// @ts-ignore
import {convert} from './objparser';
import {initBuffers, deleteBuffers} from './buffers';

/**
 * Fetch an obj file
 * @param {string} url the url to fetch the object from
 * @return {string} the raw data of the obj file
 */
export async function fetchObj(url: string) {
	const response = await fetch(url);
	const data = await response.text();
	return data;
}

/**
 * Pushes a new obj file to the gl buffer
 * @param {any} context the program context
 * @param {any} obj the obj file to push
 * @return {any} the initiated buffers
 */
export function pushBuffersToScene(
	context: any,
	obj: any) {
	return initBuffers(context.gl,
		obj.positions, obj.indices, obj.normals, obj.uvs);
}


/**
 * Pushes a new obj file to the gl buffer
 * @param {any} context the program context
 * @param {any} obj the obj file to push
 */
export function loadObjBuffers(
	context: any,
	obj: any) {
	if (context.buffers != null) {
		deleteBuffers(context.gl, context.buffers);
	}
	context.obj = {
		positions: obj.positions,
		indices: obj.indices,
		normals: obj.normals,
		uvs: obj.uvs,
	};
	context.buffers = initBuffers(context.gl,
		obj.positions, obj.indices, obj.normals, obj.uvs);
}

/**
 * Load a new obj file to the cache
 * @param {string} data the obj file to push
 * @return {any} the obj file loaded
 */
export function loadObj(
	data: string) {
	const [
		positions,
		normals,
		uvs,
		indices,
	] = convert(data);
	let x = 0;
	let y = 0;
	let z = 0;
	let maxx = positions[0];
	let maxy = positions[1];
	let maxz = positions[2];
	let minx = positions[0];
	let miny = positions[1];
	let minz = positions[2];
	for (let i = 0; i < positions.length; i++) {
		if (i % 3 == 0) {
			if (positions[i] > maxx) {
				maxx = positions[i];
			} else if (positions[i] < minx) {
				minx = positions[i];
			}
			x += positions[i];
		} else if (i % 3 == 1) {
			if (positions[i] > maxy) {
				maxy = positions[i];
			} else if (positions[i] < miny) {
				miny = positions[i];
			}
			y += positions[i];
		} else {
			if (positions[i] > maxz) {
				maxz = positions[i];
			} else if (positions[i] < minz) {
				minz = positions[i];
			}
			z += positions[i];
		}
	}
	const avgx = x / (positions.length / 3);
	const avgy = y / (positions.length / 3);
	const avgz = z / (positions.length / 3);
	for (let i = 0; i < positions.length; i++) {
		if (i % 3 == 0) {
			positions[i] -= avgx;
		} else if (i % 3 == 1) {
			positions[i] -= avgy;
		} else {
			positions[i] -= avgz;
		}
	}
	return {
		positions: positions,
		indices: indices,
		normals: normals,
		uvs: uvs,
		range: Math.max(maxx - minx, maxy - miny, maxz - minz),
	};
}