/**
 * Copyright (c) Facebook, Inc. and its affiliates.
 *
 * This source code is licensed under the MIT license found in the
 * LICENSE file in the root directory of this source tree.
 *
 * @format
 * @flow
 * @emails oncall+draft_js
 *
 * This file is a fork of DraftEditorBlock.react.js and DraftEditorContents.react.js
 *
 * This is unstable and not part of the public API and should not be used by
 * production systems. This file may be update/removed without notice.
 */
'use strict';

import type { BlockNodeRecord } from "./BlockNodeRecord";
import type ContentState from "./ContentState";
import type { DraftBlockRenderMap } from "./DraftBlockRenderMap";
import type { DraftDecoratorType } from "./DraftDecoratorType";
import type { DraftInlineStyle } from "./DraftInlineStyle";
import type EditorState from "./EditorState";
import type SelectionState from "./SelectionState";
import type { BidiDirection } from "fbjs/lib/UnicodeBidiDirection";

const DraftEditorNode = require("./DraftEditorNode.react");

const DraftOffsetKey = require("./DraftOffsetKey");

const React = require("react");

const Scroll = require("fbjs/lib/Scroll");

const Style = require("fbjs/lib/Style");

const getElementPosition = require("fbjs/lib/getElementPosition");

const getScrollPosition = require("fbjs/lib/getScrollPosition");

const getViewportDimensions = require("fbjs/lib/getViewportDimensions");

const Immutable = require("immutable");

const invariant = require("fbjs/lib/invariant");

const isHTMLElement = require("./isHTMLElement");

const SCROLL_BUFFER = 10;
const {
  List
} = Immutable; // we should harden up the bellow flow types to make them more strict

type CustomRenderConfig = Object;
type DraftRenderConfig = Object;
type BlockRenderFn = (block: BlockNodeRecord) => ?Object;
type BlockStyleFn = (block: BlockNodeRecord) => string;
type Props = {
  block: BlockNodeRecord,
  blockProps?: Object,
  blockRenderMap: DraftBlockRenderMap,
  blockRendererFn: BlockRenderFn,
  blockStyleFn: BlockStyleFn,
  contentState: ContentState,
  customStyleFn: (style: DraftInlineStyle, block: BlockNodeRecord) => ?Object,
  customStyleMap: Object,
  decorator: ?DraftDecoratorType,
  direction: BidiDirection,
  editorKey: string,
  editorState: EditorState,
  forceSelection: boolean,
  selection: SelectionState,
  startIndent?: boolean,
  tree: List<any>,
  ...
};
/**
 * Return whether a block overlaps with either edge of the `SelectionState`.
 */

const isBlockOnSelectionEdge = (selection: SelectionState, key: string): boolean => {
  return selection.getAnchorKey() === key || selection.getFocusKey() === key;
};
/**
 * We will use this helper to identify blocks that need to be wrapped but have siblings that
 * also share the same wrapper element, this way we can do the wrapping once the last sibling
 * is added.
 */


const shouldNotAddWrapperElement = (block: BlockNodeRecord, contentState: ContentState): boolean => {
  const nextSiblingKey = block.getNextSiblingKey();
  return nextSiblingKey ? contentState.getBlockForKey(nextSiblingKey).getType() === block.getType() : false;
};

const applyWrapperElementToSiblings = (wrapperTemplate: *, Element: string, nodes: Array<React.Node>): Array<React.Node> => {
  const wrappedSiblings = []; // we check back until we find a sibling that does not have same wrapper

  for (const sibling: any of nodes.reverse()) {
    if (sibling.type !== Element) {
      break;
    }

    wrappedSiblings.push(sibling);
  } // we now should remove from acc the wrappedSiblings and add them back under same wrap


  nodes.splice(nodes.indexOf(wrappedSiblings[0]), wrappedSiblings.length + 1);
  const childrenIs = wrappedSiblings.reverse();
  const key = childrenIs[0].key;
  nodes.push(React.cloneElement(wrapperTemplate, {
    key: `${key}-wrap`,
    'data-offset-key': DraftOffsetKey.encode(key, 0, 0)
  }, childrenIs));
  return nodes;
};

const getDraftRenderConfig = (block: BlockNodeRecord, blockRenderMap: DraftBlockRenderMap): DraftRenderConfig => {
  const configForType = blockRenderMap.get(block.getType()) || blockRenderMap.get('unstyled');
  const wrapperTemplate = configForType.wrapper;
  const Element = configForType.element || blockRenderMap.get('unstyled').element;
  return {
    Element,
    wrapperTemplate
  };
};

const getCustomRenderConfig = (block: BlockNodeRecord, blockRendererFn: BlockRenderFn): CustomRenderConfig => {
  const customRenderer = blockRendererFn(block);

  if (!customRenderer) {
    return {};
  }

  const {
    component: CustomComponent,
    props: customProps,
    editable: customEditable
  } = customRenderer;
  return {
    CustomComponent,
    customProps,
    customEditable
  };
};

const getElementPropsConfig = (block: BlockNodeRecord, editorKey: string, offsetKey: string, blockStyleFn: BlockStyleFn, customConfig: *, ref: null | {|
  current: null | Element
|}): Object => {
  let elementProps: Object = {
    'data-block': true,
    'data-editor': editorKey,
    'data-offset-key': offsetKey,
    key: block.getKey(),
    ref
  };
  const customClass = blockStyleFn(block);

  if (customClass) {
    elementProps.className = customClass;
  }

  if (customConfig.customEditable !== undefined) {
    elementProps = { ...elementProps,
      contentEditable: customConfig.customEditable,
      suppressContentEditableWarning: true
    };
  }

  return elementProps;
};

class DraftEditorBlockNode extends React.Component<Props> {
  wrapperRef: {|
    current: null | Element
  |} = React.createRef<Element>();

  shouldComponentUpdate(nextProps: Props): boolean {
    const {
      block,
      direction,
      tree
    } = this.props;
    const isContainerNode = !block.getChildKeys().isEmpty();
    const blockHasChanged = block !== nextProps.block || tree !== nextProps.tree || direction !== nextProps.direction || isBlockOnSelectionEdge(nextProps.selection, nextProps.block.getKey()) && nextProps.forceSelection; // if we have children at this stage we always re-render container nodes
    // else if its a root node we avoid re-rendering by checking for block updates

    return isContainerNode || blockHasChanged;
  }
  /**
   * When a block is mounted and overlaps the selection state, we need to make
   * sure that the cursor is visible to match native behavior. This may not
   * be the case if the user has pressed `RETURN` or pasted some content, since
   * programatically creating these new blocks and setting the DOM selection
   * will miss out on the browser natively scrolling to that position.
   *
   * To replicate native behavior, if the block overlaps the selection state
   * on mount, force the scroll position. Check the scroll state of the scroll
   * parent, and adjust it to align the entire block to the bottom of the
   * scroll parent.
   */


  componentDidMount(): void {
    const selection = this.props.selection;
    const endKey = selection.getEndKey();

    if (!selection.getHasFocus() || endKey !== this.props.block.getKey()) {
      return;
    }

    const blockNode = this.wrapperRef.current;

    if (!blockNode) {
      // This Block Node was rendered without a wrapper element.
      return;
    }

    const scrollParent = Style.getScrollParent(blockNode);
    const scrollPosition = getScrollPosition(scrollParent);
    let scrollDelta;

    if (scrollParent === window) {
      const nodePosition = getElementPosition(blockNode);
      const nodeBottom = nodePosition.y + nodePosition.height;
      const viewportHeight = getViewportDimensions().height;
      scrollDelta = nodeBottom - viewportHeight;

      if (scrollDelta > 0) {
        window.scrollTo(scrollPosition.x, scrollPosition.y + scrollDelta + SCROLL_BUFFER);
      }
    } else {
      invariant(isHTMLElement(blockNode), 'blockNode is not an HTMLElement');
      const htmlBlockNode: HTMLElement = (blockNode: any);
      const blockBottom = htmlBlockNode.offsetHeight + htmlBlockNode.offsetTop;
      const scrollBottom = scrollParent.offsetHeight + scrollPosition.y;
      scrollDelta = blockBottom - scrollBottom;

      if (scrollDelta > 0) {
        Scroll.setTop(scrollParent, Scroll.getTop(scrollParent) + scrollDelta + SCROLL_BUFFER);
      }
    }
  }

  render(): React.Node {
    const {
      block,
      blockRenderMap,
      blockRendererFn,
      blockStyleFn,
      contentState,
      decorator,
      editorKey,
      editorState,
      customStyleFn,
      customStyleMap,
      direction,
      forceSelection,
      selection,
      tree
    } = this.props;
    let children = null;

    if (block.children.size) {
      children = block.children.reduce((acc, key) => {
        const offsetKey = DraftOffsetKey.encode(key, 0, 0);
        const child = contentState.getBlockForKey(key);
        const customConfig = getCustomRenderConfig(child, blockRendererFn);
        const Component = customConfig.CustomComponent || DraftEditorBlockNode;
        const {
          Element,
          wrapperTemplate
        } = getDraftRenderConfig(child, blockRenderMap);
        const elementProps = getElementPropsConfig(child, editorKey, offsetKey, blockStyleFn, customConfig, null);
        const childProps = { ...this.props,
          tree: editorState.getBlockTree(key),
          blockProps: customConfig.customProps,
          offsetKey,
          block: child
        };
        acc.push(React.createElement(Element, elementProps, <Component {...childProps} />));

        if (!wrapperTemplate || shouldNotAddWrapperElement(child, contentState)) {
          return acc;
        } // if we are here it means we are the last block
        // that has a wrapperTemplate so we should wrap itself
        // and all other previous siblings that share the same wrapper


        applyWrapperElementToSiblings(wrapperTemplate, Element, acc);
        return acc;
      }, []);
    }

    const blockKey = block.getKey();
    const offsetKey = DraftOffsetKey.encode(blockKey, 0, 0);
    const customConfig = getCustomRenderConfig(block, blockRendererFn);
    const Component = customConfig.CustomComponent;
    const blockNode = Component != null ? <Component {...this.props} tree={editorState.getBlockTree(blockKey)} blockProps={customConfig.customProps} offsetKey={offsetKey} block={block} /> : <DraftEditorNode block={block} children={children} contentState={contentState} customStyleFn={customStyleFn} customStyleMap={customStyleMap} decorator={decorator} direction={direction} forceSelection={forceSelection} hasSelection={isBlockOnSelectionEdge(selection, blockKey)} selection={selection} tree={tree} />;

    if (block.getParentKey()) {
      return blockNode;
    }

    const {
      Element
    } = getDraftRenderConfig(block, blockRenderMap);
    const elementProps = getElementPropsConfig(block, editorKey, offsetKey, blockStyleFn, customConfig, this.wrapperRef); // root block nodes needs to be wrapped

    return React.createElement(Element, elementProps, blockNode);
  }

}

module.exports = DraftEditorBlockNode;