#!/usr/bin/bash

set -e

# Setup default values
USER_NAME="ubuntu"

# Parse arguments
while [ $# -gt 0 ]; do
    case "$1" in
        --user|-u)
            USER_NAME="$2"
            shift 2
            ;;
        --)
            # Stop parsing arguments
            shift
            break
            ;;
        *)
            break
            ;;
    esac
done

# Check, if we are running as root
if [ "$(id -u)" -eq 0 ]; then
    # Check, if the home directory exists for the specified user
    if [ ! -d "/home/${USER_NAME}" ]; then
        echo "Error: Home directory for user '${USER_NAME}' does not exist." >&2
        exit 1
    fi

    # Check, ownership of the home directory
    OWNER_UID=$(stat -c '%u' "/home/${USER_NAME}")
    OWNER_GID=$(stat -c '%g' "/home/${USER_NAME}")
    if [ "${OWNER_UID}" -ne 0 ] || [ "${OWNER_GID}" -ne 0 ]; then
        # The home directory is not owned by the specfied user, correct it
        chown "${USER_NAME}:${USER_NAME}" "/home/${USER_NAME}"
    fi

    # Re-initialize the contents of the home directory
    su - "${USER_NAME}" -c "cp -a /etc/skel/. /home/${USER_NAME}/"

    # We are done as root, quit. The container will be re-run as the specified user.
    exit 0
fi

# Verify that we are running as the user owning the home directory
if [ "$(id -un)" != "${USER_NAME}" ]; then
    echo "Error: The script must be run as user '${USER_NAME}'." >&2
    exit 1
fi

# Run shell
exec /usr/bin/bash "$@"