import { nanoid } from "nanoid";
import { toast } from "@webstudio-is/design-system";
import { equalMedia, type StyleValue } from "@webstudio-is/css-engine";
import {
  type Instance,
  type Instances,
  type StyleSource,
  getStyleDeclKey,
  findTreeInstanceIds,
  StyleSourceSelection,
  StyleDecl,
  Asset,
  StyleSources,
  Breakpoints,
  DataSources,
  Props,
  DataSource,
  Prop,
  Breakpoint,
  Pages,
} from "@webstudio-is/sdk";
import { findTreeInstanceIdsExcludingSlotDescendants } from "@webstudio-is/sdk";
import {
  type WsComponentMeta,
  generateDataFromEmbedTemplate,
  type EmbedTemplateData,
  decodeDataSourceVariable,
  validateExpression,
  encodeDataSourceVariable,
  portalComponent,
  collectionComponent,
} from "@webstudio-is/react-sdk";
import {
  propsStore,
  stylesStore,
  selectedInstanceSelectorStore,
  styleSourceSelectionsStore,
  styleSourcesStore,
  instancesStore,
  selectedStyleSourceSelectorStore,
  breakpointsStore,
  registeredComponentMetasStore,
  dataSourcesStore,
  assetsStore,
  $instances,
  $assets,
  $project,
  $dataSources,
  $props,
  $breakpoints,
  $styleSources,
  $styles,
  $styleSourceSelections,
  $pages,
} from "./nano-states";
import {
  type DroppableTarget,
  type InstanceSelector,
  findLocalStyleSourcesWithinInstances,
  insertInstancesMutable,
  reparentInstanceMutable,
  getAncestorInstanceSelector,
  insertPropsCopyMutable,
} from "./tree-utils";
import { removeByMutable } from "./array-utils";
import { isBaseBreakpoint } from "./breakpoints";
import { humanizeString } from "./string-utils";
import { serverSyncStore } from "./sync";

const getLabelFromComponentName = (component: Instance["component"]) => {
  if (component.includes(":")) {
    // strip namespace
    const [_namespace, baseName] = component.split(":");
    component = baseName;
  }
  return humanizeString(component);
};

export const getInstanceLabel = (
  instance: { component: string; label?: string },
  meta: WsComponentMeta
) => {
  return (
    instance.label ||
    meta.label ||
    getLabelFromComponentName(instance.component)
  );
};

export const findClosestEditableInstanceSelector = (
  instanceSelector: InstanceSelector,
  instances: Instances,
  metas: Map<string, WsComponentMeta>
) => {
  for (const instanceId of instanceSelector) {
    const instance = instances.get(instanceId);
    if (instance === undefined) {
      return;
    }
    const meta = metas.get(instance.component);
    if (meta === undefined) {
      return;
    }
    if (meta.type !== "container") {
      continue;
    }
    // only container with rich-text-child children and text can be edited
    for (const child of instance.children) {
      if (child.type === "id") {
        const childInstance = instances.get(child.value);
        if (childInstance === undefined) {
          return;
        }
        const childMeta = metas.get(childInstance.component);
        if (childMeta?.type !== "rich-text-child") {
          return;
        }
      }
    }
    return getAncestorInstanceSelector(instanceSelector, instanceId);
  }
};

export const findClosestDetachableInstanceSelector = (
  instanceSelector: InstanceSelector,
  instances: Instances,
  metas: Map<string, WsComponentMeta>
) => {
  for (const instanceId of instanceSelector) {
    const instance = instances.get(instanceId);
    if (instance === undefined) {
      return;
    }
    const meta = metas.get(instance.component);
    if (meta === undefined) {
      return;
    }
    const detachable = meta.detachable ?? true;
    if (meta.type === "rich-text-child" || detachable === false) {
      continue;
    }
    return getAncestorInstanceSelector(instanceSelector, instanceId);
  }
};

export const isInstanceDetachable = (instanceSelector: InstanceSelector) => {
  const instances = instancesStore.get();
  const metas = registeredComponentMetasStore.get();
  const [instanceId] = instanceSelector;
  const instance = instances.get(instanceId);
  if (instance === undefined) {
    return false;
  }
  const meta = metas.get(instance.component);
  if (meta === undefined) {
    return false;
  }
  return meta.detachable ?? true;
};

const traverseInstancesConstraints = (
  metas: Map<string, WsComponentMeta>,
  instances: Instances,
  instanceId: Instance["id"],
  requiredAncestors: Set<Instance["component"]>,
  invalidAncestors: Set<Instance["component"]>,
  componentSelector: string[] = []
) => {
  const instance = instances.get(instanceId);
  if (instance === undefined) {
    return;
  }
  const meta = metas.get(instance.component);
  if (meta === undefined) {
    return;
  }
  if (meta.requiredAncestors) {
    for (const requiredAncestor of meta.requiredAncestors) {
      if (componentSelector.includes(requiredAncestor) === false) {
        requiredAncestors.add(requiredAncestor);
      }
    }
  }
  if (meta.invalidAncestors) {
    for (const invalidAncestor of meta.invalidAncestors) {
      invalidAncestors.add(invalidAncestor);
    }
  }
  for (const child of instance.children) {
    if (child.type === "id") {
      traverseInstancesConstraints(
        metas,
        instances,
        child.value,
        requiredAncestors,
        invalidAncestors,
        [instance.component, ...componentSelector]
      );
    }
  }
};

export type InsertConstraints = {
  requiredAncestors: Set<Instance["component"]>;
  invalidAncestors: Set<Instance["component"]>;
};

export const computeInstancesConstraints = (
  metas: Map<string, WsComponentMeta>,
  instances: Instances,
  rootInstanceIds: Instance["id"][]
): InsertConstraints => {
  const requiredAncestors = new Set<string>();
  const invalidAncestors = new Set<string>();
  for (const instanceId of rootInstanceIds) {
    traverseInstancesConstraints(
      metas,
      instances,
      instanceId,
      requiredAncestors,
      invalidAncestors
    );
  }
  return {
    requiredAncestors,
    invalidAncestors,
  };
};

export const findClosestDroppableComponentIndex = (
  metas: Map<string, WsComponentMeta>,
  componentSelector: string[],
  constraints: InsertConstraints
) => {
  const { requiredAncestors, invalidAncestors } = constraints;

  let containerIndex = -1;
  let requiredFound = false;
  for (let index = 0; index < componentSelector.length; index += 1) {
    const ancestorComponent = componentSelector[index];
    if (invalidAncestors.has(ancestorComponent) === true) {
      containerIndex = -1;
      requiredFound = false;
      continue;
    }
    if (requiredAncestors.has(ancestorComponent) === true) {
      requiredFound = true;
    }
    const ancestorMeta = metas.get(ancestorComponent);
    if (containerIndex === -1 && ancestorMeta?.type === "container") {
      containerIndex = index;
    }
  }

  if (requiredFound || requiredAncestors.size === 0) {
    return containerIndex;
  }
  return -1;
};

export const findClosestDroppableTarget = (
  metas: Map<string, WsComponentMeta>,
  instances: Instances,
  instanceSelector: InstanceSelector,
  insertConstraints: InsertConstraints
): undefined | DroppableTarget => {
  const componentSelector: string[] = [];
  for (const instanceId of instanceSelector) {
    const component = instances.get(instanceId)?.component;
    // collection produce fake instances
    // and fragment does not have constraints
    if (component === undefined) {
      componentSelector.push("Fragment");
      continue;
    }
    componentSelector.push(component);
  }

  const droppableIndex = findClosestDroppableComponentIndex(
    metas,
    componentSelector,
    insertConstraints
  );
  if (droppableIndex === -1) {
    return;
  }
  if (droppableIndex === 0) {
    return {
      parentSelector: instanceSelector,
      position: "end",
    };
  }

  const dropTargetSelector = instanceSelector.slice(droppableIndex);
  const dropTargetInstanceId = instanceSelector[droppableIndex];
  const dropTargetInstance = instances.get(dropTargetInstanceId);
  if (dropTargetInstance === undefined) {
    return;
  }
  const lastChildInstanceId = instanceSelector[droppableIndex - 1];
  const lastChildPosition = dropTargetInstance.children.findIndex(
    (child) => child.type === "id" && child.value === lastChildInstanceId
  );
  return {
    parentSelector: dropTargetSelector,
    position: lastChildPosition + 1,
  };
};

export const insertTemplateData = (
  templateData: EmbedTemplateData,
  dropTarget: DroppableTarget
) => {
  const {
    children,
    instances: insertedInstances,
    props: insertedProps,
    dataSources: insertedDataSources,
  } = templateData;
  const rootInstanceId = insertedInstances[0].id;
  serverSyncStore.createTransaction(
    [
      instancesStore,
      // insert data sources before props to avoid error
      // about missing data source when compute data source logic
      dataSourcesStore,
      propsStore,
      styleSourceSelectionsStore,
      styleSourcesStore,
      stylesStore,
    ],
    (
      instances,
      dataSources,
      props,
      styleSourceSelections,
      styleSources,
      styles
    ) => {
      insertInstancesMutable(
        instances,
        props,
        registeredComponentMetasStore.get(),
        insertedInstances,
        children,
        dropTarget
      );
      insertPropsCopyMutable(props, insertedProps, new Map());
      for (const dataSource of insertedDataSources) {
        dataSources.set(dataSource.id, dataSource);
      }

      // insert only new style sources and their styles to support
      // embed template tokens which have persistent id
      // so when user changes these styles and then again add component with token
      // nothing breaks visually
      const insertedStyleSources = new Set<StyleSource["id"]>();
      for (const styleSource of templateData.styleSources) {
        if (styleSources.has(styleSource.id) === false) {
          insertedStyleSources.add(styleSource.id);
          styleSources.set(styleSource.id, styleSource);
        }
      }
      for (const styleDecl of templateData.styles) {
        if (insertedStyleSources.has(styleDecl.styleSourceId)) {
          styles.set(getStyleDeclKey(styleDecl), styleDecl);
        }
      }
      for (const styleSourceSelection of templateData.styleSourceSelections) {
        styleSourceSelections.set(
          styleSourceSelection.instanceId,
          styleSourceSelection
        );
      }
    }
  );

  selectedInstanceSelectorStore.set([
    rootInstanceId,
    ...dropTarget.parentSelector,
  ]);
  selectedStyleSourceSelectorStore.set(undefined);
};

export const getComponentTemplateData = (component: string) => {
  const metas = registeredComponentMetasStore.get();
  const componentMeta = metas.get(component);
  // when template not specified fallback to template with the component
  const template = componentMeta?.template ?? [
    {
      type: "instance",
      component,
      children: [],
    },
  ];
  const breakpoints = breakpointsStore.get();
  const breakpointValues = Array.from(breakpoints.values());
  const baseBreakpoint = breakpointValues.find(isBaseBreakpoint);
  if (baseBreakpoint === undefined) {
    return;
  }
  return generateDataFromEmbedTemplate(template, metas, baseBreakpoint.id);
};

export const reparentInstance = (
  targetInstanceSelector: InstanceSelector,
  dropTarget: DroppableTarget
) => {
  serverSyncStore.createTransaction(
    [instancesStore, propsStore],
    (instances, props) => {
      reparentInstanceMutable(
        instances,
        props,
        registeredComponentMetasStore.get(),
        targetInstanceSelector,
        dropTarget
      );
    }
  );
  selectedInstanceSelectorStore.set(targetInstanceSelector);
  selectedStyleSourceSelectorStore.set(undefined);
};

export const deleteInstance = (instanceSelector: InstanceSelector) => {
  // @todo tell user they can't delete root
  if (instanceSelector.length === 1) {
    return false;
  }
  if (isInstanceDetachable(instanceSelector) === false) {
    toast.error(
      "This instance can not be moved outside of its parent component."
    );
    return false;
  }
  serverSyncStore.createTransaction(
    [
      instancesStore,
      propsStore,
      styleSourceSelectionsStore,
      styleSourcesStore,
      stylesStore,
      dataSourcesStore,
    ],
    (
      instances,
      props,
      styleSourceSelections,
      styleSources,
      styles,
      dataSources
    ) => {
      let targetInstanceId = instanceSelector[0];
      const parentInstanceId = instanceSelector[1];
      let parentInstance =
        parentInstanceId === undefined
          ? undefined
          : instances.get(parentInstanceId);
      const grandparentInstanceId = instanceSelector[2];
      const grandparentInstance = instances.get(grandparentInstanceId);

      // delete parent fragment too if its last child is going to be deleted
      // use case for slots: slot became empty and remove display: contents
      // to be displayed properly on canvas
      if (
        parentInstance?.component === "Fragment" &&
        parentInstance.children.length === 1 &&
        grandparentInstance
      ) {
        targetInstanceId = parentInstance.id;
        parentInstance = grandparentInstance;
      }

      // skip parent fake "item" instance and use grandparent collection as parent
      if (grandparentInstance?.component === collectionComponent) {
        parentInstance = grandparentInstance;
      }

      const instanceIds = findTreeInstanceIdsExcludingSlotDescendants(
        instances,
        targetInstanceId
      );
      const localStyleSourceIds = findLocalStyleSourcesWithinInstances(
        styleSources.values(),
        styleSourceSelections.values(),
        instanceIds
      );

      // may not exist when delete root
      if (parentInstance) {
        removeByMutable(
          parentInstance.children,
          (child) => child.type === "id" && child.value === targetInstanceId
        );
      }

      for (const instanceId of instanceIds) {
        instances.delete(instanceId);
      }
      // delete props, data sources and styles of deleted instance and its descendants
      for (const prop of props.values()) {
        if (instanceIds.has(prop.instanceId)) {
          props.delete(prop.id);
        }
      }
      for (const dataSource of dataSources.values()) {
        if (
          dataSource.scopeInstanceId !== undefined &&
          instanceIds.has(dataSource.scopeInstanceId)
        ) {
          dataSources.delete(dataSource.id);
        }
      }
      for (const instanceId of instanceIds) {
        styleSourceSelections.delete(instanceId);
      }
      for (const styleSourceId of localStyleSourceIds) {
        styleSources.delete(styleSourceId);
      }
      for (const [styleDeclKey, styleDecl] of styles) {
        if (localStyleSourceIds.has(styleDecl.styleSourceId)) {
          styles.delete(styleDeclKey);
        }
      }
    }
  );
  return true;
};

const traverseStyleValue = (
  value: StyleValue,
  callback: (value: StyleValue) => void
) => {
  if (
    value.type === "fontFamily" ||
    value.type === "image" ||
    value.type === "unit" ||
    value.type === "keyword" ||
    value.type === "unparsed" ||
    value.type === "invalid" ||
    value.type === "unset" ||
    value.type === "rgb"
  ) {
    callback(value);
    return;
  }
  if (value.type === "var") {
    for (const item of value.fallbacks) {
      traverseStyleValue(item, callback);
    }
    return;
  }
  if (value.type === "tuple" || value.type === "layers") {
    for (const item of value.value) {
      traverseStyleValue(item, callback);
    }
    return;
  }
  value satisfies never;
};

type InstancesSlice = {
  instances: Instance[];
  styleSourceSelections: StyleSourceSelection[];
  styleSources: StyleSource[];
  breakpoints: Breakpoint[];
  styles: StyleDecl[];
  dataSources: DataSource[];
  props: Prop[];
  assets: Asset[];
};

export const getInstancesSlice = (rootInstanceId: string) => {
  const assets = assetsStore.get();
  const instances = instancesStore.get();
  const dataSources = dataSourcesStore.get();
  const props = propsStore.get();
  const styleSourceSelections = styleSourceSelectionsStore.get();
  const styleSources = styleSourcesStore.get();
  const breakpoints = breakpointsStore.get();
  const styles = stylesStore.get();

  // collect the instance by id and all its descendants including portal instances
  const slicedInstanceIds = findTreeInstanceIds(instances, rootInstanceId);
  const slicedInstances: Instance[] = [];
  const slicedStyleSourceSelections: StyleSourceSelection[] = [];
  const slicedStyleSources: StyleSources = new Map();
  for (const instanceId of slicedInstanceIds) {
    const instance = instances.get(instanceId);
    if (instance) {
      slicedInstances.push(instance);
    }

    // collect all style sources bound to these instances
    const styleSourceSelection = styleSourceSelections.get(instanceId);
    if (styleSourceSelection) {
      slicedStyleSourceSelections.push(styleSourceSelection);
      for (const styleSourceId of styleSourceSelection.values) {
        if (slicedStyleSources.has(styleSourceId)) {
          continue;
        }
        const styleSource = styleSources.get(styleSourceId);
        if (styleSource === undefined) {
          continue;
        }
        slicedStyleSources.set(styleSourceId, styleSource);
      }
    }
  }

  const slicedAssetIds = new Set<Asset["id"]>();
  const slicedFontFamilies = new Set<string>();

  // collect styles bound to these style sources
  const slicedStyles: StyleDecl[] = [];
  const slicedBreapoints: Breakpoints = new Map();
  for (const styleDecl of styles.values()) {
    if (slicedStyleSources.has(styleDecl.styleSourceId) === false) {
      continue;
    }
    slicedStyles.push(styleDecl);

    // collect breakpoints
    if (slicedBreapoints.has(styleDecl.breakpointId) === false) {
      const breakpoint = breakpoints.get(styleDecl.breakpointId);
      if (breakpoint) {
        slicedBreapoints.set(styleDecl.breakpointId, breakpoint);
      }
    }

    // collect assets including fonts
    traverseStyleValue(styleDecl.value, (value) => {
      if (value.type === "fontFamily") {
        for (const fontFamily of value.value) {
          slicedFontFamilies.add(fontFamily);
        }
      }
      if (value.type === "image") {
        if (value.value.type === "asset") {
          slicedAssetIds.add(value.value.value);
        }
      }
    });
  }

  // collect props bound to these instances
  const slicedProps: Props = new Map();
  const usedDataSourceIds = new Set<DataSource["id"]>();
  for (const prop of props.values()) {
    if (slicedInstanceIds.has(prop.instanceId) === false) {
      continue;
    }

    slicedProps.set(prop.id, prop);

    if (prop.type === "expression") {
      validateExpression(prop.value, {
        transformIdentifier(identifier) {
          const id = decodeDataSourceVariable(identifier);
          if (id !== undefined) {
            usedDataSourceIds.add(id);
          }
          return identifier;
        },
      });
    }

    if (prop.type === "action") {
      for (const value of prop.value) {
        if (value.type === "execute") {
          validateExpression(value.code, {
            effectful: true,
            transformIdentifier(identifier) {
              const id = decodeDataSourceVariable(identifier);
              if (id !== undefined) {
                usedDataSourceIds.add(id);
              }
              return identifier;
            },
          });
        }
      }
    }

    // collect assets
    if (prop.type === "asset") {
      slicedAssetIds.add(prop.value);
    }
  }

  // collect variables scoped to instances slice
  // or used by expressions or actions even outside of the tree
  // such variables can be bound to sliced root on paste
  const slicedDataSources: DataSources = new Map();
  for (const dataSource of dataSources.values()) {
    if (
      // check if data source itself can be copied
      (dataSource.scopeInstanceId !== undefined &&
        slicedInstanceIds.has(dataSource.scopeInstanceId)) ||
      usedDataSourceIds.has(dataSource.id)
    ) {
      slicedDataSources.set(dataSource.id, dataSource);
    }
  }

  const slicedAssets: Asset[] = [];
  for (const asset of assets.values()) {
    if (
      slicedAssetIds.has(asset.id) ||
      (asset.type === "font" && slicedFontFamilies.has(asset.meta.family))
    ) {
      slicedAssets.push(asset);
    }
  }

  return {
    instances: slicedInstances,
    styleSourceSelections: slicedStyleSourceSelections,
    styleSources: Array.from(slicedStyleSources.values()),
    breakpoints: Array.from(slicedBreapoints.values()),
    styles: slicedStyles,
    dataSources: Array.from(slicedDataSources.values()),
    props: Array.from(slicedProps.values()),
    assets: slicedAssets,
  };
};

export const findAvailableDataSources = (
  dataSources: DataSources,
  instanceSelector: InstanceSelector
) => {
  const instanceIds = new Set(instanceSelector);
  const availableDataSources = new Set<DataSource["id"]>();
  for (const { id, scopeInstanceId } of dataSources.values()) {
    if (scopeInstanceId && instanceIds.has(scopeInstanceId)) {
      availableDataSources.add(id);
    }
  }
  return availableDataSources;
};

const inlineUnavailableDataSources = ({
  code,
  availableDataSources,
  dataSources,
}: {
  code: string;
  availableDataSources: Set<DataSource["id"]>;
  dataSources: DataSources;
}) => {
  let isDiscarded = false;
  const newCode = validateExpression(code, {
    effectful: true,
    transformIdentifier: (identifier, assignee) => {
      const dataSourceId = decodeDataSourceVariable(identifier);
      if (
        dataSourceId === undefined ||
        availableDataSources.has(dataSourceId)
      ) {
        return identifier;
      }
      // left operand of assign operator cannot be inlined
      if (assignee) {
        isDiscarded = true;
      }
      const dataSource = dataSources.get(dataSourceId);
      // inline variable not scoped to portal content instances
      if (dataSource?.type === "variable") {
        return JSON.stringify(dataSource.value.value);
      }
      return "";
    },
  });
  return { code: newCode, isDiscarded };
};

const replaceDataSources = (
  code: string,
  replacements: Map<DataSource["id"], DataSource["id"]>
) => {
  return validateExpression(code, {
    effectful: true,
    transformIdentifier: (identifier) => {
      const dataSourceId = decodeDataSourceVariable(identifier);
      if (dataSourceId === undefined) {
        return identifier;
      }
      return encodeDataSourceVariable(
        replacements.get(dataSourceId) ?? dataSourceId
      );
    },
  });
};

export const insertInstancesSliceCopy = ({
  slice,
  availableDataSources,
  beforeTransactionEnd,
}: {
  slice: InstancesSlice;
  availableDataSources: Set<DataSource["id"]>;
  beforeTransactionEnd?: (
    rootInstanceId: Instance["id"],
    draft: { instances: Instances; props: Props; pages: undefined | Pages }
  ) => void;
}) => {
  const projectId = $project.get()?.id;
  if (projectId === undefined) {
    return;
  }

  const sliceInstances: Instances = new Map();
  const portalContentIds = new Set<Instance["id"]>();
  for (const instance of slice.instances) {
    sliceInstances.set(instance.id, instance);
    if (instance.component === portalComponent) {
      for (const child of instance.children) {
        if (child.type === "id") {
          portalContentIds.add(child.value);
        }
      }
    }
  }

  const sliceDataSources: DataSources = new Map();
  for (const dataSource of slice.dataSources) {
    sliceDataSources.set(dataSource.id, dataSource);
  }

  serverSyncStore.createTransaction(
    [
      $assets,
      $instances,
      $dataSources,
      $props,
      $breakpoints,
      $styleSources,
      $styles,
      $styleSourceSelections,
      $pages,
    ],
    (
      assets,
      instances,
      dataSources,
      props,
      breakpoints,
      styleSources,
      styles,
      styleSourceSelections,
      pages
    ) => {
      /**
       * insert reusables without changing their ids to not bloat data
       * and catch up with user changes
       * - assets
       * - breakpoints
       * - token styles
       * - portals
       *
       * breakpoints behave slightly differently and merged with existing ones
       * and those ids are used instead
       */

      // insert assets

      for (const asset of slice.assets) {
        // asset can be already present if pasting to the same project
        if (assets.has(asset.id) === false) {
          // we use the same asset.id so the references are preserved
          assets.set(asset.id, { ...asset, projectId });
        }
      }

      // merge breakpoints

      const mergedBreakpointIds = new Map<Breakpoint["id"], Breakpoint["id"]>();
      for (const newBreakpoint of slice.breakpoints) {
        let matched = false;
        for (const breakpoint of breakpoints.values()) {
          if (equalMedia(breakpoint, newBreakpoint)) {
            matched = true;
            mergedBreakpointIds.set(newBreakpoint.id, breakpoint.id);
            break;
          }
        }
        if (matched === false) {
          breakpoints.set(newBreakpoint.id, newBreakpoint);
        }
      }

      // insert tokens with their styles

      const tokenStyleSourceIds = new Set<StyleSource["id"]>();
      for (const styleSource of slice.styleSources) {
        // prevent inserting styles when token is already present
        if (styleSource.type === "local" || styleSources.has(styleSource.id)) {
          continue;
        }
        styleSource.type satisfies "token";
        tokenStyleSourceIds.add(styleSource.id);
        styleSources.set(styleSource.id, styleSource);
      }
      for (const styleDecl of slice.styles) {
        if (tokenStyleSourceIds.has(styleDecl.styleSourceId)) {
          const { breakpointId } = styleDecl;
          const newStyleDecl: StyleDecl = {
            ...styleDecl,
            breakpointId: mergedBreakpointIds.get(breakpointId) ?? breakpointId,
          };
          styles.set(getStyleDeclKey(newStyleDecl), newStyleDecl);
        }
      }

      // insert portal contents
      // - instances
      // - data sources
      // - props
      // - local styles
      for (const rootInstanceId of portalContentIds) {
        // prevent reinserting portals which could be already changed by user
        if (instances.has(rootInstanceId)) {
          continue;
        }

        const instanceIds = findTreeInstanceIdsExcludingSlotDescendants(
          sliceInstances,
          rootInstanceId
        );
        for (const instance of slice.instances) {
          if (instanceIds.has(instance.id)) {
            instances.set(instance.id, instance);
          }
        }

        const availablePortalDataSources = new Set(availableDataSources);
        for (const dataSource of slice.dataSources) {
          // insert only data sources within portal content
          if (
            dataSource.scopeInstanceId &&
            instanceIds.has(dataSource.scopeInstanceId)
          ) {
            availablePortalDataSources.add(dataSource.id);
            dataSources.set(dataSource.id, dataSource);
          }
        }

        for (let prop of slice.props) {
          if (instanceIds.has(prop.instanceId) === false) {
            continue;
          }
          // inline data sources not available in scope into expressions
          if (prop.type === "expression") {
            const { code } = inlineUnavailableDataSources({
              code: prop.value,
              availableDataSources: availablePortalDataSources,
              dataSources: sliceDataSources,
            });
            prop = { ...prop, value: code };
          }
          if (prop.type === "action") {
            prop = {
              ...prop,
              value: prop.value.flatMap((value) => {
                if (value.type !== "execute") {
                  return [value];
                }
                const { code, isDiscarded } = inlineUnavailableDataSources({
                  code: value.code,
                  availableDataSources: availablePortalDataSources,
                  dataSources: sliceDataSources,
                });
                if (isDiscarded) {
                  return [];
                }
                return [{ ...value, code }];
              }),
            };
          }
          props.set(prop.id, prop);
        }

        // insert local style sources with their styles

        const instanceStyleSourceIds = new Set<StyleSource["id"]>();
        for (const styleSourceSelection of slice.styleSourceSelections) {
          const { instanceId } = styleSourceSelection;
          if (instanceIds.has(instanceId) === false) {
            continue;
          }
          styleSourceSelections.set(instanceId, styleSourceSelection);
          for (const styleSourceId of styleSourceSelection.values) {
            instanceStyleSourceIds.add(styleSourceId);
          }
        }
        const localStyleSourceIds = new Set<StyleSource["id"]>();
        for (const styleSource of slice.styleSources) {
          if (
            styleSource.type === "local" &&
            instanceStyleSourceIds.has(styleSource.id)
          ) {
            localStyleSourceIds.add(styleSource.id);
            styleSources.set(styleSource.id, styleSource);
          }
        }
        for (const styleDecl of slice.styles) {
          if (localStyleSourceIds.has(styleDecl.styleSourceId)) {
            const { breakpointId } = styleDecl;
            const newStyleDecl: StyleDecl = {
              ...styleDecl,
              breakpointId:
                mergedBreakpointIds.get(breakpointId) ?? breakpointId,
            };
            styles.set(getStyleDeclKey(newStyleDecl), newStyleDecl);
          }
        }
      }

      /**
       * inserting unique content is structurally similar to inserting portal content
       * but all ids are regenerated to support duplicating existing content
       * - instances
       * - data sources
       * - props
       * - local styles
       */

      // generate new ids only instances outside of portals
      const sliceInstanceIds = findTreeInstanceIdsExcludingSlotDescendants(
        sliceInstances,
        slice.instances[0].id
      );
      const newInstanceIds = new Map<Instance["id"], Instance["id"]>();
      for (const instanceId of sliceInstanceIds) {
        newInstanceIds.set(instanceId, nanoid());
      }
      for (const instance of slice.instances) {
        if (sliceInstanceIds.has(instance.id)) {
          const newId = newInstanceIds.get(instance.id) ?? instance.id;
          instances.set(newId, {
            ...instance,
            id: newId,
            children: instance.children.map((child) => {
              if (child.type === "id") {
                return {
                  type: "id",
                  value: newInstanceIds.get(child.value) ?? child.value,
                };
              }
              return child;
            }),
          });
        }
      }

      const availablePortalDataSources = new Set(availableDataSources);
      const newDataSourceIds = new Map<DataSource["id"], DataSource["id"]>();
      for (const dataSource of slice.dataSources) {
        const { scopeInstanceId } = dataSource;
        // insert only data sources within portal content
        if (scopeInstanceId && sliceInstanceIds.has(scopeInstanceId)) {
          availablePortalDataSources.add(dataSource.id);
          const newId = nanoid();
          newDataSourceIds.set(dataSource.id, newId);
          dataSources.set(newId, {
            ...dataSource,
            id: newId,
            scopeInstanceId: newInstanceIds.get(scopeInstanceId),
          });
        }
      }

      for (let prop of slice.props) {
        if (sliceInstanceIds.has(prop.instanceId) === false) {
          continue;
        }
        // inline data sources not available in scope into expressions
        if (prop.type === "expression") {
          const { code } = inlineUnavailableDataSources({
            code: prop.value,
            availableDataSources: availablePortalDataSources,
            dataSources: sliceDataSources,
          });
          prop = { ...prop, value: replaceDataSources(code, newDataSourceIds) };
        }
        if (prop.type === "action") {
          prop = {
            ...prop,
            value: prop.value.flatMap((value) => {
              if (value.type !== "execute") {
                return [value];
              }
              const { code, isDiscarded } = inlineUnavailableDataSources({
                code: value.code,
                availableDataSources: availablePortalDataSources,
                dataSources: sliceDataSources,
              });
              if (isDiscarded) {
                return [];
              }
              return [
                { ...value, code: replaceDataSources(code, newDataSourceIds) },
              ];
            }),
          };
        }
        if (prop.type === "parameter") {
          prop = {
            ...prop,
            value: newDataSourceIds.get(prop.value) ?? prop.value,
          };
        }
        const newId = nanoid();
        props.set(newId, {
          ...prop,
          id: newId,
          instanceId: newInstanceIds.get(prop.instanceId) ?? prop.instanceId,
        });
      }

      // insert local styles with new ids

      const instanceStyleSourceIds = new Set<StyleSource["id"]>();
      for (const styleSourceSelection of slice.styleSourceSelections) {
        if (sliceInstanceIds.has(styleSourceSelection.instanceId) === false) {
          continue;
        }
        for (const styleSourceId of styleSourceSelection.values) {
          instanceStyleSourceIds.add(styleSourceId);
        }
      }
      const newLocalStyleSourceIds = new Map<
        StyleSource["id"],
        StyleSource["id"]
      >();
      for (const styleSource of slice.styleSources) {
        if (
          styleSource.type === "local" &&
          instanceStyleSourceIds.has(styleSource.id)
        ) {
          const newId = nanoid();
          newLocalStyleSourceIds.set(styleSource.id, newId);
          styleSources.set(newId, { ...styleSource, id: newId });
        }
      }
      for (const styleSourceSelection of slice.styleSourceSelections) {
        const { instanceId, values } = styleSourceSelection;
        if (sliceInstanceIds.has(instanceId) === false) {
          continue;
        }
        const newInstanceId = newInstanceIds.get(instanceId) ?? instanceId;
        styleSourceSelections.set(newInstanceId, {
          instanceId: newInstanceId,
          values: values.map(
            (styleSourceId) =>
              newLocalStyleSourceIds.get(styleSourceId) ?? styleSourceId
          ),
        });
        for (const styleSourceId of styleSourceSelection.values) {
          instanceStyleSourceIds.add(styleSourceId);
        }
      }
      for (const styleDecl of slice.styles) {
        const { breakpointId, styleSourceId } = styleDecl;
        if (newLocalStyleSourceIds.has(styleDecl.styleSourceId)) {
          const newStyleDecl: StyleDecl = {
            ...styleDecl,
            styleSourceId:
              newLocalStyleSourceIds.get(styleSourceId) ?? styleSourceId,
            breakpointId: mergedBreakpointIds.get(breakpointId) ?? breakpointId,
          };
          styles.set(getStyleDeclKey(newStyleDecl), newStyleDecl);
        }
      }

      // invoke callback to allow additional changes within same transaction
      const rootInstanceId =
        newInstanceIds.get(slice.instances[0].id) ?? slice.instances[0].id;
      beforeTransactionEnd?.(rootInstanceId, { instances, props, pages });
    }
  );
};