ha

#!/bin/sh
#
# ha.sh - Quick hack to control HA switches from the cmdline
#
# Copyright (C) 2019 Michael Davies <michael@the-davies.net>
#
# This program is free software; you can redistribute it and/or
# modify it under the terms of the GNU General Public License
# as published by the Free Software Foundation; either version 2
# of the License, or (at your option) any later version.
#
# This program is distributed in the hope that it will be useful,
# but WITHOUT ANY WARRANTY; without even the implied warranty of
# MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
# GNU General Public License for more details.
#
# You should have received a copy of the GNU General Public License
# along with this program; if not, write to the Free Software
# Foundation, Inc., 59 Temple Place - Suite 330, Boston, MA  02111-1307, USA.
# Or try here: http://www.fsf.org/copyleft/gpl.html

declare -a KNOWN_SWITCHES=($(ha-list-entities.py))
declare -a VALID_STATES=('on' 'off')

BASENAME=$(basename $0)

# Include bash library
command -v bashlib.sh &> /dev/null || \
{ echo >&2 "$(basename $0): Can't find bashlib.sh.  Aborting."; exit 1; }
. bashlib.sh

# The base URL and authentication token can be either in the
# environment, or in a file.  Either way, we need to retrieve this
# information from somewhere.  Fail otherwise.
if [[ -z "$HA_BASE_URL" || -z "$HA_TOKEN" ]]; then
    CREDS=${HOME}/.ha.sh
    if [ ! -r $CREDS ]; then
        printf "%s: Cannot find required credentials file %s\n" $BASENAME $CREDS
        exit 1
    fi
    . $CREDS
fi

# Use DEBUG from the environment, but ensure that we don't error if it's not
if [ -z "$DEBUG" ]; then
  DEBUG=0
fi

array_contains () {
  # $1 = Thing to look for
  # $2 = the array to search
  local e match="$1"
  shift
  for e; do [[ "$e" == "$match" ]] && return 0; done
  return 1
}

check_switch() {
  # Check to see if we have a known switch
  # $1 == the switch to check
  # $2 == the array of switches
  local SWITCH=$1
  shift
  local ARR=("$@")
  array_contains $SWITCH "${ARR[@]}"
  local ALLOWED=$?

  if [ $ALLOWED -eq 1 ]; then
    printf "%s: Unknown switch '%s'. Exiting...\n" $BASENAME $SWITCH
    exit 2
  fi
}

# Check to see if we have a valid state
check_states() {
  # Check to see if we have a known switch
  # $1 == the state to check
  # $2 == the array of states
  local STATE=$1
  shift
  local ARR=("$@")
  array_contains $STATE "${ARR[@]}"
  local ALLOWED=$?

  if [ $ALLOWED -eq 1 ]; then
    printf "%s: Unknown state '%s'. Exiting...\n" $BASENAME $STATE
    exit 2
  fi
}

get_state() {
  local SWITCH=$1
  local AUTH="Authorization: Bearer $HA_TOKEN"
  local CONTENT="Content-Type: application/json"
  local CMD=$(curl -s -X GET -H "$AUTH" -H "$CONTENT" ${HA_BASE_URL}/api/states/${SWITCH})
  if [ $DEBUG -eq 1 ]; then
    echo curl -s -X GET -H \"$AUTH\" -H \"$CONTENT\" ${HA_BASE_URL}/api/states/${SWITCH}
  fi
  echo $CMD | python3 -m json.tool
}

set_state() {
  local SWITCH=$1
  local STATE=$2
  local AUTH="Authorization: Bearer $HA_TOKEN"
  local CONTENT="Content-Type: application/json"
  local ENTITY="{\"entity_id\": \"$SWITCH\"}"
  if [ $DEBUG -eq 1 ]; then
    echo curl -s -X POST -H \"$AUTH\" -H \"$CONTENT\" -d \'$ENTITY\' ${HA_BASE_URL}/api/services/switch/turn_$STATE
  fi
  local CMD=$(curl -s -X POST -H "$AUTH" -H "$CONTENT" -d "$ENTITY" ${HA_BASE_URL}/api/services/switch/turn_$STATE)
}

is_available jq
if [ $? -eq 1 ]; then
    PIPECMD=jq
else
    PIPECMD=cat
fi

# cmdline processing
if [ "$#" -eq 1 ]; then
  check_switch $1 "${KNOWN_SWITCHES[@]}"
  get_state $1 | $PIPECMD
elif [ "$#" -eq 2 ]; then
  check_switch $1 "${KNOWN_SWITCHES[@]}"
  check_states $2 "${VALID_STATES[@]}"
  set_state $1 $2
else
  # Unknown command
  printf "Usage: %s <switch> [<state>]\n" $BASENAME
  exit 3
fi