#!/bin/bash

# License GPLv3+: GNU GPL version 3 or later <http://gnu.org/licenses/gpl.html>
# This is free software; you are free to change and redistribute it.
# There is NO WARRANTY, to the extent permitted by law.

args=($@)

if [[ -n "${args[@]}" ]]; then
  argsl=$(printf '%s\n' "${args[@]}")
  while read line; do
    case "$line" in
      -*)
	plugin_path="${line#-}"
	if [[ -f "$plugin_path" ]] && [[ -x "$plugin_path" ]]; then
	  insert_tmp+=("$(sed -n "3 {s/# //p}" "$plugin_path")")
	else
	  exit 1
	fi
	;;
      *)
	if [[ -d "$line" ]] && [[ -x "$line" ]]; then
	  workdir="$line"
	  export workdir
	else
	  workdir="$HOME"
	fi
	;;
    esac
  done <<< "$argsl"
fi

insert_cmd=("$(printf '%s\n' "${insert_tmp[@]}" | sort -rg -ti -k1)")

if [[ -n "${insert_cmd[@]}" ]]; then
  fm_file=$(< /opt/scripts/fm_slmenu.sh)
  for x in "${!insert_cmd[@]}"; do
    fm_file="$(sed -e "${insert_cmd[x]}" <<< "$fm_file")"
  done
  bash <(echo "$fm_file")
  exit 0
fi

apps_path="$HOME/.local/share/applications/"

[[ -z "$workdir" ]] && workdir="$HOME"
cd "$workdir" || exit

slmenu_cmd () {
  slmenu "$1" -t -i -l 61
}

check_root () {
  case "$(pwd)" in
    '/')
      pardir=""
      ;;
    *)
      pardir="../\n"
      ;;
  esac
}

input_short () {
  check_root
  short_ls () { ls -1 --group-directories-first -F; }
  printf "%s\n$pardir%s\n" "$(pwd)" "$(short_ls)" | slmenu_cmd
}

input_verbose () {
  check_root
  long_ls () { LC_ALL="C" ls -lAh --group-directories-first -F; }
  printf "%s\n$pardir%s\n" "$(pwd)" "$(long_ls)" | slmenu_cmd -d
}

type_cmd () {
  file -b --mime-type -- "$list"
}

tool_cmd () {
  sed -n "/^${type//\//\\/}/ {s@^.*=@$apps_path@;s/\;.*//p;q}" -- \
    "$HOME/.config/mimeapps.list"
}

comppre_cmd () {
  sed -n '/\[Desktop Entry\]/,/^Exec=/!d;s/^Exec=//p' -- "$tool"
}

testterm_cmd () {
  grep -q '^Terminal=true' -- "$tool"
}

error_cmd () {
  echo "$list" >> tmp
  printf '%s' 'An error occurred. Please press Enter.' | 
  slmenu_cmd > /dev/null
}

perm_cmd () {
  printf '%s' "$list: Permission denied" | slmenu_cmd > /dev/null
}

noapp_cmd () {
  printf '%s' "There's no app specified for $type in mimeapps.list" | 
  slmenu_cmd > /dev/null
}

exec_terminal () {
  urxvt -e bash -c -- "$(comppre_cmd) -- $list" > /dev/null 2>&1
}

exec_gui () {
  exec $(comppre_cmd) "$list" > /dev/null 2>&1
}

sed_cmd () {
  sed -E 's/([,.:a-zA-Z0-9-]*[[:space:]]*){8}//'
}

while true; do
  list="$(input_short)"; [[ -z $list ]] && { clear && exit; }
  case "$list" in *"*") list="${list%?}";; esac; [[ -z $list ]] && exit
  if [[ -d "$list" ]]; then
    if [[ -x "$list" ]]; then
      cd -- "$list" || { error_cmd && continue; }
    else
      perm_cmd && continue
    fi
  elif [[ -f "$list" ]]; then
    [[ ! -r "$list" ]] && { perm_cmd && continue; }
    type="$(type_cmd)"; [[ -z $type ]] && { error_cmd && continue; }
    tool="$(tool_cmd)"; [[ ! -r $tool ]] && { noapp_cmd; continue; }
    if testterm_cmd; then
      exec_terminal &
    else
      exec_gui &
    fi
    clear && exit
  elif [[ $list == '//+' ]]; then
    while true; do
      input="$(input_verbose)"; [[ -z $input ]] && { clear && exit; }
      case "$input" in
	"../")
	  cd ../ || { error_cmd && continue; }
	  ;;
	"//q")
	  continue 2
	  ;;
	"//"*)
	  eval "${input#\/\/}" || { error_cmd && continue; }
	  continue
	  ;;
	*)
	  list="$(sed_cmd <<< "$input")"; [[ -z $list ]] && { error_cmd && continue; }
	  case "$input" in
	    *"*")
	      list="${list%?}"; [[ -z $list ]] && { error_cmd && continue; }
	      ;;
	  esac
	  if [[ -d "$list" ]]; then
	    if [[ -x "$list" ]]; then
	      cd -- "$list" || { error_cmd && continue; }
	    else
	      perm_cmd && continue
	    fi
	  elif [[ -f "$list" ]]; then
	    if [[ -r "$list" ]]; then
	      type="$(type_cmd)"; [[ -z $type ]] && { error_cmd && continue; }
	      tool="$(tool_cmd)"; [[ ! -r $tool ]] && { noapp_cmd; continue; }
	      if testterm_cmd; then
		exec_terminal &
	      else
		exec_gui &
	      fi
	    else
	      perm_cmd && continue
	    fi
	  else
	    error_cmd && continue
	  fi
	  ;;
      esac
    done
  else
    case "$list" in
      "//"*)
	eval "${list#\/\/}" || { error_cmd && continue; }
	continue
	;;
      *)
	error_cmd && continue
	;;
    esac
  fi
done