feat: more completeness of spec and start at embedding

lib/bds/post_links.ex

@@ -0,0 +1,146 @@
+defmodule BDS.PostLinks do
+  @moduledoc false
+
+  import Ecto.Query
+
+  alias BDS.Posts.Link
+  alias BDS.Posts.Post
+  alias BDS.Projects
+  alias BDS.Repo
+
+  def sync_post_links(%Post{} = post) do
+    links =
+      post
+      |> post_body()
+      |> extract_links()
+      |> Enum.map(&resolve_post_link(post.project_id, &1))
+      |> Enum.reject(&is_nil/1)
+      |> Enum.uniq_by(fn %{target_post_id: target_post_id, link_text: link_text} ->
+        {target_post_id, link_text}
+      end)
+
+    Repo.transaction(fn ->
+      Repo.delete_all(from link in Link, where: link.source_post_id == ^post.id)
+
+      now = System.system_time(:second)
+
+      Enum.each(links, fn %{target_post_id: target_post_id, link_text: link_text} ->
+        %Link{}
+        |> Link.changeset(%{
+          id: Ecto.UUID.generate(),
+          source_post_id: post.id,
+          target_post_id: target_post_id,
+          link_text: link_text,
+          created_at: now
+        })
+        |> Repo.insert!()
+      end)
+    end)
+
+    :ok
+  end
+
+  def delete_post_links(post_id) when is_binary(post_id) do
+    Repo.delete_all(
+      from link in Link,
+        where: link.source_post_id == ^post_id or link.target_post_id == ^post_id
+    )
+
+    :ok
+  end
+
+  def list_outgoing_links(post_id) when is_binary(post_id) do
+    Repo.all(from link in Link, where: link.source_post_id == ^post_id, order_by: [asc: link.created_at])
+  end
+
+  def list_incoming_links(post_id) when is_binary(post_id) do
+    Repo.all(from link in Link, where: link.target_post_id == ^post_id, order_by: [asc: link.created_at])
+  end
+
+  defp post_body(%Post{content: content}) when is_binary(content), do: content
+
+  defp post_body(%Post{project_id: project_id, file_path: file_path}) do
+    if file_path in [nil, ""] do
+      ""
+    else
+      project = Projects.get_project!(project_id)
+      full_path = Path.join(Projects.project_data_dir(project), file_path)
+
+      case File.read(full_path) do
+        {:ok, contents} ->
+          case String.split(contents, "\n---\n", parts: 2) do
+            [_frontmatter, body] -> String.trim_trailing(body, "\n")
+            _parts -> contents
+          end
+
+        {:error, _reason} ->
+          ""
+      end
+    end
+  end
+
+  defp extract_links(body) when is_binary(body) do
+    markdown_links =
+      Regex.scan(~r/\[([^\]]+)\]\(([^)]+)\)/, body)
+      |> Enum.map(fn [_full, link_text, href] -> %{link_text: normalize_link_text(link_text), href: href} end)
+
+    html_links =
+      Regex.scan(~r/<a\s+[^>]*href=["']([^"']+)["'][^>]*>(.*?)<\/a>/is, body)
+      |> Enum.map(fn [_full, href, link_text] -> %{link_text: normalize_link_text(link_text), href: href} end)
+
+    markdown_links ++ html_links
+  end
+
+  defp resolve_post_link(project_id, %{href: href, link_text: link_text}) do
+    path =
+      href
+      |> to_string()
+      |> String.trim()
+      |> URI.parse()
+      |> Map.get(:path)
+
+    with path when is_binary(path) <- path,
+         slug when is_binary(slug) <- extract_slug(path),
+         %Post{id: target_post_id} <- Repo.get_by(Post, project_id: project_id, slug: slug) do
+      %{target_post_id: target_post_id, link_text: link_text}
+    else
+      _ -> nil
+    end
+  end
+
+  defp extract_slug(path) do
+    segments = path |> String.split("/", trim: true)
+
+    case segments do
+      [year, month, day, slug] ->
+        if numeric_year?(year) and numeric_month_or_day?(month) and numeric_month_or_day?(day),
+          do: slug,
+          else: nil
+
+      [language, year, month, day, slug] ->
+        if language_code?(language) and numeric_year?(year) and numeric_month_or_day?(month) and
+             numeric_month_or_day?(day),
+          do: slug,
+          else: nil
+
+      [slug] -> slug
+      [language, slug] -> if(language_code?(language), do: slug, else: nil)
+      _other -> nil
+    end
+  end
+
+  defp numeric_year?(value), do: String.match?(value, ~r/^\d{4}$/)
+  defp numeric_month_or_day?(value), do: String.match?(value, ~r/^\d{2}$/)
+  defp language_code?(value), do: String.match?(value, ~r/^[a-z]{2}$/)
+
+  defp normalize_link_text(value) do
+    value
+    |> to_string()
+    |> String.replace(~r/<[^>]+>/, "")
+    |> String.trim()
+    |> case do
+      "" -> nil
+      trimmed -> trimmed
+    end
+  end
+end