gtd

#!/bin/bash

set -e

# Command configuration
CUSTOM_CMD="${CUSTOM_CMD:-"clear"}"
MPD_CMD="${MPD_CMD:-"mpc -q toggle"}"
NOTIFY_CMD="${NOTIFY_CMD:-"notify-send"}"
SPEAK_CMD="${SPEAK_CMD:-"&>/dev/null espeak"}"

# Setting configuration
DEFAULT_WORK_LENGTH="${DEFAULT_WORK_LENGTH:-15}"
DEFAULT_BREAK_LENGTH="${DEFAULT_BREAK_LENGTH}"
NOTIFY_WORK="${NOTIFY_WORK:-"\"Get things done.\""}"
NOTIFY_BREAK="${NOTIFY_BREAK:-"\"Take a break.\""}"
SPEAK_WORK="${SPEAK_WORK:-"$NOTIFY_WORK"}"
SPEAK_BREAK="${SPEAK_BREAK:-"$NOTIFY_BREAK"}"

# File configuration
CFG_FILE="${CFG_FILE:-$HOME/.gtdrc}"

# Check for configuration file and source it
if [[ -e "$CFG_FILE" ]]; then
   source "$CFG_FILE"
fi

# Display help
usage() {
cat << EOF
USAGE:

   gtd [ -bcmnst ] [ work length ] [ break length ]

OPTIONS:

   -b : start on a break
   -c : custom command (defaults to "clear")
   -m : toggle MPD on change
   -n : notify on change
   -s : speak command
   -t : show time in tmux status bar
   -T : update time in /tmp file
   -e : specify time to end at (e.g. 2:45pm today)

EOF
}

# Show an error message and print usage
error() {
   echo -e "\033[0;31m$1\033[0m"
   usage && exit 1
}

# Set flag options
while getopts "bcmnpstTe:h" opt; do
   case "$opt" in
      b) [[ -n "$DO_BREAK"    ]] && unset DO_BREAK    || DO_BREAK=true;;
      c) [[ -n "$DO_CUSTOM"   ]] && unset DO_CUSTOM   || DO_CUSTOM=true;;
      m) [[ -n "$DO_MPD"      ]] && unset DO_MPD      || DO_MPD=true;;
      n) [[ -n "$DO_NOTIFY"   ]] && unset DO_NOTIFY   || DO_NOTIFY=true;;
      s) [[ -n "$DO_SPEAK"    ]] && unset DO_SPEAK    || DO_SPEAK=true;;
      t) [[ -n "$DO_TMUX"     ]] && unset DO_TMUX     || DO_TMUX=true;;
      T) [[ -n "$DO_TMP_FILE" ]] && unset DO_TMP_FILE || DO_TMP_FILE=true;;
      e) END_TIME="$OPTARG";;
      h) usage && exit 0;;
      *) error "Invalid flag.";;
   esac
done 2>/dev/null
shift "$((OPTIND-1))"

# Make sure tmux is installed if it is required
if [[ -n "$DO_TMUX" ]]; then
   which tmux &>/dev/null || error "This feature requires \`tmux\` to be installed."
fi

if [[ -n "$END_TIME" ]]; then
   # Make sure at is installed if it is required
   which at &>/dev/null || error "This feature requires \`at\` to be installed."

   # Kill this process at $END_TIME
   at "$END_TIME" <<<"kill $$"
fi

# Set work length if specified and is a number
if [[ -z "$1" ]]; then
   work_length="$DEFAULT_WORK_LENGTH"
elif [[ "$1" =~ [^0-9] ]]; then
   error "Work length must be a number of minutes."
else
   work_length="$1"
fi

# Set break length if specified and is a number
if [[ -z "$2" ]]; then
   break_length="${DEFAULT_BREAK_LENGTH:-$(( $work_length / 5 ))}"
elif [[ "$2" =~ [^0-9] ]]; then
   error "Break length must be a number of minutes."
else
   break_length="$2"
fi

# Show error message for three arguments or more
[[ -n "$3" ]] && error "Only two arguments are allowed."

# Collect session statistics
total_working_time=0
count=1

# Displays milliseconds as HH:MM:SS
hms() {
   local S="$1"
   ((h=S/3600))
   ((m=S%3600/60))
   ((s=S%60))
   printf "%02d:%02d:%02d\n" "$h" "$m" "$s"
}

# Displays a countdown using hms() while sleeping ("visual" sleep)
vsleep() {
   left="$1"
   while [[ "$left" -gt 0 ]]; do
      hms="$(hms $left)"

      # Updates a temporary file for tmux to read from and refreshes the client
      if [[ -n "$DO_TMUX" ]]; then
         (echo -ne "$hms |" > /tmp/gtd-tmux)
         (tmux refresh-client -S)
      fi

      if [[ -n "$DO_TMP_FILE" ]]; then
         (echo -ne "$hms" > /tmp/gtd)
      fi

      # Prints time information to terminal title bar
      if [[ -n "$in_break" ]]; then
         printf "\e]1;(brk) $hms\a"
      else
         printf "\e]1;(gtd) $hms\a"
      fi

      # Print the countdown to the terminal and decrement one second
      echo -e "$hms $(tput el)\r\c"
      sleep 1
      left="$(( $left - 1 ))"
   done
}

# Do various tasks based on the user-specified flags
do_options() {
   [[ -n "$DO_CUSTOM" ]] && eval "$CUSTOM_CMD"

   if [[ -n "$DO_NOTIFY" ]]; then
      if [[ -n "$in_break" ]]; then
         eval "$NOTIFY_CMD $NOTIFY_BREAK"
      else
         eval "$NOTIFY_CMD $NOTIFY_WORK"
      fi
   fi

   if [[ -n "$DO_SPEAK" ]]; then
      if [[ -n "$in_break" ]]; then
         eval "$SPEAK_CMD $SPEAK_BREAK"
      else
         eval "$SPEAK_CMD $SPEAK_WORK"
      fi
   fi

   [[ -n "$DO_MPD" ]] && (sleep 1 && eval "$MPD_CMD")

   return 0
}

# Handle CTRL-C interrupt
ctrl_c() {
   if [[ -n "$in_break" ]]; then
      total="$(hms $(( $total_working_time * 60 )) )"
   else
      total="$(hms $(( ($total_working_time + $work_length) * 60 - $left )))"
   fi

   echo -e "\rTotal working time: $total"

   # Prints total time to terminal title bar
   printf "\e]1;(tot) $total\a"

   exit 0
}

cleanup() {
   # Clear the temporary file and refresh tmux when interrupted/terminated
   [[ -n "$DO_TMP_FILE" ]] && rm /tmp/gtd

   [[ -n "$DO_TMUX" ]] && (tmux refresh-client -S && rm /tmp/gtd-tmux)

   exit 0
}

main() {
   # Display the initial session settings
   clear && echo "$work_length minute sessions with $break_length minute breaks."

   # Loop through work and break cycles
   while true; do
      # Break period
      if [[ -n "$DO_BREAK" ]]; then
         echo -e "Break. Total working time: $(hms $(( $total_working_time * 60 )))"
         in_break=true && do_options
         vsleep "$(( $break_length * 60 ))"
      else DO_BREAK=true; fi

      # Work period
      echo -e "Period #$count. Total working time: $(hms $(( $total_working_time * 60 )))"
      unset in_break && do_options
      vsleep "$(( $work_length * 60 ))"

      # Calculate totals
      total_working_time="$(( ($total_working_time + $work_length) ))"
      count="$(( $count + 1 ))"
   done
}

if [[ -z "$DEBUG" ]]; then
   trap ctrl_c INT TERM
   trap cleanup EXIT
   main
fi