#!/bin/sh -ue
#
# Use apcaccess(1) and rrdtool(1) to monitor and graph APC UPS status.
#       - Cameron Simpson <cs@zip.com.au> 23jan2009
#

trace=set-x     ##eecho
poll=300

cmd=$0
usage="Usage:
  $cmd [-n] create rrdfile [rrdtool-create-options...]
  $cmd [-n] update rrdfile
  $cmd [-n] {graph|sparkline} rrdfile fields... [rrdtool-graph-options...] >output.png"

mod=

badopts=

while [ $# -gt 0 ]
do
  case $1 in
    -n) trace=eecho ;;
    --) shift; break ;;
    -?*)echo "$cmd: unrecognised leading option: $1" >&2
        badopts=1
        ;;
    *)  break ;;
  esac
  shift
done

if [ $# = 0 ]
then
  echo "$cmd: missing mode (create, update, graph)" >&2
  badopts=1
else
  rrdmode=$1
  shift
  case $rrdmode in
    create|update|graph|sparkline)
      ;;
    *)
      echo "$cmd: unsupport mode: $rrdmode" >&2
      badopts=1
      ;;
  esac
  if [ $# = 0 ]
  then
    echo "$cmd: missing rrdfile" >&2
    badopts=1
  else
    rrdfile=$1
    shift
  fi
fi

[ $badopts ] && { echo "$usage" >&2; exit 2; }

hb=`expr $poll \* 2`

case $rrdmode in
  create)
    [ -s "$rrdfile" ] && { echo "$cmd: RRD file alredy exists: $rrdfile" >&2; exit 1; }
    dslist=
    for field in `apcaccess | awk '{print $1}'`
    do
      ds=
      case $field in
        BATTV)  ds=DS:$field:GAUGE:$hb:0:42 ;;
        LINEV)  ds=DS:$field:GAUGE:$hb:0:300 ;;
        OUTPUTV)ds=DS:$field:GAUGE:$hb:0:300 ;;
        LOADPCT)ds=DS:$field:GAUGE:$hb:0:120 ;;
        ITEMP)  ds=DS:$field:GAUGE:$hb:0:100 ;;
        NUMXFERS)ds=DS:$field:COUNTER:$hb:0:100 ;;
        CUMONBATT)ds=DS:$field:COUNTER:$hb:0:10000 ;;
      esac
      [ -z "$ds" ] || dslist="$dslist $ds"
    done
    $trace rrdtool create "$rrdfile" ${1+"$@"} \
                $dslist \
                RRA:AVERAGE:0.5:1:9216 RRA:AVERAGE:0.1:12:16800 RRA:AVERAGE:0.01:288:3600 \
                RRA:MIN:0.1:1:9216 RRA:MIN:0.1:12:16800 RRA:MIN:0.0001:288:3600 \
                RRA:MAX:0.1:1:9216 RRA:MAX:0.1:12:16800 RRA:MAX:0.0001:288:3600
    ;;
  update)
    [ -s "$rrdfile" ] || { echo "$cmd: no RRD file: $rrdfile" >&2; exit 1; }
    apcaccess \
    | \
    {
      dslist=
      dssep=
      dsvalues=N
      while read field colon value etc
      do
        case $field in
          BATTV|LINEV|OUTPUTV|LOADPCT|ITEMP|NUMXFERS|CUMONBATT)
            dslist="$dslist$dssep$field"
            dssep=:
            dsvalues="$dsvalues:$value"
            ;;
        esac
      done
      $trace rrdtool updatev "$rrdfile" -t "$dslist" $dsvalues
    }
    ;;
  graph|sparkline)
    [ -s "$rrdfile" ] || { echo "$cmd: no RRD file: $rrdfile" >&2; exit 1; }
    case $rrdmode in
      graph)    w=800 h=100 jopt= ;;
      sparkline)w=64 h=16 jopt=-j ;;
      *)        echo "$cmd: warning: unhandled rrdmode=$rrdmode" >&2
                exit 1
                ;;
    esac
    graph=
    nlines=0
    while [ $# -gt 0 ]
    do
      case $1 in
        BATTV)          title='Battery Voltage (min)' mode=MIN ;;
        LINEV)          title='Line Voltage (min)' mode=MIN ;;
        OUTPUTV)        title='Output Voltage (min)' mode=min ;;
        LOADPCT)        title='Percent Load Capacity (max)' mode=MAX ;;
        ITEMP)          title='Internal Temperature (max)' mode=MAX ;;
        CUMONBATT)      title='Cumulative Time on Battery' mode=AVERAGE ;;
        [A-Z]*)         title=$1 mode=AVERAGE ;;
        *)              break ;;
      esac
      nlines=`expr $nlines + 1`
      graph="$graph DEF:$1=$rrdfile:$1:$mode \"LINE$nlines:$1#000080:\$title\""
      shift
    done
    eval "\$trace rrdtool graph - -a PNG -l 0 -w $w -h $h $jopt \${1+\"\$@\"} --title=\"\$title\" $graph"
    ;;
  *)echo "$cmd: unimplemented mode: $rrdmode" >&2
    exit 1
    ;;
esac