document.js

// @flow

type Element<ET> = ET & {
  uniqueId: string,
  groupId?: ?string,
};

type Group<GT> = GT & {
  id: string,
  elements: Array<string>,
};

type Page<PT, ET, GT> = PT & {
  elements: Array<Element<ET>>,
  groups?: Array<Group<GT>>,
};

type Document<PT, ET, GT> = {
  pages: Array<Page<PT, ET, GT>>,
};

export function getElementById(document: Document<*, *, *>, uniqueId: string) {
  const { pages } = document;
  for (let pageIndex = 0; pageIndex < pages.length; pageIndex++) {
    const { elements } = pages[pageIndex];
    for (let elementIndex = 0; elementIndex < elements.length; elementIndex++) {
      const element = elements[elementIndex];
      if (element.uniqueId === uniqueId) {
        return { pageIndex, elementIndex, element };
      }
    }
  }

  return { pageIndex: -1, elementIndex: -1, element: null };
}

export function getGroupById(document: Document<*, *, *>, groupId: string) {
  const { pages } = document;
  for (let pageIndex = 0; pageIndex < pages.length; pageIndex++) {
    const { groups = [] } = pages[pageIndex];
    for (let groupIndex = 0; groupIndex < groups.length; groupIndex++) {
      const group = groups[groupIndex];
      if (group.id === groupId) {
        return { pageIndex, groupIndex, group };
      }
    }
  }

  return { pageIndex: -1, groupIndex: -1, group: null };
}

export function getGroupByIdFromPage(page: Page<*, *, *>, groupId: string) {
  const { groups = [] } = page;
  for (let groupIndex = 0; groupIndex < groups.length; groupIndex++) {
    const group = groups[groupIndex];
    if (group.id === groupId) {
      return { groupIndex, group };
    }
  }

  return { groupIndex: -1, group: null };
}