defmodule JOL.Blog do
  alias JOL.Blog.{Post, Tag}
  alias JOL.Repo
  import Ecto.Query

  defmodule NotFoundError do
    defexception [:message, plug_status: 404]
  end

  def all_posts do
    []
  end

  def unique_tag_list do
    Repo.all(Tag, order_by: :name)
  end

  def recent_posts(num \\ 10) do
    Repo.all(
      from p in Post,
        limit: ^num,
        order_by: {:desc, :published_at}
    )
  end

  def get_post_by_slug!(slug) do
    Repo.one(
      from p in Post,
        where: [slug: ^slug],
        preload: [:tags]
      )
  end

  def get_posts_by_tag!(tag) do
    Repo.all(
      from p in Post,
      join: t in assoc(p, :tags),
      preload: [tags: t],
      where: t.name == ^tag
    )
  end

  def get_tag_by_id!(id) do
    Repo.one(
      from t in Tag,
        where: t.id == ^id,
        preload: [:posts]
    )
  end

  def format_date(date) do
    Calendar.strftime(date, "%Y-%m-%d")
  end
end