import { For, createSignal, createMemo, onCleanup, onMount } from "solid-js";
import {
  DragDropProvider,
  DragDropSensors,
  SortableProvider,
  useDragDropContext,
  closestCenter,
} from "@thisbeyond/solid-dnd";
import type { DeckStore } from "../hooks/deckStore";
import { LayerRow } from "./LayerRow";

export interface LayerEditorPanelProps {
  store: DeckStore;
}

function LayerEditorPanel(props: LayerEditorPanelProps) {
  const { store } = props;
  const [openDropdown, setOpenDropdown] = createSignal<string | null>(null);
  const [hoveredIndex, setHoveredIndex] = createSignal<number | null>(null);
  const [addMenuOpen, setAddMenuOpen] = createSignal(false);
  let addMenuRef: HTMLDivElement | undefined;

  const side = () => store.state.activeSide;
  const layers = () =>
    side() === "front"
      ? store.state.frontLayerConfigs
      : store.state.backLayerConfigs;

  // Stable IDs for SortableProvider — simply the indices
  const ids = createMemo(() => layers().map((_, i) => i));

  const updater = () =>
    side() === "front"
      ? store.actions.updateFrontLayerConfig
      : store.actions.updateBackLayerConfig;

  const availableFields = createMemo(() => {
    const cards = store.state.cards;
    if (!cards?.length) return [];
    return Object.keys(cards[0]).filter((k) => k !== "label");
  });

  const update = (
    index: number,
    patch: Partial<import("../types").LayerConfig>,
    closeDropdown = false,
  ) => {
    updater()(index, patch);
    if (closeDropdown) setOpenDropdown(null);
  };

  onMount(() => {
    const h = (e: MouseEvent) => {
      if (addMenuRef && !addMenuRef.contains(e.target as Node))
        setAddMenuOpen(false);
    };
    document.addEventListener("click", h);
    onCleanup(() => document.removeEventListener("click", h));
  });

  return (
    <div class="w-64 shrink-0">
      <h3 class="font-bold mb-2 mt-0">
        图层 ({side() === "front" ? "正面" : "背面"})
      </h3>

      <div class="relative mb-2" ref={addMenuRef}>
        <button
          onClick={() => setAddMenuOpen(!addMenuOpen())}
          class="w-full flex items-center gap-2 px-3 py-1.5 text-sm rounded cursor-pointer border border-dashed border-gray-300 bg-gray-50 hover:bg-gray-100 text-gray-600"
        >
          <span class="text-lg leading-none">+</span>
          <span>添加图层</span>
        </button>
        {addMenuOpen() && (
          <div
            class="absolute top-full left-0 mt-1 w-full bg-white border border-gray-300 rounded shadow-lg z-20 max-h-48 overflow-y-auto"
            onClick={(e) => e.stopPropagation()}
          >
            <For each={availableFields()}>
              {(f) => (
                <button
                  onClick={() => {
                    store.actions.addLayer(side(), f);
                    setAddMenuOpen(false);
                  }}
                  class="block w-full text-left px-3 py-1.5 text-sm hover:bg-blue-50 hover:text-blue-600 cursor-pointer"
                >
                  {f}
                </button>
              )}
            </For>
          </div>
        )}
      </div>

      <DragDropProvider
        onDragEnd={({ draggable, droppable }) => {
          if (droppable && draggable.id !== droppable.id) {
            store.actions.reorderLayers(
              side(),
              draggable.id as number,
              droppable.id as number,
            );
          }
        }}
        collisionDetector={closestCenter}
      >
        <DragDropSensors>
          <SortableProvider ids={ids()}>
            <For each={layers()}>
              {(layer, index) => (
                <LayerRow
                  store={store}
                  index={index()}
                  layer={layer}
                  hovered={hoveredIndex() === index()}
                  onHoverChange={setHoveredIndex}
                  openDropdown={openDropdown()}
                  setOpenDropdown={setOpenDropdown}
                  onUpdateOrientation={(o) =>
                    update(index(), { orientation: o }, true)
                  }
                  onUpdateFontSize={(fs) => update(index(), { fontSize: fs })}
                  onUpdateAlign={(a) => update(index(), { align: a }, true)}
                  onSelect={() =>
                    store.actions.setSelectedLayer(
                      store.state.selectedLayer === index() ? null : index(),
                    )
                  }
                  onRemove={() => store.actions.removeLayer(side(), index())}
                />
              )}
            </For>
          </SortableProvider>
        </DragDropSensors>
      </DragDropProvider>

      <hr class="my-4" />
      <button
        onClick={() => store.actions.copyCode()}
        class="w-full bg-blue-600 hover:bg-blue-700 text-white px-3 py-2 rounded text-sm font-medium cursor-pointer flex items-center gap-2 justify-center"
      >
        <span>📋</span>
        <span>复制代码</span>
      </button>
    </div>
  );
}

export { LayerEditorPanel };