/**
 * 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 strict-local
 * @emails oncall+draft_js
 */
'use strict';

import type { BlockNodeRecord } from "./BlockNodeRecord";
import type { DraftInsertionType } from "./DraftInsertionType";
import type SelectionState from "./SelectionState";

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

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

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

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

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

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

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

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

const Immutable = require("immutable");

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

const experimentalTreeDataSupport = gkx('draft_tree_data_support');
const ContentBlockRecord = experimentalTreeDataSupport ? ContentBlockNode : ContentBlock;
const {
  List,
  Repeat
} = Immutable;
const AtomicBlockUtils = {
  insertAtomicBlock: function (editorState: EditorState, entityKey: string, character: string): EditorState {
    const contentState = editorState.getCurrentContent();
    const selectionState = editorState.getSelection();
    const afterRemoval = DraftModifier.removeRange(contentState, selectionState, 'backward');
    const targetSelection = afterRemoval.getSelectionAfter();
    const afterSplit = DraftModifier.splitBlock(afterRemoval, targetSelection);
    const insertionTarget = afterSplit.getSelectionAfter();
    const asAtomicBlock = DraftModifier.setBlockType(afterSplit, insertionTarget, 'atomic');
    const charData = CharacterMetadata.create({
      entity: entityKey
    });
    let atomicBlockConfig = {
      key: generateRandomKey(),
      type: 'atomic',
      text: character,
      characterList: List(Repeat(charData, character.length))
    };
    let atomicDividerBlockConfig = {
      key: generateRandomKey(),
      type: 'unstyled'
    };

    if (experimentalTreeDataSupport) {
      atomicBlockConfig = { ...atomicBlockConfig,
        nextSibling: atomicDividerBlockConfig.key
      };
      atomicDividerBlockConfig = { ...atomicDividerBlockConfig,
        prevSibling: atomicBlockConfig.key
      };
    }

    const fragmentArray = [new ContentBlockRecord(atomicBlockConfig), new ContentBlockRecord(atomicDividerBlockConfig)];
    const fragment = BlockMapBuilder.createFromArray(fragmentArray);
    const withAtomicBlock = DraftModifier.replaceWithFragment(asAtomicBlock, insertionTarget, fragment);
    const newContent = withAtomicBlock.merge({
      selectionBefore: selectionState,
      selectionAfter: withAtomicBlock.getSelectionAfter().set('hasFocus', true)
    });
    return EditorState.push(editorState, newContent, 'insert-fragment');
  },
  moveAtomicBlock: function (editorState: EditorState, atomicBlock: BlockNodeRecord, targetRange: SelectionState, insertionMode?: DraftInsertionType): EditorState {
    const contentState = editorState.getCurrentContent();
    const selectionState = editorState.getSelection();
    let withMovedAtomicBlock;

    if (insertionMode === 'before' || insertionMode === 'after') {
      const targetBlock = contentState.getBlockForKey(insertionMode === 'before' ? targetRange.getStartKey() : targetRange.getEndKey());
      withMovedAtomicBlock = moveBlockInContentState(contentState, atomicBlock, targetBlock, insertionMode);
    } else {
      const afterRemoval = DraftModifier.removeRange(contentState, targetRange, 'backward');
      const selectionAfterRemoval = afterRemoval.getSelectionAfter();
      const targetBlock = afterRemoval.getBlockForKey(selectionAfterRemoval.getFocusKey());

      if (selectionAfterRemoval.getStartOffset() === 0) {
        withMovedAtomicBlock = moveBlockInContentState(afterRemoval, atomicBlock, targetBlock, 'before');
      } else if (selectionAfterRemoval.getEndOffset() === targetBlock.getLength()) {
        withMovedAtomicBlock = moveBlockInContentState(afterRemoval, atomicBlock, targetBlock, 'after');
      } else {
        const afterSplit = DraftModifier.splitBlock(afterRemoval, selectionAfterRemoval);
        const selectionAfterSplit = afterSplit.getSelectionAfter();
        const targetBlock = afterSplit.getBlockForKey(selectionAfterSplit.getFocusKey());
        withMovedAtomicBlock = moveBlockInContentState(afterSplit, atomicBlock, targetBlock, 'before');
      }
    }

    const newContent = withMovedAtomicBlock.merge({
      selectionBefore: selectionState,
      selectionAfter: withMovedAtomicBlock.getSelectionAfter().set('hasFocus', true)
    });
    return EditorState.push(editorState, newContent, 'move-block');
  }
};
module.exports = AtomicBlockUtils;