#!/bin/bash
# SPDX-License-Identifier: GPL-2.0-or-later
# Copyright (C) 2021 Ayush Agarwal <ayush at fastmail dot in>
#
# tessen - a data selection interface for pass on Wayland
# ------------------------------------------------------------------------------

# shell "strict" mode
set -uo pipefail
readonly PATH="/bin:/sbin:/usr/bin:/usr/sbin:/usr/local/bin:/usr/local/sbin"
export PATH
umask 077

# don't leak password data if debug mode is enabled
set +x

# initialize the global variables
readonly VERSION="1.1.2"
readonly PREFIX="${PASSWORD_STORE_DIR:-$HOME/.password-store}"
readonly CLIP_TIME="${PASSWORD_STORE_CLIP_TIME:-15}"
BACKEND="${TESSEN_BACKEND:-bemenu}" # uses the value of TESSEN_BACKEND if set by user
BACKEND_OPTS=""
ACTION="${TESSEN_ACTION-}" # uses the value of TESSEN_ACTION if set by user
PASSFILE=""
declare -A PASSDATA_ARR
USERNAME=""
PASSWORD=""

# display and get the shortened path of the password file
get_pass_file() {
  local tmp_pass_1 tmp_pass_2 tmp_pass_3

  # temporarily enable globbing to get the list of gpg files
  shopt -s nullglob globstar
  tmp_pass_1=("$PREFIX"/**/*.gpg)
  tmp_pass_2=("${tmp_pass_1[@]#"$PREFIX"/}")
  tmp_pass_3=("${tmp_pass_2[@]%.gpg}")
  shopt -u nullglob globstar

  PASSFILE="$(printf '%s\n' "${tmp_pass_3[@]}" | "$BACKEND" "$BACKEND_OPTS")"

  if ! [[ -e "$PREFIX/$PASSFILE".gpg ]]; then
    exit 1
  fi
}

# get the password data including every key-value pair inside the encrypted file
get_pass_data() {
  local passdata passdata_regex idx key val

  mapfile -t passdata < <(pass "$PASSFILE")
  # ASSUMPTION: the key can contain alphanumerics, spaces, hyphen, underscore
  #             the value can contain anything but it has to follow after a space
  passdata_regex="^[[:alnum:][:blank:]_-]+:[[:blank:]].+$"
  # ASSUMPTION: the basename of the gpg file is the username although one can still
  #             select a username field inside the file, if it exists
  USERNAME="${PASSFILE##*/}"
  # ASSUMPTION: the first line of $PASSFILE will contain the password
  PASSWORD="${passdata[0]}"

  # skip the password, validate each entry against $passdata_regex, store valid results
  # ASSUMPTION: each key is unique otherwise, the value of the last non-unique key will be used
  for idx in "${passdata[@]:1}"; do
    if [[ "${idx%%:*}" != "username" && "${idx%%:*}" != "password" && "$idx" =~ $passdata_regex ]]; then
      key="${idx%%:*}"
      val="${idx#*: }"
      PASSDATA_ARR["$key"]="$val"
    else
      continue
    fi
  done
}

# get the key that the user will choose to autotype or copy
get_key() {
  local ch="" flag=false key_arr=()

  if [[ "${1-}" == "pass_key_list" ]]; then
    key_arr=("autotype username and password" "username" "password" "${!PASSDATA_ARR[@]}")
    shift
  elif [[ "${1-}" == "opt_key_list" ]]; then
    key_arr=("autotype" "copy")
    shift
  else
    exit 1
  fi

  _KEY="$(printf '%s\n' "${key_arr[@]}" | "$BACKEND" "$BACKEND_OPTS")"

  # validate the chosen key name
  for ch in "${key_arr[@]}"; do
    if [[ "$_KEY" == "$ch" ]]; then
      flag=true
      break
    fi
  done
  if [[ "$flag" == "false" ]]; then
    exit 1
  fi
}

# the 2nd, and possibly 3rd, stage of the menu
key_menu() {
  local tmp_key

  get_key pass_key_list

  if [[ "$_KEY" == "autotype username and password" ]]; then
    auto_type username_password
    exit 0
  fi

  if [[ "${ACTION-}" == "autotype" ]]; then
    auto_type "$_KEY"
    exit 0
  elif [[ "${ACTION-}" == "copy" ]]; then
    wld_copy "$_KEY"
  elif [[ "${ACTION-}" == "both" ]]; then
    auto_type "$_KEY"
    wld_copy "$_KEY"
  elif [[ -z "${ACTION-}" ]]; then
    tmp_key="$_KEY"
    get_key opt_key_list
    if [[ "$_KEY" == "autotype" ]]; then
      auto_type "$tmp_key"
      exit 0
    elif [[ "$_KEY" == "copy" ]]; then
      wld_copy "$tmp_key"
    else
      exit 1
    fi
  else
    printf '%s\n' "Please specify a valid option: autotype|copy|both" >&2
    exit 1
  fi
}

auto_type() {
  if [[ "${1-}" == "username_password" ]]; then
    printf '%s' "$USERNAME" | wtype -s 100 -
    wtype -s 100 -k Tab --
    printf '%s' "$PASSWORD" | wtype -s 100 -
    shift
  elif [[ "${1-}" == "username" ]]; then
    printf '%s' "$USERNAME" | wtype -s 100 -
    shift
  elif [[ "${1-}" == "password" ]]; then
    printf '%s' "$PASSWORD" | wtype -s 100 -
    shift
  elif [[ -n "${PASSDATA_ARR[${1-}]}" ]]; then
    printf '%s' "${PASSDATA_ARR[${1-}]}" | wtype -s 100 -
    shift
  else
    exit 1
  fi
}

wld_copy() {
  if [[ "${1-}" == "username" ]]; then
    printf '%s' "$USERNAME" | wl-copy
    notify-send -t $((CLIP_TIME * 1000)) "Copied username to clipboard. Will clear in $CLIP_TIME seconds." || true
    shift
    clean
  elif [[ "${1-}" == "password" ]]; then
    printf '%s' "$PASSWORD" | wl-copy
    notify-send -t $((CLIP_TIME * 1000)) "Copied password to clipboard. Will clear in $CLIP_TIME seconds." || true
    shift
    clean
  elif [[ -n "${PASSDATA_ARR[${1-}]}" ]]; then
    printf '%s' "${PASSDATA_ARR[${1-}]}" | wl-copy
    notify-send -t $((CLIP_TIME * 1000)) "Copied ${1-} to clipboard. Will clear in $CLIP_TIME seconds." || true
    shift
    clean
  else
    exit 1
  fi
}

print_help() {
  printf '%s\n' "${0##*/} - autotype and copy data from password-store on wayland" ""
  printf '%s\n' "Usage: ${0##*/} [options]" ""
  printf '%s\n' "  ${0##*/}                        use bemenu and either autotype OR copy data"
  printf '%s\n' "  ${0##*/} -b rofi                use rofi and either autotype OR copy data"
  printf '%s\n' "  ${0##*/} -b rofi -a autotype    use rofi and always autotype data"
  printf '%s\n' "  ${0##*/} -b rofi -a copy        use rofi and always copy data"
  printf '%s\n' "  ${0##*/} -b rofi -a both        use rofi and always autotype AND copy data" ""
  printf '%s\n' "  -b, --backend, --backend=     choose 'bemenu', 'rofi', or 'wofi' as backend (default: bemenu)"
  printf '%s\n' "  -a, --action, --action=       choose 'autotype', 'copy', or 'both'"
  printf '%s\n' "  -h, --help                    print this help menu"
  printf '%s\n' "  -v, --version                 print the version of ${0##*/}" ""
  printf '%s\n' "For more details, visit https://github.com/ayushnix/tessen"
}

validate_backend() {
  local bmn_opt=()

  if [[ "$BACKEND" == "bemenu" ]]; then
    bmn_opt=("-i -l 10 -w --scrollbar=autohide -n")
    export BEMENU_OPTS="${BEMENU_OPTS:-${bmn_opt[*]}}"
    readonly BACKEND="bemenu"
    readonly BACKEND_OPTS=""
  elif [[ "$BACKEND" == "rofi" ]]; then
    readonly BACKEND="rofi"
    readonly BACKEND_OPTS="-dmenu"
  elif [[ "$BACKEND" == "wofi" ]]; then
    readonly BACKEND="wofi"
    readonly BACKEND_OPTS="-d"
  else
    printf '%s\n' "Please specify a backend: bemenu|rofi|wofi" >&2
    exit 1
  fi
}

validate_clip_time() {
  local clip_regex

  clip_regex="^[[:digit:]]+$"

  if [[ "$CLIP_TIME" =~ $clip_regex ]]; then
    return 0
  else
    printf '%s\n' "invalid clipboard time provided" >&2
    exit 1
  fi
}

clean() {
  {
    sleep "$CLIP_TIME" || exit 1
    wl-copy --clear
  } > /dev/null 2>&1 &
  disown
  unset -v PASSFILE USERNAME PASSWORD PASSDATA_ARR
}

die() {
  wl-copy --clear
  unset -v PASSFILE USERNAME PASSWORD PASSDATA_ARR
}

main() {
  local _opt

  # exit if the password store directory doesn't exist
  if ! [[ -d "$PREFIX" ]]; then
    printf '%s\n' "password store not found" >&2
    exit 1
  fi

  # parse any options given by the user
  while [[ "$#" -gt 0 ]]; do
    _opt="${1-}"
    case "$_opt" in
      -b | --backend)
        [[ "$#" -lt 2 ]] && {
          printf '%s\n' "Please specify a backend: bemenu|rofi|wofi" >&2
          exit 1
        }
        BACKEND="${2-}"
        validate_backend
        shift
        ;;
      --backend=*)
        BACKEND="${_opt##--backend=}"
        validate_backend
        ;;
      -a | --action)
        [[ "$#" -lt 2 ]] && {
          printf '%s\n' "Please specify a valid option: autotype|copy|both" >&2
          exit 1
        }
        ACTION="${2-}"
        shift
        ;;
      --action=*)
        ACTION="${_opt##--action=}"
        ;;
      -h | --help)
        print_help
        exit 0
        ;;
      -v | --version)
        printf '%s\n' "${0##*/} version $VERSION"
        exit 0
        ;;
      --)
        shift
        break
        ;;
      *)
        printf '%s\n' "invalid argument detected" >&2
        exit 1
        ;;
    esac
    shift
  done
  unset -v _opt

  if unset -v BACKEND_OPTS 2> /dev/null; then
    validate_backend
  fi
  validate_clip_time

  readonly ACTION

  trap 'die' EXIT TERM
  get_pass_file
  get_pass_data
  key_menu
  trap - EXIT TERM
}

main "$@"