import applyTransform, { notify } from '@webitel/ui-sdk/api/transformers/index';
import { computed, type Ref, ref } from 'vue';
import { useRoute } from 'vue-router';

import CSVExport from '../CSVExport';

export type CSVRow = Record<string, unknown>;

export type FetchMethod = (params: Record<string, unknown>) => Promise<{
	items: CSVRow[];
	next: boolean;
}>;

interface CSVExportOptions {
	filename?: string;
	delimiter?: string;
}

const CSV_EXPORT_BATCH_SIZE = 5000;

export function useCSVExport({ selected }: { selected: Ref<number[]> }) {
	const CSVExportInstance = ref<null | InstanceType<typeof CSVExport>>(null);
	const route = useRoute();

	const CSVDownloadProgress = computed(() =>
		CSVExportInstance.value
			? CSVExportInstance.value.downloadProgress.count
			: 0,
	);

	const isCSVLoading = computed(() => !!CSVDownloadProgress.value);

	const isAnySelected = computed(() => !!selected.value.length);

	function initCSVExport(
		fetchMethod: FetchMethod,
		options: CSVExportOptions = {},
	) {
		CSVExportInstance.value = new CSVExport(fetchMethod, options);
	}

	async function exportCSV(exportParams?: Record<string, unknown>) {
		const routeQuery = route.query;
		const params = {
			...(exportParams || routeQuery),
			size: CSV_EXPORT_BATCH_SIZE,
		};

		if (isAnySelected.value) {
			params.id = selected.value;
		}

		try {
			await CSVExportInstance.value?.export(params);
		} catch (err) {
			throw applyTransform(err, [
				notify,
			]);
		}
	}

	return {
		CSVExportInstance,

		CSVDownloadProgress,
		isCSVLoading,
		isAnySelected,

		initCSVExport,
		exportCSV,
	};
}