import { Page } from "../types/api";

export default class PageTree {
  items: Page[] = [];

  constructor(pageList: Page[]) {
    this.items = this.sortPages(this.parsePageTree(pageList));
  }

  parsePageTree(pageList: Page[]): Page[] {
    pageList.forEach(page => page.path = page.parentId ? '/' + page.name : '');
    const getSubPagesById = (id: string) => pageList.filter(page => page.parentId === id);

    pageList.forEach((page) => {
      page.children = getSubPagesById(page.id);

      page.children.forEach((subPage: any) => {
        subPage.path = page.path + subPage.path;
        // Mark subpages as child so we can remove them later.
        subPage.isChild = true;
      });

      page.path = page.path || '/';
    });

    return pageList.filter(page => !page.isChild);
  }

  sortPages(pageTree: Page[]): Page[] {
    const sortByName = (a: any, b: any) => {
      if(a.name < b.name) {
        return -1;
      }
      if(a.name > b.name) {
        return 1;
      }
      return 0;
    };
    const pageSorter = (a: any, b: any) => {
      if(a.children && a.children.length && b.children && b.children.length) {
        // Both have child pages.
        return sortByName(a, b);
      }
      if(a.children && a.children.length) {
        return -1;
      }
      if(b.children && b.children.length) {
        return 1;
      }
      // Both pages do not have child pages, only use name to sort.
      return sortByName(a, b);
    };

    pageTree = pageTree.sort(pageSorter);

    // Apply recursive sorting on sub arrays.
    pageTree.forEach(page => {
      if(page.children && page.children.length) {
        page.children = this.sortPages(page.children);
      }
    });

    return pageTree;
  }
}