import { onMounted, ref } from 'vue';
import { useRouter, useRoute } from 'vue-router';
import axios from 'axios';
import { useArrayDataStore } from 'stores/useArrayDataStore';

const arrayDataStore = useArrayDataStore();

export function useArrayData(key, userOptions) {
    if (!key) throw new Error('ArrayData: A key is required to use this composable');

    if (!arrayDataStore.get(key)) {
        arrayDataStore.set(key);
    }

    const store = arrayDataStore.get(key);
    const hasMoreData = ref(false);
    const router = useRouter();
    const route = useRoute();
    let canceller = null;

    const page = ref(1);

    if (typeof userOptions === 'object') {
        if (userOptions.filter) store.filter = userOptions.filter;
        if (userOptions.url) store.url = userOptions.url;
        if (userOptions.limit) store.limit = userOptions.limit;
        if (userOptions.order) store.order = userOptions.order;
    }

    onMounted(() => {
        const query = route.query;
        if (query.params) {
            store.userParams = JSON.parse(query.params);
        }
    });

    async function fetch({ append = false }) {
        if (!store.url) return;

        cancelRequest();
        canceller = new AbortController();

        const filter = {
            order: store.order,
            limit: store.limit,
            skip: store.skip,
        };

        Object.assign(filter, store.userFilter);
        Object.assign(filter, store.filter);

        store.filter = filter;

        const params = {
            filter: JSON.stringify(filter),
        };

        Object.assign(params, store.userParams);

        const response = await axios.get(store.url, {
            signal: canceller.signal,
            params,
        });

        const { limit } = filter;

        hasMoreData.value = response.data.length === limit;

        if (append === true) {
            for (const row of response.data) store.data.push(row);
        }

        if (append === false) {
            store.data = response.data;

            updateStateParams();
        }

        canceller = null;
    }

    
    function clear() {
        if (arrayDataStore.get(key)) {
            arrayDataStore.clear(key);
        }
    }

    function cancelRequest() {
        if (canceller) {
            canceller.abort();
            canceller = null;
        }
    }

    async function applyFilter({ filter, params }) {
        if (filter) store.userFilter = filter;
        if (params) store.userParams = Object.assign({}, params);

        await fetch({ append: false });
    }

    async function addFilter({ filter, params }) {
        if (filter) store.userFilter = Object.assign(store.userFilter, filter);
        if (params) store.userParams = Object.assign(store.userParams, params);

        await fetch({ append: false });
    }

    async function loadMore() {
        if (!hasMoreData.value) return;

        store.skip = store.limit * (page.value - 1);
        page.value += 1;

        await fetch({ append: true });
    }

    async function refresh() {
        await fetch({ append: false });
    }

    function updateStateParams() {
        const query = {};
        if (store.order) query.order = store.order;
        if (store.limit) query.limit = store.limit;
        if (store.skip) query.skip = store.skip;
        if (store.userParams && Object.keys(store.userParams).length !== 0)
            query.params = JSON.stringify(store.userParams);

        router.replace({
            path: route.path,
            query: query,
        });
    }

    return {
        fetch,
        applyFilter,
        addFilter,
        refresh,
        clear,
        loadMore,
        store,
        hasMoreData,
        updateStateParams,
    };
}