import type { Vec2 } from '../geometry/Vec2';
import type { BearColor } from './BearCrush';

export type OddJellyVariant = 'normal' | 'ears' | 'horn' | 'tail' | 'body' | 'face';
export interface OddJellyBody {
  id: number;
  variant: OddJellyVariant;
  strength: number;
  position: Vec2;
  rotation: number;
  color: BearColor;
}
export interface OddJellyDefinition {
  difficulty: 'Easy' | 'Normal' | 'Hard' | 'Very hard';
  bodies: readonly OddJellyBody[];
}
export const ODD_JELLY = {
  limit: 30, down: 0.10, hold: 0.05, up: 0.15, cycle: 0.30,
  halfW: 5.4, halfH: 7.6,
} as const;

// 스테이지별 고정 시드를 사용해 재시작과 앱 재실행 뒤에도 같은 개체·자세를 유지한다.
function scatteredPositions(stage:number):Vec2[] {
  let seed=4709+stage*7919;
  const random=()=>((seed=(Math.imul(seed,1664525)+1013904223)>>>0)/4294967296);
  const positions:Vec2[]=[];
  // 고정 시드의 후보 중 기존 개체에서 가장 먼 곳을 골라 격자 없이 간격을 확보한다.
  for(let id=0;id<32;id++) {
    let best:Vec2={x:0,y:0},distance=-1;
    for(let candidate=0;candidate<256;candidate++) {
      const p={x:(random()*2-1)*4.45,y:(random()*2-1)*6.4};
      const nearest=positions.reduce((min,q)=>Math.min(min,Math.hypot(p.x-q.x,p.y-q.y)),20);
      if(nearest>distance){best=p;distance=nearest;}
    }
    positions.push(best);
  }
  return positions;
}
const colors:readonly BearColor[]=['red','green','blue','yellow','white'];
const targets = [[5,18,27],[2,9,14,23,30],[1,6,10,15,21,26,29],[0,4,8,12,16,20,24,28,31]];
const variants: readonly OddJellyVariant[][] = [
  ['horn','tail','ears'],
  ['tail','ears','horn','body','ears'],
  ['ears','horn','body','tail','ears','body','horn'],
  ['ears','body','face','horn','body','ears','tail','face','horn'],
];
export const ODD_JELLY_LEVELS: readonly OddJellyDefinition[] = (['Easy','Normal','Hard','Very hard'] as const).map((difficulty,stage) => ({
  difficulty,
  bodies: scatteredPositions(stage).map((position,id) => {
    const target=targets[stage].indexOf(id);
    return {
      id,variant:target<0?'normal':variants[stage][target],strength:target<0?0:[1,0.75,0.5,0.35][stage],
      position,
      rotation:(((id*13+stage*7)%31)-15)*Math.PI/40,
      color:colors[(id*3+stage)%colors.length],
    };
  }),
}));