import { Line, Point } from '../../geometry'
import { ResolveOptions, resolve, getPointAtEdge } from '../node-anchor/util'
import { getClosestPoint } from './closest'
import { EdgeAnchor } from './index'
import { FunctionExt } from '../../util'

export interface OrthEndpointOptions extends ResolveOptions {
  fallbackAt?: number | string
}

const orthogonal: EdgeAnchor.ResolvedDefinition<OrthEndpointOptions> = function (
  view,
  magnet,
  refPoint,
  options,
): Point {
  const OFFSET = 1e6
  const path = view.getConnection()!
  const segmentSubdivisions = view.getConnectionSubdivisions()
  const vLine = new Line(
    refPoint.clone().translate(0, OFFSET),
    refPoint.clone().translate(0, -OFFSET),
  )
  const hLine = new Line(
    refPoint.clone().translate(OFFSET, 0),
    refPoint.clone().translate(-OFFSET, 0),
  )

  const vIntersections = vLine.intersect(path, {
    segmentSubdivisions,
  })

  const hIntersections = hLine.intersect(path, {
    segmentSubdivisions,
  })

  const intersections = []
  if (vIntersections) {
    intersections.push(...vIntersections)
  }
  if (hIntersections) {
    intersections.push(...hIntersections)
  }

  if (intersections.length > 0) {
    return refPoint.closest(intersections)!
  }

  if (options.fallbackAt != null) {
    return getPointAtEdge(view, options.fallbackAt)!
  }

  return FunctionExt.call(
    getClosestPoint,
    this,
    view,
    magnet,
    refPoint,
    options,
  )
}

export const orth = resolve<
  EdgeAnchor.ResolvedDefinition<OrthEndpointOptions>,
  EdgeAnchor.Definition<OrthEndpointOptions>
>(orthogonal)
