defmodule ServerWeb.AdminHostsLive do
  use ServerWeb, :live_view

  alias Server.{Hosts, Repo, Schema.Host}

  @impl true
  def mount(_params, _session, socket) do
    {:ok,
     socket
     |> assign(:hosts, Hosts.list_all())
     |> assign(:new_token, nil)
     |> assign(:error, nil)}
  end

  @impl true
  def handle_event("create", %{"host" => %{"name" => name}}, socket) do
    case Hosts.create_host(name) do
      {:ok, {host, token}} ->
        {:noreply,
         socket
         |> assign(:hosts, Hosts.list_all())
         |> assign(:new_token, %{name: host.name, token: token})
         |> assign(:error, nil)}

      {:error, cs} ->
        {:noreply, assign(socket, :error, changeset_message(cs))}
    end
  end

  def handle_event("rotate", %{"id" => id}, socket) do
    %Host{} = host = Repo.get!(Host, id)
    {:ok, {_, token}} = Hosts.rotate_token(host)

    {:noreply,
     socket
     |> assign(:hosts, Hosts.list_all())
     |> assign(:new_token, %{name: host.name, token: token})}
  end

  def handle_event("delete", %{"id" => id}, socket) do
    %Host{} = host = Repo.get!(Host, id)
    {:ok, _} = Hosts.delete_host(host)
    {:noreply, assign(socket, :hosts, Hosts.list_all())}
  end

  defp changeset_message(cs) do
    cs.errors
    |> Enum.map_join(", ", fn {k, {msg, _}} -> "#{k}: #{msg}" end)
  end

  @impl true
  def render(assigns) do
    ~H"""
    <div class="p-6 max-w-4xl mx-auto space-y-6">
      <.link navigate={~p"/"} class="text-sm text-zinc-500 hover:text-zinc-900">← Back</.link>
      <h1 class="text-2xl font-bold">Hosts</h1>

      <section class="bg-white border rounded-lg p-4">
        <h2 class="font-semibold mb-2">Register a new host</h2>
        <form phx-submit="create" class="flex gap-2">
          <input
            name="host[name]"
            placeholder="pve-hostname"
            required
            class="flex-1 rounded-md border-zinc-300 focus:border-zinc-400 focus:ring-0"
          />
          <button type="submit" class="rounded-md bg-zinc-900 text-white px-4">Add</button>
        </form>
        <p :if={@error} class="text-sm text-red-600 mt-2">{@error}</p>

        <div :if={@new_token} class="mt-4 p-3 bg-amber-50 border border-amber-200 rounded">
          <p class="text-sm font-semibold text-amber-900">
            Token for {@new_token.name} (shown once):
          </p>
          <code class="block mt-1 break-all text-sm">{@new_token.token}</code>
        </div>
      </section>

      <section class="bg-white border rounded-lg">
        <table class="w-full text-sm">
          <thead>
            <tr class="text-left text-zinc-500 border-b">
              <th class="py-2 px-3">Name</th>
              <th class="py-2 px-3">Status</th>
              <th class="py-2 px-3">Agent</th>
              <th class="py-2 px-3">Last seen</th>
              <th class="py-2 px-3 text-right">Actions</th>
            </tr>
          </thead>
          <tbody>
            <tr :for={h <- @hosts} class="border-b last:border-b-0">
              <td class="py-2 px-3 font-mono">{h.name}</td>
              <td class="py-2 px-3">{h.status}</td>
              <td class="py-2 px-3">{h.agent_version || "—"}</td>
              <td class="py-2 px-3">{format_seen(h.last_seen_at)}</td>
              <td class="py-2 px-3 text-right space-x-2">
                <button
                  phx-click="rotate"
                  phx-value-id={h.id}
                  class="text-xs text-zinc-700 underline"
                  data-confirm={"Rotate token for #{h.name}? Old token will stop working."}
                >
                  Rotate
                </button>
                <button
                  phx-click="delete"
                  phx-value-id={h.id}
                  class="text-xs text-red-600 underline"
                  data-confirm={"Delete #{h.name} and all its metrics?"}
                >
                  Delete
                </button>
              </td>
            </tr>
            <tr :if={@hosts == []}>
              <td colspan="5" class="py-4 px-3 text-center text-zinc-500">
                No hosts yet.
              </td>
            </tr>
          </tbody>
        </table>
      </section>
    </div>
    """
  end

  defp format_seen(nil), do: "never"

  defp format_seen(%DateTime{} = dt) do
    Calendar.strftime(dt, "%Y-%m-%d %H:%M UTC")
  end
end