/* This Source Code Form is subject to the terms of the Mozilla Public
 * License, v. 2.0. If a copy of the MPL was not distributed with this
 * file, You can obtain one at <http://mozilla.org/MPL/2.0/>. */

export function initialPreviewState() {
  return {
    preview: null,
    previewCount: 0,
  };
}

function update(state = initialPreviewState(), action) {
  switch (action.type) {
    case "CLEAR_PREVIEW": {
      return { ...state, preview: null };
    }

    case "START_PREVIEW": {
      return { ...state, previewCount: state.previewCount + 1 };
    }

    case "SET_PREVIEW": {
      return { ...state, preview: action.value };
    }
  }

  return state;
}

export default update;