defmodule ExESDBDashboard.ClusterComponent do
  @moduledoc """
  LiveComponent for cluster view that can be embedded within other LiveViews.
  
  This provides a reusable cluster dashboard component with real-time updates
  via PubSub integration.
  """
  use Phoenix.LiveComponent
  
  @impl true
  def mount(socket) do
    {:ok, socket}
  end

  @impl true
  def update(assigns, socket) do
    socket = 
      socket
      |> assign(assigns)
      |> assign_new(:cluster_data, fn -> get_cluster_data() end)
      |> assign_new(:last_updated, fn -> DateTime.utc_now() end)

    {:ok, socket}
  end

  @impl true
  def handle_event("refresh", _params, socket) do
    cluster_data = get_cluster_data()
    
    socket =
      socket
      |> assign(:cluster_data, cluster_data)
      |> assign(:last_updated, DateTime.utc_now())
    
    # Send update to parent LiveView
    send(self(), {:cluster_refreshed, cluster_data})
    
    {:noreply, socket}
  end

  @impl true
  def render(assigns) do
    ~H"""
    <div class="cluster-component">
      <div class="cluster-header">
        <div class="header-content">
          <h2>🏢 Cluster Overview</h2>
          <p class="subtitle">Real-time cluster monitoring</p>
        </div>
        <div class="header-controls">
          <button 
            type="button" 
            phx-click="refresh"
            phx-target={@myself}
            class="refresh-btn"
            title="Refresh cluster data"
          >
            🔄 Refresh
          </button>
        </div>
      </div>

      <div class="cluster-content">
        <!-- Cluster Health Overview -->
        <div class="health-section">
          <h3>📊 Cluster Health</h3>
          <div class="health-indicator">
            <div class={"health-status #{health_status_class(@cluster_data.cluster_health)}"}>
              <span class="health-icon"><%= health_icon(@cluster_data.cluster_health) %></span>
              <span class="health-text"><%= health_text(@cluster_data.cluster_health) %></span>
            </div>
          </div>
        </div>

        <!-- Cluster Nodes -->
        <div class="nodes-section">
          <h3>🖥️ Cluster Nodes</h3>
          <div class="nodes-grid">
            <%= for node <- @cluster_data.nodes do %>
              <div class={"node-card #{node_status_class(node.status)}"}>
                <div class="node-header">
                  <span class="node-name"><%= node.name %></span>
                  <span class="node-status"><%= node_status_text(node.status) %></span>
                </div>
                <div class="node-details">
                  <div class="node-detail">
                    <span class="detail-label">Type:</span>
                    <span class="detail-value"><%= if node.is_ex_esdb, do: "ExESDB", else: "Gater" %></span>
                  </div>
                  <div class="node-detail">
                    <span class="detail-label">Uptime:</span>
                    <span class="detail-value"><%= format_uptime(node.uptime) %></span>
                  </div>
                  <div class="node-detail">
                    <span class="detail-label">Last seen:</span>
                    <span class="detail-value"><%= format_datetime(node.last_seen) %></span>
                  </div>
                </div>
              </div>
            <% end %>
          </div>
        </div>

        <!-- Data Stores -->
        <div class="stores-section">
          <h3>🏪 Data Stores</h3>
          <div class="stores-grid">
            <%= for store <- @cluster_data.stores do %>
              <div class="store-card">
                <div class="store-header">
                  <span class="store-name"><%= store.name %></span>
                  <span class={"store-status #{store_status_class(store.status)}"}><%= store.status %></span>
                </div>
                <div class="store-stats">
                  <div class="store-stat">
                    <span class="stat-value"><%= store.stream_count %></span>
                    <span class="stat-label">Streams</span>
                  </div>
                  <div class="store-stat">
                    <span class="stat-value"><%= store.subscription_count %></span>
                    <span class="stat-label">Subscriptions</span>
                  </div>
                  <div class="store-stat">
                    <span class="stat-value"><%= length(store.nodes) %></span>
                    <span class="stat-label">Nodes</span>
                  </div>
                </div>
              </div>
            <% end %>
          </div>
        </div>

        <!-- Cluster Summary -->
        <div class="summary-section">
          <h3>📈 Cluster Summary</h3>
          <div class="summary-stats">
            <div class="summary-stat">
              <span class="stat-value"><%= length(@cluster_data.nodes) %></span>
              <span class="stat-label">Total Nodes</span>
            </div>
            <div class="summary-stat">
              <span class="stat-value"><%= length(@cluster_data.stores) %></span>
              <span class="stat-label">Data Stores</span>
            </div>
            <div class="summary-stat">
              <span class="stat-value"><%= @cluster_data.total_streams %></span>
              <span class="stat-label">Total Streams</span>
            </div>
            <div class="summary-stat">
              <span class="stat-value"><%= format_datetime(@cluster_data.updated_at) %></span>
              <span class="stat-label">Last Updated</span>
            </div>
          </div>
        </div>

        <!-- Last Update Info -->
        <div class="update-info">
          <p class="last-updated">
            🕐 Last updated: <%= format_datetime(@last_updated) %>
          </p>
        </div>
      </div>
    </div>
    """
  end

  # Private helper functions
  
  defp get_cluster_data do
    try do
      ExESDBDashboard.get_cluster_data()
    rescue
      _ ->
        # Fallback data if ExESDBDashboard is not available
        %{
          nodes: [%{name: Node.self(), status: :self, is_ex_esdb: false, uptime: 0, last_seen: DateTime.utc_now()}],
          stores: [],
          total_streams: 0,
          cluster_health: :no_cluster,
          updated_at: DateTime.utc_now()
        }
    end
  end

  defp health_status_class(health) do
    case health do
      :healthy -> "healthy"
      :degraded -> "degraded"
      :unhealthy -> "unhealthy"
      :no_cluster -> "no-cluster"
      :no_stores -> "no-stores"
      _ -> "unknown"
    end
  end

  defp health_icon(health) do
    case health do
      :healthy -> "✅"
      :degraded -> "⚠️"
      :unhealthy -> "❌"
      :no_cluster -> "🔍"
      :no_stores -> "📦"
      _ -> "❓"
    end
  end

  defp health_text(health) do
    case health do
      :healthy -> "All systems operational"
      :degraded -> "Some issues detected"
      :unhealthy -> "Critical issues found"
      :no_cluster -> "No cluster detected"
      :no_stores -> "No data stores available"
      _ -> "Health status unknown"
    end
  end

  defp node_status_class(status) do
    case status do
      :connected -> "connected"
      :self -> "self"
      _ -> "unknown"
    end
  end

  defp node_status_text(status) do
    case status do
      :connected -> "Connected"
      :self -> "Local Node"
      _ -> "Unknown"
    end
  end

  defp store_status_class(status) do
    case status do
      :healthy -> "healthy"
      :degraded -> "degraded"
      :unhealthy -> "unhealthy"
      _ -> "unknown"
    end
  end

  defp format_uptime(uptime_ms) when is_integer(uptime_ms) do
    seconds = div(uptime_ms, 1000)
    
    cond do
      seconds < 60 -> "#{seconds}s"
      seconds < 3600 -> "#{div(seconds, 60)}m"
      seconds < 86400 -> "#{div(seconds, 3600)}h"
      true -> "#{div(seconds, 86400)}d"
    end
  end
  
  defp format_uptime(_), do: "unknown"

  defp format_datetime(%DateTime{} = dt) do
    Calendar.strftime(dt, "%H:%M:%S")
  end
  
  defp format_datetime(_), do: "unknown"
end