def deps do
  [
    {:phoenix_seo, "~> 0.1.9"}
  ]
end

defmodule MyAppWeb.SEO do
  use MyAppWeb, :verified_routes

  use SEO, [
    json_library: Jason,
    # a function reference will be called with a conn during render
    # arity 1 will be passed the conn, arity 0 is also supported.
    site: &__MODULE__.site_config/1,
    open_graph: SEO.OpenGraph.build(
      description: "A blog about development",
      site_name: "My Blog",
      locale: "en_US"
    ),
    facebook: SEO.Facebook.build(app_id: "123"),
    twitter: SEO.Twitter.build(
      site: "@example",
      site_id: "27704724",
      creator: "@example",
      creator_id: "27704724",
      card: :summary
    )
  ]

  # Or arity 0 is also supported, which can be great if you're using
  # Phoenix verified routes and don't need the conn to generate paths.
  def site_config(conn) do
    SEO.Site.build(
      default_title: "Default Title",
      description: "A blog about development",
      title_suffix: " · My App",
      theme_color: "#663399",
      windows_tile_color: "#663399",
      mask_icon_color: "#663399",
      mask_icon_url: static_url(conn, "/images/safari-pinned-tab.svg"),
      manifest_url: url(conn, ~p"/site.webmanifest")
    )
  end
end

defmodule MyApp.Article do
  # This might be an Ecto schema or a plain struct
  defstruct [:id, :title, :description, :author, :reading, :published_at]
end

defimpl SEO.OpenGraph.Build, for: MyApp.Article do
  use MyAppWeb, :verified_routes

  def build(article, conn) do
    SEO.OpenGraph.build(
      detail:
        SEO.OpenGraph.Article.build(
          published_time: article.published_at,
          author: article.author,
          section: "Tech"
        ),
      image: image(article, conn),
      title: article.title,
      description: article.description
    )
  end

  defp image(article, conn) do
    file = "/images/article/#{article.id}.png"

    exists? =
      [:code.priv_dir(:my_app), "static", file]
      |> Path.join()
      |> File.exists?()

    if exists? do
      SEO.OpenGraph.Image.build(
        url: static_url(conn, file),
        alt: article.title
      )
    end
  end
end

defimpl SEO.Site.Build, for: MyApp.Article do
  use MyAppWeb, :verified_routes

  def build(article, conn) do
    # Because of `Phoenix.Param`, structs will assume the key of `:id` when
    # interpolating the struct into the verified route.
    SEO.Site.build(
      url: url(conn, ~p"/articles/#{article}"),
      title: article.title,
      description: article.description
    )
  end
end

defimpl SEO.Twitter.Build, for: MyApp.Article do
  def build(article, _conn) do
    SEO.Twitter.build(description: article.description, title: article.title)
  end
end

defimpl SEO.Unfurl.Build, for: MyApp.Article do
  def build(article, _conn) do
    SEO.Unfurl.build(
      label1: "Reading Time",
      data1: "5 minutes",
      label2: "Published",
      data2: DateTime.to_iso8601(article.published_at)
    )
  end
end

defimpl SEO.Breadcrumb.Build, for: MyApp.Article do
  use MyAppWeb, :verified_routes

  def build(article, conn) do
    # Because of `Phoenix.Param`, structs will assume the key of `:id` when
    # interpolating the struct into the verified route.
    SEO.Breadcrumb.List.build([
      %{name: "Articles", item: url(conn, ~p"/articles")},
      %{name: article.title, item: url(conn, ~p"/articles/#{article}")}
    ])
  end
end

# In a plain Phoenix Controller
def show(conn, params) do
  article = load_article(params)

  conn
  |> SEO.assign(article)
  |> render("show.html")
end

def index(conn, params) do
  # Note: it's better to implement a struct that represent a route like this,
  # so you can customize it per implementation. In this example below, the
  # `:title` attribute will be passed to all domains.
  conn
  |> SEO.assign(%{title: "Listing Best Hugs"})
  |> render("show.html")
end

# In a Phoenix LiveView, make sure you handle with
# mount/3 or handle_params/3 so it's present on
# first static render.
def mount(_params, _session, socket) do
  # You may mark it as temporary since it's only needed on the first render.
  {:ok, socket, temporary_assigns: [{SEO.key(), nil}]}
end

def handle_params(params, _uri, socket) do
  {:noreply, SEO.assign(socket, load_article(params))}
end