// @ts-check
import { readSharedData } from '@redocly/realm/dist/server/utils/shared-data.js' // TODO: export function from root package
const INDEX_PAGE_INFO_DATA_KEY = 'index-page-items'

export function indexPages() {
  /** @type {import("@redocly/realm/dist/server/plugins/types").PluginInstance } */
  const instance = {
    // hook that gets executed after all routes were created
    async afterRoutesCreated(actions, { cache }) {
      // get all the routes that are ind pages
      const indexRoutes = actions.getAllRoutes().filter((route) => route.metadata?.indexPage)

      for (const route of indexRoutes) {
        // @ts-ignore this uses some internals, we will expose them in nicer way in the future releases
        const sidebarId = actions.routesSharedData.get(route.slug)?.['sidebar'] // TODO: implement a helper function for this
        /** @type {any} */
        const sidebar = await readSharedData(sidebarId, actions.outdir)

        if (!sidebar) {
          console.log('[warn] Index route used with no sidebar', route.fsPath)
          continue
        }

        const item = findItemDeep(sidebar.items, route.fsPath)
        const childrenPaths = (item.items || []).map((item) => item.fsPath).filter(Boolean)

        const childRoutes = childrenPaths.map((fsPath) => actions.getRouteByFsPath(fsPath))
        const childRoutesData = await Promise.all(
          childRoutes.map(async (route) => {
            const { data } = await cache.load(route.fsPath, 'markdown-frontmatter')
            const slug = route.slug
            const title = await route.getNavText()
            return {
              ...data?.frontmatter,
              slug,
              title,
            }
          }),
        )

        const sharedDataId = await actions.createSharedData(route.slug + '_' + INDEX_PAGE_INFO_DATA_KEY, childRoutesData)
        actions.addRouteSharedData(route.slug, INDEX_PAGE_INFO_DATA_KEY, sharedDataId)
      }
    },
  }
  return instance
}

function findItemDeep(items, fsPath) {
  for (const item of items) {
    if (item.fsPath === fsPath) {
      return item
    }

    if (item.items) {
      const found = findItemDeep(item.items, fsPath)
      if (found) {
        return found
      }
    }
  }
}