feat(iso): Interactively ask for ZFS/EFI partition choice if needed (#1)

setup.sh

@@ -105,6 +105,35 @@ function zpool_drive_id () {
     exit 1
 }
 
+function select_part () {
+    local parts enriched_parts enriched_parts_count part_number part_type
+    declare part
+    part_type="${1:?}" # 'efi' or 'zfs'
+    parts="$(get_parts "${part_type}")"
+
+    if we_have_exactly_one_part "${part_type}" "${parts}"; then
+        part="${parts}"
+    else
+        printf -- '%s\n' 'Which '"${part_type^^}"' partition do you want us to use?'
+        while IFS= read -r found_part; do
+            enriched_parts+=("'${found_part}'"' (aka ID '"'$(get_drive_id "${found_part}")'"')')
+        done <<<"${parts}"
+        enriched_parts_count="${#enriched_parts[@]}"
+        select part in "${enriched_parts[@]}"; do
+            part_number="${REPLY}"
+            if [[ "${part_number}" -le "${enriched_parts_count}" ]]; then
+                part="$(sed "${REPLY}q;d" <<<"${parts}")"
+                printf -- '%s\n' 'You'"'"'ve selected '"'${part}'"' ...'
+                break
+            else
+                printf -- '%s\n' 'Invalid option, please choose between 1 and '"${enriched_parts_count}"
+            fi
+        done
+    fi
+    printf -- '%s' "${part}"
+    return 0
+}
+
 function set_zpool_password () {
     # May or may not have a newline at the end, ZFS doesn't care
     printf -- '%s' 'password' > '/etc/zfs/'"${zpool_name}"'.key'