#!/usr/bin/env bash

#######################################################################

# (C) Copyright Armaan Bhojwani, 2020

# 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 <https://www.gnu.org/licenses/>.

########################################################################

VERSION=2.0.7

# 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
  -v         print version

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
if [[ ! -d $LOCALCHARDIR ]]
then
  mkdir -p $LOCALCHARDIR
fi

localdirfiles=($LOCALCHARDIR/*)
if [[ ! -z "${#localdirfiles[*]}" ]]
then
  cp -rf $LOCALCHARDIR/../* $CHARDIR
fi

globaldirfiles=($/usr/share/charfiles/)
if [[ ! -z "${#globaldirfiles[*]}" ]]
then
  cp -rf /usr/share/charsel/* $CHARDIR
fi

# 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
if [ $# -eq 0 ]; then
  usage
  exit 3
fi
while getopts ":abcdhlLnv" 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"
      ;; 
    v)
      echo "charsel" $VERSION
      exit 0
      ;;
    ?)
      echo "Invalid option"
      usage
      exit 3
      ;;
  esac
done
shift $((OPTIND-1))

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

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

if [[ $(echo $LANG | grep UTF-8) -ne 0 ]]
then
  echo "Please enable unicode support"
  exit 4
fi

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

clear

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

if [[ $COLOR == bw ]]
then
  magenta=$(tput setaf 7)
else
  magenta=$(tput setaf 5)
fi

white=$(tput setaf 7)

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

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

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

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

  if [[ $INPUT == ";"* ]] # Semicolon exts
  then
    clear
    exit 0
  elif [[ $INPUT == " "* ]]  # Spaces dont count
  then
    OUTPUT=""
    clear
  else
    # Finds line number of shortcode
    LINENUMBER=$(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