#!/bin/sh
#
# pash - simple password manager.

pw_add() {
    pass_name=$1
    set -- -c

    yn "Generate a password?"

    if glob "$REPLY" '[yY]'; then
        pass=$("$gpg" --gen-random --armor "${PASH_LENGTH:-50}" |\
               cut -c -"${PASH_LENGTH:-50}")

    else
        printf 'Enter password: '
        stty -echo
        read -r pass
        stty echo
        printf '\n'
    fi

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

    [ "$PASH_KEYID" ] &&
        set -- --trust-model always -aer "$PASH_KEYID"

    echo "$pass" | GPG_TTY=$(tty) "$gpg" "$@" -o "$pass_name.gpg"
}

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

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

pw_show() {
    pass=$("$gpg" -dq "$1.gpg")

    [ "$2" ] || printf '%s\n' "$pass"
}

pw_copy() {
    pw_show "$1" copy

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

pw_list() {
    if has tree; then
        tree --noreport
    else
        find . -mindepth 1
    fi
}

yn() {
    printf '%s [y/n]: ' "$1"
    stty -icanon
    REPLY=$(dd ibs=1 count=1 2>/dev/null)
    stty icanon
    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
}

has() {
    command -v "$1" >/dev/null 2>&1
}

glob() {
    case $1 in $2) return 0; esac; return 1
}

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

    has gpg  && gpg=gpg
    has gpg2 && gpg=gpg2

    [ "$gpg" ] || 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."

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

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

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

    glob "$2" '*/*' && glob "$2" '*../*' &&
        die "Category went out of bounds."

    glob "$2" '/*' &&
        die "Category can't start with '/'."

    glob "$2" '*/*' &&
        { mkdir -p "${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 "$@"