defmodule SloaneSH.Layouts.Helpers do
  require Logger
  alias SloaneSH.Context
  alias SloaneSH.OutputDirs

  def cx(classes) do
    classes
    |> Enum.map(fn
      {_, _} = t -> t
      c -> {c, true}
    end)
    |> Enum.filter(fn {_, v} -> !!v end)
    |> Enum.map_join(" ", fn {class, _} -> class end)
  end

  def sorted_post_attrs(%Context{} = ctx) do
    ctx.posts
    |> Enum.map(& &1.attrs)
    |> Enum.sort_by(& &1[:date], {:desc, Date})
  end

  def fmt_date(date) do
    Timex.format!(date, "{Mfull} {D}, {YYYY}")
  end

  def picture(ctx, src, alt \\ "", class \\ "") do
    image = Enum.find(ctx.images, fn i ->
      output = OutputDirs.image(ctx.config, i.src)
      src == OutputDirs.to_permalink(ctx.config, output)
    end)

    if is_nil(image) do
      Logger.warning("Could not find #{inspect(src)} to make picture element")
      ~s|<img src="#{src}" alt="#{alt}" class="#{class}">|
    else
      [{_, src} | srcsets] = [
        {"image/jpg", ".jpg"},
        {"image/webp", ".webp"},
        {"image/png", ".png"},
      ]
        |> Enum.map(fn {type, ext} ->
          {type, OutputDirs.replace_ext(src, ext)}
        end)


      EEx.eval_string(~S"""
      <picture class="<%= class %>">
        <%= for {type, srcset} <- srcsets do %>
          <source srcset="<%= srcset %>" type="<%= type %>" />
        <% end %>
        <img src="<%= src %>" alt="<%= alt %>" />
      </picture>
      """, src: src, srcsets: srcsets, alt: alt, class: class)
    end
  end
end