defmodule ToweropsWeb.CoverageLive.Map do
  @moduledoc """
  cnHeat-style unified coverage map.

  Shows every ready coverage in the organisation as a single composite
  heatmap on a Leaflet map, with:

    * a per-tower toggle list (top-right) including Show All / Hide All
    * an opacity slider (bottom-centre)
    * a base-map toggle (Streets / Satellite, top-left)
    * an address search bar (Nominatim, top-left)
    * a Distance Tool (click the map → side panel with each tower's
      distance from the click and predicted RSSI at that location)

  All ready coverages share the same colour palette so the composite
  read like a single map instead of N independent overlays.
  """
  use ToweropsWeb, :live_view

  alias Towerops.Coverages
  alias Towerops.Coverages.Coverage

  @impl true
  def mount(_params, _session, socket) do
    organization = socket.assigns.current_scope.organization

    if connected?(socket), do: Coverages.subscribe_organization(organization.id)

    coverages = Coverages.list_ready_for_organization(organization.id)

    {:ok,
     socket
     |> assign(:page_title, t("Coverage Map"))
     |> assign(:organization, organization)
     |> assign(:coverages, coverages)
     |> assign(:enabled_ids, Enum.map(coverages, & &1.id))
     |> assign(:probe, nil)
     |> assign(:probe_units, "ft")}
  end

  @impl true
  def handle_event("toggle_coverage", %{"id" => id}, socket) do
    enabled =
      if id in socket.assigns.enabled_ids,
        do: List.delete(socket.assigns.enabled_ids, id),
        else: [id | socket.assigns.enabled_ids]

    {:noreply,
     socket
     |> assign(:enabled_ids, enabled)
     |> push_event("coverage:enabled-changed", %{enabled: enabled})}
  end

  @impl true
  def handle_event("show_all", _params, socket) do
    enabled = Enum.map(socket.assigns.coverages, & &1.id)

    {:noreply,
     socket
     |> assign(:enabled_ids, enabled)
     |> push_event("coverage:enabled-changed", %{enabled: enabled})}
  end

  @impl true
  def handle_event("hide_all", _params, socket) do
    {:noreply,
     socket
     |> assign(:enabled_ids, [])
     |> push_event("coverage:enabled-changed", %{enabled: []})}
  end

  @impl true
  def handle_event("probe_point", %{"lat" => lat, "lon" => lon}, socket) do
    lat = to_float(lat)
    lon = to_float(lon)

    rows =
      socket.assigns.organization.id
      |> Coverages.query_point(lat, lon)
      |> Enum.sort_by(& &1.distance_m)

    probe = %{lat: lat, lon: lon, rows: rows}

    {:noreply, assign(socket, :probe, probe)}
  end

  @impl true
  def handle_event("close_probe", _params, socket) do
    {:noreply, assign(socket, :probe, nil)}
  end

  @impl true
  def handle_event("set_probe_units", %{"units" => units}, socket) when units in ["ft", "m"] do
    {:noreply, assign(socket, :probe_units, units)}
  end

  @impl true
  def handle_info({:coverage_status, _status, _arg}, socket) do
    coverages = Coverages.list_ready_for_organization(socket.assigns.organization.id)

    enabled =
      socket.assigns.enabled_ids
      |> MapSet.new()
      |> MapSet.intersection(MapSet.new(Enum.map(coverages, & &1.id)))
      |> MapSet.to_list()

    new_ids =
      coverages
      |> Enum.map(& &1.id)
      |> Enum.reject(&(&1 in socket.assigns.enabled_ids))

    enabled = enabled ++ new_ids

    {:noreply,
     socket
     |> assign(:coverages, coverages)
     |> assign(:enabled_ids, enabled)
     |> push_event("coverage:list-changed", %{
       coverages: coverages_payload(coverages),
       enabled: enabled
     })}
  end

  @doc false
  def coverages_payload(coverages) do
    Enum.map(coverages, fn c ->
      {tx_lat, tx_lon} = Coverage.location(c) || {nil, nil}

      %{
        id: c.id,
        name: c.name,
        png: c.png_path,
        bbox: [c.bbox_min_lat, c.bbox_min_lon, c.bbox_max_lat, c.bbox_max_lon],
        tx: %{lat: tx_lat, lon: tx_lon, azimuth: c.azimuth_deg},
        site: c.site && c.site.name,
        # cnHeat-style mode/height tier maps. `height_tiers` is the
        # LOS view (height-above-clutter), `nlos_tiers` the NLOS view
        # (height-above-ground, buildings as obstacles). Both empty
        # for coverages that haven't been recomputed since the
        # multi-mode pipeline shipped.
        height_tiers: c.height_tiers || %{},
        nlos_tiers: c.nlos_tiers || %{}
      }
    end)
  end

  @doc false
  def fmt_distance(m, "ft") when is_number(m), do: "#{:erlang.float_to_binary(m * 3.28084 / 5280.0, decimals: 2)} mi"
  def fmt_distance(m, "m") when is_number(m), do: "#{:erlang.float_to_binary(m / 1000.0, decimals: 2)} km"
  def fmt_distance(_, _), do: "—"

  @doc false
  def fmt_rssi(:no_coverage), do: "N/A"
  def fmt_rssi(nil), do: "—"
  def fmt_rssi(v) when is_number(v), do: "#{:erlang.float_to_binary(v * 1.0, decimals: 1)} dBm"

  defp to_float(v) when is_number(v), do: v * 1.0

  defp to_float(v) when is_binary(v) do
    case Float.parse(v) do
      {n, _} -> n
      :error -> 0.0
    end
  end
end