import { pointInPolygon } from '../geometry/Polygon';
import { rotateY, type Vec2 } from '../geometry/Vec2';
import type { StageResult } from './StageSession';
import type { Stars } from './Stars';
import { ODD_JELLY, type OddJellyDefinition } from './OddJelly';

export interface OddJellySnapshot {
  elapsed: number;
  remaining: number;
  found: number;
  target: number;
  mistakes: number;
  stars: number;
  outcome: 'playing' | 'clear' | 'mistakes' | 'timeout';
  selected: number[];
  activeId: number | null;
  pressAge: number;
}

/** 원래 외곽을 바꾸지 않고 개체 위치·회전만 되돌려 탭을 판정한다. */
export function oddJellyHit(point: Vec2, bodies: readonly {id:number;position:Vec2;rotation:number;outline:readonly Vec2[];selected:boolean}[]): number | null {
  for(const b of bodies) {
    if(b.selected)continue;
    const local=rotateY({x:point.x-b.position.x,y:point.y-b.position.y},-b.rotation);
    if(pointInPolygon(b.outline,local))return b.id;
  }
  return null;
}

/** 시간과 선택은 탭 시점에 확정하고, 압착은 끝난 판에서도 마지막 한 번을 마친다. */
export class OddJellySession {
  private elapsed=0;
  private found=0;
  private mistakes=0;
  private outcome:OddJellySnapshot['outcome']='playing';
  private readonly selected=new Set<number>();
  private activeId:number|null=null;
  private pressAge:number=ODD_JELLY.cycle;
  readonly target:number;
  constructor(readonly definition:OddJellyDefinition) {
    const bodies=definition.bodies;
    this.target=bodies.filter(b=>b.variant!=='normal').length;
    if(!this.target||this.target>=bodies.length||new Set(bodies.map(b=>b.id)).size!==bodies.length||
      bodies.some(b=>!Number.isInteger(b.id)||!Number.isFinite(b.position.x)||!Number.isFinite(b.position.y)||!Number.isFinite(b.rotation)||!Number.isFinite(b.strength)||b.strength<0||b.strength>1)) {
      throw new Error('다른 젤리 찾기 구성이 유효하지 않음');
    }
  }
  advance(dt:number):void {
    if(!Number.isFinite(dt)||dt<0)throw new Error('게임 시간은 유한한 양수여야 함');
    this.pressAge=Math.min(ODD_JELLY.cycle,this.pressAge+dt);
    if(this.outcome!=='playing')return;
    this.elapsed=Math.min(ODD_JELLY.limit,this.elapsed+dt);
    if(this.elapsed>=ODD_JELLY.limit-1e-9){this.elapsed=ODD_JELLY.limit;this.outcome='timeout';}
  }
  select(id:number):boolean {
    if(this.outcome!=='playing'||this.pressAge<ODD_JELLY.cycle-1e-9||this.selected.has(id))return false;
    const b=this.definition.bodies.find(b=>b.id===id);
    if(!b)return false;
    this.selected.add(id);this.activeId=id;this.pressAge=0;
    if(b.variant==='normal')this.mistakes++;
    else this.found++;
    if(this.mistakes===3)this.outcome='mistakes';
    else if(this.found===this.target)this.outcome='clear';
    return true;
  }
  snapshot():OddJellySnapshot {
    return {elapsed:this.elapsed,remaining:ODD_JELLY.limit-this.elapsed,found:this.found,target:this.target,mistakes:this.mistakes,
      stars:3-this.mistakes,outcome:this.outcome,selected:[...this.selected],activeId:this.activeId,pressAge:this.pressAge};
  }
  getResult():StageResult {
    const isClear=this.outcome==='clear';
    const accuracy=isClear?100:0;
    return {accuracy,displayAccuracy:String(accuracy),stars:(isClear?3-this.mistakes:0) as Stars,isClear,pieceCount:this.found,targetPieceCount:this.target,guideScores:{}};
  }
}