defmodule JOL.Blog.Post do
  use Ecto.Schema
  import Ecto.Changeset

  schema "posts" do
    field :title, :string
    field :body, :string
    field :published_at, :naive_datetime
    field :slug, :string
    many_to_many :tags, JOL.Blog.Tag, join_through: "post_tags"

    timestamps(type: :utc_datetime)
  end

  @doc false
  def changeset(post, attrs) do
    post
    |> cast(attrs, [:title, :body, :published_at, :slug])
    |> validate_required([:title, :body, :slug])
    |> cast_assoc(:tags)
  end

  def extract_lede(post) do
    case Regex.named_captures(~r/(?<lede>.*)\n<!-- more -->/s, post.body) do
      %{"lede" => lede} ->
        lede

      _ ->
        post.body
        |> String.split()
        |> Enum.take(50)
        |> Enum.join(" ")
    end
  end
end