import { ColorRGB, ColorReference } from './color.js'
import { Length } from './length.js'

export const GradientColorStop = (props: any) => ({
  color: ColorReference(props.color) as ColorReference | ColorRGB,
  start: props.start != null ? Length(props.start) : null,
  end: props.end != null ? Length(props.end) : null
})

export const Gradient = (gradient?: any) => {
  let angle = 0
  let stops: GradientColorStop[] = []

  if (!gradient) {
    return { angle, stops }
  }

  if (gradient.angle) {
    angle = gradient.angle
  }

  if (Array.isArray(gradient.stops)) {
    stops = gradient.stops.map(GradientColorStop)
  }

  return { angle, stops }
}

Gradient.isValid = (gradient: Gradient) =>
  gradient.stops.length > 0 && gradient.stops.every((stop) => ColorReference.isValid(stop.color))

export type GradientColorStop = ReturnType<typeof GradientColorStop>
export type Gradient = ReturnType<typeof Gradient>