defmodule PlausibleWeb.StatsController do
  use PlausibleWeb, :controller
  use Plausible.Repo
  alias PlausibleWeb.Api
  alias Plausible.Stats.{Query, Filters}

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

  def stats(%{assigns: %{site: site}} = conn, _params) do
    has_stats = Plausible.Sites.has_stats?(site)
    can_see_stats = !site.locked || conn.assigns[:current_user_role] == :super_admin

    cond do
      has_stats && can_see_stats ->
        demo = site.domain == PlausibleWeb.Endpoint.host()
        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
        )

      !has_stats && can_see_stats ->
        conn
        |> assign(:skip_plausible_tracking, true)
        |> render("waiting_first_pageview.html", site: site)

      site.locked ->
        owner = Plausible.Sites.owner_for(site)

        conn
        |> assign(:skip_plausible_tracking, true)
        |> render("site_locked.html", owner: owner, site: site)
    end
  end

  @doc """
  The export is limited to 300 entries for other reports and 100 entries for pages because bigger result sets
  start causing failures. Since we request data like time on page or bounce_rate for pages in a separate query
  using the IN filter, it causes the requests to balloon in payload size.
  """
  def csv_export(conn, params) do
    site = conn.assigns[:site]
    query = Query.from(site.timezone, params) |> Filters.add_prefix()

    metrics = ["visitors", "pageviews", "bounce_rate", "visit_duration"]
    graph = Plausible.Stats.timeseries(site, query, metrics)
    headers = ["date" | metrics]

    visitors =
      Enum.map(graph, fn row -> Enum.map(headers, &row[&1]) end)
      |> (fn data -> [headers | data] end).()
      |> CSV.encode()
      |> Enum.join()

    filename =
      "Plausible export #{params["domain"]} #{Timex.format!(query.date_range.first, "{ISOdate} ")} to #{Timex.format!(query.date_range.last, "{ISOdate} ")}.zip"

    params = Map.merge(params, %{"limit" => "300", "csv" => "True", "detailed" => "True"})
    limited_params = Map.merge(params, %{"limit" => "100"})

    csvs = [
      {'sources.csv', fn -> Api.StatsController.sources(conn, params) end},
      {'utm_mediums.csv', fn -> Api.StatsController.utm_mediums(conn, params) end},
      {'utm_sources.csv', fn -> Api.StatsController.utm_sources(conn, params) end},
      {'utm_campaigns.csv', fn -> Api.StatsController.utm_campaigns(conn, params) end},
      {'utm_contents.csv', fn -> Api.StatsController.utm_contents(conn, params) end},
      {'utm_terms.csv', fn -> Api.StatsController.utm_terms(conn, params) end},
      {'pages.csv', fn -> Api.StatsController.pages(conn, limited_params) end},
      {'entry_pages.csv', fn -> Api.StatsController.entry_pages(conn, params) end},
      {'exit_pages.csv', fn -> Api.StatsController.exit_pages(conn, limited_params) end},
      {'countries.csv', fn -> Api.StatsController.countries(conn, params) end},
      {'regions.csv', fn -> Api.StatsController.regions(conn, params) end},
      {'cities.csv', fn -> Api.StatsController.cities(conn, params) end},
      {'browsers.csv', fn -> Api.StatsController.browsers(conn, params) end},
      {'operating_systems.csv', fn -> Api.StatsController.operating_systems(conn, params) end},
      {'devices.csv', fn -> Api.StatsController.screen_sizes(conn, params) end},
      {'conversions.csv', fn -> Api.StatsController.conversions(conn, params) end},
      {'prop_breakdown.csv', fn -> Api.StatsController.all_props_breakdown(conn, params) end}
    ]

    csvs =
      csvs
      |> Enum.map(fn {file, task} -> {file, Task.async(task)} end)
      |> Enum.map(fn {file, task} -> {file, Task.await(task)} end)

    csvs = [{'visitors.csv', visitors} | csvs]

    {:ok, {_, zip_content}} = :zip.create(filename, csvs, [:memory])

    conn
    |> put_resp_content_type("application/zip")
    |> put_resp_header("content-disposition", "attachment; filename=\"#{filename}\"")
    |> delete_resp_cookie("exporting")
    |> send_resp(200, zip_content)
  end

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

    if shared_link && shared_link.site.domain == domain do
      if shared_link.password_hash do
        with conn <- Plug.Conn.fetch_cookies(conn),
             {:ok, token} <- Map.fetch(conn.req_cookies, shared_link_cookie_name(auth)),
             {:ok, %{slug: token_slug}} <- Plausible.Auth.Token.verify_shared_link(token),
             true <- token_slug == shared_link.slug do
          render_shared_link(conn, shared_link)
        else
          _e ->
            conn
            |> assign(:skip_plausible_tracking, true)
            |> render("shared_link_password.html",
              link: shared_link,
              layout: {PlausibleWeb.LayoutView, "focus.html"}
            )
        end
      else
        render_shared_link(conn, shared_link)
      end
    end
  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
      redirect(conn, to: "/share/#{URI.encode_www_form(shared_link.site.domain)}?auth=#{slug}")
    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
        token = Plausible.Auth.Token.sign_shared_link(slug)

        conn
        |> put_resp_cookie(shared_link_cookie_name(slug), token)
        |> redirect(to: "/share/#{URI.encode_www_form(shared_link.site.domain)}?auth=#{slug}")
      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 render_shared_link(conn, shared_link) do
    cond do
      !shared_link.site.locked ->
        conn
        |> assign(:skip_plausible_tracking, true)
        |> put_resp_header("x-robots-tag", "noindex")
        |> delete_resp_header("x-frame-options")
        |> render("stats.html",
          site: shared_link.site,
          has_goals: Plausible.Sites.has_goals?(shared_link.site),
          title: "Plausible · " <> shared_link.site.domain,
          offer_email_report: false,
          demo: false,
          skip_plausible_tracking: true,
          shared_link_auth: shared_link.slug,
          embedded: conn.params["embed"] == "true",
          background: conn.params["background"],
          theme: conn.params["theme"]
        )

      shared_link.site.locked ->
        owner = Plausible.Sites.owner_for(shared_link.site)

        conn
        |> assign(:skip_plausible_tracking, true)
        |> render("site_locked.html", owner: owner, site: shared_link.site)
    end
  end

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

  defp shared_link_cookie_name(slug), do: "shared-link-" <> slug
end