import { PureContainerBase, PureContainerConfig } from "../ui/PureContainer";
import { RenderingContext } from "../ui/RenderingContext";
import { Instance } from "../ui/Instance";
import { NonOverlappingRectInstance } from "./NonOverlappingRect";

export interface NonOverlappingRectGroupConfig extends PureContainerConfig {}

interface NonOverlappingRectGroupInstance extends Instance {
   nonOverlappingObjects: NonOverlappingRectInstance[];
}

export class NonOverlappingRectGroup extends PureContainerBase<NonOverlappingRectGroupConfig, NonOverlappingRectGroupInstance> {
   constructor(config?: NonOverlappingRectGroupConfig) {
      super(config);
   }

   prepare(context: RenderingContext, instance: NonOverlappingRectGroupInstance) {
      instance.nonOverlappingObjects = [];
      context.push("addNonOverlappingBoundingObject", (objectInstance: NonOverlappingRectInstance) => {
         instance.nonOverlappingObjects.push(objectInstance);
      });
   }

   prepareCleanup(context: RenderingContext, instance: NonOverlappingRectGroupInstance) {
      context.pop("addNonOverlappingBoundingObject");
      instance.nonOverlappingObjects.sort((a, b) => a.data.bounds.r - b.data.bounds.r);
      let visibleObjects = [];
      for (let item of instance.nonOverlappingObjects) {
         let overlapping = false;
         let at = visibleObjects.length - 1;
         while (at >= 0 && visibleObjects[at].data.bounds.r > item.data.bounds.l) {
            let r1 = visibleObjects[at].data.bounds;
            let r2 = item.data.bounds;
            let width = Math.min(r1.r, r2.r) - Math.max(r1.l, r2.l);
            let height = Math.min(r1.b, r2.b) - Math.max(r1.t, r2.t);
            if (width > 0 && height > 0) {
               overlapping = true;
               break;
            }
            at--;
         }
         if (item.overlapping !== overlapping) {
            item.overlapping = overlapping;
            item.markShouldUpdate(context);
         }
         if (!overlapping) visibleObjects.push(item);
      }
   }
}