#!/usr/bin/env bash
# Charsel - terminal character selector
# Copyright Armaan Bhojwani 2020, MIT License

# Define argument functions
function usage() {
  echo "Usage: /usr/bin/charsel [OPTION]... [CHARFILE]...

A simple terminal character selector
  -a         include hidden shortcodes
  -b         disable color support
  -c         check charfile validity
  -d         show readme
  -h         show this message
  -L         show installed charfiles without the message
  -l         show installed charfiles
  -n         dont copy character to clipboard, avoids Xclip dependency

Exit status:
   0         okay,
   1         charfile does not exist,
   2         charfile syntax error,
   3         usage error/invalid option,
   4         other error"
}

CHARDIR=$HOME/.cache/charsel
function list() {
  ls "$CHARDIR"/charfiles
}

function readme() {
  cat /usr/share/doc/charsel/README.md
}

function missing_charfile() {
  echo "The selected charfile is missing or invalid"
  list
  exit 1
}

# Merge global and local charfiles
if [[ -d $CHARDIR ]]; then
  rm -rf "${CHARDIR:?}"/*
else
  mkdir "$CHARDIR"
fi

LOCALCHARDIR=$HOME/.local/share/charsel/charfiles
[[ -d $LOCALCHARDIR ]] || mkdir -p "$LOCALCHARDIR"

localdirfiles="$LOCALCHARDIR"/*
[[ -n "${#localdirfiles[*]}" ]] && cp -rf "$LOCALCHARDIR"/../* "$CHARDIR"

globaldirfiles=($/usr/share/charfiles/)
[[ -n "${#globaldirfiles[*]}" ]] && cp -rf /usr/share/charsel/* "$CHARDIR"

# Check if charfile exists
CHARFILE="$CHARDIR/charfiles/$2"
function existence() {
  if [[ ! -f $CHARFILE ]]; then
    missing_charfile
  fi
}

# VERY basic syntax check
function validity() {
  if [[ $(grep , "$CHARFILE" && grep - "$CHARFILE") ]]; then
    echo "valid charfile"
  else
    existence
    echo "invalid charfile"
    exit 2
  fi
}

# Look for arguments
while getopts ":abcdhlLnvV" arg
do
  case ${arg} in
    a)
      SHOWALL="true"
      ;;
    b)
      COLOR="bw"
      ;;
    c)
      validity
      exit 0
      ;;
    d)
      readme
      exit 0
      ;;
    h)
      usage
      exit 0
      ;;
    l)
      echo "The following charfiles are installed:"
      list
      exit 0
      ;;
    L)
      list
      exit 0
      ;;
    n)
      COPY="no"
      ;;
    ?)
      echo "Invalid option"
      usage
      exit 3
      ;;
  esac
done
shift $((OPTIND-1))

if [ $# -eq 0 ]; then
  echo "Please enter a valid charfile, or use charsel -h for help."
  charsel -l
  exit 3
fi

# Redefine charfile and check file validity
CHARFILE="$CHARDIR/charfiles/$1"
existence
validity

# Dependency check
if [[ $COPY == "no" ]]; then
  if [[ ! -x /usr/bin/xclip ]]; then
    echo "Please install xclip."
    exit 4
  fi
fi

# Define length of shortcode
LENGTH=$(cut "$CHARFILE" -f 1 -d ',' -s \
  | wc -L \
  | cut -b 1)

clear

# Define text formatting
bold=$(tput bold)
normal=$(tput sgr0)

highlight=$(tput setaf 5)
[[ $COLOR == bw ]] && highlight=$(tput setaf 7)

white=$(tput setaf 7)

# Main program
while true
do
  # Format output
  echo "*---------*---------------*"
  echo "| ${bold}${highlight}CHARSEL${white}${normal} |" "$1"
  echo "*---------*---------------*"
  echo ""

  if [[ $SHOWALL == true ]]; then
    sed "$CHARFILE" -e '/^[ \t]*#/d' | tail -n +2 \
      | column -t -N "input","output" --output-separator ' | ' --separator ','
  else
    sed "$CHARFILE" -e '/^[ \t]*#/d' | grep -A 100 - | tail -n +2 \
      | column -t -N "input","output" --output-separator ' | ' --separator ','
  fi

  echo ""
  echo "*-------------------------*"
  echo "| previous shorcode:" "$(echo $INPUT)"
  echo "| previous output:  " "$OUTPUT"
  echo "*-------------------------*"

  # User input
  read -r -p "| ${bold}input shortcode: ${normal}  " -N "$LENGTH" INPUT

  if [[ $INPUT == ";"* ]]; then # Semicolon exts
    clear
    exit 0
  else
    # Finds line number of shortcode
    LINENUMBER=$(cut -f 1 -d ',' -s "$CHARFILE" | grep -wn "$INPUT" | cut -d : -f 1)

    # Outputs character selected above
    OUTPUT=$(cut -f 2 -d ',' -s "$CHARFILE" | head -"$LINENUMBER" | tail +"$LINENUMBER")

    # Check to see if the shortcode actually exists
    if [[ $(cut -f 1 -d ',' -s "$CHARFILE" | grep -wnc "$INPUT") == "0" ]]; then
      OUTPUT=""
    fi

    # Copy output to clipboard
    if [[ ! $COPY == "no" ]]; then
      echo -n "$OUTPUT" | xclip -selection clipboard
    fi

    clear
  fi
done