// Spiel-Parameter, live per Admin-Panel einstellbar, persistent in data/config.json.
// Wird pro Request frisch gelesen -> Aenderungen wirken SOFORT (Server + Client).

import { existsSync, readFileSync, writeFileSync, mkdirSync } from 'node:fs';
import { dirname, join } from 'node:path';
import { fileURLToPath } from 'node:url';

const __dirname = dirname(fileURLToPath(import.meta.url));
const DATA_DIR = join(__dirname, '..', 'data');
const CONFIG_FILE = join(DATA_DIR, 'config.json');

// Defaults = die bisherigen Konstanten aus public/js/app.js + server/index.js
export const DEFAULT_CONFIG = {
  // Timer
  startTime: 15,
  maxTime: 30,
  bonus: 1.2,
  penalty: 2.0,
  // Objekt-Anzahl-Kurve
  countBase: 10,
  countPerScore: 1.5,
  stepStart: 25,
  stepEvery: 3,
  stepAdd: 2,
  countCap: 100,
  // Schwierigkeits-Stufen (Score-Grenzen) + Tempo
  stageScatter: 3, // ab hier "scatter"
  stageGroups: 6, // ab hier "groups"
  stageIndividual: 11, // ab hier "individual"
  speedGroupsBase: 45,
  speedGroupsPer: 10,
  speedGroupsMax: 150,
  speedIndivBase: 70,
  speedIndivPer: 12,
  speedIndivMax: 320,
};

// Nur bekannte Keys uebernehmen, Werte auf sinnvolle Zahlen begrenzen
function sanitize(input) {
  const out = { ...DEFAULT_CONFIG };
  if (input && typeof input === 'object') {
    for (const key of Object.keys(DEFAULT_CONFIG)) {
      const v = Number(input[key]);
      if (Number.isFinite(v)) out[key] = clampField(key, v);
    }
  }
  return out;
}

function clampField(key, v) {
  const bounds = {
    startTime: [3, 120],
    maxTime: [5, 300],
    bonus: [0, 30],
    penalty: [0, 30],
    countBase: [1, 200],
    countPerScore: [0, 20],
    stepStart: [0, 500],
    stepEvery: [1, 100],
    stepAdd: [0, 50],
    countCap: [5, 400],
    stageScatter: [0, 1000],
    stageGroups: [0, 1000],
    stageIndividual: [0, 1000],
    speedGroupsBase: [0, 2000],
    speedGroupsPer: [0, 500],
    speedGroupsMax: [0, 5000],
    speedIndivBase: [0, 2000],
    speedIndivPer: [0, 500],
    speedIndivMax: [0, 5000],
  };
  const [min, max] = bounds[key] || [-1e9, 1e9];
  return Math.max(min, Math.min(max, v));
}

export function getConfig() {
  try {
    if (!existsSync(CONFIG_FILE)) return { ...DEFAULT_CONFIG };
    return sanitize(JSON.parse(readFileSync(CONFIG_FILE, 'utf8')));
  } catch {
    return { ...DEFAULT_CONFIG };
  }
}

export function setConfig(input) {
  if (!existsSync(DATA_DIR)) mkdirSync(DATA_DIR, { recursive: true });
  const next = sanitize(input);
  writeFileSync(CONFIG_FILE, JSON.stringify(next, null, 2));
  return next;
}

// Objekt-Anzahl aus Config + Score (identisch fuer Server & Client)
export function objectCount(cfg, score) {
  let count = cfg.countBase + Math.floor(score * cfg.countPerScore);
  if (score >= cfg.stepStart) count += Math.floor((score - cfg.stepStart) / cfg.stepEvery) * cfg.stepAdd;
  return Math.min(count, cfg.countCap);
}