defmodule DashboardWeb.HostsLive do
  @moduledoc """
  LiveView for real-time systant host monitoring.
  """
  use DashboardWeb, :live_view

  alias Phoenix.PubSub

  @pubsub_topic "systant:hosts"

  @impl true
  def mount(_params, _session, socket) do
    if connected?(socket) do
      # Subscribe to host updates from MQTT
      PubSub.subscribe(Dashboard.PubSub, @pubsub_topic)
    end

    # Start with empty hosts - will be populated by MQTT
    hosts = %{}

    socket = 
      socket
      |> assign(:hosts, hosts)
      |> assign(:show_raw_data, %{})  # Track which hosts show raw data
      |> assign(:page_title, "Systant Hosts")

    {:ok, socket}
  end

  @impl true
  def handle_info({:host_update, hostname, host_data}, socket) do
    require Logger
    Logger.info("LiveView received host update for #{hostname}: #{inspect(host_data)}")
    updated_hosts = Map.put(socket.assigns.hosts, hostname, host_data)
    {:noreply, assign(socket, :hosts, updated_hosts)}
  end

  @impl true
  def handle_event("toggle_raw", %{"hostname" => hostname}, socket) do
    current_state = Map.get(socket.assigns.show_raw_data, hostname, false)
    updated_raw_data = Map.put(socket.assigns.show_raw_data, hostname, !current_state)
    {:noreply, assign(socket, :show_raw_data, updated_raw_data)}
  end


  @impl true
  def render(assigns) do
    ~H"""
    <div class="px-4 py-10 sm:px-6 sm:py-28 lg:px-8 xl:px-28 xl:py-32">
      <div class="mx-auto max-w-xl lg:mx-0 lg:max-w-3xl">
        <h1 class="text-brand mt-10 flex items-center text-sm font-semibold leading-6">
          <.icon name="hero-computer-desktop" class="h-4 w-4" />
          Systant Host Monitor
        </h1>
        <p class="text-[2rem] mt-4 font-semibold leading-10 tracking-tighter text-zinc-900">
          Real-time system monitoring across all hosts
        </p>
        <p class="mt-4 text-base leading-7 text-zinc-600">
          Live MQTT-powered dashboard showing statistics from all your systant-enabled hosts.
        </p>
        
        <div class="mt-10 grid gap-6">
          <%= if Enum.empty?(@hosts) do %>
            <div class="rounded-lg border border-zinc-200 p-8 text-center">
              <.icon name="hero-signal-slash" class="mx-auto h-12 w-12 text-zinc-400" />
              <h3 class="mt-4 text-lg font-semibold text-zinc-900">No hosts detected</h3>
              <p class="mt-2 text-sm text-zinc-600">
                Waiting for systant hosts to publish data via MQTT...
              </p>
            </div>
          <% else %>
            <%= for {hostname, host_data} <- @hosts do %>
              <.host_card 
                hostname={hostname} 
                data={host_data} 
                show_raw={Map.get(@show_raw_data, hostname, false)}
              />
            <% end %>
          <% end %>
        </div>
      </div>
    </div>
    """
  end

  attr :hostname, :string, required: true
  attr :data, :map, required: true
  attr :show_raw, :boolean, default: false

  defp host_card(assigns) do
    assigns = assign(assigns, :show_raw, assigns[:show_raw] || false)
    
    ~H"""
    <div class="rounded-lg border border-zinc-200 bg-white p-6 shadow-sm">
      <!-- Host Header -->
      <div class="flex items-center justify-between mb-6">
        <div class="flex items-center space-x-3">
          <div class="rounded-full bg-green-100 p-2">
            <.icon name="hero-server" class="h-5 w-5 text-green-600" />
          </div>
          <div>
            <h3 class="text-lg font-semibold text-zinc-900"><%= @hostname %></h3>
            <p class="text-sm text-zinc-600">
              Last seen: <%= format_datetime(@data["last_seen"]) %>
            </p>
          </div>
        </div>
        <div class="flex items-center space-x-2">
          <button 
            phx-click="toggle_raw" 
            phx-value-hostname={@hostname}
            class="text-xs px-2 py-1 rounded border border-zinc-300 hover:bg-zinc-50"
          >
            <%= if @show_raw, do: "Hide Raw", else: "Show Raw" %>
          </button>
          <div class="rounded-full bg-green-100 px-3 py-1">
            <span class="text-xs font-medium text-green-800">Online</span>
          </div>
        </div>
      </div>

      <%= if @show_raw do %>
        <!-- Raw Data View -->
        <div class="mt-4">
          <h4 class="text-sm font-medium text-zinc-700 mb-2">Raw Data:</h4>
          <pre class="text-xs bg-zinc-50 p-3 rounded border overflow-x-auto">
            <%= Jason.encode!(@data, pretty: true) %>
          </pre>
        </div>
      <% else %>
        <!-- Graphical Dashboard View -->
        <div class="grid grid-cols-1 md:grid-cols-2 lg:grid-cols-3 gap-6">
          <!-- CPU Load Averages -->
          <.metric_card 
            title="CPU Load Average" 
            icon="hero-cpu-chip" 
            data={@data["cpu"]}
            type={:load_average}
          />
          
          <!-- Memory Usage -->
          <.metric_card 
            title="Memory Usage" 
            icon="hero-circle-stack" 
            data={@data["memory"]}
            type={:memory}
          />
          
          <!-- Disk Usage -->
          <.metric_card 
            title="Disk Usage" 
            icon="hero-hard-drive" 
            data={@data["disk"]}
            type={:disk}
          />
          
          <!-- GPU Metrics -->
          <%= if @data["gpu"] do %>
            <.metric_card 
              title="GPU Status" 
              icon="hero-tv" 
              data={@data["gpu"]}
              type={:gpu}
            />
          <% end %>
          
          <!-- Network Interfaces -->
          <%= if @data["network"] && length(@data["network"]) > 0 do %>
            <.metric_card 
              title="Network Interfaces" 
              icon="hero-signal" 
              data={@data["network"]}
              type={:network}
            />
          <% end %>
          
          <!-- Temperature Sensors -->
          <%= if @data["temperature"] do %>
            <.metric_card 
              title="Temperature" 
              icon="hero-fire" 
              data={@data["temperature"]}
              type={:temperature}
            />
          <% end %>
        </div>

        <!-- Additional Metrics Row -->
        <%= if @data["processes"] do %>
          <div class="mt-6">
            <.metric_card 
              title="Top Processes" 
              icon="hero-list-bullet" 
              data={@data["processes"]}
              type={:processes}
            />
          </div>
        <% end %>

        <!-- System Info -->
        <div class="mt-6 p-4 bg-zinc-50 rounded-lg">
          <h4 class="text-sm font-medium text-zinc-700 mb-2">System Information</h4>
          <div class="grid grid-cols-2 md:grid-cols-4 gap-4 text-sm">
            <div>
              <span class="text-zinc-600">Uptime:</span>
              <span class="ml-1 font-medium"><%= format_uptime(@data["system"]["uptime_seconds"]) %></span>
            </div>
            <div>
              <span class="text-zinc-600">Erlang:</span>
              <span class="ml-1 font-medium"><%= @data["system"]["erlang_version"] %></span>
            </div>
            <div>
              <span class="text-zinc-600">OTP:</span>
              <span class="ml-1 font-medium"><%= @data["system"]["otp_release"] %></span>
            </div>
            <div>
              <span class="text-zinc-600">Schedulers:</span>
              <span class="ml-1 font-medium"><%= @data["system"]["schedulers"] %></span>
            </div>
          </div>
        </div>
      <% end %>
    </div>
    """
  end

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

  defp format_datetime(_), do: "Unknown"

  defp format_uptime(nil), do: "Unknown"
  defp format_uptime(seconds) when is_integer(seconds) do
    days = div(seconds, 86400)
    hours = div(rem(seconds, 86400), 3600)
    minutes = div(rem(seconds, 3600), 60)
    
    cond do
      days > 0 -> "#{days}d #{hours}h #{minutes}m"
      hours > 0 -> "#{hours}h #{minutes}m"
      true -> "#{minutes}m"
    end
  end
  defp format_uptime(_), do: "Unknown"

  attr :title, :string, required: true
  attr :icon, :string, required: true
  attr :data, :map, required: true
  attr :type, :atom, required: true

  defp metric_card(assigns) do
    ~H"""
    <div class="bg-white border border-zinc-200 rounded-lg p-4">
      <div class="flex items-center space-x-2 mb-3">
        <.icon name={@icon} class="h-5 w-5 text-zinc-600" />
        <h4 class="font-medium text-zinc-900"><%= @title %></h4>
      </div>
      
      <%= case @type do %>
        <% :load_average -> %>
          <.load_average_display data={@data} />
        <% :memory -> %>
          <.memory_display data={@data} />
        <% :disk -> %>
          <.disk_display data={@data} />
        <% :gpu -> %>
          <.gpu_display data={@data} />
        <% :network -> %>
          <.network_display data={@data} />
        <% :temperature -> %>
          <.temperature_display data={@data} />
        <% :processes -> %>
          <.processes_display data={@data} />
        <% _ -> %>
          <p class="text-sm text-zinc-500">No data available</p>
      <% end %>
    </div>
    """
  end

  defp load_average_display(assigns) do
    ~H"""
    <%= if @data do %>
      <div class="space-y-2">
        <div class="flex justify-between items-center">
          <span class="text-sm text-zinc-600">1 min</span>
          <span class="font-mono text-sm"><%= format_float(@data["avg1"]) %></span>
        </div>
        <.progress_bar value={@data["avg1"]} max={4.0} color={load_color(@data["avg1"])} />
        
        <div class="flex justify-between items-center">
          <span class="text-sm text-zinc-600">5 min</span>
          <span class="font-mono text-sm"><%= format_float(@data["avg5"]) %></span>
        </div>
        <.progress_bar value={@data["avg5"]} max={4.0} color={load_color(@data["avg5"])} />
        
        <div class="flex justify-between items-center">
          <span class="text-sm text-zinc-600">15 min</span>
          <span class="font-mono text-sm"><%= format_float(@data["avg15"]) %></span>
        </div>
        <.progress_bar value={@data["avg15"]} max={4.0} color={load_color(@data["avg15"])} />
      </div>
    <% else %>
      <p class="text-sm text-zinc-500">No load data available</p>
    <% end %>
    """
  end

  defp memory_display(assigns) do
    ~H"""
    <%= if @data && @data["total_kb"] do %>
      <div class="space-y-2">
        <div class="flex justify-between items-center">
          <span class="text-sm text-zinc-600">Used</span>
          <span class="font-mono text-sm"><%= @data["used_percent"] %>%</span>
        </div>
        <.progress_bar value={@data["used_percent"]} max={100} color={memory_color(@data["used_percent"])} />
        
        <div class="text-xs text-zinc-500 space-y-1">
          <div class="flex justify-between">
            <span>Total:</span>
            <span><%= format_kb(@data["total_kb"]) %></span>
          </div>
          <div class="flex justify-between">
            <span>Used:</span>
            <span><%= format_kb(@data["used_kb"]) %></span>
          </div>
          <div class="flex justify-between">
            <span>Available:</span>
            <span><%= format_kb(@data["available_kb"]) %></span>
          </div>
        </div>
      </div>
    <% else %>
      <p class="text-sm text-zinc-500">No memory data available</p>
    <% end %>
    """
  end

  defp disk_display(assigns) do
    ~H"""
    <%= if @data && @data["disks"] do %>
      <div class="space-y-3">
        <%= for disk <- @data["disks"] do %>
          <div class="space-y-1">
            <div class="flex justify-between items-center">
              <span class="text-xs text-zinc-600 truncate"><%= disk["mounted_on"] %></span>
              <span class="font-mono text-xs"><%= disk["use_percent"] %>%</span>
            </div>
            <.progress_bar value={disk["use_percent"]} max={100} color={disk_color(disk["use_percent"])} />
            <div class="flex justify-between text-xs text-zinc-500">
              <span><%= disk["used"] %> used</span>
              <span><%= disk["available"] %> free</span>
            </div>
          </div>
        <% end %>
      </div>
    <% else %>
      <p class="text-sm text-zinc-500">No disk data available</p>
    <% end %>
    """
  end

  attr :value, :any, required: true
  attr :max, :any, required: true
  attr :color, :string, default: "bg-blue-500"

  defp progress_bar(assigns) do
    assigns = assign(assigns, :percentage, min(assigns.value / assigns.max * 100, 100))
    
    ~H"""
    <div class="w-full bg-zinc-200 rounded-full h-2">
      <div 
        class={"h-2 rounded-full transition-all duration-300 #{@color}"} 
        style={"width: #{@percentage}%"}
      >
      </div>
    </div>
    """
  end

  # Helper functions for formatting and colors
  defp format_float(nil), do: "N/A"
  defp format_float(value) when is_float(value), do: :erlang.float_to_binary(value, decimals: 2)
  defp format_float(value), do: to_string(value)

  defp format_kb(nil), do: "N/A"
  defp format_kb(kb) when is_integer(kb) do
    cond do
      kb >= 1_048_576 -> "#{Float.round(kb / 1_048_576, 1)} GB"
      kb >= 1_024 -> "#{Float.round(kb / 1_024, 1)} MB"
      true -> "#{kb} KB"
    end
  end

  defp load_color(load) when is_float(load) do
    cond do
      load >= 2.0 -> "bg-red-500"
      load >= 1.0 -> "bg-yellow-500"
      true -> "bg-green-500"
    end
  end
  defp load_color(_), do: "bg-zinc-400"

  defp memory_color(percent) when is_float(percent) do
    cond do
      percent >= 90 -> "bg-red-500"
      percent >= 75 -> "bg-yellow-500"
      true -> "bg-blue-500"
    end
  end
  defp memory_color(_), do: "bg-zinc-400"

  defp disk_color(percent) when is_integer(percent) do
    cond do
      percent >= 90 -> "bg-red-500"
      percent >= 80 -> "bg-yellow-500"
      true -> "bg-green-500"
    end
  end
  defp disk_color(_), do: "bg-zinc-400"

  # GPU Display Component
  defp gpu_display(assigns) do
    ~H"""
    <%= if @data do %>
      <div class="space-y-3">
        <!-- NVIDIA GPUs -->
        <%= if @data["nvidia"] && length(@data["nvidia"]) > 0 do %>
          <div class="text-xs text-zinc-600 font-medium mb-2">NVIDIA</div>
          <%= for gpu <- @data["nvidia"] do %>
            <div class="space-y-1">
              <div class="flex justify-between items-center">
                <span class="text-xs text-zinc-600 truncate"><%= gpu["name"] %></span>
                <span class="font-mono text-xs"><%= gpu["utilization_percent"] %>%</span>
              </div>
              <.progress_bar value={gpu["utilization_percent"]} max={100} color={gpu_color(gpu["utilization_percent"])} />
              <div class="flex justify-between text-xs text-zinc-500">
                <span><%= gpu["temperature_c"] %>°C</span>
                <span><%= format_mb(gpu["memory_used_mb"]) %>/<%= format_mb(gpu["memory_total_mb"]) %></span>
              </div>
            </div>
          <% end %>
        <% end %>
        
        <!-- AMD GPUs -->
        <%= if @data["amd"] && length(@data["amd"]) > 0 do %>
          <div class="text-xs text-zinc-600 font-medium mb-2">AMD</div>
          <%= for gpu <- @data["amd"] do %>
            <div class="space-y-1">
              <div class="flex justify-between items-center">
                <span class="text-xs text-zinc-600 truncate"><%= gpu["name"] %></span>
                <span class="font-mono text-xs"><%= gpu["utilization_percent"] || "N/A" %>%</span>
              </div>
              <.progress_bar value={gpu["utilization_percent"] || 0} max={100} color={gpu_color(gpu["utilization_percent"])} />
              <div class="text-xs text-zinc-500">
                <span><%= format_float(gpu["temperature_c"]) %>°C</span>
              </div>
            </div>
          <% end %>
        <% end %>
        
        <%= if (length(@data["nvidia"] || []) + length(@data["amd"] || [])) == 0 do %>
          <p class="text-sm text-zinc-500">No GPUs detected</p>
        <% end %>
      </div>
    <% else %>
      <p class="text-sm text-zinc-500">No GPU data available</p>
    <% end %>
    """
  end

  # Network Display Component  
  defp network_display(assigns) do
    ~H"""
    <%= if @data && length(@data) > 0 do %>
      <div class="space-y-3">
        <%= for interface <- Enum.take(@data, 3) do %>
          <div class="space-y-1">
            <div class="flex justify-between items-center">
              <span class="text-xs text-zinc-600 font-medium"><%= interface["interface"] %></span>
            </div>
            <div class="grid grid-cols-2 gap-2 text-xs">
              <div class="text-zinc-500">
                <span class="text-green-600">↓</span> <%= format_bytes(interface["rx_bytes"]) %>
              </div>
              <div class="text-zinc-500">  
                <span class="text-blue-600">↑</span> <%= format_bytes(interface["tx_bytes"]) %>
              </div>
            </div>
            <%= if (interface["rx_errors"] + interface["tx_errors"]) > 0 do %>
              <div class="text-xs text-red-500">
                Errors: RX <%= interface["rx_errors"] %>, TX <%= interface["tx_errors"] %>
              </div>
            <% end %>
          </div>
        <% end %>
      </div>
    <% else %>
      <p class="text-sm text-zinc-500">No network interfaces</p>
    <% end %>
    """
  end

  # Temperature Display Component
  defp temperature_display(assigns) do
    ~H"""
    <%= if @data do %>
      <div class="space-y-3">
        <!-- CPU Temperature -->
        <%= if @data["cpu"] do %>
          <div class="space-y-1">
            <div class="flex justify-between items-center">
              <span class="text-xs text-zinc-600">CPU</span>
              <span class={"font-mono text-xs text-#{temp_color(@data["cpu"])}"}><%= format_float(@data["cpu"]) %>°C</span>
            </div>
          </div>
        <% end %>
        
        <!-- Sensor Data -->
        <%= if @data["sensors"] && map_size(@data["sensors"]) > 0 do %>
          <%= for {chip_name, temps} <- Enum.take(@data["sensors"], 3) do %>
            <div class="text-xs text-zinc-600 font-medium"><%= chip_name %></div>
            <%= for {sensor, temp} <- Enum.take(temps, 2) do %>
              <div class="flex justify-between items-center">
                <span class="text-xs text-zinc-500"><%= sensor %></span>
                <span class={"font-mono text-xs text-#{temp_color(temp)}"}><%= format_float(temp) %>°C</span>
              </div>
            <% end %>
          <% end %>
        <% end %>
        
        <%= if !@data["cpu"] && (!@data["sensors"] || map_size(@data["sensors"]) == 0) do %>
          <p class="text-sm text-zinc-500">No temperature sensors</p>
        <% end %>
      </div>
    <% else %>
      <p class="text-sm text-zinc-500">No temperature data</p>
    <% end %>
    """
  end

  # Processes Display Component
  defp processes_display(assigns) do
    ~H"""
    <%= if @data && length(@data) > 0 do %>
      <div class="space-y-2">
        <%= for process <- Enum.take(@data, 8) do %>
          <div class="flex justify-between items-center text-xs">
            <div class="flex-1 min-w-0">
              <div class="truncate font-mono text-zinc-700"><%= process["command"] %></div>
              <div class="text-zinc-500"><%= process["user"] %> (PID <%= process["pid"] %>)</div>
            </div>
            <div class="text-right ml-2">
              <div class="font-mono text-zinc-700"><%= format_float(process["cpu_percent"]) %>%</div>
              <div class="text-zinc-500"><%= format_float(process["memory_percent"]) %>%</div>
            </div>
          </div>
        <% end %>
      </div>
    <% else %>
      <p class="text-sm text-zinc-500">No process data</p>
    <% end %>
    """
  end

  # Additional helper functions
  defp format_mb(nil), do: "N/A"
  defp format_mb(mb) when is_integer(mb) do
    cond do
      mb >= 1024 -> "#{Float.round(mb / 1024, 1)} GB"
      true -> "#{mb} MB"
    end
  end

  defp format_bytes(bytes) when is_integer(bytes) do
    cond do
      bytes >= 1_073_741_824 -> "#{Float.round(bytes / 1_073_741_824, 1)} GB"
      bytes >= 1_048_576 -> "#{Float.round(bytes / 1_048_576, 1)} MB"
      bytes >= 1_024 -> "#{Float.round(bytes / 1_024, 1)} KB"
      true -> "#{bytes} B"
    end
  end
  defp format_bytes(_), do: "N/A"

  defp gpu_color(util) when is_integer(util) do
    cond do
      util >= 80 -> "bg-red-500"
      util >= 50 -> "bg-yellow-500"
      true -> "bg-green-500"
    end
  end
  defp gpu_color(_), do: "bg-zinc-400"

  defp temp_color(temp) when is_number(temp) do
    cond do
      temp >= 80 -> "red-600"
      temp >= 70 -> "yellow-600"
      temp >= 60 -> "yellow-500"
      true -> "green-600"
    end
  end
  defp temp_color(_), do: "zinc-500"
end