# -*- coding: utf-8 -*-
"""Shared helper for the L2 collectors: read the module config, resolve the
selected templates to template ids, and list the hosts that should be collected.
"""
import os
import json

DEFAULT_PATHS = [
    os.environ.get('L2_CONFIG') or '',
    '/opt/zabbix/zabbix-server/web-modules/WecomCenter/assets/l2topology/config.json',
    '/usr/share/zabbix/modules/WecomCenter/assets/l2topology/config.json',
    os.path.join(os.path.dirname(os.path.abspath(__file__)), 'config.json'),
]


def config():
    for p in DEFAULT_PATHS:
        if p and os.path.isfile(p):
            try:
                with open(p, encoding='utf-8') as f:
                    return json.load(f)
            except Exception:
                pass
    return {}


def template_ids(call):
    """Resolve configured template names -> [templateid]. Empty list => no filter."""
    cfg = config()
    names = [str(n).strip() for n in (cfg.get('templates') or []) if str(n).strip()]
    if not names:
        return []
    try:
        tpls = call('template.get', {'output': ['templateid', 'name']})['result']
    except Exception:
        return []
    want = {n.lower() for n in names}
    return [t['templateid'] for t in tpls if t.get('name', '').strip().lower() in want]


def hosts(call, output=None, interfaces='extend'):
    """host.get restricted to the configured templates (when resolvable)."""
    p = {'output': output or ['hostid', 'name'], 'selectInterfaces': interfaces}
    tids = template_ids(call)
    if tids:
        p['templateids'] = tids
    return call('host.get', p)['result']