#!/usr/bin/env python3
"""Silent read-only inventory in the existing Platform Backup-account procedure.

Runs only inside the attended platform-admin envelope. Reuses Platform's owner
custody accessor and fixed provider/account contract; no age key is read and no
backup is downloaded, uploaded, deleted, rotated or granted.
"""
import argparse
import base64
from datetime import datetime, timezone
import hashlib
import json
import os
from pathlib import Path
import re
import sys
import urllib.parse
import urllib.request
import xml.etree.ElementTree as ET

ROOT=Path(__file__).resolve().parents[2]
OWNER=ROOT.parent/'railiance-platform/scripts'
sys.path.insert(0,str(OWNER))
from state_hub_preflight_lane import bao, data
from migrate_nextcloud_backup_account import HOST, OPERATOR_PATH
BASE='/remote.php/dav/files/Backup/railiance-backups/'
LIMIT=4*1024*1024
NAME=re.compile(r'[A-Za-z0-9._-]{1,160}\Z')


class Refused(Exception):pass


class NoRedirect(urllib.request.HTTPRedirectHandler):
    def redirect_request(self,*args,**kwargs):raise Refused()


def parse_listing(raw, relative):
    if len(raw)>LIMIT:raise Refused()
    rows=[]
    for item in ET.fromstring(raw).findall('{DAV:}response'):
        href=urllib.parse.urlsplit(item.findtext('{DAV:}href') or '')
        if href.netloc and href.netloc!=urllib.parse.urlsplit(HOST).netloc:raise Refused()
        path=urllib.parse.unquote(href.path)
        if not path.startswith(BASE+relative):raise Refused()
        name=path[len(BASE+relative):].rstrip('/')
        if not name:continue
        if not NAME.fullmatch(name) or name in {'.','..'}:raise Refused()
        for row in item.findall('{DAV:}propstat'):
            if ' 200 ' not in (row.findtext('{DAV:}status') or ''):continue
            prop=row.find('{DAV:}prop')
            if prop is None:continue
            folder=prop.find('{DAV:}resourcetype/{DAV:}collection') is not None
            size=prop.findtext('{DAV:}getcontentlength')
            if size is not None and not size.isdigit():raise Refused()
            # Export only known-safe operational names/size, not arbitrary DAV
            # properties, URLs, account metadata or raw provider responses.
            if folder or name.endswith(('.age','.json','.yaml')):
                rows.append({'name':name,'directory':folder,'bytes':int(size) if size else None})
    if len(rows)>10000 or len({r['name'] for r in rows})!=len(rows):raise Refused()
    return sorted(rows,key=lambda x:x['name'])


def listing(relative,credentials):
    if relative and (not relative.endswith('/') or not NAME.fullmatch(relative[:-1])):raise Refused()
    auth=base64.b64encode((credentials['BACKUP_USERNAME']+':'+credentials['BACKUP_PASSWORD']).encode()).decode()
    req=urllib.request.Request(HOST+BASE+relative,
        data=b'<d:propfind xmlns:d="DAV:"><d:prop><d:resourcetype/><d:getcontentlength/></d:prop></d:propfind>',
        method='PROPFIND',headers={'Authorization':'Basic '+auth,'Depth':'1','Content-Type':'application/xml'})
    opener=urllib.request.build_opener(urllib.request.ProxyHandler({}),NoRedirect())
    with opener.open(req,timeout=30) as response:
        if response.status!=207 or response.url!=HOST+BASE+relative:raise Refused()
        raw=response.read(LIMIT+1)
    return parse_listing(raw,relative)


def caller_credentials():
    # Lookup payload contains a token: retain only safe caller/role facts.
    identity=data(bao(['token','lookup','-format=json']))['data']
    if 'platform-admin' not in identity.get('policies',[]) or 'root' in identity.get('policies',[]):raise Refused()
    if not str(identity.get('path','')).startswith('auth/netkingdom/'):raise Refused()
    credentials=data(bao(['read','-format=json',OPERATOR_PATH]))['data']['data']
    if credentials.get('BACKUP_USERNAME')!='Backup' or not isinstance(credentials.get('BACKUP_PASSWORD'),str) or not credentials['BACKUP_PASSWORD']:raise Refused()
    return identity,credentials


def inventory():
    identity,credentials=caller_credentials()
    root=listing('',credentials)
    folders={}
    for row in root:
        if row['directory'] and re.match(r'^(?:r01-|core-|identity|sso|bootstrap|net-kingdom|openbao)',row['name']):
            if len(folders)>=32:raise Refused()
            folders[row['name']]=listing(row['name']+'/',credentials)
    return {'root':root,'folders':folders,'caller_auth_path':identity['path'],
            'caller_entity_id':identity.get('entity_id'),'scope':'Backup/railiance-backups root and bounded identity/database subfolders; other accounts/folders unassessed'}


def main():
    p=argparse.ArgumentParser(description=__doc__);p.add_argument('--receipt',required=True)
    a=p.parse_args();fd=os.open(a.receipt,os.O_WRONLY|os.O_CREAT|os.O_EXCL|os.O_NOFOLLOW,0o600)
    r={'schema':'netkingdom.storage-share-inventory.v1','status':'failed','started_at':datetime.now(timezone.utc).isoformat(),
       'read_only':True,'age_keys_read':False,'backup_contents_downloaded':False,'secret_values_exported':False,
       'source_sha256':hashlib.sha256(Path(__file__).read_bytes()).hexdigest(),
       'owner_sources':[{'path':str(OWNER/name),'sha256':hashlib.sha256((OWNER/name).read_bytes()).hexdigest()} for name in ['state_hub_preflight_lane.py','migrate_nextcloud_backup_account.py']]}
    try:r.update(inventory());r['status']='metadata_inventory_complete'
    except Exception:r['error']='inventory_failed_diagnostics_suppressed'
    finally:
        r['finished_at']=datetime.now(timezone.utc).isoformat()
        with os.fdopen(fd,'w') as out:json.dump(r,out,indent=2);out.write('\n')
    return int(r['status']=='failed')


if __name__=='__main__':raise SystemExit(main())