defmodule FirehoseWeb.MicroprintsLive do
  use FirehoseWeb, :live_view

  alias Microprints.MicroprintCache
  alias Microprints.MicroprintComponent

  @source_dirs ["app", "blogex"]

  @impl true
  def mount(_params, _session, socket) do
    files = scan_source_files()

    microprints =
      files
      |> Enum.map(&process_file/1)

    {:ok,
     socket
     |> assign(:page_title, "Microprints")
     |> assign(:microprints, microprints)
     |> assign(:expanded_path, nil)
     |> assign(:highlighted_path, nil)
     |> assign(:highlighted_line, nil)}
  rescue
    e ->
      {:ok,
       socket
       |> assign(:page_title, "Microprints")
       |> assign(:microprints, [])
       |> assign(:expanded_path, nil)
       |> assign(:highlighted_path, nil)
       |> assign(:highlighted_line, nil)
       |> put_flash(:error, "Error loading microprints: #{inspect(e)}")}
  end

  @impl true
  def render(assigns) do
    ~H"""
    <div class="max-w-6xl mx-auto">
      <h1 class="text-2xl font-bold mb-2">Microprints</h1>
      <p class="text-sm text-zinc-500 mb-6">
        Visual fingerprints of source code files. Click a line to highlight it.
        Click a card to expand and view the source.
      </p>

      <.microprint_legend />

      <div class="grid grid-cols-1 sm:grid-cols-2 lg:grid-cols-3 gap-6 mt-6">
        <%= for %{path: path, microprint: microprint, source: source} = item <- @microprints do %>
          {error = item[:error]}
          <div class="card bg-base-100 shadow-sm border border-zinc-200">
            <div class="card-body p-4">
              <h3 class="text-sm font-mono font-medium truncate" title={path}>
                {path}
              </h3>

              <%= if microprint do %>
                <.microprint
                  microprint={microprint}
                  width={200}
                  max_height={100}
                  clickable={true}
                  file_path={path}
                  highlighted_line={@highlighted_line}
                />

                <button
                  phx-click="toggle_expand"
                  phx-value-path={path}
                  class="btn btn-xs btn-ghost mt-2 w-full"
                >
                  <%= if @expanded_path == path do %>
                    Collapse
                  <% else %>
                    Expand
                  <% end %>
                </button>

                <%= if @expanded_path == path and source do %>
                  <.source_viewer
                    content={source}
                    highlighted_line={@highlighted_line}
                    language="elixir"
                  />
                <% end %>
              <% else %>
                <div class="text-xs text-red-500 mt-1">
                  Error: {inspect(error)}
                </div>
              <% end %>
            </div>
          </div>
        <% end %>
      </div>
    </div>
    """
  end

  @impl true
  def handle_event("highlight_line", %{"line" => line, "path" => path}, socket) do
    highlighted =
      case socket.assigns.highlighted_path do
        ^path -> nil
        _ -> String.to_integer(line)
      end

    {:noreply,
     socket
     |> assign(:highlighted_path, path)
     |> assign(:highlighted_line, highlighted)}
  end

  @impl true
  def handle_event("toggle_expand", %{"path" => path}, socket) do
    expanded =
      case socket.assigns.expanded_path do
        ^path -> nil
        _ -> path
      end

    {:noreply, assign(socket, :expanded_path, expanded)}
  end

  # Private helpers

  defp sort_by_mtime(files) do
    app_root = Mix.Project.project_file() |> Path.dirname()

    files
    |> Enum.map(fn file ->
      abs_path = Path.join(app_root, file)
      {file, File.stat!(abs_path).mtime}
    end)
    |> Enum.sort_by(fn {_file, mtime} -> mtime end, :desc)
    |> Enum.map(fn {file, _mtime} -> file end)
  end

  @doc false
  def scan_source_files do
    @source_dirs
    |> Enum.flat_map(&collect_elixir_files/1)
    |> Enum.uniq()
    |> Enum.sort()
    |> sort_by_mtime()
    |> Enum.take(2)
  end

  defp resolve_absolute_paths(files) do
    app_root = Mix.Project.project_file() |> Path.dirname()

    Enum.map(files, fn path ->
      Path.expand(Path.join(app_root, path))
    end)
  end

  defp excluded_path?(path) do
    path =~ "/_build/" or
      path =~ "/deps/" or
      path =~ "/examples/" or
      path =~ "/test/" or
      path =~ "/lib_dev/"
  end

  defp collect_elixir_files(dir) do
    app_root = Mix.Project.project_file() |> Path.dirname()
    monorepo_root = app_root |> Path.dirname()
    base = Path.join(monorepo_root, dir)

    case File.dir?(base) do
      true ->
        base
        |> Path.join("**/*.ex")
        |> Path.wildcard()
        |> Enum.filter(&File.regular?(&1))
        |> Enum.reject(&excluded_path?/1)
        |> Enum.map(&format_path(&1, monorepo_root, dir))

      false ->
        []
    end
  end

  defp format_path(path, monorepo_root, dir) do
    relative = Path.relative_to(path, monorepo_root)

    case dir do
      "app" ->
        String.replace_prefix(relative, "app/", "")

      _ ->
        "../" <> relative
    end
  end

  defp process_file(rel_path) do
    abs_path = resolve_absolute_paths([rel_path]) |> List.first()

    case MicroprintCache.get_microprint(abs_path) do
      {:ok, microprint} ->
        # Add line numbers to each line for highlighting
        lines_with_numbers =
          microprint.lines
          |> Enum.with_index(1)
          |> Enum.map(fn {line, num} -> Map.put(line, :line_number, num) end)

        # Read source code for expand/contract
        source = read_source(abs_path)

        %{
          path: rel_path,
          microprint: Map.put(microprint, :lines, lines_with_numbers),
          source: source
        }

      {:error, reason} ->
        %{path: rel_path, microprint: nil, error: reason}
    end
  end

  defp read_source(abs_path) do
    case File.read(abs_path) do
      {:ok, content} ->
        content
        |> String.replace("<", "&lt;")
        |> String.replace(">", "&gt;")

      {:error, _} ->
        nil
    end
  end

  # Delegate to MicroprintComponent
  defdelegate microprint(assigns), to: MicroprintComponent
  defdelegate microprint_legend(assigns), to: MicroprintComponent
  defdelegate source_viewer(assigns), to: MicroprintComponent
end