#!/usr/bin/env bash
#
# pash - simple password manager.

pw_add() {
    yn "Generate a password?"

    case $REPLY in
        [yY])
            pass=$("${gpg[0]}" --armor --gen-random 0 "${PASH_LENGTH:-50}")
            pass=${pass:0:${PASH_LENGTH:-50}}
        ;;

        *)  read -rsp "Enter password: " pass ;;
    esac

    [[ $pass ]] ||
        die "Failed to generate a password."

    [[ $PASH_KEYID ]] &&
        flags=(--trust-model always -aer "$PASH_KEYID")

    echo "$pass" | GPG_TTY=$(tty) "${gpg[0]}" "${flags[@]:--c}" -o "$1.gpg"
}

pw_del() {
    yn "Delete pass file '$1'?"

    [[ $REPLY == [yY] ]] && {
        rm -f "$1.gpg"
        rmdir -p "${1%/*}" 2>/dev/null
    }
}

pw_show() {
    read -r pass < <("${gpg[0]}" -dq "$1.gpg")

    [[ ${FUNCNAME[1]} != pw_copy ]] &&
        printf '%s\n' "$pass"
}

pw_copy() {
    pw_show "$1"

    if [[ $TMUX ]]; then
        tmux load-buffer "$pass"
    else
        hash xclip && echo "$pass" | xclip -selection clipboard
    fi
}

pw_list() {
    shopt -s globstar nullglob

    printf '%s\n' "pash"

    for pwrd in **; do
        [[ -d $pwrd ]] && dir=/ || dir=

        nest=${pwrd//[^\/]}
        pwrd=${pwrd//[^[:print:]]/^[}
        pwrd=${pwrd//.gpg}

        printf '%s\n' "${nest//\//│  }├─ ${pwrd##*/}${dir}"
    done

    printf '└%s\b┘\n' "${nest//\//──┴}"
}

yn() {
    read -rn 1 -p "$1 [y/n]: "
    printf '\n'
}

die() {
    printf 'error: %s\n' "$1" >&2
    exit 1
}

usage() { printf %s "\
pash 1.0.0 - simple password manager.

=> [a]dd  [name] - Create a new password entry.
=> [c]opy [name] - Copy entry to the clipboard.
=> [d]el  [name] - Delete a password entry.
=> [l]ist        - List all entries.
=> [s]how [name] - Show password for an entry.

Using a key pair: export PASH_KEYID=XXXXXXXX
Password length:  export PASH_LENGTH=50
Store location:   export PASH_DIR=~/.local/share/pash
"
exit 1
}

main() {
    [[ $1 == -? || -z $1 ]] &&
        usage

    mapfile -t gpg < <(type -p gpg gpg2) && [[ ! -x ${gpg[0]} ]] &&
        die "GPG not found."

    mkdir -p "${PASH_DIR:=${XDG_DATA_HOME:=$HOME/.local/share}/pash}" ||
        die "Couldn't create password directory."

    cd "$PASH_DIR" ||
        die "Can't access password directory."

    [[ $1 == [acds]* && -z $2 ]] &&
        die "Missing [name] argument."

    [[ $1 == [cds]* && ! -f $2.gpg ]] &&
        die "Pass file '$2' doesn't exist."

    [[ $1 == a* && -f $2.gpg ]] &&
        die "Pass file '$2' already exists."

    [[ $2 == */* && $2 == *../* ]] &&
        die "Category went out of bounds."

    [[ $2 == /* ]] &&
        die "Category can't start with '/'."

    [[ $2 == */* ]] &&
        { mkdir -p "${2%/*}" || die "Couldn't create category '${2%/*}'."; }

    umask 077

    case $1 in
        a*) pw_add  "$2" && printf '%s\n' "Saved '$2' to store." ;;
        c*) pw_copy "$2" ;;
        d*) pw_del  "$2" ;;
        s*) pw_show "$2" ;;
        l*) pw_list ;;
        *)  usage
    esac
}

main "$@"