#!/bin/sh

# This file defines track - a minimalist data tracker

# Copyright (C) 2024 James Tomasino

# 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 3 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, see <http://www.gnu.org/licenses/>.

#-----------------------------------------------------------------------

version="2024.04.15"

show_help () {
  cat > /dev/stdout << END
track [options...] <metric> [<value>]

DIRECTORY:
  If the environment variable \$TRACK_DIR is set, track will store
  all data in that location. Otherwise the default is the current
  working directory.

USAGE:
  track weight 150            Log 150lbs for today's weight
  track steps +500            Increase the numeric log of today's steps by 500
  track -n 10 calories        Show last 10 days calorie values
  track mood                  Show last value logged for mood

OPTIONS:
  -a                          Show all values of metric
  -n N                        Show N values of metric
  -x                          Remove metric file
  -c                          Output CSV
  -l                          List metrics being tracked
  -h                          Show this help
  -v                          Show current version info
  -d                          Debug mode
END
}

# Determine tracking directory and ensure it is a directory
TRACK_DIR=${TRACK_DIR:-.}
if [ -f "$TRACK_DIR" ]; then
  TRACK_DIR="$(dirname "${TRACK_DIR}")"
fi

arg_metric=""
arg_value=""
arg_listnum=""
arg_remove=""
flag_options="hvdan:x:lc"
flag_debug=0
flag_help=0
flag_listall=0
flag_listnum=0
flag_remove=0
flag_version=0
flag_shortlist=0
flag_csv=0

parse_input () {
  if ! parsed=$(getopt ${flag_options} "$@"); then
    printf "Invalid input\\n" >&2
    exit 2
  fi

  eval set -- "${parsed}"

  while true; do
    case "$1" in
      -h)
        flag_help=1
        shift
        ;;
      -v)
        flag_version=1
        shift
        ;;
      -d)
        flag_debug=1
        shift
        ;;
      -a)
        flag_listall=1
        shift
        ;;
      -n)
        flag_listnum=1
        shift
        arg_listnum="$1"
        shift
        ;;
      -x)
        flag_remove=1
        shift
        arg_remove="$1"
        shift
        ;;
      -l)
        flag_shortlist=1
        shift
        ;;
      -c)
        flag_csv=1
        shift
        ;;
      --)
        shift
        break
        ;;
      *)
        printf "Internal error: %s\\n" "$1" >&2
        exit 3
        ;;
    esac
  done

  while [ "$#" -gt 0 ]; do
    if [ -z "${arg_metric}" ]; then
      arg_metric="$(printf "%s" "${1}" | tr '[:upper:]' '[:lower:]')"
      shift
    else [ -z "${arg_value}" ]
      arg_value="$*"
      break
    fi
  done
}

main () {
  parse_input "$@"

  if [ ${flag_shortlist} -gt 0 ]; then
    out=$(find "${TRACK_DIR}"/*.csv -maxdepth 1 2>/dev/null | sed -e 's/.*\///' | sed -e 's/\..*$//')
    printf "%s\\n" "${out}"
    exit 0
  fi

  if [ ${flag_version} -gt 0 ]; then
    printf "%s\\n" "${version}"
    exit 0
  fi

  if [ ${flag_help} -gt 0 ]; then
    show_help
    exit 0
  fi

  if [ ${flag_debug} -gt 0 ]; then
    set -x
  fi

  if [ ${flag_remove} -gt 0 ]; then
    rm "${TRACK_DIR}/${arg_remove}.csv"
  fi

  if [ "${arg_metric}" != "" ]; then
    f="${TRACK_DIR}/${arg_metric}.csv"

    # If new file, add header
    if [ ! -f "$f" ]; then
      printf "year,month,day,%s\\n" "${arg_metric}" > "$f"
    fi

    # Get arg parts
    first_letter=$(printf %.1s "${arg_value}")

    if [ "${arg_value}" != "" ]; then # add/update
      d=$(date '+%Y,%0m,%0d')
      l=$(sed -n "/$d/{=;}" "$f")

      if [ "${first_letter}" = "+" ]; then # Add to existing value
        rest="${arg_value#+}"
        if [ -z "$l" ]; then
          printf "%s,%s\\n" "$d" "${rest}" >> "$f"
        else
          val="$(sed "${l}q;d" "$f" | awk -F "," '{print $4}')" # get current value
          # check if existing value is numeric before attempting to sum
          if printf "%s" "$val" | grep -vEq '^[0-9]+([.][0-9]+)?$'; then
            printf "Current value is not numeric. Abort.\\n"-
            exit 1
          fi
          # check if new value is numeric before attempting to sum
          if printf "%s" "$rest" | grep -vEq '^[0-9]+([.][0-9]+)?$'; then
            printf "New value is not numeric. Abort.\\n"-
            exit 1
          fi
          # sum new and previous values
          newval=$((val+rest)) || exit 1
          sed -i"" "$l c $d,${newval}" "$f"
        fi
      else # Replace existing value
        if [ -z "$l" ]; then
          printf "%s,%s\\n" "$d" "${arg_value}" >> "$f"
        else
          sed -i"" "$l c $d,${arg_value}" "$f"
        fi
      fi
    else # display value
      if [ ${flag_listall} -gt 0 ]; then
        if [ ${flag_csv} -gt 0 ]; then
          awk -F "," '{printf "%02d-%02d-%02d,%s\n", $1, $2, $3, $4;}' "$f"
        else
          awk -F "," '{printf "%02d-%02d-%02d\t%s\n", $1, $2, $3, $4;}' "$f"
        fi
      elif [ ${flag_listnum} -gt 0 ]; then
        if [ ${flag_csv} -gt 0 ]; then
          tail -n "${arg_listnum}" "$f" | awk -F "," '{printf "%02d-%02d-%02d,%s\n", $1, $2, $3, $4;}'
        else
          tail -n "${arg_listnum}" "$f" | awk -F "," '{printf "%02d-%02d-%02d\t%s\n", $1, $2, $3, $4;}'
        fi
      else
        if [ ${flag_csv} -gt 0 ]; then
          tail -n 1 "$f" | awk -F "," '{printf "%02d-%02d-%02d,%s\n", $1, $2, $3, $4;}'
        else
          tail -n 1 "$f" | awk -F "," '{printf "%02d-%02d-%02d\t%s\n", $1, $2, $3, $4;}'
        fi
      fi
    fi
  fi
}

main "$@"