"""Helpers for LCN component."""
import re

import voluptuous as vol

from homeassistant.const import CONF_NAME

from .const import DEFAULT_NAME

# Regex for address validation
PATTERN_ADDRESS = re.compile('^((?P<conn_id>\\w+)\\.)?s?(?P<seg_id>\\d+)'
                             '\\.(?P<type>m|g)?(?P<id>\\d+)$')


def get_connection(connections, connection_id=None):
    """Return the connection object from list."""
    if connection_id is None:
        connection = connections[0]
    else:
        for connection in connections:
            if connection.connection_id == connection_id:
                break
        else:
            raise ValueError('Unknown connection_id.')
    return connection


def has_unique_connection_names(connections):
    """Validate that all connection names are unique.

    Use 'pchk' as default connection_name (or add a numeric suffix if
    pchk' is already in use.
    """
    for suffix, connection in enumerate(connections):
        connection_name = connection.get(CONF_NAME)
        if connection_name is None:
            if suffix == 0:
                connection[CONF_NAME] = DEFAULT_NAME
            else:
                connection[CONF_NAME] = '{}{:d}'.format(DEFAULT_NAME, suffix)

    schema = vol.Schema(vol.Unique())
    schema([connection.get(CONF_NAME) for connection in connections])
    return connections


def is_address(value):
    """Validate the given address string.

    Examples for S000M005 at myhome:
        myhome.s000.m005
        myhome.s0.m5
        myhome.0.5    ("m" is implicit if missing)

    Examples for s000g011
        myhome.0.g11
        myhome.s0.g11
    """
    matcher = PATTERN_ADDRESS.match(value)
    if matcher:
        is_group = (matcher.group('type') == 'g')
        addr = (int(matcher.group('seg_id')),
                int(matcher.group('id')),
                is_group)
        conn_id = matcher.group('conn_id')
        return addr, conn_id
    raise vol.error.Invalid('Not a valid address string.')


def is_relays_states_string(states_string):
    """Validate the given states string and return states list."""
    if len(states_string) == 8:
        states = []
        for state_string in states_string:
            if state_string == '1':
                state = 'ON'
            elif state_string == '0':
                state = 'OFF'
            elif state_string == 'T':
                state = 'TOGGLE'
            elif state_string == '-':
                state = 'NOCHANGE'
            else:
                raise vol.error.Invalid('Not a valid relay state string.')
            states.append(state)
        return states
    raise vol.error.Invalid('Wrong length of relay state string.')


def is_key_lock_states_string(states_string):
    """Validate the given states string and returns states list."""
    if len(states_string) == 8:
        states = []
        for state_string in states_string:
            if state_string == '1':
                state = 'ON'
            elif state_string == '0':
                state = 'OFF'
            elif state_string == 'T':
                state = 'TOGGLE'
            elif state_string == '-':
                state = 'NOCHANGE'
            else:
                raise vol.error.Invalid('Not a valid key lock state string.')
            states.append(state)
        return states
    raise vol.error.Invalid('Wrong length of key lock state string.')