import re
import socket

# sorry for hardwiring this ... there is no CNAME reverse lookup!
# taking the original address as unique name would need a call to
# gethostbyaddr, which might take some time - also not what we want
reverse_alias = {
    'pc15139': 'linse-c',
    'pc16392': 'linse-a',
}


def normalizeuri(uri):
    host, sep, port = uri.partition(':')
    if host[0].isdigit():
        try:
            socket.setdefaulttimeout(1)
            host = socket.gethostbyaddr(host)[0].split('.', 1)[0]
        except socket.gaierror:
            pass  # keep numbered IP
        finally:
            socket.setdefaulttimeout(None)
    else:
        host = host.split('.',1 )[0]
    if host == 'localhost':
        host = socket.gethostname()
    else:
        # this resolves CNAME entries (network aliases):
        host = reverse_alias.get(host, host)
    # strip appended IP when a host is registered twice (at PSI):
    match = re.match(r'([^-]+)-129129\d{6}$', host)
    host = match.group(1) if match else host
    return f'{host}{sep}{port}'