defmodule VaccinsWeb.IndexLive do
  use VaccinsWeb, :live_view
  alias Vaccins.LocationStore

  @impl true
  def mount(_params, %{"is_local?" => is_local?}, socket) do
    locations = LocationStore.get_locations()
    Phoenix.PubSub.subscribe(Vaccins.PubSub, "locations")

    {:ok,
     socket
     |> assign(
       noob_mode: false,
       is_local?: is_local?,
       locations: locations,
       locations_with_early_slots: MapSet.new(),
       locations_with_slots: MapSet.new(),
       pending: %{},
       location_cs: LocationStore.LocationRaw.changeset(%{}),
       display_cs: false
     )
     |> set_all_areas
     |> init_area_filters()
     |> set_title()}
  end

  defp set_title(socket = %{assigns: %{locations_with_early_slots: early}}) do
    if early |> Enum.empty?(),
      do: socket |> assign(page_title: "Disponibilités vaccins"),
      else: socket |> assign(page_title: "(!!) Disponibilités vaccins")
  end

  @impl true
  def handle_params(params, _url, socket) when params == %{},
    do:
      {:noreply,
       socket
       |> assign(noob_mode: false, area_filters: socket.assigns.all_areas, params: params)}

  def handle_params(params, _url, socket)
      when is_map_key(params, "noob") or is_map_key(params, "geographic_areas") do
    all_areas = socket.assigns.all_areas
    areas = params |> Map.get("geographic_areas", all_areas)

    {:noreply,
     socket
     |> assign(
       noob_mode: params |> Map.has_key?("noob"),
       area_filters: areas |> MapSet.new() |> MapSet.intersection(all_areas),
       params: params
     )}
  end

  @impl true
  def handle_event("areas_filter_change", %{"areas_filter" => %{"areas" => areas}}, socket) do
    {:noreply,
     socket |> push_patch(to: Routes.index_path(socket, :index, geographic_areas: areas))}
  end

  def handle_event("areas_filter_change", params, socket)
      when not is_map_key(params, "areas_filter") do
    {:noreply, socket |> push_patch(to: Routes.index_path(socket, :index))}
  end

  def handle_event("add_location", %{"location_raw" => params}, socket) do
    case params |> LocationStore.add_location() do
      :ok -> {:noreply, socket |> push_patch(to: Routes.index_path(socket, :index))}
      {:error, cs} -> {:noreply, socket |> assign(location_cs: cs)}
    end
  end

  def handle_event("reload_file", _, socket) do
    :ok = LocationStore.reload()
    {:noreply, socket |> assign(locations: LocationStore.get_locations())}
  end

  def handle_event("toggle_form", _, socket = %{assigns: %{display_cs: display}}),
    do: {:noreply, socket |> assign(display_cs: not display)}

  def handle_event("trigger_noob_mode", _, socket = %{assigns: %{noob_mode: true}}),
    do:
      {:noreply,
       socket |> assign(noob_mode: false) |> push_patch(to: Routes.index_path(socket, :index))}

  def handle_event("trigger_noob_mode", _, socket = %{assigns: %{noob_mode: false}}),
    do: {:noreply, socket |> push_patch(to: Routes.index_path(socket, :index, noob: true))}

  @impl true
  def handle_info({:location_has_slots, id, true}, socket) do
    {:noreply,
     socket |> update(:locations_with_early_slots, &(&1 |> MapSet.put(id))) |> set_title}
  end

  def handle_info({:location_has_slots, id, false}, socket) do
    {:noreply, socket |> update(:locations_with_slots, &(&1 |> MapSet.put(id))) |> set_title}
  end

  def handle_info({:location_no_more_slots, id}, socket) do
    {:noreply,
     socket
     |> update(:locations_with_slots, &(&1 |> MapSet.delete(id)))
     |> update(:locations_with_early_slots, &(&1 |> MapSet.delete(id)))
     |> set_title}
  end

  def handle_info({:location_deleted, _}, socket),
    do: socket |> push_patch(to: Routes.index_path(socket, :index))

  @impl true
  def handle_info({:new_availabilities, id, res}, socket) do
    send_update(VaccinsWeb.LocationComponent, id: id, availabilities: res)
    {:noreply, socket}
  end

  defp filter(locations, %{area_filters: filters}),
    do:
      locations
      |> Enum.filter(&(&1.geographic_area in filters))

  defp locations_by_availability(%{
         locations: locations,
         locations_with_slots: with_slots,
         locations_with_early_slots: with_early_slots
       }) do
    locations
    |> Enum.sort(fn e1, e2 ->
      e1_has_early_spot? = e1.id in with_early_slots
      e1_has_spot? = e1.id in with_slots
      e2_has_early_spot? = e2.id in with_early_slots
      e2_has_spot? = e2.id in with_slots

      cond do
        e2_has_early_spot? -> false
        e2_has_spot? and not e1_has_early_spot? -> false
        e2_has_spot? and e1_has_spot? -> false
        true -> true
      end
    end)
  end

  defp set_all_areas(socket), do: socket |> assign(all_areas: socket |> get_all_areas)

  defp init_area_filters(socket), do: socket |> assign(area_filters: socket.assigns.all_areas)

  defp get_all_areas(%{assigns: %{locations: locations}}),
    do: locations |> Enum.map(& &1.geographic_area) |> MapSet.new()
end