#!/bin/sh

# shtrash - a pure POSIX shell script implementation of the
# FreeDesktop.org Trash Specification.

# Copyright (c) 2020, Bruce Hill <bruce@bruce-hill.com>
# Copyright (c) 2009-2011, Robert Rothenberg <robrwo@gmail.com>

# 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 2 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.

version="0.5.0"

progname="$(basename "$0")"
verbose_flag=
interactive_flag=
force_flag=
[ -z "$FS" ] && FS='\t'
[ -z "$RS" ] && RS='\n'

fail() {
  echo "$@" 1>&2
  exit 1
}

show_usage() {
  cat << EOU
Usage: $progname [OPTION]... FILE...

Move files into the trash.

Options:
  -h, --help           show this help message and exit
  -V, --version        show program's version number and exit
  -v, --verbose        explain what is being done
  -i, --interactive    prompt before moving every file
  -f, --force          ignore non-existent files, never prompt
  -r, -R, --recursive  ignored (for compatability with rm)
  -u, --untrash        restore file(s) from the trash
  -e, --empty          choose files to empty from the trash
  -E, --empty-all      empty all the files in the trash
  -l, --list           list files in the trash
  --                   Any arguments after '--' will be treated as filenames
EOU
}

pick_trashfiles() {
  td="$1"
  shift
  prompt="$1"
  shift
  ls -A "$td"/info | \
    fzf -1 --prompt="$prompt" --query="$@" --multi \
    --preview="sh -c 'f=\"$td/files/\${1%.trashinfo}\"; [ -d \"\$f\" ] && tree \"\$f\" || echo \"\$f\" && cat \"\$f\"' -- {}"
}

confirm() {
  [ "$force_flag" = "-f" ] && return 0
  if type ask >/dev/null; then
    ask -n "$@"
  else
    # Get one character of input
    tput civis >/dev/tty;
    printf '\033[1m%s\033[0m' "$2" >/dev/tty;
    stty -icanon -echo >/dev/tty 2>/dev/tty;
    if [ "$(uname)" = "Darwin" ]; then
      read -n 1 REPLY </dev/tty >/dev/tty;
    else
      REPLY="$(dd bs=1 count=1 2>/dev/null </dev/tty)"
    fi
    stty icanon echo >/dev/tty 2>/dev/tty
    tput cvvis >/dev/tty
    [ "$REPLY" = "y" ]
  fi
}

has_arg() {
  if type arg >/dev/null; then
    arg "$@" >/dev/null
  else
    target="$1"
    while [ $# -gt 0 ]; do
      [ "$1" = "$target" ] && return 0
      [ "$1" = "--" ] && break
    done
    false
  fi
}

is_valid_trashdir() {
  [ -d "$1" ] && expr "$(stat -c '%a' "$1")" : '^1[0-7]\{3\}' >/dev/null && ! [ -L "$1" ]
}

get_trashdir() {
  file="$(readlink -f -- "$1")"
  if [ -e "$file" ]; then
    file_base="$(df -h "$file" | awk 'NR==2 {print $NF}')"
  else
    file_base="$(awk -v f="$file" 'substr(f,1,length($2)+1)==($2 "/") && $2>best {best=$2} END {print best}' /proc/mounts)"
  fi
  home_base="$(df -h "$HOME" | awk 'NR==2 {print $NF}')"
  if [ "$file_base" = "$home_base" ]; then
    echo "$HOME/.Trash"
  elif is_valid_trashdir "$file_base/.Trash"; then
    echo "$file_base/.Trash"
  else
    echo "$file_base/.Trash-$(id -u)"
  fi
}

can_trash() {
  filename="$1"
  if [ ! -e "$filename" ]; then
    if [ "$force_flag" != "-f" ]; then
      fail "$progname: cannot move '$filename' to trash: No such file or directory"
    fi
    return 0
  fi

  if [ "$interactive_flag" = "-i" ]; then
    [ -d "$filename" ] && type=directory || type="file"
    confirm "$progname: move $type '$filename' to trash?"
  fi
}

init_trashdir() {
  trashdir=$1
  if ! [ -d "$trashdir" ]; then
    mkdir -m 1755 "$trashdir" || fail "Could not create trash directory"
  fi
  mkdir -p "$trashdir/files" || fail "$progname: unable to write to $trashdir"
  mkdir -p "$trashdir/info" || fail "$progname: unable to write to $trashdir"
}

path_from_trashinfo() {
  #sed -n 's/^Path=//p' "$1" | php -r 'echo urldecode(fgets(STDIN));'
  sed -n 's/^Path=//p' "$1" | perl -MURI::Escape -ne 'print uri_unescape $_'
}

date_from_trashinfo() {
  sed -n 's/^DeletionDate=//p' "$1"
}

trashinfo_for_file() {
  #php -r 'echo urlencode($argv[1]);' -- "$1"
  cat <<END
[Trash Info]
Path=$(perl -MURI::Escape -e 'print uri_escape $ARGV[0]' -- "$1")
DeletionDate=$(date +"%FT%H:%M:%S")
END
}

trash_file() {
  filename=$1
  dir=${filename%/*}
  trashdir="$(get_trashdir "$dir")"
  init_trashdir "$trashdir"

  trashname="${filename##*/}"
  origname="${trashname%%.*}"
  if [ -z "$origname" ]; then
      origname="dotfile"
  fi
  ext=".${trashname##*.}"
  if [ "$ext" = ".$trashname" ]; then
    ext=""
  fi

  # Use -u (unsafe) option because we cannot mv a directory into a
  # file.  This is technically "unsafe" but mv will ask for
  # confirmation when overwriting.
  deletedfile=$(mktemp -u "$trashdir/files/${origname}_XXXXXXXX")$ext
  deletedbase=$(basename "$deletedfile")
  deletedinfo="$trashdir/info/$deletedbase.trashinfo"

  trashinfo_for_file "$filename" > "$deletedinfo" || \
    fail "$progname: unable to create trash info for $filename at $deletedinfo"

  # Note that the trashinfo file will have the ownership and
  # permissions of the person who deleted the file, and not
  # necessarily of the original file.

  if ! mv $verbose_flag -- "$filename" "$deletedfile"; then
    rm "$deletedinfo"
    fail "$progname: unable to move $filename to $deletedfile"
  fi
}

untrash_files() {
  td="$(get_trashdir "$(readlink -f -- "${1:-$PWD}")")"
  [ -d "$td/info" ] || return 1
  pick_trashfiles "$td" "Pick file(s) to untrash: " "$@" | \
    while read -r info; do
      orig="$(path_from_trashinfo "$td/info/$info")"
      mv -i "$td/files/${info%.trashinfo}" "$orig" && rm -f "$td/info/$info"
    done
}

empty_files() {
  td="$(get_trashdir "$(readlink -f -- "${1:-$PWD}")")"
  if [ -d "$td" ] && [ -z "$(ls -A "$td/files")" ]; then
    echo "Nothing in the trash!"
    exit
  fi
  pick_trashfiles "$td" "Pick file(s) to permanently delete: " "$@" | \
    while read -r info; do
      orig="$(path_from_trashinfo "$td/info/$info")"
      rm -r $verbose_flag "$td/info/$info" "$td/files/${info%.trashinfo}" || fail "Could not remove file"
    done
  printf '\033[1mDeleted!\033[0m\n'
}

empty_trash() {
  td="$(get_trashdir "$(readlink -f -- "${1:-$PWD}")")"
  if [ -d "$td" ] && [ -z "$(ls -A "$td/files")" ]; then
    echo "Nothing in the trash!"
    exit
  fi
  ( printf '\033[1mThe following files will be deleted:\033[0m\n' &&
    printf '  \033[33;1m%s\033[0m\n' "$td"/files/* &&
    printf '\033[1mThis will free up %s of space\033[0m\n' "$(du -h --summarize "$td/files" | cut -f1)") | more
  confirm "Do you want to proceed?" || exit 1
  rm -r $verbose_flag "$td"/files/* "$td"/info/* || exit 1
  printf '\033[1mDeleted!\033[0m\n'
}

list_trash() {
  td="$(get_trashdir "$(readlink -f -- "${1:-$PWD}")")"
  if [ -d "$td" ] && [ -z "$(ls -A "$td/files")" ]; then
    echo "Nothing in the trash!"
    exit
  fi
  for f in "$td/files"/*; do
    printf '%s'"$RS"'%s'"$RS"'%s'"$FS" \
      "$f" "$(date_from_trashinfo "$td/info/$(basename "$f").trashinfo")" \
      "$(path_from_trashinfo "$td/info/$(basename "$f").trashinfo")"
  done
}

if [ $# -eq 0 ]; then
  show_usage
  fail "Try '$progname -h' for more information."
fi

(has_arg -v "$@" || has_arg --verbose "$@")     && verbose_flag=-v
(has_arg -i "$@" || has_arg --interactive "$@") && interactive_flag=-i
(has_arg -f "$@" || has_arg --force "$@")       && force_flag=-f
action=trash
(has_arg -h "$@" || has_arg --help "$@")      && action=help
(has_arg -V "$@" || has_arg --version "$@")   && action=version
(has_arg -l "$@" || has_arg --list "$@")      && action=list
(has_arg -u "$@" || has_arg --untrash "$@")   && action=untrash
(has_arg -e "$@" || has_arg --empty "$@")     && action=emptyfiles
(has_arg -E "$@" || has_arg --empty-all "$@") && action=emptyall

while a="$(expr ";$1" : "^;\(--\|-[VhvirRfueEl]\+\|--version\|--help\|--verbose\|--interactive\|--recursive\|--force\|--untrash\|--empty\|--empty-all\|--list\)$")"; do
  shift
  [ "$a" = "--" ] && break
done

case "$action" in
    help) show_usage ;;
    version) echo "$version" ;;
    list) list_trash ;;
    untrash) untrash_files "$@" ;;
    emptyfiles) empty_files "$@" ;;
    emptyall) empty_trash "$@" ;;
    trash)
        for f; do
            filename="$(readlink -f -- "$f")"
            if ! [ -e "$filename" ]; then
              [ "$force_flag" != "-f" ] || fail "File does not exist: $filename"
            else
              can_trash "$filename" && trash_file "$filename" || exit 1
            fi
        done
        ;;
esac