import { randomStr } from '@shell/utils/string';
import { sum } from 'lodash';
import { computed, inject, provide, ref } from 'vue';

const UPDATE_COUNT_PROVIDER_KEY = 'update-count';
const USE_COUNTS_KEY = 'is-inside-resource-tabs';

type UpdateCountFn = (key: string, count: number | undefined) => void;

export const useIndicateUseCounts = () => {
  provide(USE_COUNTS_KEY, true);
};

export const useTabCountWatcher = () => {
  if (!inject<boolean>(USE_COUNTS_KEY, false)) {
    return { isCountVisible: ref<boolean>(false) };
  }

  const countLedger = ref<{ [key: string]: number | undefined }>({});

  const isCountVisible = computed(() => {
    // Some tables are destroyed and recreated depending on visibility so we count keys
    // to check if a table has been present in the tab even if the count has been cleared
    return Object.keys(countLedger.value).length > 0;
  });

  const count = computed(() => {
    return sum(Object.values(countLedger.value).map((count) => count || 0));
  });

  const updateCount = (key: string, count: number | undefined) => {
    countLedger.value[key] = count;
  };

  provide(UPDATE_COUNT_PROVIDER_KEY, updateCount);

  return { isCountVisible, count };
};

export const useTabCountUpdater = () => {
  const tabKey = randomStr();
  const updateCount = inject<UpdateCountFn>(UPDATE_COUNT_PROVIDER_KEY);

  const updateTabCount = (count: number | undefined) => {
    updateCount?.(tabKey, count);
  };

  const clearTabCount = () => updateTabCount(undefined);

  return {
    updateTabCount,
    clearTabCount
  };
};