"""Helpers for config validation using voluptuous."""
from datetime import (timedelta, datetime as datetime_sys,
                      time as time_sys, date as date_sys)
import os
import re
from urllib.parse import urlparse
from socket import _GLOBAL_DEFAULT_TIMEOUT

from typing import Any, Union, TypeVar, Callable, Sequence, Dict

import voluptuous as vol

from homeassistant.loader import get_platform
from homeassistant.const import (
    CONF_PLATFORM, CONF_SCAN_INTERVAL, TEMP_CELSIUS, TEMP_FAHRENHEIT,
    CONF_ALIAS, CONF_ENTITY_ID, CONF_VALUE_TEMPLATE, WEEKDAYS,
    CONF_CONDITION, CONF_BELOW, CONF_ABOVE, CONF_TIMEOUT, SUN_EVENT_SUNSET,
    SUN_EVENT_SUNRISE, CONF_UNIT_SYSTEM_IMPERIAL, CONF_UNIT_SYSTEM_METRIC)
from homeassistant.core import valid_entity_id
from homeassistant.exceptions import TemplateError
import homeassistant.util.dt as dt_util
from homeassistant.util import slugify as util_slugify
from homeassistant.helpers import template as template_helper

# pylint: disable=invalid-name

TIME_PERIOD_ERROR = "offset {} should be format 'HH:MM' or 'HH:MM:SS'"

# Home Assistant types
byte = vol.All(vol.Coerce(int), vol.Range(min=0, max=255))
small_float = vol.All(vol.Coerce(float), vol.Range(min=0, max=1))
positive_int = vol.All(vol.Coerce(int), vol.Range(min=0))
latitude = vol.All(vol.Coerce(float), vol.Range(min=-90, max=90),
                   msg='invalid latitude')
longitude = vol.All(vol.Coerce(float), vol.Range(min=-180, max=180),
                    msg='invalid longitude')
sun_event = vol.All(vol.Lower, vol.Any(SUN_EVENT_SUNSET, SUN_EVENT_SUNRISE))
port = vol.All(vol.Coerce(int), vol.Range(min=1, max=65535))

# typing typevar
T = TypeVar('T')


# Adapted from:
# https://github.com/alecthomas/voluptuous/issues/115#issuecomment-144464666
def has_at_least_one_key(*keys: str) -> Callable:
    """Validate that at least one key exists."""
    def validate(obj: Dict) -> Dict:
        """Test keys exist in dict."""
        if not isinstance(obj, dict):
            raise vol.Invalid('expected dictionary')

        for k in obj.keys():
            if k in keys:
                return obj
        raise vol.Invalid('must contain one of {}.'.format(', '.join(keys)))

    return validate


def has_at_least_one_key_value(*items: list) -> Callable:
    """Validate that at least one (key, value) pair exists."""
    def validate(obj: Dict) -> Dict:
        """Test (key,value) exist in dict."""
        if not isinstance(obj, dict):
            raise vol.Invalid('expected dictionary')

        for item in obj.items():
            if item in items:
                return obj
        raise vol.Invalid('must contain one of {}.'.format(str(items)))

    return validate


def boolean(value: Any) -> bool:
    """Validate and coerce a boolean value."""
    if isinstance(value, str):
        value = value.lower()
        if value in ('1', 'true', 'yes', 'on', 'enable'):
            return True
        if value in ('0', 'false', 'no', 'off', 'disable'):
            return False
        raise vol.Invalid('invalid boolean value {}'.format(value))
    return bool(value)


def isdevice(value):
    """Validate that value is a real device."""
    try:
        os.stat(value)
        return str(value)
    except OSError:
        raise vol.Invalid('No device at {} found'.format(value))


def isfile(value: Any) -> str:
    """Validate that the value is an existing file."""
    if value is None:
        raise vol.Invalid('None is not file')
    file_in = os.path.expanduser(str(value))

    if not os.path.isfile(file_in):
        raise vol.Invalid('not a file')
    if not os.access(file_in, os.R_OK):
        raise vol.Invalid('file not readable')
    return file_in


def ensure_list(value: Union[T, Sequence[T]]) -> Sequence[T]:
    """Wrap value in list if it is not one."""
    if value is None:
        return []
    return value if isinstance(value, list) else [value]


def entity_id(value: Any) -> str:
    """Validate Entity ID."""
    value = string(value).lower()
    if valid_entity_id(value):
        return value
    raise vol.Invalid('Entity ID {} is an invalid entity id'.format(value))


def entity_ids(value: Union[str, Sequence]) -> Sequence[str]:
    """Validate Entity IDs."""
    if value is None:
        raise vol.Invalid('Entity IDs can not be None')
    if isinstance(value, str):
        value = [ent_id.strip() for ent_id in value.split(',')]

    return [entity_id(ent_id) for ent_id in value]


def enum(enumClass):
    """Create validator for specified enum."""
    return vol.All(vol.In(enumClass.__members__), enumClass.__getitem__)


def icon(value):
    """Validate icon."""
    value = str(value)

    if value.startswith('mdi:'):
        return value

    raise vol.Invalid('Icons should start with prefix "mdi:"')


time_period_dict = vol.All(
    dict, vol.Schema({
        'days': vol.Coerce(int),
        'hours': vol.Coerce(int),
        'minutes': vol.Coerce(int),
        'seconds': vol.Coerce(int),
        'milliseconds': vol.Coerce(int),
    }),
    has_at_least_one_key('days', 'hours', 'minutes',
                         'seconds', 'milliseconds'),
    lambda value: timedelta(**value))


def time(value) -> time_sys:
    """Validate and transform a time."""
    if isinstance(value, time_sys):
        return value

    try:
        time_val = dt_util.parse_time(value)
    except TypeError:
        raise vol.Invalid('Not a parseable type')

    if time_val is None:
        raise vol.Invalid('Invalid time specified: {}'.format(value))

    return time_val


def date(value) -> date_sys:
    """Validate and transform a date."""
    if isinstance(value, date_sys):
        return value

    try:
        date_val = dt_util.parse_date(value)
    except TypeError:
        raise vol.Invalid('Not a parseable type')

    if date_val is None:
        raise vol.Invalid("Could not parse date")

    return date_val


def time_period_str(value: str) -> timedelta:
    """Validate and transform time offset."""
    if isinstance(value, int):
        raise vol.Invalid('Make sure you wrap time values in quotes')
    elif not isinstance(value, str):
        raise vol.Invalid(TIME_PERIOD_ERROR.format(value))

    negative_offset = False
    if value.startswith('-'):
        negative_offset = True
        value = value[1:]
    elif value.startswith('+'):
        value = value[1:]

    try:
        parsed = [int(x) for x in value.split(':')]
    except ValueError:
        raise vol.Invalid(TIME_PERIOD_ERROR.format(value))

    if len(parsed) == 2:
        hour, minute = parsed
        second = 0
    elif len(parsed) == 3:
        hour, minute, second = parsed
    else:
        raise vol.Invalid(TIME_PERIOD_ERROR.format(value))

    offset = timedelta(hours=hour, minutes=minute, seconds=second)

    if negative_offset:
        offset *= -1

    return offset


def time_period_seconds(value: Union[int, str]) -> timedelta:
    """Validate and transform seconds to a time offset."""
    try:
        return timedelta(seconds=int(value))
    except (ValueError, TypeError):
        raise vol.Invalid('Expected seconds, got {}'.format(value))


time_period = vol.Any(time_period_str, time_period_seconds, timedelta,
                      time_period_dict)


def match_all(value):
    """Validate that matches all values."""
    return value


def platform_validator(domain):
    """Validate if platform exists for given domain."""
    def validator(value):
        """Test if platform exists."""
        if value is None:
            raise vol.Invalid('platform cannot be None')
        if get_platform(domain, str(value)):
            return value
        raise vol.Invalid(
            'platform {} does not exist for {}'.format(value, domain))
    return validator


def positive_timedelta(value: timedelta) -> timedelta:
    """Validate timedelta is positive."""
    if value < timedelta(0):
        raise vol.Invalid('Time period should be positive')
    return value


def service(value):
    """Validate service."""
    # Services use same format as entities so we can use same helper.
    if valid_entity_id(value):
        return value
    raise vol.Invalid('Service {} does not match format <domain>.<name>'
                      .format(value))


def slug(value):
    """Validate value is a valid slug."""
    if value is None:
        raise vol.Invalid('Slug should not be None')
    value = str(value)
    slg = util_slugify(value)
    if value == slg:
        return value
    raise vol.Invalid('invalid slug {} (try {})'.format(value, slg))


def slugify(value):
    """Coerce a value to a slug."""
    if value is None:
        raise vol.Invalid('Slug should not be None')
    slg = util_slugify(str(value))
    if slg:
        return slg
    raise vol.Invalid('Unable to slugify {}'.format(value))


def string(value: Any) -> str:
    """Coerce value to string, except for None."""
    if value is not None:
        return str(value)
    raise vol.Invalid('string value is None')


def temperature_unit(value) -> str:
    """Validate and transform temperature unit."""
    value = str(value).upper()
    if value == 'C':
        return TEMP_CELSIUS
    elif value == 'F':
        return TEMP_FAHRENHEIT
    raise vol.Invalid('invalid temperature unit (expected C or F)')


unit_system = vol.All(vol.Lower, vol.Any(CONF_UNIT_SYSTEM_METRIC,
                                         CONF_UNIT_SYSTEM_IMPERIAL))


def template(value):
    """Validate a jinja2 template."""
    if value is None:
        raise vol.Invalid('template value is None')
    elif isinstance(value, (list, dict, template_helper.Template)):
        raise vol.Invalid('template value should be a string')

    value = template_helper.Template(str(value))

    try:
        value.ensure_valid()
        return value
    except TemplateError as ex:
        raise vol.Invalid('invalid template ({})'.format(ex))


def template_complex(value):
    """Validate a complex jinja2 template."""
    if isinstance(value, list):
        for idx, element in enumerate(value):
            value[idx] = template_complex(element)
        return value
    if isinstance(value, dict):
        for key, element in value.items():
            value[key] = template_complex(element)
        return value

    return template(value)


def datetime(value):
    """Validate datetime."""
    if isinstance(value, datetime_sys):
        return value

    try:
        date_val = dt_util.parse_datetime(value)
    except TypeError:
        date_val = None

    if date_val is None:
        raise vol.Invalid('Invalid datetime specified: {}'.format(value))

    return date_val


def time_zone(value):
    """Validate timezone."""
    if dt_util.get_time_zone(value) is not None:
        return value
    raise vol.Invalid(
        'Invalid time zone passed in. Valid options can be found here: '
        'http://en.wikipedia.org/wiki/List_of_tz_database_time_zones')


weekdays = vol.All(ensure_list, [vol.In(WEEKDAYS)])


def socket_timeout(value):
    """Validate timeout float > 0.0.

    None coerced to socket._GLOBAL_DEFAULT_TIMEOUT bare object.
    """
    if value is None:
        return _GLOBAL_DEFAULT_TIMEOUT
    else:
        try:
            float_value = float(value)
            if float_value > 0.0:
                return float_value
            raise vol.Invalid('Invalid socket timeout value.'
                              ' float > 0.0 required.')
        except Exception as _:
            raise vol.Invalid('Invalid socket timeout: {err}'.format(err=_))


# pylint: disable=no-value-for-parameter
def url(value: Any) -> str:
    """Validate an URL."""
    url_in = str(value)

    if urlparse(url_in).scheme in ['http', 'https']:
        return vol.Schema(vol.Url())(url_in)

    raise vol.Invalid('invalid url')


def x10_address(value):
    """Validate an x10 address."""
    regex = re.compile(r'([A-Pa-p]{1})(?:[2-9]|1[0-6]?)$')
    if not regex.match(value):
        raise vol.Invalid('Invalid X10 Address')
    return str(value).lower()


def ensure_list_csv(value: Any) -> Sequence:
    """Ensure that input is a list or make one from comma-separated string."""
    if isinstance(value, str):
        return [member.strip() for member in value.split(',')]
    return ensure_list(value)


# Validator helpers

def key_dependency(key, dependency):
    """Validate that all dependencies exist for key."""
    def validator(value):
        """Test dependencies."""
        if not isinstance(value, dict):
            raise vol.Invalid('key dependencies require a dict')
        if key in value and dependency not in value:
            raise vol.Invalid('dependency violation - key "{}" requires '
                              'key "{}" to exist'.format(key, dependency))

        return value
    return validator


# Schemas

PLATFORM_SCHEMA = vol.Schema({
    vol.Required(CONF_PLATFORM): string,
    vol.Optional(CONF_SCAN_INTERVAL): time_period
}, extra=vol.ALLOW_EXTRA)

EVENT_SCHEMA = vol.Schema({
    vol.Optional(CONF_ALIAS): string,
    vol.Required('event'): string,
    vol.Optional('event_data'): dict,
})

SERVICE_SCHEMA = vol.All(vol.Schema({
    vol.Optional(CONF_ALIAS): string,
    vol.Exclusive('service', 'service name'): service,
    vol.Exclusive('service_template', 'service name'): template,
    vol.Optional('data'): dict,
    vol.Optional('data_template'): {match_all: template_complex},
    vol.Optional(CONF_ENTITY_ID): entity_ids,
}), has_at_least_one_key('service', 'service_template'))

NUMERIC_STATE_CONDITION_SCHEMA = vol.All(vol.Schema({
    vol.Required(CONF_CONDITION): 'numeric_state',
    vol.Required(CONF_ENTITY_ID): entity_id,
    CONF_BELOW: vol.Coerce(float),
    CONF_ABOVE: vol.Coerce(float),
    vol.Optional(CONF_VALUE_TEMPLATE): template,
}), has_at_least_one_key(CONF_BELOW, CONF_ABOVE))

STATE_CONDITION_SCHEMA = vol.All(vol.Schema({
    vol.Required(CONF_CONDITION): 'state',
    vol.Required(CONF_ENTITY_ID): entity_id,
    vol.Required('state'): str,
    vol.Optional('for'): vol.All(time_period, positive_timedelta),
    # To support use_trigger_value in automation
    # Deprecated 2016/04/25
    vol.Optional('from'): str,
}), key_dependency('for', 'state'))

SUN_CONDITION_SCHEMA = vol.All(vol.Schema({
    vol.Required(CONF_CONDITION): 'sun',
    vol.Optional('before'): sun_event,
    vol.Optional('before_offset'): time_period,
    vol.Optional('after'): vol.All(vol.Lower, vol.Any('sunset', 'sunrise')),
    vol.Optional('after_offset'): time_period,
}), has_at_least_one_key('before', 'after'))

TEMPLATE_CONDITION_SCHEMA = vol.Schema({
    vol.Required(CONF_CONDITION): 'template',
    vol.Required(CONF_VALUE_TEMPLATE): template,
})

TIME_CONDITION_SCHEMA = vol.All(vol.Schema({
    vol.Required(CONF_CONDITION): 'time',
    'before': time,
    'after': time,
    'weekday': weekdays,
}), has_at_least_one_key('before', 'after', 'weekday'))

ZONE_CONDITION_SCHEMA = vol.Schema({
    vol.Required(CONF_CONDITION): 'zone',
    vol.Required(CONF_ENTITY_ID): entity_id,
    'zone': entity_id,
    # To support use_trigger_value in automation
    # Deprecated 2016/04/25
    vol.Optional('event'): vol.Any('enter', 'leave'),
})

AND_CONDITION_SCHEMA = vol.Schema({
    vol.Required(CONF_CONDITION): 'and',
    vol.Required('conditions'): vol.All(
        ensure_list,
        # pylint: disable=unnecessary-lambda
        [lambda value: CONDITION_SCHEMA(value)],
    )
})

OR_CONDITION_SCHEMA = vol.Schema({
    vol.Required(CONF_CONDITION): 'or',
    vol.Required('conditions'): vol.All(
        ensure_list,
        # pylint: disable=unnecessary-lambda
        [lambda value: CONDITION_SCHEMA(value)],
    )
})

CONDITION_SCHEMA = vol.Any(
    NUMERIC_STATE_CONDITION_SCHEMA,
    STATE_CONDITION_SCHEMA,
    SUN_CONDITION_SCHEMA,
    TEMPLATE_CONDITION_SCHEMA,
    TIME_CONDITION_SCHEMA,
    ZONE_CONDITION_SCHEMA,
    AND_CONDITION_SCHEMA,
    OR_CONDITION_SCHEMA,
)

_SCRIPT_DELAY_SCHEMA = vol.Schema({
    vol.Optional(CONF_ALIAS): string,
    vol.Required("delay"): vol.Any(
        vol.All(time_period, positive_timedelta),
        template)
})

_SCRIPT_WAIT_TEMPLATE_SCHEMA = vol.Schema({
    vol.Optional(CONF_ALIAS): string,
    vol.Required("wait_template"): template,
    vol.Optional(CONF_TIMEOUT): vol.All(time_period, positive_timedelta),
})

SCRIPT_SCHEMA = vol.All(
    ensure_list,
    [vol.Any(SERVICE_SCHEMA, _SCRIPT_DELAY_SCHEMA,
             _SCRIPT_WAIT_TEMPLATE_SCHEMA, EVENT_SCHEMA, CONDITION_SCHEMA)],
)
