defmodule PlausibleWeb.StatsController do
  use PlausibleWeb, :controller
  use Plausible.Repo
  alias Plausible.Stats.Clickhouse, as: Stats
  alias Plausible.Stats.Query

  plug PlausibleWeb.AuthorizeStatsPlug when action in [:stats, :csv_export]

  def base_domain() do
    PlausibleWeb.Endpoint.host()
  end

  def stats(conn, _params) do
    site = conn.assigns[:site]
    user = conn.assigns[:current_user]

    if user && Plausible.Billing.needs_to_upgrade?(conn.assigns[:current_user]) do
      redirect(conn, to: "/billing/upgrade")
    else
      if Stats.has_pageviews?(site) do
        demo = site.domain == base_domain()
        offer_email_report = get_session(conn, site.domain <> "_offer_email_report")

        conn
        |> assign(:skip_plausible_tracking, !demo)
        |> remove_email_report_banner(site)
        |> put_resp_header("x-robots-tag", "noindex")
        |> render("stats.html",
          site: site,
          has_goals: Plausible.Sites.has_goals?(site),
          title: "Plausible · " <> site.domain,
          offer_email_report: offer_email_report,
          demo: demo
        )
      else
        conn
        |> assign(:skip_plausible_tracking, true)
        |> render("waiting_first_pageview.html", site: site)
      end
    end
  end

  def csv_export(conn, %{"domain" => domain}) do
    site = conn.assigns[:site]

    query = Query.from(site.timezone, conn.params)
    {plot, _, labels, _} = Stats.calculate_plot(site, query)
    csv_content = Enum.zip(labels, plot)
                  |> Enum.map(fn {k, v} -> [k, v] end)
                  |> (fn data -> [["Date", "Visitors"] | data] end).()
                  |> CSV.encode
                  |> Enum.into([])
                  |> Enum.join()

    filename = "Visitors #{domain} #{Timex.format!(query.date_range.first, "{ISOdate} ")} to #{Timex.format!(query.date_range.last, "{ISOdate} ")}.csv"

    conn
    |> put_resp_content_type("text/csv")
    |> put_resp_header("content-disposition", "attachment; filename=\"#{filename}\"")
      |> send_resp(200, csv_content)
  end

  def shared_link(conn, %{"slug" => slug}) do
    shared_link = Repo.get_by(Plausible.Site.SharedLink, slug: slug)
                  |> Repo.preload(:site)

    if shared_link do
      if shared_link.password_hash do
        conn
        |> assign(:skip_plausible_tracking, true)
        |> render("shared_link_password.html", link: shared_link, layout: {PlausibleWeb.LayoutView, "focus.html"})
      else
        shared_link_auth_success(conn, shared_link)
      end
    else
      render_error(conn, 404)
    end
  end

  def authenticate_shared_link(conn, %{"slug" => slug, "password" => password}) do
    shared_link = Repo.get_by(Plausible.Site.SharedLink, slug: slug)
                  |> Repo.preload(:site)

    if shared_link do
      if Plausible.Auth.Password.match?(password, shared_link.password_hash) do
        shared_link_auth_success(conn, shared_link)
      else
        conn
        |> assign(:skip_plausible_tracking, true)
        |> render("shared_link_password.html", link: shared_link, error: "Incorrect password. Please try again.", layout: {PlausibleWeb.LayoutView, "focus.html"})
      end
    else
      render_error(conn, 404)
    end
  end

  defp shared_link_auth_success(conn, shared_link) do
    shared_link_key = "shared_link_auth_" <> shared_link.site.domain

    conn
    |> put_session(shared_link_key, %{
      valid_until: Timex.now() |> Timex.shift(hours: 1) |> DateTime.to_unix()
    })
    |> redirect(to: "/#{shared_link.site.domain}")
  end

  defp remove_email_report_banner(conn, site) do
    if conn.assigns[:current_user] do
      put_session(conn, site.domain <> "_offer_email_report", nil)
    else
      conn
    end
  end
end