import { derived, readable, writable } from 'svelte/store';
import { createClient } from '@supabase/supabase-js';
import { supabase } from '$lib/config';
import { maxSize } from '$lib/config';

const boxParser = /\(([0-9]+),([0-9]+)\),\(([0-9]+),([0-9]+)\)/;
const client = createClient(supabase.url, supabase.key);

export const sensor = writable({ left: 0, top: 0, right: 0, bottom: 0 });

const getBoxes = function getBoxes({ left, top, right, bottom }) {
	const results = [
		`box.ov."((${left},${top}),(${right},${bottom}))"`,
		`box.ov."((${left + maxSize},${top + maxSize}),(${right + maxSize},${bottom + maxSize}))"`,
		`box.ov."((${left + maxSize},${top}),(${right + maxSize},${bottom}))"`,
		`box.ov."((${left},${top + maxSize}),(${right},${bottom + maxSize}))"`,
		`box.ov."((${left - maxSize},${top - maxSize}),(${right - maxSize},${bottom - maxSize}))"`,
		`box.ov."((${left - maxSize},${top}),(${right - maxSize},${bottom}))"`,
		`box.ov."((${left},${top - maxSize}),(${right},${bottom - maxSize}))"`
	];

	return results;
};

const serialize = function serialize(widget) {
	const boxComponents = widget.box.match(boxParser).slice(1, 5).map(Number);
	const box = {
		left: Math.min(boxComponents[0], boxComponents[2]),
		right: Math.max(boxComponents[0], boxComponents[2]),
		top: Math.min(boxComponents[1], boxComponents[3]),
		bottom: Math.max(boxComponents[1], boxComponents[3])
	};

	return { ...widget, box };
};

let ac = null;
export const widgets = derived(sensor, async function ($sensor, set) {
	const boxes = getBoxes($sensor);
	ac && ac.abort();
	ac = new AbortController();
	const { data } = await client.from('widgets').select().or(boxes.join(',')).abortSignal(ac.signal);
	if (data) {
		return set(data.map(serialize));
	}
});

export const countElements = function countElements(left, top, right, bottom) {
	let countAc = null;
	return readable(0, (set) => {
		(async function () {
			countAc && countAc.abort();
			countAc = new AbortController();
			const { data } = await client
				.from('widgets')
				.select('*', { head: true, count: 'estimated' })
				.or(`box.ov."((${left},${top}),(${right},${bottom}))"`)
				.abortSignal(countAc.signal);
			if (data) {
				return set(data);
			}
		})();
	});
};