/*!
 * Copyright (c) Microsoft. All rights reserved.
 * Licensed under the MIT license. See LICENSE file in the project.
 */
import { Position } from '@graspologic/graph'

/**
 * @internal
 *
 * Moves __pos1__ closer to __pos2__ by a __damping__ factor
 * @param pos1 The start position
 * @param pos2 The end position
 * @param damping The damping factor
 */
export function jumpTowards(
	pos1: Position,
	pos2: Position,
	damping: number,
): Position {
	if (damping < 0.0 || damping > 1.0) {
		throw new Error('jump factor must be between 0-1')
	} else {
		const inverse = 1.0 - damping
		return {
			x: pos1.x * inverse + damping * pos2.x,
			y: pos1.y * inverse + damping * pos2.y,
		}
	}
}

/**
 * @internal
 *
 * Moves __source__ a random __distance__ away from it's current position
 * @param source The source position
 * @param distance The distance of the jump
 */
export function jumpRandom(source: Position, distance: number): Position {
	const r1 = Math.random()
	const r2 = Math.random()
	const x = source.x + (0.5 - r1) * distance
	const y = source.y + (0.5 - r2) * distance
	return { x, y }
}