import { findLayerLocation, isReferencedMaskLayer, mapLayerInDocument, insertLayer, replaceLayerListInDocument, replaceSelectedLayersWithGroup, removeLayerFromDocument, ungroupLayerInDocument, findGroup, removeLayerMaskReference, withLayerMask, removeUnreferencedMaskLayer, removeMissingMaskReferences, isMaskEditFor, isMaskEditValid, collectLayerIds, collectClippingMaskIds, collectAttachedMaskIds, removeInpaintRegionsForTargets } from "./document-tree";
import type { Asset } from "@core/asset";
import type { ImageDocument } from "@core/document";
import type { Rect } from "@core/geometry";
import type { ArtboardId, AssetId, LayerId } from "@core/id";
import type { ImageLayer } from "@core/image-layer";
import { getLayerMask } from "@core/layer-mask-utils";
import type { RasterLayer } from "@core/raster-layer";
import type { Layer } from "@core/layer";
import type { LayerGroup } from "@core/layer-group";
import type { AdjustmentLayer, ColorAdjustment } from "@core/adjustment-layer";
import type { TextLayer, TextStyle } from "@core/text-layer";
import { isValidTextStyle } from "@core/text-layer";
import type { Command } from "./command";
import { commandIds } from "./ids";

export type DocumentAddArtboardPayload = {
  id: ArtboardId;
  name: string;
  bounds: Rect;
};

export type DocumentSetArtboardBoundsPayload = {
  id: ArtboardId;
  bounds: Rect;
};

export type DocumentResizeArtboardPayload = {
  id: ArtboardId;
  bounds: Rect;
  scaleContents: boolean;
};

export type DocumentRemoveArtboardPayload = {
  id: ArtboardId;
};

export type DocumentSetArtboardVisiblePayload = {
  id: ArtboardId;
  visible: boolean;
};

export type DocumentSetArtboardLockedPayload = {
  id: ArtboardId;
  locked: boolean;
};

export type DocumentRenameArtboardPayload = {
  id: ArtboardId;
  name: string;
};

export type DocumentAddAssetPayload = {
  asset: Asset;
};

export type DocumentUpdateAssetSourcePayload = {
  assetId: AssetId;
  source: string;
};

export type DocumentAddImageLayerPayload = {
  artboardId: ArtboardId;
  parentGroupId?: LayerId;
  layer: ImageLayer;
};

export type DocumentAddRasterLayerPayload = {
  artboardId: ArtboardId;
  parentGroupId?: LayerId;
  layer: RasterLayer;
};

export type DocumentAddGroupLayerPayload = {
  artboardId: ArtboardId;
  parentGroupId?: LayerId;
  group: LayerGroup;
};
export type DocumentAddAdjustmentLayerPayload = { artboardId: ArtboardId; parentGroupId?: LayerId; layer: AdjustmentLayer };
export type DocumentSetAdjustmentPayload = { layerId: LayerId; adjustment: ColorAdjustment };
export type DocumentAddTextLayerPayload = { artboardId: ArtboardId; parentGroupId?: LayerId; layer: TextLayer };
export type DocumentSetTextLayerPayload = { layerId: LayerId; content: string; style: TextStyle };

export type DocumentMoveLayerPayload = {
  layerId: LayerId;
  toArtboardId: ArtboardId;
  toParentGroupId?: LayerId;
  toIndex: number;
};

export type DocumentGroupLayersPayload = {
  artboardId: ArtboardId;
  layerIds: LayerId[];
  group: LayerGroup;
};

export type DocumentUngroupLayerPayload = {
  groupId: LayerId;
};

export type DocumentRemoveLayerPayload = {
  layerId: LayerId;
};

export type DocumentSetLayerVisiblePayload = {
  layerId: LayerId;
  visible: boolean;
};

export type DocumentSetLayerLockedPayload = {
  layerId: LayerId;
  locked: boolean;
};

export type DocumentSetLayerOpacityPayload = {
  layerId: LayerId;
  opacity: number;
};

export type DocumentSetLayerSourceRectPayload = {
  layerId: LayerId;
  sourceRect?: Rect;
};

export type DocumentDuplicateLayerPayload = {
  layerId: LayerId;
  idByLayerId: Record<LayerId, LayerId>;
};

export type DocumentRenameLayerPayload = {
  layerId: LayerId;
  name: string;
};

export type DocumentSetLayerClippingMaskPayload = {
  layerId: LayerId;
  maskLayerId?: LayerId;
};

export type DocumentAddLayerMaskPayload = {
  layerId: LayerId;
  asset: Asset;
  maskLayer: RasterLayer;
  activeTool?: "brush" | "feather";
};

export type LayerMaskOperation =
  | { type: "paint" }
  | { type: "magicWand" }
  | { type: "chromaKey" }
  | { type: "invert" }
  | { type: "fill"; fill: "white" | "black" | "clear" }
  | { type: "feather"; radius: number }
  | { type: "expand"; radius: number }
  | { type: "contract"; radius: number }
  | { type: "blur"; radius: number }
  | { type: "despeckle"; strength: number };

export type DocumentApplyLayerMaskOperationPayload = {
  maskLayerId: LayerId;
  source: string;
  mimeType?: string;
  operation: LayerMaskOperation;
};

export type DocumentRemoveLayerMaskPayload = {
  layerId: LayerId;
};

export const documentAddArtboardCommand: Command<DocumentAddArtboardPayload> = {
  id: commandIds.documentAddArtboard,
  name: "Add artboard",
  execute({ state }, payload) {
    return {
      ...state,
      document: {
        ...state.document,
        artboards: [
          ...state.document.artboards,
          {
            id: payload.id,
            name: payload.name,
            bounds: payload.bounds,
            backgroundColor: "transparent",
            visible: true,
            locked: false,
            layers: [],
          },
        ],
      },
    };
  },
};

export const documentSetArtboardBoundsCommand: Command<DocumentSetArtboardBoundsPayload> = {
  id: commandIds.documentSetArtboardBounds,
  name: "Set artboard bounds",
  execute({ state }, payload) {
    return {
      ...state,
      document: {
        ...state.document,
        artboards: state.document.artboards.map((artboard) =>
          artboard.id === payload.id ? { ...artboard, bounds: { ...payload.bounds } } : artboard,
        ),
      },
    };
  },
};

export const documentResizeArtboardCommand: Command<DocumentResizeArtboardPayload> = {
  id: commandIds.documentResizeArtboard,
  name: "Resize artboard",
  execute({ state }, payload) {
    const artboard = state.document.artboards.find((candidate) => candidate.id === payload.id);
    const bounds = validRect(payload.bounds);
    if (!artboard || artboard.locked || !bounds) return state;
    const scaleX = bounds.w / artboard.bounds.w;
    const scaleY = bounds.h / artboard.bounds.h;
    return {
      ...state,
      document: {
        ...state.document,
        artboards: state.document.artboards.map((candidate) => candidate.id !== payload.id ? candidate : {
          ...candidate,
          bounds,
          layers: payload.scaleContents ? scaleLayerTree(candidate.layers, artboard.bounds, bounds, scaleX, scaleY) : candidate.layers,
        }),
      },
    };
  },
};

export const documentRemoveArtboardCommand: Command<DocumentRemoveArtboardPayload> = {
  id: commandIds.documentRemoveArtboard,
  name: "Remove artboard",
  execute({ state }, payload) {
    const removedSelectedArtboard = state.editor.selection.artboardId === payload.id;
    const removedArtboard = state.document.artboards.find((artboard) => artboard.id === payload.id);
    const withoutArtboard = {
      ...state.document,
      artboards: state.document.artboards.filter((artboard) => artboard.id !== payload.id),
    };
    const removedLayerIds = new Set<LayerId>();
    for (const layer of removedArtboard?.layers ?? []) collectLayerIds(layer, removedLayerIds);
    const document = removeInpaintRegionsForTargets(withoutArtboard, removedLayerIds);

    return {
      ...state,
      document,
      editor: {
        ...state.editor,
        selection: removedSelectedArtboard ? { layerIds: [] } : state.editor.selection,
        maskEdit: isMaskEditValid(state.editor.maskEdit, document) ? state.editor.maskEdit : undefined,
      },
    };
  },
};

export const documentSetArtboardVisibleCommand: Command<DocumentSetArtboardVisiblePayload> = {
  id: commandIds.documentSetArtboardVisible,
  name: "Set artboard visible",
  execute({ state }, payload) {
    return {
      ...state,
      document: {
        ...state.document,
        artboards: state.document.artboards.map((artboard) => (artboard.id === payload.id ? { ...artboard, visible: payload.visible } : artboard)),
      },
    };
  },
};

export const documentSetArtboardLockedCommand: Command<DocumentSetArtboardLockedPayload> = {
  id: commandIds.documentSetArtboardLocked,
  name: "Set artboard locked",
  execute({ state }, payload) {
    return {
      ...state,
      document: {
        ...state.document,
        artboards: state.document.artboards.map((artboard) => (artboard.id === payload.id ? { ...artboard, locked: payload.locked } : artboard)),
      },
    };
  },
};

export const documentRenameArtboardCommand: Command<DocumentRenameArtboardPayload> = {
  id: commandIds.documentRenameArtboard,
  name: "Rename artboard",
  execute({ state }, payload) {
    const name = payload.name.trim();
    if (!name) return state;
    return {
      ...state,
      document: {
        ...state.document,
        artboards: state.document.artboards.map((artboard) => (artboard.id === payload.id ? { ...artboard, name } : artboard)),
      },
    };
  },
};

export const documentAddAssetCommand: Command<DocumentAddAssetPayload> = {
  id: commandIds.documentAddAsset,
  name: "Add asset",
  execute({ state }, payload) {
    if (state.document.assets.some((asset) => asset.id === payload.asset.id)) return state;

    return {
      ...state,
      document: {
        ...state.document,
        assets: [...state.document.assets, payload.asset],
      },
    };
  },
};

export const documentUpdateAssetSourceCommand: Command<DocumentUpdateAssetSourcePayload> = {
  id: commandIds.documentUpdateAssetSource,
  name: "Update asset source",
  execute({ state }, payload) {
    return {
      ...state,
      document: {
        ...state.document,
        assets: state.document.assets.map((asset) => (asset.id === payload.assetId ? { ...asset, source: payload.source } : asset)),
      },
    };
  },
};

export const documentAddImageLayerCommand: Command<DocumentAddImageLayerPayload> = {
  id: commandIds.documentAddImageLayer,
  name: "Add image layer",
  execute({ state }, payload) {
    return {
      ...state,
      document: insertLayer(state.document, payload.artboardId, payload.parentGroupId, payload.layer),
    };
  },
};

export const documentAddRasterLayerCommand: Command<DocumentAddRasterLayerPayload> = {
  id: commandIds.documentAddRasterLayer,
  name: "Add raster layer",
  execute({ state }, payload) {
    return {
      ...state,
      document: insertLayer(state.document, payload.artboardId, payload.parentGroupId, payload.layer),
    };
  },
};

export const documentAddGroupLayerCommand: Command<DocumentAddGroupLayerPayload> = {
  id: commandIds.documentAddGroupLayer,
  name: "Add group layer",
  execute({ state }, payload) {
    return {
      ...state,
      document: insertLayer(state.document, payload.artboardId, payload.parentGroupId, payload.group),
      editor: { ...state.editor, selection: { artboardId: payload.artboardId, layerIds: [payload.group.id] } },
    };
  },
};

export const documentAddAdjustmentLayerCommand: Command<DocumentAddAdjustmentLayerPayload> = {
  id: commandIds.documentAddAdjustmentLayer,
  name: "Add adjustment layer",
  execute({ state }, payload) {
    if (payload.parentGroupId || !validAdjustment(payload.layer.adjustment)) return state;
    return { ...state, document: insertLayer(state.document, payload.artboardId, undefined, payload.layer, 0), editor: { ...state.editor, selection: { artboardId: payload.artboardId, layerIds: [payload.layer.id] } } };
  },
};

export const documentAddTextLayerCommand: Command<DocumentAddTextLayerPayload> = {
  id: commandIds.documentAddTextLayer,
  name: "Add text layer",
  execute({ state }, payload) {
    if (!payload.layer.content.trim() || !isValidTextStyle(payload.layer.style)) return state;
    const document = insertLayer(state.document, payload.artboardId, payload.parentGroupId, payload.layer);
    return { ...state, document, editor: { ...state.editor, selection: { artboardId: payload.artboardId, layerIds: [payload.layer.id] } } };
  },
};

export const documentSetTextLayerCommand: Command<DocumentSetTextLayerPayload> = {
  id: commandIds.documentSetTextLayer,
  name: "Edit text layer",
  execute({ state }, payload) {
    const location = findLayerLocation(state.document, payload.layerId);
    if (!location || location.layer.type !== "text" || location.layer.locked || !payload.content.trim() || !isValidTextStyle(payload.style)) return state;
    return { ...state, document: mapLayerInDocument(state.document, payload.layerId, (layer) => layer.type === "text" ? { ...layer, content: payload.content, style: { ...payload.style } } : layer) };
  },
};

export const documentSetAdjustmentCommand: Command<DocumentSetAdjustmentPayload> = {
  id: commandIds.documentSetAdjustment,
  name: "Edit adjustment layer",
  execute({ state }, payload) {
    const location = findLayerLocation(state.document, payload.layerId);
    if (!location || location.layer.type !== "adjustment" || location.layer.locked || !validAdjustment(payload.adjustment)) return state;
    return { ...state, document: mapLayerInDocument(state.document, payload.layerId, (layer) => layer.type === "adjustment" ? { ...layer, adjustment: payload.adjustment } : layer) };
  },
};

export const documentMoveLayerCommand: Command<DocumentMoveLayerPayload> = {
  id: commandIds.documentMoveLayer,
  name: "Move layer",
  execute({ state }, payload) {
    const source = findLayerLocation(state.document, payload.layerId);
    if (source?.layer.type === "adjustment" && payload.toParentGroupId) return state;
    if (payload.toParentGroupId && !findGroup(state.document, payload.toParentGroupId)) return state;

    const removed = removeLayerFromDocument(state.document, payload.layerId);
    if (!removed.layer) return state;

    const maskLayerId = getLayerMask(removed.layer)?.maskLayerId;
    const removedMask = maskLayerId ? removeLayerFromDocument(removed.document, maskLayerId) : undefined;
    const documentAfterRemoval = removedMask?.document ?? removed.document;
    if (payload.toParentGroupId && !findGroup(documentAfterRemoval, payload.toParentGroupId)) return state;

    const documentWithMask = removedMask?.layer
      ? insertLayer(documentAfterRemoval, payload.toArtboardId, payload.toParentGroupId, removedMask.layer, payload.toIndex)
      : documentAfterRemoval;

    return {
      ...state,
      document: insertLayer(documentWithMask, payload.toArtboardId, payload.toParentGroupId, removed.layer, payload.toIndex + (removedMask?.layer ? 1 : 0)),
    };
  },
};

export const documentGroupLayersCommand: Command<DocumentGroupLayersPayload> = {
  id: commandIds.documentGroupLayers,
  name: "Group layers",
  execute({ state }, payload) {
    const requestedIds = [...new Set(payload.layerIds)];
    if (requestedIds.length === 0) return state;
    if (findLayerLocation(state.document, payload.group.id)) return state;

    const requestedLocations = requestedIds.flatMap((layerId) => {
      const location = findLayerLocation(state.document, layerId);
      return location ? [location] : [];
    });
    if (requestedLocations.some((location) => location.layer.type === "adjustment")) return state;
    if (requestedLocations.length !== requestedIds.length) return state;

    const firstLocation = requestedLocations[0];
    if (!firstLocation || firstLocation.artboardId !== payload.artboardId) return state;
    if (requestedLocations.some((location) => location.artboardId !== firstLocation.artboardId || location.parentGroupId !== firstLocation.parentGroupId)) return state;

    const uniqueIds = new Set([...requestedIds, ...collectAttachedMaskIds(firstLocation.siblings, requestedIds)]);
    const selected = firstLocation.siblings.filter((layer) => uniqueIds.has(layer.id));
    if (selected.length === 0) return state;

    const group: LayerGroup = { ...payload.group, children: selected };
    const document = replaceLayerListInDocument(
      state.document,
      firstLocation.artboardId,
      firstLocation.parentGroupId,
      replaceSelectedLayersWithGroup(firstLocation.siblings, uniqueIds, group),
    );

    return {
      ...state,
      document,
      editor: { ...state.editor, selection: { artboardId: payload.artboardId, layerIds: [group.id] } },
    };
  },
};

export const documentUngroupLayerCommand: Command<DocumentUngroupLayerPayload> = {
  id: commandIds.documentUngroupLayer,
  name: "Ungroup layer",
  execute({ state }, payload) {
    const result = ungroupLayerInDocument(state.document, payload.groupId);
    if (!result.changed) return state;

    return {
      ...state,
      document: result.document,
      editor: { ...state.editor, selection: { artboardId: result.artboardId, layerIds: result.children.map((layer) => layer.id) } },
    };
  },
};

export const documentSetLayerVisibleCommand: Command<DocumentSetLayerVisiblePayload> = {
  id: commandIds.documentSetLayerVisible,
  name: "Set layer visible",
  execute({ state }, payload) {
    return { ...state, document: mapLayerInDocument(state.document, payload.layerId, (layer) => ({ ...layer, visible: payload.visible })) };
  },
};

export const documentSetLayerLockedCommand: Command<DocumentSetLayerLockedPayload> = {
  id: commandIds.documentSetLayerLocked,
  name: "Set layer locked",
  execute({ state }, payload) {
    return { ...state, document: mapLayerInDocument(state.document, payload.layerId, (layer) => ({ ...layer, locked: payload.locked })) };
  },
};

export const documentSetLayerOpacityCommand: Command<DocumentSetLayerOpacityPayload> = {
  id: commandIds.documentSetLayerOpacity,
  name: "Set layer opacity",
  execute({ state }, payload) {
    const location = findLayerLocation(state.document, payload.layerId);
    if (!location || location.layer.locked || !Number.isFinite(payload.opacity)) return state;
    const opacity = Math.min(1, Math.max(0, payload.opacity));
    return { ...state, document: mapLayerInDocument(state.document, payload.layerId, (layer) => ({ ...layer, opacity })) };
  },
};

export const documentSetLayerSourceRectCommand: Command<DocumentSetLayerSourceRectPayload> = {
  id: commandIds.documentSetLayerSourceRect,
  name: "Crop layer",
  execute({ state }, payload) {
    const location = findLayerLocation(state.document, payload.layerId);
    if (!location || (location.layer.type !== "image" && location.layer.type !== "raster") || location.layer.locked || location.layer.transform.rotation !== 0) return state;
    const leaf = location.layer;
    const asset = state.document.assets.find((candidate) => candidate.id === leaf.assetId);
    if (!asset) return state;
    const sourceRect = payload.sourceRect ? clampSourceRect(payload.sourceRect, asset.intrinsicSize.w, asset.intrinsicSize.h) : undefined;
    if (payload.sourceRect && !sourceRect) return state;
    return { ...state, document: mapLayerInDocument(state.document, payload.layerId, (layer) => {
      if (layer.type !== "image" && layer.type !== "raster") return layer;
      if (sourceRect) return { ...layer, sourceRect };
      const uncropped = { ...layer };
      delete uncropped.sourceRect;
      return uncropped;
    }) };
  },
};

export const documentDuplicateLayerCommand: Command<DocumentDuplicateLayerPayload> = {
  id: commandIds.documentDuplicateLayer,
  name: "Duplicate layer",
  execute({ state }, payload) {
    const location = findLayerLocation(state.document, payload.layerId);
    if (!location || location.layer.locked) return state;
    const maskId = getLayerMask(location.layer)?.maskLayerId;
    const mask = maskId ? location.siblings.find((layer) => layer.id === maskId) : undefined;
    const sourceLayers = mask ? [mask, location.layer] : [location.layer];
    const sourceIds = new Set(sourceLayers.flatMap((layer) => [...collectLayerIds(layer)]));
    const mappedIds = [...sourceIds].map((id) => payload.idByLayerId[id]);
    if (mappedIds.some((id) => !id) || new Set(mappedIds).size !== mappedIds.length || mappedIds.some((id) => findLayerLocation(state.document, id!))) return state;

    const duplicates = sourceLayers.map((layer) => duplicateLayerTree(layer, payload.idByLayerId));
    const insertionIndex = Math.max(...sourceLayers.map((layer) => location.siblings.findIndex((candidate) => candidate.id === layer.id))) + 1;
    const siblings = [...location.siblings.slice(0, insertionIndex), ...duplicates, ...location.siblings.slice(insertionIndex)];
    const duplicatedLayerId = payload.idByLayerId[payload.layerId];
    if (!duplicatedLayerId) return state;
    return {
      ...state,
      document: replaceLayerListInDocument(state.document, location.artboardId, location.parentGroupId, siblings),
      editor: { ...state.editor, selection: { artboardId: location.artboardId, layerIds: [duplicatedLayerId] } },
    };
  },
};

function duplicateLayerTree(layer: Layer, idByLayerId: Record<LayerId, LayerId>): Layer {
  const layerMask = getLayerMask(layer);
  const duplicatedMaskId = layerMask ? idByLayerId[layerMask.maskLayerId] : undefined;
  const duplicated = {
    ...layer,
    id: idByLayerId[layer.id]!,
    name: `${layer.name} copy`,
    transform: { ...layer.transform, position: { ...layer.transform.position }, scale: { ...layer.transform.scale } },
    ...(layerMask && duplicatedMaskId ? { layerMask: { ...layerMask, maskLayerId: duplicatedMaskId }, clippingMask: layer.clippingMask ? { maskLayerId: duplicatedMaskId } : undefined } : {}),
  };
  return layer.type === "group" ? { ...duplicated, type: "group", children: layer.children.map((child) => duplicateLayerTree(child, idByLayerId)) } : duplicated;
}

export const documentRenameLayerCommand: Command<DocumentRenameLayerPayload> = {
  id: commandIds.documentRenameLayer,
  name: "Rename layer",
  execute({ state }, payload) {
    const name = payload.name.trim();
    if (!name) return state;
    return { ...state, document: mapLayerInDocument(state.document, payload.layerId, (layer) => ({ ...layer, name })) };
  },
};

export const documentSetLayerClippingMaskCommand: Command<DocumentSetLayerClippingMaskPayload> = {
  id: commandIds.documentSetLayerClippingMask,
  name: "Set layer clipping mask",
  execute({ state }, payload) {
    if (payload.maskLayerId === payload.layerId) return state;

    if (!payload.maskLayerId) {
      const previousMaskId = getLayerMask(findLayerLocation(state.document, payload.layerId)?.layer)?.maskLayerId;
      return {
        ...state,
        document: mapLayerInDocument(state.document, payload.layerId, (layer) => removeLayerMaskReference(layer)),
        editor: {
          ...state.editor,
          maskEdit: previousMaskId && isMaskEditFor(state.editor.maskEdit, payload.layerId, previousMaskId) ? undefined : state.editor.maskEdit,
        },
      };
    }

    const targetLocation = findLayerLocation(state.document, payload.layerId);
    const maskLocation = findLayerLocation(state.document, payload.maskLayerId);
    if (!targetLocation || !maskLocation) return state;
    if (targetLocation.layer.type === "adjustment" || targetLocation.layer.type === "text") return state;
    if (targetLocation.artboardId !== maskLocation.artboardId || targetLocation.parentGroupId !== maskLocation.parentGroupId) return state;

    const removed = removeLayerFromDocument(state.document, payload.layerId);
    if (!removed.layer) return state;

    const maskLocationAfterRemoval = findLayerLocation(removed.document, payload.maskLayerId);
    if (!maskLocationAfterRemoval) return state;

    return {
      ...state,
      document: insertLayer(
        removed.document,
        maskLocationAfterRemoval.artboardId,
        maskLocationAfterRemoval.parentGroupId,
        withLayerMask(removed.layer, payload.maskLayerId),
        maskLocationAfterRemoval.index + 1,
      ),
    };
  },
};

export const documentAddLayerMaskCommand: Command<DocumentAddLayerMaskPayload> = {
  id: commandIds.documentAddLayerMask,
  name: "Add layer mask",
  execute({ state }, payload) {
    const targetLocation = findLayerLocation(state.document, payload.layerId);
    if (!targetLocation || (targetLocation.layer.type !== "image" && targetLocation.layer.type !== "raster")) return state;

    const existingMaskId = getLayerMask(targetLocation.layer)?.maskLayerId;
    if (existingMaskId) {
      const existingMaskLocation = findLayerLocation(state.document, existingMaskId);
      const existingMaskLayer = existingMaskLocation?.layer;
      if (existingMaskLayer && existingMaskLayer.type !== "image" && existingMaskLayer.type !== "raster") return state;
      if (existingMaskLocation && existingMaskLayer) {
        return {
          ...state,
          editor: {
            ...state.editor,
            selection: { artboardId: targetLocation.artboardId, layerIds: [payload.layerId] },
            maskEdit: { kind: "layerMask", targetLayerId: payload.layerId, maskLayerId: existingMaskId, maskAssetId: existingMaskLayer.assetId },
            tools: {
              ...state.editor.tools,
              activeTool: payload.activeTool ?? "brush",
              interactionMode: { type: "tool", tool: payload.activeTool ?? "brush" },
            },
          },
        };
      }
    }

    if (payload.maskLayer.id === payload.layerId) return state;
    if (state.document.assets.some((asset) => asset.id === payload.asset.id)) return state;
    if (findLayerLocation(state.document, payload.maskLayer.id)) return state;

    const maskLayer: RasterLayer = {
      ...payload.maskLayer,
      visible: true,
      locked: false,
      opacity: 1,
      layerMask: undefined,
      clippingMask: undefined,
    };
    const withAsset: ImageDocument = { ...state.document, assets: [...state.document.assets, payload.asset] };
    const withMaskLayer = insertLayer(withAsset, targetLocation.artboardId, targetLocation.parentGroupId, maskLayer, targetLocation.index);
    const document = mapLayerInDocument(withMaskLayer, payload.layerId, (layer) => withLayerMask(layer, maskLayer.id));

    return {
      ...state,
      document,
      editor: {
        ...state.editor,
        selection: { artboardId: targetLocation.artboardId, layerIds: [payload.layerId] },
        maskEdit: { kind: "layerMask", targetLayerId: payload.layerId, maskLayerId: maskLayer.id, maskAssetId: payload.asset.id },
        tools: {
          ...state.editor.tools,
          activeTool: payload.activeTool ?? "brush",
          interactionMode: { type: "tool", tool: payload.activeTool ?? "brush" },
        },
      },
    };
  },
};

export const documentApplyLayerMaskOperationCommand: Command<DocumentApplyLayerMaskOperationPayload> = {
  id: commandIds.documentApplyLayerMaskOperation,
  name: "Apply layer mask operation",
  execute({ state }, payload) {
    if (!payload.source.trim()) return state;

    const maskLocation = findLayerLocation(state.document, payload.maskLayerId);
    if (!maskLocation || (maskLocation.layer.type !== "image" && maskLocation.layer.type !== "raster")) return state;
    if (!isReferencedMaskLayer(state.document, payload.maskLayerId)) return state;
    const maskAssetId = maskLocation.layer.assetId;

    return {
      ...state,
      document: {
        ...state.document,
        assets: state.document.assets.map((asset) =>
          asset.id === maskAssetId
            ? {
                ...asset,
                source: payload.source,
                mimeType: payload.mimeType ?? asset.mimeType,
              }
            : asset,
        ),
      },
      editor: {
        ...state.editor,
        brushStrokePreview: state.editor.brushStrokePreview?.assetId === maskAssetId ? undefined : state.editor.brushStrokePreview,
      },
    };
  },
};

export const documentRemoveLayerMaskCommand: Command<DocumentRemoveLayerMaskPayload> = {
  id: commandIds.documentRemoveLayerMask,
  name: "Remove layer mask",
  execute({ state }, payload) {
    const targetLocation = findLayerLocation(state.document, payload.layerId);
    const maskLayerId = targetLocation?.layer ? getLayerMask(targetLocation.layer)?.maskLayerId : undefined;
    if (!targetLocation || !maskLayerId) {
      return state.editor.maskEdit?.targetLayerId === payload.layerId ? { ...state, editor: { ...state.editor, maskEdit: undefined } } : state;
    }

    const unmasked = mapLayerInDocument(state.document, payload.layerId, (layer) => removeLayerMaskReference(layer));
    const document = removeUnreferencedMaskLayer(unmasked, maskLayerId);

    return {
      ...state,
      document,
      editor: {
        ...state.editor,
        selection: { artboardId: targetLocation.artboardId, layerIds: [payload.layerId] },
        maskEdit: isMaskEditFor(state.editor.maskEdit, payload.layerId, maskLayerId) ? undefined : state.editor.maskEdit,
      },
    };
  },
};

export const documentRemoveLayerCommand: Command<DocumentRemoveLayerPayload> = {
  id: commandIds.documentRemoveLayer,
  name: "Remove layer",
  execute({ state }, payload) {
    const removed = removeLayerFromDocument(state.document, payload.layerId);
    if (!removed.layer) return state;

    const removedLayerIds = collectLayerIds(removed.layer);
    const removedMaskLayerIds = collectClippingMaskIds([removed.layer]);
    const cleanedReferences = removeMissingMaskReferences(removed.document);
    const withoutMasks = [...removedMaskLayerIds].reduce((nextDocument, maskLayerId) => removeUnreferencedMaskLayer(nextDocument, maskLayerId), cleanedReferences);
    const document = removeInpaintRegionsForTargets(withoutMasks, removedLayerIds);
    const selection = {
      ...state.editor.selection,
      layerIds: state.editor.selection.layerIds.filter((id) => !removedLayerIds.has(id)),
    };

    return {
      ...state,
      document,
      editor: {
        ...state.editor,
        selection,
        maskEdit: isMaskEditValid(state.editor.maskEdit, document) ? state.editor.maskEdit : undefined,
      },
    };
  },
};

export const documentCommands = [
  documentAddArtboardCommand,
  documentSetArtboardBoundsCommand,
  documentResizeArtboardCommand,
  documentRemoveArtboardCommand,
  documentSetArtboardVisibleCommand,
  documentSetArtboardLockedCommand,
  documentRenameArtboardCommand,
  documentAddAssetCommand,
  documentUpdateAssetSourceCommand,
  documentAddImageLayerCommand,
  documentAddRasterLayerCommand,
  documentAddGroupLayerCommand,
  documentAddAdjustmentLayerCommand,
  documentAddTextLayerCommand,
  documentSetTextLayerCommand,
  documentSetAdjustmentCommand,
  documentMoveLayerCommand,
  documentGroupLayersCommand,
  documentUngroupLayerCommand,
  documentRemoveLayerCommand,
  documentSetLayerVisibleCommand,
  documentSetLayerLockedCommand,
  documentSetLayerOpacityCommand,
  documentSetLayerSourceRectCommand,
  documentDuplicateLayerCommand,
  documentRenameLayerCommand,
  documentSetLayerClippingMaskCommand,
  documentAddLayerMaskCommand,
  documentApplyLayerMaskOperationCommand,
  documentRemoveLayerMaskCommand,
] satisfies Command<unknown>[];

function validRect(rect: Rect): Rect | undefined {
  return [rect.x, rect.y, rect.w, rect.h].every(Number.isFinite) && rect.w >= 1 && rect.h >= 1 ? { ...rect } : undefined;
}

function validAdjustment(value: ColorAdjustment): boolean {
  return [value.brightness, value.contrast, value.saturation, value.colorBalance.red, value.colorBalance.green, value.colorBalance.blue].every((number) => Number.isFinite(number) && number >= -1 && number <= 1);
}

function clampSourceRect(rect: Rect, width: number, height: number): Rect | undefined {
  if (![rect.x, rect.y, rect.w, rect.h].every(Number.isFinite)) return undefined;
  const x = Math.max(0, Math.min(width - 1, rect.x));
  const y = Math.max(0, Math.min(height - 1, rect.y));
  const w = Math.min(width - x, rect.w);
  const h = Math.min(height - y, rect.h);
  return w >= 1 && h >= 1 ? { x, y, w, h } : undefined;
}

function scaleLayerTree(layers: Layer[], before: Rect, after: Rect, scaleX: number, scaleY: number): Layer[] {
  return layers.map((layer) => layer.type === "adjustment" ? layer : layer.type === "group" ? {
    ...layer,
    children: scaleLayerTree(layer.children, before, after, scaleX, scaleY),
  } : {
    ...layer,
    transform: {
      ...layer.transform,
      position: {
        x: after.x + (layer.transform.position.x - before.x) * scaleX,
        y: after.y + (layer.transform.position.y - before.y) * scaleY,
      },
      scale: { x: layer.transform.scale.x * scaleX, y: layer.transform.scale.y * scaleY },
    },
  });
}