
    ast.parse(text);return text

def patch_tariff(text):
    if '# ENELIX_V4_SHADOW_BRIDGE' in text:return text
    text='from netplan_v4_publisher import publish_ckw as _v4_publish_ckw\n'+text
    anchor='                    return candidate_points\n'
    text=once(text,anchor,"                    # ENELIX_V4_SHADOW_BRIDGE\n                    _v4_publish_ckw(source['label'], rows, data.get('publication_timestamp') if isinstance(data, dict) else None, tariff_type)\n"+anchor)
    for name in ('row','integrated'):
        old=f'{name}.get("value") or {name}.get("price") or {name}.get("amount")'
        if old in text:text=once(text,old,f'next(({name}[key] for key in ("value", "price", "amount") if {name}.get(key) is not None), None)')
    ast.parse(text);return text

def patch_portal(text):
    if '// ENELIX_V4_SHADOW_BRIDGE' in text:return text
    anchor='const server = createServer(async (req, res) => {'
    extra="""// ENELIX_V4_SHADOW_BRIDGE
// No dependency or changed route while NETPLAN_V4_URL is absent.
const plannerV4Bridge = process.env.NETPLAN_V4_URL
  ? (await import('./netplan-v4-bridge.mjs')).createPlannerV4Bridge({
      configuredPrognosisPlant, roleAllowed, bodyJson, json, deviceActivation,
      checkDeviceRate, ownedLicenseState, serviceToken: prognosisServiceToken,
      upstreamUrl: process.env.NETPLAN_V4_URL
    })
  : null;

"""
    text=once(text,anchor,extra+anchor)
    anchor='    if (url.pathname === "/healthz" && req.method === "GET") return json(res, 200, {'
    return once(text,anchor,'    if (plannerV4Bridge && await plannerV4Bridge(req, res, url)) return;\n'+anchor)

def plan(root=SERVICES, approved_assets=None):
    root=Path(root).resolve();project=root/'prognosis-manager-enelix2';result={}
    if approved_assets is None:
        manifest=ROOT/'approved_previous_assets.json'
        approved_assets=json.loads(manifest.read_text()) if manifest.is_file() else {}
    for path,patch in [(project/'api/main.py',patch_api),(project/'forecast_engine/main.py',patch_forecast),(project/'tariff_importer/main.py',patch_tariff),(root/'license/server.mjs',patch_portal)]:
        if path.is_symlink() or not path.resolve().is_relative_to(root):raise ValueError('External/symlink target refused')
        old=path.read_bytes();new=patch(old.decode()).encode()
        if old!=new:result[path]=(old,new)
    files={project/service/'netplan_v4_publisher.py':ROOT/'integrations/netplan_v4_publisher.py' for service in ('api','forecast_engine','tariff_importer')}
    files[root/'license/netplan-v4-bridge.mjs']=ROOT/'integrations/netplan-v4-bridge.mjs'
    for name in ('netplan-v4.html','netplan-v4.js','netplan-v4.css'):files[root/'license/public'/name]=ROOT/'gui'/name
    for path,source in files.items():
        if path.is_symlink() or not path.resolve().is_relative_to(root):raise ValueError('External/symlink target refused')
        old=path.read_bytes() if path.exists() else None;new=source.read_bytes()
        if old is not None and old!=new:
            approved=approved_assets.get(str(path.relative_to(root)),[])
            if hashlib.sha256(old).hexdigest() not in approved:
                raise ValueError('Existing V4 file differs from the reviewed previous release; explicit merge required: '+str(path))
        if old!=new:result[path]=(old,new)
    return result

def atomic(path,data,mode=0o644):
    path.parent.mkdir(parents=True,exist_ok=True);fd,tmp=tempfile.mkstemp(prefix=path.name+'.v4-',dir=path.parent)
    try:
        with os.fdopen(fd,'wb') as out:out.write(data);out.flush();os.fsync(out.fileno())
        os.chmod(tmp,mode);os.replace(tmp,path)
    finally:
        if os.path.exists(tmp):os.unlink(tmp)

def apply(entries,root=SERVICES):
    root=Path(root).resolve()
    for path,(old,new) in entries.items():
        if (path.read_bytes() if path.exists() else None)!=old:raise ValueError('Concurrent change: no files modified')
    if not entries:return None
    backup=root/'change-backups'/'netplan-v4'/datetime.now(timezone.utc).strftime('%Y%m%dT%H%M%S%fZ')
    backup.mkdir(parents=True);receipt={'root':str(root),'files':[]};written=[]
    try:
        for path,(old,new) in entries.items():
            if (path.read_bytes() if path.exists() else None)!=old:raise ValueError('Concurrent source change during install')
            rel=path.relative_to(root);mode=path.stat().st_mode&0o777 if path.exists() else 0o644
            if old is not None:
                original=backup/'originals'/rel;original.parent.mkdir(parents=True,exist_ok=True);original.write_bytes(old)
            atomic(path,new,mode);written.append(path)
            receipt['files'].append({'path':str(rel),'before':hashlib.sha256(old).hexdigest() if old is not None else None,'after':hashlib.sha256(new).hexdigest(),'mode':mode})
        atomic(backup/'receipt.json',json.dumps(receipt,indent=2).encode());return backup/'receipt.json'
    except Exception:
        for path in reversed(written):
            old,new=entries[path]
            if path.read_bytes()==new:
                if old is None:path.unlink()
                else:atomic(path,old)
        raise

def rollback(receipt_path):
    path=Path(receipt_path).resolve();data=json.loads(path.read_text());root=Path(data['root']).resolve()
    for item in data['files']:
        target=(root/item['path']).resolve()
        if not target.is_relative_to(root) or hashlib.sha256(target.read_bytes()).hexdigest()!=item['after']:raise ValueError('Later change detected; automatic rollback refused')
    for item in reversed(data['files']):
        target=root/item['path']
        if item['before'] is None:target.unlink()
        else:
            original=(path.parent/'originals'/item['path']).read_bytes()
            if hashlib.sha256(original).hexdigest()!=item['before']:raise ValueError('Backup checksum mismatch')
            atomic(target,original,item['mode'])

if __name__=='__main__':
    parser=argparse.ArgumentParser(description=__doc__);parser.add_argument('--apply',action='store_true');parser.add_argument('--rollback');args=parser.parse_args()
    if args.rollback:rollback(args.rollback);print('Source rollback completed. No service restart.')
    else:
        entries=plan()
        for path in entries:print(path)
        print('Receipt:',apply(entries)) if args.apply else print('CHECK ONLY:',len(entries),'files. No source/database/service changed.')