defmodule ArcanaWeb.CollectionsLive do
  @moduledoc """
  LiveView for managing collections in Arcana.
  """
  use Phoenix.LiveView

  import Ecto.Query
  import ArcanaWeb.DashboardComponents

  alias Arcana.Collection

  @impl true
  def mount(_params, session, socket) do
    repo = get_repo_from_session(session)

    {:ok,
     socket
     |> assign(repo: repo)
     |> assign(editing_collection: nil, confirm_delete_collection: nil)
     |> assign(stats: nil, collections: [], show_graph_stats: false)}
  end

  @impl true
  def handle_params(_params, _uri, socket) do
    {:noreply, load_data(socket)}
  end

  defp load_data(socket) do
    repo = socket.assigns.repo
    {collections, has_graph_data} = load_collections_with_stats(repo)

    socket
    |> assign(stats: load_stats(repo))
    |> assign(collections: collections)
    |> assign(show_graph_stats: has_graph_data)
  end

  defp load_collections_with_stats(repo) do
    # Base collection data with document count
    collections =
      repo.all(
        from(c in Collection,
          left_join: d in Arcana.Document,
          on: d.collection_id == c.id,
          group_by: c.id,
          order_by: c.name,
          select: %{
            id: c.id,
            name: c.name,
            description: c.description,
            document_count: count(d.id)
          }
        )
      )

    # Add chunk counts
    chunk_counts =
      repo.all(
        from(ch in Arcana.Chunk,
          join: d in Arcana.Document,
          on: ch.document_id == d.id,
          group_by: d.collection_id,
          select: {d.collection_id, count(ch.id)}
        )
      )
      |> Map.new()

    collections =
      Enum.map(collections, fn c ->
        Map.put(c, :chunk_count, Map.get(chunk_counts, c.id, 0))
      end)

    # Always try to add graph stats - show columns if any data exists
    add_graph_stats(repo, collections)
  end

  defp add_graph_stats(repo, collections) do
    entity_counts =
      repo.all(
        from(e in Arcana.Graph.Entity,
          group_by: e.collection_id,
          select: {e.collection_id, count(e.id)}
        )
      )
      |> Map.new()

    # Relationships don't have collection_id directly - join through source entity
    relationship_counts =
      repo.all(
        from(r in Arcana.Graph.Relationship,
          join: e in Arcana.Graph.Entity,
          on: r.source_id == e.id,
          group_by: e.collection_id,
          select: {e.collection_id, count(r.id)}
        )
      )
      |> Map.new()

    community_counts =
      repo.all(
        from(c in Arcana.Graph.Community,
          group_by: c.collection_id,
          select: {c.collection_id, count(c.id)}
        )
      )
      |> Map.new()

    has_graph_data = map_size(entity_counts) > 0 or map_size(relationship_counts) > 0

    collections_with_stats =
      Enum.map(collections, fn c ->
        c
        |> Map.put(:entity_count, Map.get(entity_counts, c.id, 0))
        |> Map.put(:relationship_count, Map.get(relationship_counts, c.id, 0))
        |> Map.put(:community_count, Map.get(community_counts, c.id, 0))
      end)

    {collections_with_stats, has_graph_data}
  rescue
    # Tables might not exist
    _ -> {collections, false}
  end

  @impl true
  def handle_event("create_collection", %{"collection" => params}, socket) do
    repo = socket.assigns.repo
    name = params["name"] || ""
    description = params["description"]

    case Collection.get_or_create(name, repo, description) do
      {:ok, _collection} ->
        {:noreply, load_data(socket)}

      {:error, changeset} ->
        {:noreply,
         put_flash(socket, :error, "Failed to create collection: #{inspect(changeset.errors)}")}
    end
  end

  def handle_event("edit_collection", %{"id" => id}, socket) do
    repo = socket.assigns.repo
    collection = repo.get(Collection, id)
    {:noreply, assign(socket, editing_collection: collection)}
  end

  def handle_event("cancel_edit_collection", _params, socket) do
    {:noreply, assign(socket, editing_collection: nil)}
  end

  def handle_event("update_collection", %{"id" => id, "collection" => params}, socket) do
    repo = socket.assigns.repo
    collection = repo.get!(Collection, id)

    changeset =
      Collection.changeset(collection, %{
        name: params["name"] || collection.name,
        description: params["description"]
      })

    case repo.update(changeset) do
      {:ok, _updated} ->
        {:noreply, socket |> assign(editing_collection: nil) |> load_data()}

      {:error, changeset} ->
        {:noreply, put_flash(socket, :error, "Failed to update: #{inspect(changeset.errors)}")}
    end
  end

  def handle_event("confirm_delete_collection", %{"id" => id}, socket) do
    {:noreply, assign(socket, confirm_delete_collection: id)}
  end

  def handle_event("cancel_delete_collection", _params, socket) do
    {:noreply, assign(socket, confirm_delete_collection: nil)}
  end

  def handle_event("delete_collection", %{"id" => id}, socket) do
    repo = socket.assigns.repo

    case repo.get(Collection, id) do
      nil ->
        {:noreply, assign(socket, confirm_delete_collection: nil)}

      collection ->
        repo.delete!(collection)
        {:noreply, socket |> assign(confirm_delete_collection: nil) |> load_data()}
    end
  end

  @impl true
  def render(assigns) do
    ~H"""
    <.dashboard_layout stats={@stats} current_tab={:collections}>
      <div class="arcana-collections">
        <h2>Collections</h2>
        <p class="arcana-tab-description">
          Organize documents into collections for scoped searches and better organization.
        </p>

        <div class="arcana-ingest-form">
          <h3>Create Collection</h3>
          <form id="new-collection-form" phx-submit="create_collection">
            <div class="arcana-form-row" style="margin-bottom: 0.75rem;">
              <input
                type="text"
                name="collection[name]"
                placeholder="Collection name"
                class="arcana-input"
                style="flex: 1; max-width: 300px;"
                required
              />
            </div>
            <div class="arcana-form-row">
              <input
                type="text"
                name="collection[description]"
                placeholder="Description (optional) - helps the agent select the right collection"
                class="arcana-input"
                style="flex: 1;"
              />
              <button type="submit" class="arcana-btn arcana-btn-primary">
                Create
              </button>
            </div>
          </form>
        </div>

        <div class="arcana-doc-list">
          <%= if Enum.empty?(@collections) do %>
            <div class="arcana-empty">No collections yet. Create one above.</div>
          <% else %>
            <table class="arcana-table">
              <thead>
                <tr>
                  <th>Name</th>
                  <th>Description</th>
                  <th>Docs</th>
                  <th>Chunks</th>
                  <%= if @show_graph_stats do %>
                    <th>Entities</th>
                    <th>Rels</th>
                    <th>Communities</th>
                  <% end %>
                  <th style="width: 120px;">Actions</th>
                </tr>
              </thead>
              <tbody>
                <%= for collection <- @collections do %>
                  <tr id={"collection-#{collection.name}"}>
                    <%= if @editing_collection && @editing_collection.id == collection.id do %>
                      <td colspan={if @show_graph_stats, do: 8, else: 5}>
                        <form
                          id={"edit-collection-form-#{collection.id}"}
                          phx-submit="update_collection"
                          phx-value-id={collection.id}
                          class="arcana-edit-form"
                        >
                          <div class="arcana-form-row">
                            <input
                              type="text"
                              name="collection[name]"
                              value={collection.name}
                              class="arcana-input"
                              disabled
                            />
                            <input
                              type="text"
                              name="collection[description]"
                              value={collection.description || ""}
                              placeholder="Description"
                              class="arcana-input"
                              style="flex: 2;"
                            />
                            <button type="submit" class="arcana-btn arcana-btn-primary">Save</button>
                            <button
                              type="button"
                              class="arcana-btn"
                              phx-click="cancel_edit_collection"
                            >
                              Cancel
                            </button>
                          </div>
                        </form>
                      </td>
                    <% else %>
                      <td><code><%= collection.name %></code></td>
                      <td><%= collection.description || "-" %></td>
                      <td><%= collection.document_count %></td>
                      <td><%= collection.chunk_count %></td>
                      <%= if @show_graph_stats do %>
                        <td><%= collection[:entity_count] || 0 %></td>
                        <td><%= collection[:relationship_count] || 0 %></td>
                        <td><%= collection[:community_count] || 0 %></td>
                      <% end %>
                      <td>
                        <%= if @confirm_delete_collection == collection.id do %>
                          <div class="arcana-confirm-delete">
                            <span>Delete?</span>
                            <button
                              id="confirm-delete"
                              class="arcana-btn arcana-btn-danger"
                              phx-click="delete_collection"
                              phx-value-id={collection.id}
                            >
                              Yes
                            </button>
                            <button
                              class="arcana-btn"
                              phx-click="cancel_delete_collection"
                            >
                              No
                            </button>
                          </div>
                        <% else %>
                          <div class="arcana-actions-cell">
                            <button
                              id={"edit-collection-#{collection.id}"}
                              class="arcana-icon-btn"
                              phx-click="edit_collection"
                              phx-value-id={collection.id}
                              title="Edit collection"
                            >
                              <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
                                <path d="M11 4H4a2 2 0 0 0-2 2v14a2 2 0 0 0 2 2h14a2 2 0 0 0 2-2v-7"></path>
                                <path d="M18.5 2.5a2.121 2.121 0 0 1 3 3L12 15l-4 1 1-4 9.5-9.5z"></path>
                              </svg>
                            </button>
                            <button
                              id={"delete-collection-#{collection.id}"}
                              class="arcana-delete-btn"
                              phx-click="confirm_delete_collection"
                              phx-value-id={collection.id}
                              title="Delete collection"
                            >
                              <svg xmlns="http://www.w3.org/2000/svg" width="16" height="16" viewBox="0 0 24 24" fill="none" stroke="currentColor" stroke-width="2" stroke-linecap="round" stroke-linejoin="round">
                                <polyline points="3 6 5 6 21 6"></polyline>
                                <path d="M19 6v14a2 2 0 0 1-2 2H7a2 2 0 0 1-2-2V6m3 0V4a2 2 0 0 1 2-2h4a2 2 0 0 1 2 2v2"></path>
                                <line x1="10" y1="11" x2="10" y2="17"></line>
                                <line x1="14" y1="11" x2="14" y2="17"></line>
                              </svg>
                            </button>
                          </div>
                        <% end %>
                      </td>
                    <% end %>
                  </tr>
                <% end %>
              </tbody>
            </table>
          <% end %>
        </div>
      </div>
    </.dashboard_layout>
    """
  end
end