/**
 * @module AnchorBehavior
 *
 * An anchor is a container that takes physical priority in the representation :
 * - It cannot be moved by other rigid siblings container
 * - It cannot be resized by any other siblings container
 * - It cannot overlap any other siblings rigid container :
 *  - overlapping container are shifted to the nearest available space/width
 *  - or resized when there is no available space left other than theirs
 *  - or lose their rigid body properties when there is no available space left)
 * Meaning that:
 * - Moving an anchor container will resize the width of an overlapping container
 *   or make them lose their property as a rigid body
 */

import { IContainerModel } from '../../../Interfaces/IContainerModel';
import { constraintBodyInsideUnallocatedWidth } from './RigidBodyBehaviors';

/**
 * Impose the container position to its siblings
 * Apply the following modification to the overlapping rigid body container :
 * @param container Container to impose its position
 */
export function ApplyAnchor(container: IContainerModel): IContainerModel {
  if (container.parent === undefined ||
    container.parent === null) {
    return container;
  }

  const rigidBodies = container.parent.children.filter(
    child => child.properties.isRigidBody && !child.properties.isAnchor
  );

  const overlappingContainers = getOverlappingContainers(container, rigidBodies);
  for (const overlappingContainer of overlappingContainers) {
    constraintBodyInsideUnallocatedWidth(overlappingContainer);
  }
  return container;
}

/**
 * Returns the overlapping containers with container
 * @param container A container
 * @param containers A list of containers
 * @returns A list of overlapping containers
 */
function getOverlappingContainers(
  container: IContainerModel,
  containers: IContainerModel[]
): IContainerModel[] {
  const min1 = container.properties.x;
  const max1 = container.properties.x + container.properties.width;
  const overlappingContainers: IContainerModel[] = [];
  for (const other of containers) {
    if (other === container) {
      continue;
    }

    const min2 = other.properties.x;
    const max2 = other.properties.x + other.properties.width;
    const isOverlapping = Math.min(max1, max2) - Math.max(min1, min2) > 0;

    if (!isOverlapping) {
      continue;
    }

    overlappingContainers.push(other);
  }
  return overlappingContainers;
}