import * as d3 from 'd3'

export function class2color(
  classes2colors: Record<string, string>,
  cls: string,
  colors: string[],
  numClasses: number
): string {
  if (!classes2colors[cls]) {
    classes2colors[cls] = colors[numClasses % colors.length]
  }
  return classes2colors[cls]
}

export function class2darkenColor(color: string): string {
  return d3.rgb(color).darker(1).toString()
}

export function unitaryVector(source: any, target: any, newLength?: number) {
  const length =
    Math.sqrt(Math.pow(target.x - source.x, 2) + Math.pow(target.y - source.y, 2)) / Math.sqrt(newLength || 1)
  return {
    x: (target.x - source.x) / length,
    y: (target.y - source.y) / length
  }
}

export function unitaryNormalVector(source: any, target: any, newLength?: number) {
  const vector = unitaryVector(source, target, newLength)
  return rotate({ x: 0, y: 0 }, vector, 90)
}

export function rotate(center: { x: number; y: number }, point: { x: number; y: number }, angle: number) {
  const radians = (Math.PI / 180) * angle
  const cos = Math.cos(radians)
  const sin = Math.sin(radians)
  return {
    x: cos * (point.x - center.x) + sin * (point.y - center.y) + center.x,
    y: cos * (point.y - center.y) - sin * (point.x - center.x) + center.y
  }
}