defmodule SyntropyWeb.AgentLive do
  use SyntropyWeb, :live_view

  import SyntropyWeb.RuntimeViewHelpers

  alias Syntropy.{HistoryStore, LatticeSupervisor, RecommendationStore, TaskScheduler}

  @history_limit 20

  @impl true
  def mount(_params, _session, socket) do
    if connected?(socket) do
      Phoenix.PubSub.subscribe(Syntropy.PubSub, "lattice:events")
    end

    {:ok,
     assign(socket,
       agent: nil,
       task_history: [],
       recommendation_history: [],
       snapshot_history: []
     )}
  end

  @impl true
  def handle_params(%{"id" => agent_id}, _uri, socket) do
    {:noreply, load_agent(socket, agent_id)}
  end

  @impl true
  def handle_info({:lattice_event, _event}, socket) do
    agent_id = socket.assigns.agent && socket.assigns.agent.id
    {:noreply, load_agent(socket, agent_id)}
  end

  @impl true
  def render(assigns) do
    ~H"""
    <main class="dashboard">
      <section class="dashboard-header glass-panel p-4">
        <div>
          <h1>Agent inspection</h1>
          <p class="body-copy">Retained state and recent participation for one agent.</p>
        </div>
        <nav class="dashboard-nav">
          <.link navigate={~p"/"} class="text-link">Lattice</.link>
          <span> · </span>
          <.link navigate={~p"/tasks"} class="text-link">Tasks</.link>
          <span> · </span>
          <.link navigate={~p"/history"} class="text-link">History</.link>
        </nav>
      </section>

      <%= if @agent do %>
        <section id="agent-summary" class="glass-panel detail-panel mt-4 mb-4">
          <header class="section-heading section-heading--flush">
            <div>
              <h2><%= @agent.name %></h2>
            </div>
            <div class="task-list-meta">
              <%= if @agent.temporary do %>
                <span class="status-chip status-chip--warn">temporary</span>
              <% end %>
              <.link navigate={graph_path(nil, @agent.id)} class="status-chip status-chip--muted">
                Focus in live graph
              </.link>
            </div>
          </header>

          <div class="outcome-stat-grid">
            <div>
              <span class="meta-label">ID</span>
              <strong><%= @agent.id %></strong>
            </div>
            <div>
              <span class="meta-label">Node</span>
              <strong><%= Syntropy.node_id() %></strong>
            </div>
            <div>
              <span class="meta-label">Perspective</span>
              <strong><%= @agent.perspective %></strong>
            </div>
            <div>
              <span class="meta-label">Position</span>
              <strong><%= format_score(@agent.position) %></strong>
            </div>
          </div>
        </section>

        <div class="two-column-grid mb-4">
          <article class="glass-panel detail-panel">
            <header class="section-heading section-heading--flush">
              <div>
                <h2>Connections</h2>
              </div>
            </header>
            <%= if map_size(@agent.connections) == 0 do %>
              <div class="empty-panel">
                <p id="agent-connections-empty" class="body-copy">No retained connections.</p>
              </div>
            <% else %>
              <ul id="agent-connections" class="task-list">
                <%= for {target_id, connection} <- Enum.sort_by(@agent.connections, fn {target_id, _} -> target_id end) do %>
                  <li id={"connection-#{target_id}"} class="task-list-item task-list-item--compact">
                    <div class="flex-row justify-between">
                      <strong><%= target_id %></strong>
                      <span class="meta-copy">
                        weight <%= format_score(connection.weight) %>
                        · <%= connection.interactions %> interactions
                      </span>
                    </div>
                  </li>
                <% end %>
              </ul>
            <% end %>
          </article>

          <article class="glass-panel detail-panel">
            <header class="section-heading section-heading--flush">
              <div>
                <h2>Recent task participation</h2>
              </div>
            </header>
            <%= if @task_history == [] do %>
              <div class="empty-panel">
                <p id="agent-tasks-empty" class="body-copy">No recent task participation.</p>
              </div>
            <% else %>
              <ul id="agent-task-history" class="task-list">
                <%= for entry <- @task_history do %>
                  <li id={"agent-task-#{entry.task.task_id}"} class="task-list-item task-list-item--compact">
                    <div class="flex-row justify-between">
                      <strong><%= entry.task.task_id %></strong>
                      <span class="meta-copy">node <%= node_id_for(entry.task) %></span>
                    </div>
                    <div class="task-list-meta">
                      <span class="meta-copy"><%= entry.task.strategy %> resolved <%= entry.task.resolved_mode %></span>
                      <%= if entry.snapshot do %>
                        <.link navigate={graph_path(entry.snapshot.id, @agent.id)} class="status-chip status-chip--muted">
                          <%= entry.snapshot.id %>
                        </.link>
                      <% end %>
                    </div>
                  </li>
                <% end %>
              </ul>
            <% end %>
          </article>
        </div>

        <div class="two-column-grid">
          <article class="glass-panel detail-panel">
            <header class="section-heading section-heading--flush">
              <div>
                <h2>Recent recommendation involvement</h2>
              </div>
            </header>
            <%= if @recommendation_history == [] do %>
              <div class="empty-panel">
                <p id="agent-recommendations-empty" class="body-copy">No recent recommendation involvement.</p>
              </div>
            <% else %>
              <ul id="agent-recommendations" class="task-list">
                <%= for recommendation <- @recommendation_history do %>
                  <li id={"agent-recommendation-#{recommendation.id}"} class="task-list-item task-list-item--compact">
                    <div class="flex-row justify-between">
                      <strong><%= recommendation.id %></strong>
                      <span class="meta-copy">node <%= node_id_for(recommendation) %></span>
                    </div>
                    <div class="task-list-meta">
                      <span class="status-chip status-chip--muted"><%= recommendation.kind %></span>
                      <span class="status-chip status-chip--warn"><%= recommendation.status %></span>
                    </div>
                  </li>
                <% end %>
              </ul>
            <% end %>
          </article>

          <article class="glass-panel detail-panel">
            <header class="section-heading section-heading--flush">
              <div>
                <h2>Recent snapshots</h2>
              </div>
            </header>
            <%= if @snapshot_history == [] do %>
              <div class="empty-panel">
                <p id="agent-snapshots-empty" class="body-copy">No recent snapshots for this agent.</p>
              </div>
            <% else %>
              <ul id="agent-snapshots" class="task-list">
                <%= for snapshot <- @snapshot_history do %>
                  <li id={"agent-snapshot-#{snapshot.id}"} class="task-list-item task-list-item--compact">
                    <div class="flex-row justify-between">
                      <.link navigate={graph_path(snapshot.id, @agent.id)} class="text-link">
                        <strong><%= snapshot.id %></strong>
                      </.link>
                      <span class="meta-copy">node <%= node_id_for(snapshot) %></span>
                    </div>
                    <span class="meta-copy">trigger <%= snapshot.trigger_kind %></span>
                  </li>
                <% end %>
              </ul>
            <% end %>
          </article>
        </div>
      <% else %>
        <section class="glass-panel detail-panel mt-4">
          <div class="empty-panel">
            <p id="agent-not-found" class="body-copy">Agent not found.</p>
          </div>
        </section>
      <% end %>
    </main>
    """
  end

  defp load_agent(socket, nil),
    do:
      assign(socket,
        agent: nil,
        task_history: [],
        recommendation_history: [],
        snapshot_history: []
      )

  defp load_agent(socket, agent_id) do
    agent = Enum.find(LatticeSupervisor.list_agents(), &(&1.id == agent_id))

    assign(socket,
      agent: agent,
      task_history: recent_tasks_for(agent_id),
      recommendation_history: recent_recommendations_for(agent_id),
      snapshot_history: recent_snapshots_for(agent_id)
    )
  end

  defp recent_tasks_for(nil), do: []

  defp recent_tasks_for(agent_id) do
    snapshots_by_task_id =
      HistoryStore.recent(@history_limit)
      |> Map.new(fn snapshot ->
        {snapshot.task_id, snapshot}
      end)

    TaskScheduler.recent(@history_limit)
    |> Enum.filter(fn task ->
      agent_id in task.selected_agent_ids or agent_id in task.contributing_agent_ids
    end)
    |> Enum.map(fn task ->
      %{
        task: task,
        snapshot: Map.get(snapshots_by_task_id, task.task_id)
      }
    end)
  end

  defp recent_recommendations_for(nil), do: []

  defp recent_recommendations_for(agent_id) do
    RecommendationStore.recent(@history_limit)
    |> Enum.filter(fn recommendation ->
      agent_id in recommendation.candidate_agent_ids or
        recommendation.applied_agent_id == agent_id
    end)
  end

  defp recent_snapshots_for(nil), do: []

  defp recent_snapshots_for(agent_id) do
    HistoryStore.recent(@history_limit)
    |> Enum.filter(fn snapshot ->
      Enum.any?(snapshot.agents, &(&1.id == agent_id))
    end)
  end

  defp graph_path(snapshot_id, agent_id) do
    params =
      %{}
      |> maybe_put("snapshot", snapshot_id)
      |> maybe_put("agent", agent_id)

    ~p"/?#{params}"
  end

  defp maybe_put(params, _key, nil), do: params
  defp maybe_put(params, key, value), do: Map.put(params, key, value)
end