#!/bin/bash
# -*- sh -*-

: << =cut

=head1 NAME

  switchbotplugmini - Munin plugin to monitor power consumption from Switchbot Plug Mini

=head1 CONFIGURATION

  Obtain a token and deviceid for SwitchBot API. See the following website.
  https://github.com/OpenWonderLabs/SwitchBotAPI

=head1 ENVIRONMENT VARIABLES

  env.token    : Token to access SwitchBot API. (Required)
  env.deviceid : Device ID(s) of SwitchBot Plug Mini. (Required)
                 Multiple device IDs can be set by separating with white space.
  env.interval : Interval in seconds for API access. (Optional, default is 0)

=head1 NOTES

  The amount of SwitchBot API calls per day is limited to 10000 times.
  If munin-node executes this plugin every 5 minutes, the API will be called 288 times a day.
  You can use env.interval parameter to prevent frequent API access. For example, if you set
  env.interval 900, the API response will be cached to local file for 900 seconds(15 minutes).

=head1 AUTHOR

  K.Cima https://github.com/shakemid

=head1 LICENSE

  GPLv2
  SPDX-License-Identifier: GPL-2.0-only

=head1 Magic markers

  #%# family=contrib
  #%# capabilities=

=cut

. "${MUNIN_LIBDIR}/plugins/plugin.sh"

set -o nounset
set -o pipefail

# Token to access SwitchBot API
token=${token:?}

# Device ID(s) of SwitchBot Plug Mini
deviceid=${deviceid:?}

# Interval for API access (second)
interval=${interval:-0}

config() {
    cat <<EOF
graph_title SwitchBot Plug Mini Watts
graph_category sensors
graph_scale no
graph_vlabel Watts
graph_args --base 1000
EOF

    for i in ${deviceid}; do
        echo "weight${i}.label ${i}"
    done
}

fetch() {
    do_read_cache=0
    do_store_cache=0

    if [ "${interval}" -ne 0 ]; then
        time_now=$( date +%s )

        if [ -f "${MUNIN_STATEFILE}" ]; then
            time_modified=$( stat --format=%Y "${MUNIN_STATEFILE}" )
        else
            time_modified=0
        fi

        if [ $(( time_now - time_modified )) -le "${interval}" ]; then
            do_read_cache=1
        else
            do_store_cache=1
        fi
    fi

    if [ "${do_read_cache}" -eq 1 ]; then
        cat "${MUNIN_STATEFILE}"
    else
        if [ "${do_store_cache}" -eq 1 ]; then
            cat /dev/null > "${MUNIN_STATEFILE}"
        fi

        for i in ${deviceid}; do
            weight=$( fetch_api "${i}" )
            echo "weight${i}.value ${weight}"
            if [ "${do_store_cache}" -eq 1 ]; then
               echo "weight${i}.value ${weight}" >> "${MUNIN_STATEFILE}"
            fi
        done
    fi
}

fetch_api() {
    local deviceid=$1

    response=$( curl -s -H "Authorization:${token}" "https://api.switch-bot.com/v1.0/devices/${deviceid}/status" )

    statusCode=$( echo "${response}" | jq '.statusCode' )
    if [ "${statusCode}" -ne 100 ]; then
        echo Error with statusCode = "${statusCode}" 1>&2
        exit 1
    fi

    echo "${response}" | jq '.body.weight'
}

# Main
case ${1:-} in
config)
    config
    if [ "${MUNIN_CAP_DIRTYCONFIG:-}" = "1" ]; then
        fetch
    fi
    ;;
*)
    fetch
    ;;
esac

exit 0