env-switch

#!/bin/sh
set -e
set -u

fn_list_envs() { (
    my_current="${1:-}"
    my_config_dir="${2}"

    cd ~/.config/"${my_config_dir}"/ || exit 1

    {
        echo "Available envs from ~/.config/${my_config_dir}/:"
        echo ""
    } > /dev/tty

    my_first_env=
    for my_env in *.env; do
        if test "${my_env}" = "*.env"; then

            {
                echo "    (none)"
                echo ""
            } > /dev/tty
            echo >&2 "Error: no files match ~/.config/${my_config_dir}/*.env"
            echo "" > /dev/tty

            return 1
        fi

        if test "${my_env}" = "current.env"; then
            continue
        fi

        if test -z "${my_first_env}"; then
            my_first_env="${my_env}"
            if test -z "${my_current}"; then
                my_current="${my_env}"
                my_current_new="${my_env}"
            fi
        fi

        if test "${my_current}" = "${my_env}"; then
            echo "    ${my_env} (current)" > /dev/tty
        else
            echo "    ${my_env}" > /dev/tty
        fi
    done
    echo "" > /dev/tty

    echo "${my_current_new:-}"
); }

main() { (
    my_config_dir="${1:-}"
    my_current_new="${2:-}"

    echo ""

    if test -z "${my_config_dir}" ||
        test "${my_config_dir}" = "help" ||
        test "${my_config_dir}" = "--help"; then

        echo ""
        echo "env-switch - switch the 'current.env' for any directory in ~/.config/"
        echo ""
        echo "USAGE"
        echo "        env-switch <config-dir> [env-name]"
        echo ""
        echo "EXAMPLES"
        echo "        env-switch 'proxmox-sh'"
        echo "        env-switch 'caddy-sh'"
        echo "        env-switch 'proxmox-sh' 'profile-1'"
        echo "        env-switch 'proxmox-sh' 'profile-2'"
        echo ""

        return 1
    fi

    if ! test -e ~/.config/"${my_config_dir}"/; then
        {
            echo "ERROR"
            echo "        not found: ~/.config/${my_config_dir}/"
            echo ""
            echo "SOLUTION"
            echo "        mkdir -p ~/.config/${my_config_dir}/"
            echo ""
        } >&2

        return 1
    fi

    my_current=
    if test -e ~/.config/"${my_config_dir}"/current.env; then
        if ! test -L ~/.config/"${my_config_dir}"/current.env; then
            my_ts="$(
                date '+%F_%H.%M.%S'
            )"
            echo "Moving non-link ~/.config/${my_config_dir}/current.env to ~/.config/${my_config_dir}/${my_ts}.env"
            mv ~/.config/"${my_config_dir}"/current.env ~/.config/"${my_config_dir}/${my_ts}.env"
        fi

        # shellcheck disable=SC2012
        my_current="$(
            ls -l ~/.config/"${my_config_dir}/current.env" |
                cut -d '>' -f2 |
                cut -d' ' -f2
        )"
        my_current="$(basename "${my_current}")"
    fi

    if test -n "${my_current_new}"; then
        if ! test -e ~/.config/"${my_config_dir}/${my_current_new}"; then
            if test -e ~/.config/"${my_config_dir}/${my_current_new}.env"; then
                my_current_new="${my_current_new}.env"
            fi

            if test "current.env" = "${my_current_new}"; then
                {
                    echo "ERROR"
                    echo "        can't set 'current.env' to itself"
                    echo ""
                } >&2
                return 1
            fi

            if ! test -e ~/.config/"${my_config_dir}/${my_current_new}"; then
                {
                    echo "ERROR"
                    echo "        not found: ~/.config/${my_config_dir}/${my_current_new}"
                    echo ""
                    echo "SOLUTION"
                    echo "        Pick one of the available envs"
                    echo ""
                    my_current_new="$(
                        fn_list_envs "${my_current}" "${my_config_dir}"
                    )"
                } >&2

                return 1
            fi
        fi

        echo "Selecting '~/.config/${my_config_dir}/${my_current_new}' as 'current.env'"
        ln -sf "./${my_current_new}" ~/.config/"${my_config_dir}/current.env"
        echo ""

        return 0
    fi

    my_current_new="$(
        fn_list_envs "${my_current}" "${my_config_dir}"
    )"

    if test -n "${my_current_new}"; then
        echo "Selecting '~/.config/${my_config_dir}/${my_current_new}' as 'current.env'"
        ln -sf "./${my_current_new}" ~/.config/"${my_config_dir}"/current.env
    fi
    echo ""
); }

main "${@:-}"