# -*- coding: utf-8 -*-
'''
Beacon to emit adb device state changes for Android devices

.. versionadded:: 2016.3.0
'''

# Import Python libs
from __future__ import absolute_import
import logging

# Salt libs
import salt.utils

log = logging.getLogger(__name__)

__virtualname__ = 'adb'

last_state = {}
last_state_extra = {'value': False}


def __virtual__():
    which_result = salt.utils.which('adb')
    if which_result is None:
        return False
    else:
        return __virtualname__


def validate(config):
    '''
    Validate the beacon configuration
    '''
    # Configuration for adb beacon should be a dictionary with states array
    if not isinstance(config, dict):
        log.info('Configuration for adb beacon must be a dict.')
        return False
    elif 'states' not in config.keys():
        log.info('Configuration for adb beacon must include a states array.')
        return False
    else:
        states = ['offline', 'bootloader', 'device', 'host', 'recovery', 'no permissions',
                  'sideload', 'unauthorized', 'unknown', 'missing']
        if any(s not in states for s in config['states']):
            log.info('Need a one of the following adb states: {0}'.format(', '.join(states)))
            return False
    return True


def beacon(config):
    '''
    Emit the status of all devices returned by adb

    Specify the device states that should emit an event,
    there will be an event for each device with the
    event type and device specified.

    .. code-block:: yaml

        beacons:
          adb:
            - states:
                - offline
                - unauthorized
                - missing
            - no_devices_event: True
            - battery_low: 25

    '''

    log.trace('adb beacon starting')
    ret = []

    if not validate(config):
        return ret

    out = __salt__['cmd.run']('adb devices', runas=config.get('user', None))

    lines = out.split('\n')[1:]
    last_state_devices = last_state.keys()
    found_devices = []

    for line in lines:
        try:
            device, state = line.split('\t')
            found_devices.append(device)
            if device not in last_state_devices or \
                    ('state' in last_state[device] and last_state[device]['state'] != state):
                if state in config['states']:
                    ret.append({'device': device, 'state': state, 'tag': state})
                    last_state[device] = {'state': state}

            if 'battery_low' in config:
                val = last_state.get(device, {})
                cmd = 'adb -s {0} shell cat /sys/class/power_supply/*/capacity'.format(device)
                battery_levels = __salt__['cmd.run'](cmd, runas=config.get('user', None)).split('\n')

                for l in battery_levels:
                    battery_level = int(l)
                    if 0 < battery_level < 100:
                        if 'battery' not in val or battery_level != val['battery']:
                            if ('battery' not in val or val['battery'] > config['battery_low']) and \
                                            battery_level <= config['battery_low']:
                                ret.append({'device': device, 'battery_level': battery_level, 'tag': 'battery_low'})

                        if device not in last_state:
                            last_state[device] = {}

                        last_state[device].update({'battery': battery_level})

        except ValueError:
            continue

    # Find missing devices and remove them / send an event
    for device in last_state_devices:
        if device not in found_devices:
            if 'missing' in config['states']:
                ret.append({'device': device, 'state': 'missing', 'tag': 'missing'})

            del last_state[device]

    # Maybe send an event if we don't have any devices
    if 'no_devices_event' in config and config['no_devices_event'] is True:
        if len(lines) == 0 and not last_state_extra['no_devices']:
            ret.append({'tag': 'no_devices'})

    # Did we have no devices listed this time around?

    last_state_extra['no_devices'] = len(lines) == 0

    return ret
