defmodule BerrypodWeb.Admin.GSC do
  @moduledoc """
  Google Search Console dashboard.

  Shows connection status, top queries, and top pages from GSC data.
  """

  use BerrypodWeb, :live_view

  alias Berrypod.GSC.{Cache, Client, OAuth}
  alias Berrypod.Settings

  @impl true
  def mount(_params, _session, socket) do
    # Demo mode: set GSC_DEMO=1 to see the dashboard with sample data
    demo_mode = System.get_env("GSC_DEMO") == "1"
    connected = demo_mode or OAuth.connected?()
    site_url = if demo_mode, do: "https://example.com", else: Settings.get_setting("gsc_site_url")

    socket =
      socket
      |> assign(:page_title, "Search Console")
      |> assign(:connected, connected)
      |> assign(:site_url, site_url)
      |> assign(:sites, [])
      |> assign(:loading, false)
      |> assign(:error, nil)
      |> assign(:data, nil)
      |> assign(:demo_mode, demo_mode)

    socket =
      cond do
        demo_mode -> assign(socket, :data, demo_data())
        connected && site_url -> load_data(socket)
        true -> socket
      end

    {:ok, socket}
  end

  defp demo_data do
    %{
      top_queries: [
        %{
          keys: %{"query" => "wildflower tote bag"},
          clicks: 145,
          impressions: 2340,
          ctr: 6.2,
          position: 3.2
        },
        %{
          keys: %{"query" => "custom art prints"},
          clicks: 98,
          impressions: 1890,
          ctr: 5.2,
          position: 4.1
        },
        %{
          keys: %{"query" => "botanical poster"},
          clicks: 76,
          impressions: 1456,
          ctr: 5.2,
          position: 5.8
        },
        %{
          keys: %{"query" => "nature wall art"},
          clicks: 54,
          impressions: 980,
          ctr: 5.5,
          position: 7.2
        },
        %{
          keys: %{"query" => "meadow illustration"},
          clicks: 32,
          impressions: 654,
          ctr: 4.9,
          position: 8.4
        }
      ],
      top_pages: [
        %{
          keys: %{"page" => "https://example.com/products/wildflower-tote"},
          clicks: 234,
          impressions: 4500,
          ctr: 5.2,
          position: 4.1
        },
        %{
          keys: %{"page" => "https://example.com/collections/art-prints"},
          clicks: 187,
          impressions: 3200,
          ctr: 5.8,
          position: 3.8
        },
        %{
          keys: %{"page" => "https://example.com/"},
          clicks: 156,
          impressions: 2800,
          ctr: 5.6,
          position: 2.1
        },
        %{
          keys: %{"page" => "https://example.com/products/botanical-poster"},
          clicks: 98,
          impressions: 1900,
          ctr: 5.2,
          position: 5.4
        },
        %{
          keys: %{"page" => "https://example.com/about"},
          clicks: 45,
          impressions: 890,
          ctr: 5.1,
          position: 6.2
        }
      ],
      updated_at: DateTime.utc_now()
    }
  end

  @impl true
  def handle_event("select_site", %{"site_url" => site_url}, socket) do
    Settings.put_setting("gsc_site_url", site_url, "string")
    Cache.invalidate()

    socket =
      socket
      |> assign(:site_url, site_url)
      |> load_data()

    {:noreply, socket}
  end

  def handle_event("refresh_data", _params, socket) do
    Cache.invalidate()
    {:noreply, load_data(socket)}
  end

  def handle_event("load_sites", _params, socket) do
    case Client.list_sites() do
      {:ok, sites} ->
        {:noreply, assign(socket, :sites, sites)}

      {:error, reason} ->
        {:noreply, assign(socket, :error, "Failed to load sites: #{inspect(reason)}")}
    end
  end

  defp load_data(socket) do
    site_url = socket.assigns.site_url

    case Cache.get_all() do
      {:ok, data} ->
        assign(socket, :data, data)

      :miss ->
        fetch_fresh_data(socket, site_url)
    end
  end

  defp fetch_fresh_data(socket, site_url) do
    with {:ok, queries} <- Client.top_queries(site_url, row_limit: 25),
         {:ok, pages} <- Client.top_pages(site_url, row_limit: 25) do
      Cache.put_top_queries(queries)
      Cache.put_top_pages(pages)

      data = %{
        top_queries: queries,
        top_pages: pages,
        updated_at: DateTime.utc_now()
      }

      assign(socket, :data, data)
    else
      {:error, :not_connected} ->
        assign(socket, :connected, false)

      {:error, reason} ->
        assign(socket, :error, "Failed to fetch data: #{inspect(reason)}")
    end
  end

  @impl true
  def render(assigns) do
    ~H"""
    <.header>Search Console</.header>
    <p class="admin-page-description">
      See how your site performs in Google search results
    </p>

    <div class="gsc-dashboard">
      <%= if not @connected do %>
        <.connection_card configured={gsc_configured?()} />
      <% else %>
        <.site_selector
          sites={@sites}
          site_url={@site_url}
          loading={@loading}
        />

        <%= if @site_url do %>
          <%= if @data do %>
            <.data_header updated_at={@data.updated_at} />
            <.metrics_grid data={@data} />
          <% else %>
            <.loading_state error={@error} />
          <% end %>
        <% else %>
          <.no_site_selected />
        <% end %>
      <% end %>
    </div>
    """
  end

  # Connection card for when not connected
  defp connection_card(assigns) do
    ~H"""
    <div class="gsc-card gsc-card-connect">
      <div class="gsc-card-icon">
        <.icon name="hero-magnifying-glass" class="size-8" />
      </div>
      <h2>Connect Google Search Console</h2>
      <p>
        See your search performance data, top queries, and page rankings
        directly in your admin dashboard.
      </p>
      <%= if @configured do %>
        <a href={~p"/admin/gsc/connect"} class="admin-btn admin-btn-primary">
          Connect with Google
        </a>
      <% else %>
        <p class="gsc-not-configured">
          Set <code>GSC_CLIENT_ID</code>
          and <code>GSC_CLIENT_SECRET</code>
          environment variables to enable this feature.
        </p>
      <% end %>
    </div>
    """
  end

  # Site selector dropdown
  defp site_selector(assigns) do
    ~H"""
    <div class="gsc-site-selector">
      <div class="gsc-site-row">
        <%= if @sites == [] do %>
          <button phx-click="load_sites" class="admin-btn admin-btn-outline">
            Load available sites
          </button>
        <% else %>
          <form phx-change="select_site" class="gsc-site-form">
            <label for="site_url">Site</label>
            <select name="site_url" id="site_url" class="admin-select">
              <option value="">Select a site...</option>
              <%= for site <- @sites do %>
                <option value={site["siteUrl"]} selected={@site_url == site["siteUrl"]}>
                  {site["siteUrl"]}
                </option>
              <% end %>
            </select>
          </form>
        <% end %>

        <a
          href={~p"/admin/gsc/disconnect"}
          data-method="delete"
          class="admin-btn admin-btn-ghost admin-btn-sm"
        >
          Disconnect
        </a>
      </div>
    </div>
    """
  end

  # Data header with refresh button and last updated
  defp data_header(assigns) do
    ~H"""
    <div class="gsc-data-header">
      <span class="gsc-updated">
        Last updated: {format_datetime(@updated_at)}
      </span>
      <button phx-click="refresh_data" class="admin-btn admin-btn-ghost admin-btn-sm">
        <.icon name="hero-arrow-path" class="size-4" /> Refresh
      </button>
    </div>
    """
  end

  # Metrics grid with queries and pages tables
  defp metrics_grid(assigns) do
    ~H"""
    <div class="gsc-grid">
      <div class="gsc-card">
        <h3>Top queries</h3>
        <p class="gsc-card-description">What people search for to find your site</p>
        <.queries_table queries={@data.top_queries} />
      </div>

      <div class="gsc-card">
        <h3>Top pages</h3>
        <p class="gsc-card-description">Your best performing pages in search</p>
        <.pages_table pages={@data.top_pages} />
      </div>
    </div>
    """
  end

  # Top queries table
  defp queries_table(assigns) do
    ~H"""
    <table class="gsc-table">
      <thead>
        <tr>
          <th>Query</th>
          <th class="gsc-th-num">Clicks</th>
          <th class="gsc-th-num">Impr.</th>
          <th class="gsc-th-num">CTR</th>
          <th class="gsc-th-num">Pos.</th>
        </tr>
      </thead>
      <tbody>
        <%= if @queries == [] do %>
          <tr>
            <td colspan="5" class="gsc-empty">No data yet</td>
          </tr>
        <% else %>
          <%= for row <- @queries do %>
            <tr>
              <td class="gsc-query">{row.keys["query"]}</td>
              <td class="gsc-num">{row.clicks}</td>
              <td class="gsc-num">{format_number(row.impressions)}</td>
              <td class="gsc-num">{row.ctr}%</td>
              <td class="gsc-num">{row.position}</td>
            </tr>
          <% end %>
        <% end %>
      </tbody>
    </table>
    """
  end

  # Top pages table
  defp pages_table(assigns) do
    ~H"""
    <table class="gsc-table">
      <thead>
        <tr>
          <th>Page</th>
          <th class="gsc-th-num">Clicks</th>
          <th class="gsc-th-num">Impr.</th>
          <th class="gsc-th-num">CTR</th>
          <th class="gsc-th-num">Pos.</th>
        </tr>
      </thead>
      <tbody>
        <%= if @pages == [] do %>
          <tr>
            <td colspan="5" class="gsc-empty">No data yet</td>
          </tr>
        <% else %>
          <%= for row <- @pages do %>
            <tr>
              <td class="gsc-page">{format_page_url(row.keys["page"])}</td>
              <td class="gsc-num">{row.clicks}</td>
              <td class="gsc-num">{format_number(row.impressions)}</td>
              <td class="gsc-num">{row.ctr}%</td>
              <td class="gsc-num">{row.position}</td>
            </tr>
          <% end %>
        <% end %>
      </tbody>
    </table>
    """
  end

  defp loading_state(assigns) do
    ~H"""
    <div class="gsc-loading">
      <%= if @error do %>
        <p class="gsc-error">{@error}</p>
      <% else %>
        <p>Loading data...</p>
      <% end %>
    </div>
    """
  end

  defp no_site_selected(assigns) do
    ~H"""
    <div class="gsc-no-site">
      <p>Select a site to view its search performance data.</p>
    </div>
    """
  end

  # Helper functions

  defp gsc_configured? do
    System.get_env("GSC_CLIENT_ID") != nil
  end

  defp format_datetime(nil), do: "Never"

  defp format_datetime(dt) do
    Calendar.strftime(dt, "%-d %b %Y, %H:%M")
  end

  defp format_number(n) when n >= 1000 do
    "#{Float.round(n / 1000, 1)}k"
  end

  defp format_number(n), do: to_string(n)

  defp format_page_url(url) when is_binary(url) do
    case URI.parse(url) do
      %{path: path} when is_binary(path) and path != "" -> path
      _ -> url
    end
  end

  defp format_page_url(url), do: url
end