import json
import os
from config_utils import collect_layout_tokens

_EXCLUDE_PREFIXES = ('lo', 'wg', 'docker', 'br-', 'veth', 'tun', 'tap', 'ppp', 'virbr', 'podman', 'vnet', 'macvtap', 'fc-')


def get_system_interfaces():
    try:
        return sorted(
            n for n in os.listdir('/sys/class/net')
            if not n.startswith(_EXCLUDE_PREFIXES)
            and os.path.exists(f'/sys/class/net/{n}/device')
        )
    except Exception:
        return []


def iface_info(iface):
    base = f'/sys/class/net/{iface}'

    def rd(path):
        try:
            with open(f'{base}/{path}') as f:
                return f.read().strip()
        except Exception:
            return None

    def int_val(val):
        try:
            return int(val) if val else None
        except ValueError:
            return None

    wireless = os.path.isdir(f'{base}/wireless')
    state = (rd('operstate') or 'unknown').upper()
    if state == 'UNKNOWN':
        state = 'UP'
    carrier_raw = rd('carrier')
    carrier = (carrier_raw == '1') if carrier_raw is not None else None
    speed_raw = rd('speed')
    try:
        mbps = int(speed_raw)
        if mbps <= 0:
            speed = None
        elif mbps >= 1000 and mbps % 1000 == 0:
            speed = f'{mbps // 1000} Gbps'
        else:
            speed = f'{mbps} Mbps'
    except (TypeError, ValueError):
        speed = None
    mac = rd('address')
    perm_mac = rd('perm_address')
    if perm_mac and perm_mac == '00:00:00:00:00:00':
        perm_mac = None
    return {
        'name':     iface,
        'wireless': wireless,
        'state':    state,
        'carrier':  carrier,
        'speed':    speed,
        'mtu':      rd('mtu'),
        'min_mtu':  int_val(rd('min_mtu')),
        'max_mtu':  int_val(rd('max_mtu')),
        'mac':      mac,
        'perm_mac': perm_mac,
    }


def collect_tokens(cfg):
    tokens = collect_layout_tokens(cfg)
    net = cfg.get('network_interfaces', {})
    wan = net.get('wan_interface', '')
    lan = net.get('lan_interface', '')
    sys_ifaces = get_system_interfaces()
    for configured in [wan, lan]:
        if configured and configured not in sys_ifaces:
            sys_ifaces.append(configured)
    sys_ifaces.sort()
    iface_data = [iface_info(i) for i in sys_ifaces]
    tokens['GENERAL_WAN_INTERFACE']       = str(wan or '-')
    tokens['NETWORK_INTERFACE_DATA_JSON'] = json.dumps(iface_data)
    return tokens