import { Transaction, Selection, NodeSelection } from 'prosemirror-state';
import { DatePluginState, DatePluginMeta } from './types';

export function reducer(
  pluginState: DatePluginState,
  meta: DatePluginMeta,
): DatePluginState {
  // If the same nodeview is clicked twice, calendar should close
  if (meta.showDatePickerAt === pluginState.showDatePickerAt) {
    return { ...pluginState, showDatePickerAt: null };
  }

  const { showDatePickerAt, isNew } = pluginState;
  const { showDatePickerAt: showDatePickerAtMeta } = meta;
  // If date picker position has changed, it is no longer new
  if (
    showDatePickerAt &&
    showDatePickerAtMeta &&
    showDatePickerAt !== showDatePickerAtMeta &&
    isNew
  ) {
    return { ...pluginState, ...meta, isNew: false };
  }
  return { ...pluginState, ...meta };
}

export function mapping(
  tr: Transaction,
  pluginState: DatePluginState,
): DatePluginState {
  if (!pluginState.showDatePickerAt) {
    return pluginState;
  }

  const { pos } = tr.mapping.mapResult(pluginState.showDatePickerAt);
  return {
    showDatePickerAt: pos,
    isNew: pluginState.isNew,
    isDateEmpty: pluginState.isDateEmpty,
    focusDateInput: pluginState.focusDateInput,
  };
}

export function onSelectionChanged(
  tr: Transaction,
  pluginState: DatePluginState,
): DatePluginState {
  if (!isDateNodeSelection(tr.selection)) {
    if (pluginState.showDatePickerAt) {
      return {
        showDatePickerAt: null,
        isNew: false,
        isDateEmpty: false,
        focusDateInput: false,
      };
    }

    return pluginState;
  }
  // create new object to force a re-render
  return {
    ...pluginState,
  };
}

const isDateNodeSelection = (selection: Selection) => {
  if (selection instanceof NodeSelection) {
    const nodeTypeName = selection.node.type.name;
    return nodeTypeName === 'date';
  }
  return false;
};