#!/bin/sh

COMMAND=$1
case "$COMMAND"
in
  "start")
    if [ "$#" -ne 2 ]; then
        echo "Usage: listimer start <minutes>";
        exit 1;
    fi
    DURATION_MIN=$2
    CURRENT_TIME=$(date +%s)
    echo "$CURRENT_TIME\n\n$DURATION_MIN" > /tmp/listimer
  ;;

  "restart")
    if [ "$#" -ne 1 ]; then
        echo "Usage: listimer restart";
        exit 1;
    fi
    CURRENT_TIME=$(date +%s)
    sed -i "1s/.*/$CURRENT_TIME/" /tmp/listimer
  ;;

  "stop")
    if [ "$#" -ne 1 ]; then
        echo "Usage: listimer stop";
        exit 1;
    fi
    CURRENT_TIME=$(date +%s)
    rm /tmp/listimer
  ;;

  "query")
    if [ ! -f /tmp/listimer ]; then
      echo "No timer"
      exit 0;
    fi

    START_TIME=$(sed -n '1p' < /tmp/listimer)
    DURATION_MIN=$(sed -n '3p' < /tmp/listimer)
    DURATION_SEC=$DURATION_MIN*60
    CURRENT_TIME=$(date +%s)

    ELAPSED_TIME_SEC=$(($CURRENT_TIME-$START_TIME))
    ELAPSED_TIME_MIN=$(($ELAPSED_TIME_SEC/60))
    REMAINING_TIME_MIN=$(($DURATION_MIN-$ELAPSED_TIME_MIN))

    if [ "$REMAINING_TIME_MIN" -lt "$(($DURATION_MIN / 2))" ]; then
      echo "<span weight=\"bold\" size=\"larger\" background=\"#FF0000\">$REMAINING_TIME_MIN minutes</span>" 
    elif [ "$REMAINING_TIME_MIN" -lt "0" ]; then
      echo "TIME OUT!"
    else
      echo "$REMAINING_TIME_MIN minutes" 
    fi
  ;;
  *) echo "Unexpected command."
esac