import { derived, writable } from 'svelte/store';

import { stop_refresh } from './common';

let refresh_interval_teams = null;

function createTeamsStore() {
  const { subscribe, set, update } = writable({teams:{}, teams_count: 0, rank: []});

  function updateFunc(res_teams, cb=null) {
    if (res_teams.status === 200) {
      res_teams.json().then((teams) => {
	const teams_count = Object.keys(teams).length

	const rank = [];
        for (const tid in teams) {
	  teams[tid].id = Number(tid);
	  rank.push(teams[tid]);
	}
        rank.sort((a, b) => (a.rank > b.rank ? 1 : (a.rank == b.rank ? 0 : -1)));

        update((t) => (Object.assign(t, {teams, teams_count, rank})));

        if (cb) {
          cb(teams, teams_count, rank);
        }
      });
    }
  }

  return {
    subscribe,

    refresh: async (cb=null, interval=null) => {
      if (refresh_interval_teams)
        clearInterval(refresh_interval_teams);
      if (interval === null) {
        interval = Math.floor(Math.random() * 24000) + 32000;
      }
      if (stop_refresh) {
        return;
      }
      refresh_interval_teams = setInterval(refresh_teams, interval);

      updateFunc(await fetch('teams.json', {headers: {'Accept': 'application/json'}}), cb);
    },

    update: updateFunc,
  };
}

export const teamsStore = createTeamsStore();

export const teams = derived(
  teamsStore,
  ($teamsStore) => ($teamsStore.teams)
);

export const teams_count = derived(
  teamsStore,
  ($teamsStore) => ($teamsStore.teams_count)
);

export const rank = derived(
  teamsStore,
  ($teamsStore) => ($teamsStore.rank)
);