defmodule SelectoComponents.Components.NestedTable do
  @moduledoc """
  Component for rendering nested tables from subselect results.
  Provides expandable/collapsible sections for related data.
  """

  use Phoenix.Component
  alias Phoenix.LiveView.JS

  @doc """
  Renders a nested table for subselect results.

  ## Attributes
  - data: The subselect data (JSON array or list of maps)
  - config: Configuration for the nested table display
  - row_id: Unique identifier for this row (for expand/collapse)
  """
  attr(:data, :any, required: true)
  attr(:config, :map, required: true)
  attr(:row_id, :string, required: true)
  attr(:expanded, :boolean, default: false)

  def nested_table(assigns) do
    assigns =
      assigns
      |> Map.put(:parsed_data, parse_subselect_data(assigns.data, assigns.config))
      |> Map.put(:table_id, "nested_#{assigns.row_id}")
      |> Map.put(:column_headers, get_column_headers(assigns))

    ~H"""
    <div class="nested-table-container ml-4 mt-2">
      <div class="flex items-center">
        <button
          type="button"
          class="flex items-center text-sm font-medium text-gray-700 hover:text-gray-900"
          phx-click={toggle_nested_table(@table_id)}
        >
          <svg
            class={"h-4 w-4 mr-1 transition-transform #{if @expanded, do: "rotate-90", else: ""}"}
            fill="none"
            stroke="currentColor"
            viewBox="0 0 24 24"
          >
            <path stroke-linecap="round" stroke-linejoin="round" stroke-width="2" d="M9 5l7 7-7 7" />
          </svg>
          {@config.title} ({length(@parsed_data)} items)
        </button>
      </div>

      <div id={@table_id} class={if @expanded, do: "block", else: "hidden"}>
        <%= if length(@parsed_data) > 0 do %>
          <div class="mt-2 overflow-x-auto">
            <table class="min-w-full divide-y divide-gray-200">
              <thead class="bg-gray-50">
                <tr>
                  <%= for header <- @column_headers do %>
                    <th class="px-3 py-2 text-left text-xs font-medium text-gray-500 uppercase tracking-wider">
                      {header}
                    </th>
                  <% end %>
                </tr>
              </thead>
              <tbody class="bg-white divide-y divide-gray-200">
                <%= for {item, idx} <- Enum.with_index(@parsed_data) do %>
                  <%= if idx < max_display_rows(@config) do %>
                    <tr class="hover:bg-gray-50">
                      <%= for key <- get_data_keys(@parsed_data, @config) do %>
                        <td class="px-3 py-2 whitespace-nowrap text-sm text-gray-900">
                          {format_value(Map.get(item, key, ""))}
                        </td>
                      <% end %>
                    </tr>
                  <% end %>
                <% end %>
              </tbody>
            </table>

            <%= if length(@parsed_data) > max_display_rows(@config) do %>
              <div class="px-3 py-2 text-sm text-gray-500">
                ... and {length(@parsed_data) - max_display_rows(@config)} more items
              </div>
            <% end %>
          </div>
        <% else %>
          <div class="mt-2 px-3 py-2 text-sm text-gray-500 italic">
            No related {String.downcase(@config.title)} found
          </div>
        <% end %>
      </div>
    </div>
    """
  end

  @doc """
  Renders multiple nested tables for a row with subselect data
  """
  attr(:row, :map, required: true)
  attr(:subselect_configs, :list, default: [])
  attr(:row_id, :string, required: true)

  def nested_tables(assigns) do
    ~H"""
    <div class="nested-tables">
      <%= for config <- @subselect_configs do %>
        <.nested_table
          data={Map.get(@row, config.key, [])}
          config={config}
          row_id={@row_id}
          expanded={Map.get(config, :initial_state, :collapsed) == :expanded}
        />
      <% end %>
    </div>
    """
  end

  # Helper functions (made public for inline rendering)

  def parse_subselect_data(data, config \\ %{})
  def parse_subselect_data(nil, _config), do: []

  def parse_subselect_data(data, config) when is_list(data) do
    normalize_subselect_rows(data, config)
  end

  def parse_subselect_data(data, config) when is_binary(data) do
    # Try to parse JSON string
    case Jason.decode(data) do
      {:ok, parsed} when is_list(parsed) -> normalize_subselect_rows(parsed, config)
      _ -> []
    end
  end

  def parse_subselect_data(_, _config), do: []

  defp max_display_rows(config) do
    Map.get(config, :max_rows, 10)
  end

  defp toggle_nested_table(table_id) do
    JS.toggle(to: "##{table_id}")
    |> JS.toggle_class("rotate-90", to: "[data-table='#{table_id}']")
  end

  defp get_column_headers(assigns) do
    case ordered_keys_from_config(assigns.config) do
      [] ->
        case parse_subselect_data(assigns.data, assigns.config) do
          [first | _] when is_map(first) ->
            Map.keys(first)
            |> Enum.map(&humanize_key/1)

          _ ->
            []
        end

      keys ->
        Enum.map(keys, &humanize_key/1)
    end
  end

  def get_data_keys(parsed_data, config \\ %{}) do
    case ordered_keys_from_config(config) do
      [] ->
        case parsed_data do
          [first | _] when is_map(first) -> Map.keys(first)
          _ -> []
        end

      keys ->
        keys
    end
  end

  def humanize_key(key) when is_binary(key) do
    key
    |> String.replace("_", " ")
    |> String.capitalize()
  end

  def humanize_key(key), do: to_string(key)

  defp extract_field_name(field) when is_binary(field) do
    field
    |> String.split(".")
    |> List.last()
    |> String.trim()
  end

  defp normalize_subselect_rows([], _config), do: []

  defp normalize_subselect_rows([first | _] = rows, _config) when is_map(first), do: rows

  defp normalize_subselect_rows(rows, config) do
    scalar_key = infer_scalar_column_key(config)

    Enum.map(rows, fn
      item when is_map(item) -> item
      item -> %{scalar_key => item}
    end)
  end

  defp infer_scalar_column_key(config) when not is_map(config), do: "value"

  defp infer_scalar_column_key(config) do
    field_name =
      case Map.get(config, :columns, []) do
        [first_column | _] ->
          case first_column do
            {_, field, _} -> extract_field_name(field)
            %{field: field} -> extract_field_name(field)
            field when is_binary(field) -> extract_field_name(field)
            _ -> nil
          end

        _ ->
          nil
      end

    case field_name do
      name when is_binary(name) and name != "" -> name
      _ -> "value"
    end
  end

  defp ordered_keys_from_config(config) when is_map(config) do
    config
    |> Map.get(:columns, [])
    |> Enum.map(fn
      {_, field, _} -> extract_field_name(field)
      %{field: field} -> extract_field_name(field)
      field when is_binary(field) -> extract_field_name(field)
      _ -> nil
    end)
    |> Enum.reject(&is_nil/1)
  end

  defp ordered_keys_from_config(_), do: []

  def format_value(value) when is_binary(value), do: value
  def format_value(value) when is_number(value), do: to_string(value)
  def format_value(nil), do: ""
  def format_value(value), do: inspect(value)

  @doc """
  Renders an inline nested table for subselect results.
  Designed to appear as part of the parent table column.
  """
  attr(:data, :any, required: true)
  attr(:config, :map, required: true)
  attr(:row_id, :string, required: true)

  def inline_nested_table(assigns) do
    assigns =
      assigns
      |> Map.put(:parsed_data, parse_subselect_data(assigns.data, assigns.config))

    ~H"""
    <div class="inline-nested-table">
      <%= if length(@parsed_data) > 0 do %>
        <table class="min-w-full border border-gray-300 rounded">
          <thead>
            <tr class="bg-gray-100">
              <%= for key <- get_data_keys(@parsed_data, @config) do %>
                <th class="px-2 py-1 text-xs font-medium text-gray-700 border-b border-gray-200">
                  {humanize_key(key)}
                </th>
              <% end %>
            </tr>
          </thead>
          <tbody>
            <%= for {item, _idx} <- Enum.with_index(@parsed_data) do %>
              <tr class="border-b border-gray-200 last:border-b-0 hover:bg-gray-50">
                <%= for key <- get_data_keys(@parsed_data, @config) do %>
                  <td class="px-2 py-1 text-xs text-gray-700">
                    {format_value(Map.get(item, key, ""))}
                  </td>
                <% end %>
              </tr>
            <% end %>
          </tbody>
        </table>
      <% else %>
        <div class="text-xs text-gray-500 italic">No data</div>
      <% end %>
    </div>
    """
  end

  @doc """
  Generates JavaScript hooks for nested table interactions
  """
  def hooks do
    %{
      "NestedTable" => %{
        mounted: """
        this.handleToggle = (e) => {
          const tableId = e.currentTarget.dataset.table;
          const table = document.getElementById(tableId);
          const icon = e.currentTarget.querySelector('svg');
          
          if (table.classList.contains('hidden')) {
            table.classList.remove('hidden');
            icon.classList.add('rotate-90');
          } else {
            table.classList.add('hidden');
            icon.classList.remove('rotate-90');
          }
        };

        this.el.querySelectorAll('[data-toggle]').forEach(btn => {
          btn.addEventListener('click', this.handleToggle);
        });
        """,
        destroyed: """
        this.el.querySelectorAll('[data-toggle]').forEach(btn => {
          btn.removeEventListener('click', this.handleToggle);
        });
        """
      }
    }
  end

  @doc """
  CSS styles for nested tables
  """
  def styles do
    """
    .nested-table-container {
      border-left: 2px solid #e5e7eb;
      padding-left: 1rem;
      margin-bottom: 0.5rem;
    }

    .nested-table-container table {
      font-size: 0.875rem;
    }

    .nested-table-container .rotate-90 {
      transform: rotate(90deg);
    }

    .nested-tables {
      margin-top: 0.5rem;
    }
    """
  end
end