/**
 * 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 DraftEditor from "./DraftEditor.react";
import type { DraftEditorCommand } from "./DraftEditorCommand";

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

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

const {
  isOptionKeyCommand
} = KeyBindingUtil;
const isChrome = UserAgent.isBrowser('Chrome');
/**
 * Map a `DraftEditorCommand` command value to a corresponding function.
 */

function onKeyCommand(command: DraftEditorCommand | string, editorState: EditorState, e: SyntheticKeyboardEvent<HTMLElement>): EditorState {
  switch (command) {
    case 'redo':
      return EditorState.redo(editorState);

    case 'delete':
      return keyCommandPlainDelete(editorState);

    case 'delete-word':
      return keyCommandDeleteWord(editorState);

    case 'backspace':
      return keyCommandPlainBackspace(editorState);

    case 'backspace-word':
      return keyCommandBackspaceWord(editorState);

    case 'backspace-to-start-of-line':
      return keyCommandBackspaceToStartOfLine(editorState, e);

    case 'split-block':
      return keyCommandInsertNewline(editorState);

    case 'transpose-characters':
      return keyCommandTransposeCharacters(editorState);

    case 'move-selection-to-start-of-block':
      return keyCommandMoveSelectionToStartOfBlock(editorState);

    case 'move-selection-to-end-of-block':
      return keyCommandMoveSelectionToEndOfBlock(editorState);

    case 'secondary-cut':
      return SecondaryClipboard.cut(editorState);

    case 'secondary-paste':
      return SecondaryClipboard.paste(editorState);

    default:
      return editorState;
  }
}
/**
 * Intercept keydown behavior to handle keys and commands manually, if desired.
 *
 * Keydown combinations may be mapped to `DraftCommand` values, which may
 * correspond to command functions that modify the editor or its contents.
 *
 * See `getDefaultKeyBinding` for defaults. Alternatively, the top-level
 * component may provide a custom mapping via the `keyBindingFn` prop.
 */


function editOnKeyDown(editor: DraftEditor, e: SyntheticKeyboardEvent<HTMLElement>): void {
  const keyCode = e.which;
  const editorState = editor._latestEditorState;

  function callDeprecatedHandler(handlerName: 'onDownArrow' | 'onEscape' | 'onLeftArrow' | 'onRightArrow' | 'onTab' | 'onUpArrow'): boolean {
    const deprecatedHandler = editor.props[handlerName];

    if (deprecatedHandler) {
      deprecatedHandler(e);
      return true;
    } else {
      return false;
    }
  }

  switch (keyCode) {
    case Keys.RETURN:
      e.preventDefault(); // The top-level component may manually handle newline insertion. If
      // no special handling is performed, fall through to command handling.

      if (editor.props.handleReturn && isEventHandled(editor.props.handleReturn(e, editorState))) {
        return;
      }

      break;

    case Keys.ESC:
      e.preventDefault();

      if (callDeprecatedHandler('onEscape')) {
        return;
      }

      break;

    case Keys.TAB:
      if (callDeprecatedHandler('onTab')) {
        return;
      }

      break;

    case Keys.UP:
      if (callDeprecatedHandler('onUpArrow')) {
        return;
      }

      break;

    case Keys.RIGHT:
      if (callDeprecatedHandler('onRightArrow')) {
        return;
      }

      break;

    case Keys.DOWN:
      if (callDeprecatedHandler('onDownArrow')) {
        return;
      }

      break;

    case Keys.LEFT:
      if (callDeprecatedHandler('onLeftArrow')) {
        return;
      }

      break;

    case Keys.SPACE:
      // Prevent Chrome on OSX behavior where option + space scrolls.
      if (isChrome && isOptionKeyCommand(e)) {
        e.preventDefault();
      }

  }

  const command = editor.props.keyBindingFn(e); // If no command is specified, allow keydown event to continue.

  if (command == null || command === '') {
    if (keyCode === Keys.SPACE && isChrome && isOptionKeyCommand(e)) {
      // The default keydown event has already been prevented in order to stop
      // Chrome from scrolling. Insert a nbsp into the editor as OSX would for
      // other browsers.
      const contentState = DraftModifier.replaceText(editorState.getCurrentContent(), editorState.getSelection(), '\u00a0');
      editor.update(EditorState.push(editorState, contentState, 'insert-characters'));
    }

    return;
  }

  if (command === 'undo') {
    // Since undo requires some special updating behavior to keep the editor
    // in sync, handle it separately.
    keyCommandUndo(e, editorState, editor.update);
    return;
  } // At this point, we know that we're handling a command of some kind, so
  // we don't want to insert a character following the keydown.


  e.preventDefault(); // Allow components higher up the tree to handle the command first.

  if (editor.props.handleKeyCommand && isEventHandled(editor.props.handleKeyCommand(command, editorState, e.timeStamp))) {
    return;
  }

  const newState = onKeyCommand(command, editorState, e);

  if (newState !== editorState) {
    editor.update(newState);
  }
}

module.exports = editOnKeyDown;