import json
from config_utils import collect_layout_tokens, load_datasource, fmt_timestamp, fmt_bytes
from factory import run, load_json, build_table, table_token_key, iter_table_items, PAGES_DIR


def live_vpn_sessions():
    rows = []
    out = run('wg show all dump 2>/dev/null')
    for line in out.splitlines():
        parts = line.split('\t')
        if len(parts) == 9:
            interface, pubkey, _psk, endpoint, allowed_ips, last_hs, rx, tx, _ka = parts
            rows.append({
                'peer_name':      pubkey[:16] + '...',
                'interface':      interface,
                'tunnel_ip':      allowed_ips.split(',')[0].split('/')[0] if allowed_ips else '-',
                'endpoint':       endpoint if endpoint != '(none)' else '-',
                'last_handshake': fmt_timestamp(int(last_hs)) if last_hs.isdigit() and last_hs != '0' else 'Never',
                'rx_bytes':       fmt_bytes(int(rx)) if rx.isdigit() else '-',
                'tx_bytes':       fmt_bytes(int(tx)) if tx.isdigit() else '-',
            })
    return rows


def collect_tokens(cfg):
    tokens = collect_layout_tokens(cfg)
    vlans = cfg.get('vlans', [])
    wg_vlans_list = sorted(
        [v for v in vlans if v.get('is_vpn')],
        key=lambda v: (v.get('vlan_id') is None, v.get('vlan_id') or 0)
    )
    wg_vlan = wg_vlans_list[0] if wg_vlans_list else {}
    vpn = wg_vlan.get('vpn_information', {})
    overrides = vpn.get('explicit_overrides', {})

    try:
        import ipaddress
        ident_ips = [s['ip'] for s in wg_vlan.get('server_identities', []) if s.get('ip')]
        if ident_ips:
            default_gw = str(min((ipaddress.IPv4Address(ip) for ip in ident_ips), key=lambda x: x.packed[-1]))
        else:
            wg_net = ipaddress.IPv4Network(f"{wg_vlan['subnet']}/{wg_vlan['subnet_mask']}", strict=False)
            default_gw = str(next(wg_net.hosts()))
        vpn_gateway = overrides.get('gateway') or default_gw
    except Exception:
        vpn_gateway = ''

    tokens['VPN_VLAN_OPTIONS']    = json.dumps([
        {'value': v.get('name', ''), 'label': f'wg{i} (VLAN {v.get("vlan_id") or "?"})'}
        for i, v in enumerate(wg_vlans_list)
    ])
    tokens['VPN_LISTEN_PORT']     = str(vpn.get('listen_port', ''))
    tokens['VPN_SERVER_ENDPOINT'] = str(vpn.get('server_endpoint', ''))
    tokens['VPN_DOMAIN']          = str(vpn.get('domain', ''))
    tokens['VPN_DNS_SERVER']      = str(overrides.get('dns_servers', ''))
    tokens['VPN_MTU']             = str(overrides.get('mtu', ''))
    tokens['VPN_GATEWAY']         = vpn_gateway
    content = load_json(f'{PAGES_DIR}/vpn/content.json')
    for table_item in iter_table_items(content.get('items', [])):
        ds = table_item.get('datasource', '')
        rows = live_vpn_sessions() if ds == 'live:vpn_sessions' else load_datasource(ds)
        tokens[table_token_key(ds)] = build_table(table_item, tokens, rows)
    return tokens