refactor: move pure post-editor logic to BDS.UI.PostEditor for TUI reuse (issue #26, phase 3)

lib/bds/ui/post_editor/draft.ex

@@ -0,0 +1,107 @@
+defmodule BDS.UI.PostEditor.Draft do
+  @moduledoc """
+  Pure draft/form logic for the post editor (issue #26, phase 3).
+
+  Shared by the LiveView shell and the TUI: builds the persisted form for a
+  post (canonical language or translation), normalizes editor params, and
+  provides the small pure helpers both renderers need. No socket, no
+  process state — callers own the draft maps.
+  """
+
+  alias BDS.Posts
+  alias BDS.Posts.{Post, Translation}
+  alias BDS.UI.PostEditor.Metadata
+
+  def normalize_mode(mode) when mode in [:markdown, :preview], do: mode
+  def normalize_mode("visual"), do: :markdown
+  def normalize_mode("preview"), do: :preview
+  def normalize_mode(_mode), do: :markdown
+
+  def normalize_language(value, fallback) do
+    case value |> to_string() |> String.trim() do
+      "" -> fallback
+      normalized -> String.downcase(normalized)
+    end
+  end
+
+  def normalize_params(params, current_language, next_language) do
+    %{
+      "title" => Map.get(params, "title", ""),
+      "excerpt" => Map.get(params, "excerpt", ""),
+      "content" => Map.get(params, "content", ""),
+      "tags" => Map.get(params, "tags", ""),
+      "categories" => Map.get(params, "categories", ""),
+      "author" => Map.get(params, "author", ""),
+      "language" =>
+        if(current_language == next_language,
+          do: normalize_language(Map.get(params, "language"), current_language),
+          else: next_language
+        ),
+      "do_not_translate" => truthy?(Map.get(params, "do_not_translate")),
+      "template_slug" => Map.get(params, "template_slug", "")
+    }
+  end
+
+  def persisted_form(%Post{} = post, metadata, active_language) do
+    persisted_form(post, metadata, active_language, Metadata.translations(post.id))
+  end
+
+  def persisted_form(post, metadata, active_language, translations) do
+    canonical_language = Metadata.canonical_language(post, metadata)
+    translation = Map.get(translations, active_language)
+
+    if active_language == canonical_language do
+      %{
+        "title" => post.title || "",
+        "excerpt" => post.excerpt || "",
+        "content" => Posts.editor_body(post),
+        "tags" => Enum.join(post.tags || [], ", "),
+        "categories" => Enum.join(post.categories || [], ", "),
+        "author" => post.author || metadata.default_author || "",
+        "language" => canonical_language,
+        "do_not_translate" => post.do_not_translate || false,
+        "template_slug" => post.template_slug || ""
+      }
+    else
+      %{
+        "title" => (translation && translation.title) || "",
+        "excerpt" => (translation && translation.excerpt) || "",
+        "content" => if(translation, do: Posts.editor_body(translation), else: ""),
+        "tags" => Enum.join(post.tags || [], ", "),
+        "categories" => Enum.join(post.categories || [], ", "),
+        "author" => post.author || metadata.default_author || "",
+        "language" => active_language,
+        "do_not_translate" => post.do_not_translate || false,
+        "template_slug" => post.template_slug || ""
+      }
+    end
+  end
+
+  def save_state_for_action(:publish), do: :published
+  def save_state_for_action(_action), do: :saved
+
+  def record_title(%Translation{title: title}, post),
+    do: blank_to_nil(title) || post.title || post.slug || post.id
+
+  def record_title(%Post{title: title, slug: slug, id: id}, _post),
+    do: blank_to_nil(title) || blank_to_nil(slug) || id
+
+  def record_status(%Translation{status: status}), do: status || :draft
+  def record_status(%Post{status: status}), do: status || :draft
+
+  def editing_canonical_language?(translations, active_language, canonical_language) do
+    active_language == canonical_language or not Map.has_key?(translations, active_language)
+  end
+
+  defp truthy?(value), do: BDS.Values.truthy?(value)
+
+  defp blank_to_nil(value) do
+    value
+    |> to_string()
+    |> String.trim()
+    |> case do
+      "" -> nil
+      trimmed -> trimmed
+    end
+  end
+end