import type {
  CanvasClipboard,
  CanvasContextMenuState,
  CanvasLayer,
} from './ImageCanvasEditorTypes';

export type CanvasLayerMoveMode = 'up' | 'down' | 'top' | 'bottom';

export type CanvasLayerFlipAxis = 'x' | 'y';

type CanvasPoint = {
  x: number;
  y: number;
};

function cloneLayer(layer: CanvasLayer): CanvasLayer {
  return {
    ...layer,
    generationInputs: layer.generationInputs
      ? {
          fields: layer.generationInputs.fields.map((field) => ({ ...field })),
          references: layer.generationInputs.references.map((reference) => ({
            ...reference,
          })),
        }
      : layer.generationInputs,
  };
}

export function resolveContextTargetLayerIds(
  menu: CanvasContextMenuState | null,
  selectedLayerIds: string[],
) {
  if (menu?.kind !== 'layer') {
    return [];
  }
  return selectedLayerIds.includes(menu.layerId)
    ? [...selectedLayerIds]
    : [menu.layerId];
}

export function getCanvasLayersByIds(
  layers: CanvasLayer[],
  targetIds: string[],
) {
  return layers.filter((layer) => targetIds.includes(layer.id));
}

export function duplicateCanvasLayers({
  sourceLayers,
  allLayers,
  canvasPoint,
  renameCopies = true,
  stamp = Date.now(),
}: {
  sourceLayers: CanvasLayer[];
  allLayers: CanvasLayer[];
  canvasPoint?: CanvasPoint;
  renameCopies?: boolean;
  stamp?: number | string;
}) {
  if (!sourceLayers.length) {
    return [];
  }

  const minX = Math.min(...sourceLayers.map((layer) => layer.x));
  const minY = Math.min(...sourceLayers.map((layer) => layer.y));
  const maxZIndex = allLayers.reduce(
    (maxZ, layer) => Math.max(maxZ, layer.zIndex),
    0,
  );

  return sourceLayers.map((layer, index) => ({
    ...cloneLayer(layer),
    id: `layer-copy-${stamp}-${index}`,
    resourceId: `local-resource-copy-${stamp}-${index}`,
    title: renameCopies ? `${layer.title} 副本` : layer.title,
    x: canvasPoint ? canvasPoint.x + (layer.x - minX) : layer.x + 32,
    y: canvasPoint ? canvasPoint.y + (layer.y - minY) : layer.y + 32,
    zIndex: maxZIndex + index + 1,
    groupId: null,
  }));
}

export function createCanvasLayerClipboard(
  layers: CanvasLayer[],
  targetIds: string[],
  mode: CanvasClipboard['mode'],
): CanvasClipboard | null {
  const targetLayers = getCanvasLayersByIds(layers, targetIds);
  if (!targetLayers.length) {
    return null;
  }
  return {
    layers: targetLayers.map(cloneLayer),
    mode,
  };
}

export function removeCanvasLayers(layers: CanvasLayer[], targetIds: string[]) {
  if (!targetIds.length) {
    return layers;
  }
  return layers.filter((layer) => !targetIds.includes(layer.id));
}

export function updateCanvasLayersByIds(
  layers: CanvasLayer[],
  targetIds: string[],
  updater: (layer: CanvasLayer, targetIds: string[]) => CanvasLayer,
) {
  if (!targetIds.length) {
    return layers;
  }
  return layers.map((layer) =>
    targetIds.includes(layer.id) ? updater(layer, targetIds) : layer,
  );
}

export function moveCanvasLayers(
  layers: CanvasLayer[],
  targetIds: string[],
  mode: CanvasLayerMoveMode,
) {
  if (!targetIds.length) {
    return layers;
  }
  const maxZIndex = layers.reduce(
    (maxZ, layer) => Math.max(maxZ, layer.zIndex),
    0,
  );
  const minZIndex = layers.reduce(
    (minZ, layer) => Math.min(minZ, layer.zIndex),
    0,
  );
  let offsetIndex = 0;

  return updateCanvasLayersByIds(layers, targetIds, (layer) => {
    if (mode === 'up') {
      return { ...layer, zIndex: layer.zIndex + 1 };
    }
    if (mode === 'down') {
      return { ...layer, zIndex: layer.zIndex - 1 };
    }
    offsetIndex += 1;
    if (mode === 'top') {
      return { ...layer, zIndex: maxZIndex + offsetIndex };
    }
    return {
      ...layer,
      zIndex: minZIndex - (targetIds.length - offsetIndex + 1),
    };
  });
}

export function groupCanvasLayers(
  layers: CanvasLayer[],
  targetIds: string[],
  groupId: string,
) {
  return updateCanvasLayersByIds(layers, targetIds, (layer) => ({
    ...layer,
    groupId,
  }));
}

export function ungroupCanvasLayers(
  layers: CanvasLayer[],
  targetIds: string[],
) {
  return updateCanvasLayersByIds(layers, targetIds, (layer) => ({
    ...layer,
    groupId: null,
  }));
}

export function toggleCanvasLayersVisibility(
  layers: CanvasLayer[],
  targetIds: string[],
) {
  const shouldHide = getCanvasLayersByIds(layers, targetIds).some(
    (layer) => !layer.hidden,
  );
  return updateCanvasLayersByIds(layers, targetIds, (layer) => ({
    ...layer,
    hidden: shouldHide,
  }));
}

export function toggleCanvasLayersLock(
  layers: CanvasLayer[],
  targetIds: string[],
) {
  const shouldLock = getCanvasLayersByIds(layers, targetIds).some(
    (layer) => !layer.locked,
  );
  return updateCanvasLayersByIds(layers, targetIds, (layer) => ({
    ...layer,
    locked: shouldLock,
  }));
}

export function flipCanvasLayers(
  layers: CanvasLayer[],
  targetIds: string[],
  axis: CanvasLayerFlipAxis,
) {
  return updateCanvasLayersByIds(layers, targetIds, (layer) =>
    axis === 'x'
      ? {
          ...layer,
          flipX: !layer.flipX,
        }
      : {
          ...layer,
          flipY: !layer.flipY,
        },
  );
}