#!/bin/bash

# Set this to the email address you used to set up your keypair.
recipient=

usage() {
    echo "Usage: $(basename $0) <file | dir>" >&2
} 

error() {
    printf "Error calling \`%s\', exiting...\n" $1 >&2
    exit 1
}

# Check usage.
if [[ $# < 1 ]]; then
    usage
    exit 1
fi

# Process arguments.
until [ -z "$1" ]; do

    # Tar then encrypt directories.
    if [ -d "$1" ]; then
        dir="${1%%/}"
        tar czf "${dir}.tar.gz" "${dir}" || error tar
        gpg --output "${dir}.gpg" --encrypt -r "$recipient" "${dir}.tar.gz" || error gpg
        rm -f "${dir}.tar.gz" && \
        rm -rf "$dir"

    # Unencrypt *.gpg files; untar them if necessary.
    elif [[ "$1" == *.gpg ]]; then
        result="${1%.gpg}"
        gpg --output "$result" --decrypt "$1" || error gpg
        if tar -tf "$result" &>/dev/null; then
            mv "$result" "${result}.tar.gz"
            tar -xzf "${result}.tar.gz" || error tar
            rm -f "${result}.tar.gz"
        fi
        rm -f "$1"

    # Must be a plain file, so encrypt it.
    elif [ -f "$1" ]; then
        gpg --output "${1}.gpg" --encrypt -r "$recipient" "$1" || error gpg
        rm -rf "$1"

    # Should never get here.
    else
        echo "Error, I don't know how to handle $1."
        exit 1
    fi

    shift
done