import crypto from 'node:crypto';
import { Users, Games } from './db.js';
import { pushFeed } from './realtime.js';

const HOUSE_EDGE = 0.99; // 1% Hausvorteil
const rounds = new Map(); // roundId -> state

function rid() { return crypto.randomBytes(12).toString('hex'); }
function rand() { return crypto.randomBytes(4).readUInt32BE(0) / 0xffffffff; }
function round(n, d = 2) { const f = Math.pow(10, d); return Math.round(n * f) / f; }

function debit(userId, amount) {
  const u = Users.byId(userId);
  if (!u) return { ok: false, error: 'User fehlt' };
  if (amount <= 0) return { ok: false, error: 'Einsatz muss > 0 sein' };
  if (u.balance < amount) return { ok: false, error: 'Nicht genug Guthaben' };
  Users.setBalance(userId, u.balance - amount);
  return { ok: true, balance: u.balance - amount };
}

function credit(userId, amount) {
  return Users.addBalance(userId, amount);
}

function settle(userId, game, bet, payout, result) {
  Games.add(userId, game, bet, payout, result);
  const u = Users.byId(userId);
  if (payout >= bet * 5 && payout > 0) {
    pushFeed('win', `${u?.username || 'Spieler'} gewinnt ${round(payout)} 🪙 bei ${game} (${round(payout / bet, 2)}x)`);
  }
  return Users.byId(userId)?.balance;
}

// ============ CHICKEN ROAD ============
// Huhn ueberquert Fahrbahnen. Jede Spur erhoeht den Multiplikator,
// aber es droht ein Crash (Auto). Cashout jederzeit moeglich.
const CHICKEN_DIFF = {
  easy:   { p: 0.04, lanes: 24 },
  medium: { p: 0.10, lanes: 20 },
  hard:   { p: 0.20, lanes: 16 },
  insane: { p: 0.35, lanes: 12 },
};

function chickenMultipliers(p, lanes) {
  // Faire Multiplikatoren: 1/(1-p)^k * HouseEdge
  const arr = [];
  for (let k = 1; k <= lanes; k++) {
    arr.push(round(HOUSE_EDGE / Math.pow(1 - p, k), 2));
  }
  return arr;
}

export function chickenStart(userId, bet, difficulty = 'medium') {
  bet = Number(bet);
  const diff = CHICKEN_DIFF[difficulty] || CHICKEN_DIFF.medium;
  const d = debit(userId, bet);
  if (!d.ok) return d;
  const mults = chickenMultipliers(diff.p, diff.lanes);
  const id = rid();
  rounds.set(id, { type: 'chicken', userId, bet, p: diff.p, lanes: diff.lanes, mults, lane: 0, alive: true, difficulty });
  return { ok: true, roundId: id, lanes: diff.lanes, multipliers: mults, balance: d.balance };
}

export function chickenStep(userId, roundId) {
  const r = rounds.get(roundId);
  if (!r || r.type !== 'chicken' || r.userId !== userId || !r.alive) return { ok: false, error: 'Runde ungueltig' };
  // Crash-Check auf der naechsten Spur
  if (rand() < r.p) {
    r.alive = false;
    rounds.delete(roundId);
    const bal = settle(userId, 'chicken', r.bet, 0, { crashedAt: r.lane + 1, difficulty: r.difficulty });
    return { ok: true, dead: true, lane: r.lane + 1, balance: bal };
  }
  r.lane += 1;
  const multiplier = r.mults[r.lane - 1];
  if (r.lane >= r.lanes) {
    // Maximum erreicht -> automatischer Cashout
    const payout = round(r.bet * multiplier);
    credit(userId, payout);
    rounds.delete(roundId);
    const bal = settle(userId, 'chicken', r.bet, payout, { lane: r.lane, multiplier, maxed: true });
    return { ok: true, dead: false, maxed: true, lane: r.lane, multiplier, payout, balance: bal };
  }
  return { ok: true, dead: false, lane: r.lane, multiplier, nextMultiplier: r.mults[r.lane] };
}

export function chickenCashout(userId, roundId) {
  const r = rounds.get(roundId);
  if (!r || r.type !== 'chicken' || r.userId !== userId || !r.alive) return { ok: false, error: 'Runde ungueltig' };
  if (r.lane === 0) return { ok: false, error: 'Erst mind. 1 Schritt gehen' };
  const multiplier = r.mults[r.lane - 1];
  const payout = round(r.bet * multiplier);
  credit(userId, payout);
  rounds.delete(roundId);
  const bal = settle(userId, 'chicken', r.bet, payout, { lane: r.lane, multiplier });
  return { ok: true, payout, multiplier, lane: r.lane, balance: bal };
}

// ============ 10x10 MINES KARTEN-DECK ============
const GRID = 100;
function minesMultiplier(bombs, picks) {
  let m = 1;
  for (let i = 0; i < picks; i++) {
    m *= (GRID - i) / (GRID - bombs - i);
  }
  return round(m * HOUSE_EDGE, 4);
}

export function minesStart(userId, bet, bombs = 10) {
  bet = Number(bet);
  bombs = Math.max(1, Math.min(95, Math.floor(Number(bombs))));
  const d = debit(userId, bet);
  if (!d.ok) return d;
  // Bomben-Positionen geheim ziehen
  const positions = new Set();
  while (positions.size < bombs) positions.add(Math.floor(rand() * GRID));
  const id = rid();
  rounds.set(id, { type: 'mines', userId, bet, bombs, mines: positions, revealed: new Set(), alive: true });
  return { ok: true, roundId: id, bombs, grid: GRID, balance: d.balance, nextMultiplier: minesMultiplier(bombs, 1) };
}

export function minesReveal(userId, roundId, index) {
  const r = rounds.get(roundId);
  if (!r || r.type !== 'mines' || r.userId !== userId || !r.alive) return { ok: false, error: 'Runde ungueltig' };
  index = Math.floor(Number(index));
  if (index < 0 || index >= GRID) return { ok: false, error: 'Feld ungueltig' };
  if (r.revealed.has(index)) return { ok: false, error: 'Feld schon offen' };

  if (r.mines.has(index)) {
    r.alive = false;
    rounds.delete(roundId);
    const bal = settle(userId, 'mines', r.bet, 0, { hitBomb: index, bombs: r.bombs });
    return { ok: true, bomb: true, index, mines: [...r.mines], balance: bal };
  }
  r.revealed.add(index);
  const picks = r.revealed.size;
  const safeLeft = GRID - r.bombs - picks;
  const multiplier = minesMultiplier(r.bombs, picks);
  const next = safeLeft > 0 ? minesMultiplier(r.bombs, picks + 1) : null;
  if (safeLeft === 0) {
    // Alle sicheren Felder gefunden -> Auto-Cashout
    const payout = round(r.bet * multiplier);
    credit(userId, payout);
    rounds.delete(roundId);
    const bal = settle(userId, 'mines', r.bet, payout, { picks, multiplier, cleared: true });
    return { ok: true, bomb: false, index, picks, multiplier, payout, cleared: true, balance: bal };
  }
  return { ok: true, bomb: false, index, picks, multiplier, nextMultiplier: next };
}

export function minesCashout(userId, roundId) {
  const r = rounds.get(roundId);
  if (!r || r.type !== 'mines' || r.userId !== userId || !r.alive) return { ok: false, error: 'Runde ungueltig' };
  const picks = r.revealed.size;
  if (picks === 0) return { ok: false, error: 'Erst mind. 1 Karte aufdecken' };
  const multiplier = minesMultiplier(r.bombs, picks);
  const payout = round(r.bet * multiplier);
  credit(userId, payout);
  rounds.delete(roundId);
  const bal = settle(userId, 'mines', r.bet, payout, { picks, multiplier });
  return { ok: true, payout, multiplier, picks, mines: [...r.mines], balance: bal };
}

// ============ COINFLIP ============
export function coinflip(userId, bet, choice) {
  bet = Number(bet);
  const d = debit(userId, bet);
  if (!d.ok) return d;
  const flip = rand() < 0.5 ? 'heads' : 'tails';
  const win = flip === choice;
  const mult = 2 * HOUSE_EDGE;
  const payout = win ? round(bet * mult) : 0;
  if (win) credit(userId, payout);
  const bal = settle(userId, 'coinflip', bet, payout, { flip, choice });
  return { ok: true, win, flip, payout, multiplier: win ? mult : 0, balance: bal };
}

// ============ DICE (roll under) ============
export function dice(userId, bet, target, direction = 'under') {
  bet = Number(bet);
  target = Math.max(2, Math.min(98, Number(target)));
  const d = debit(userId, bet);
  if (!d.ok) return d;
  const roll = round(rand() * 100, 2);
  const win = direction === 'under' ? roll < target : roll > target;
  const chance = direction === 'under' ? target : 100 - target;
  const mult = round((100 / chance) * HOUSE_EDGE, 4);
  const payout = win ? round(bet * mult) : 0;
  if (win) credit(userId, payout);
  const bal = settle(userId, 'dice', bet, payout, { roll, target, direction });
  return { ok: true, win, roll, target, direction, multiplier: mult, payout, balance: bal };
}

// ============ CRASH ============
// Server-autoritativ: Multiplikator = e^(k*t). Crashpunkt geheim.
const CRASH_K = 0.00006; // Wachstum pro ms
function genCrashPoint() {
  const r = rand();
  if (r < 0.03) return 1.0; // Instant-Crash 3%
  // Schwerer Tail, Median ~2x
  return round(Math.max(1, (1 - 0.01) / (1 - r)), 2);
}
function crashMultAt(ms) {
  return round(Math.exp(CRASH_K * ms), 2);
}

export function crashStart(userId, bet) {
  bet = Number(bet);
  const d = debit(userId, bet);
  if (!d.ok) return d;
  const id = rid();
  const crashPoint = genCrashPoint();
  rounds.set(id, { type: 'crash', userId, bet, crashPoint, start: Date.now(), done: false });
  return { ok: true, roundId: id, balance: d.balance, k: CRASH_K };
}

export function crashCashout(userId, roundId) {
  const r = rounds.get(roundId);
  if (!r || r.type !== 'crash' || r.userId !== userId || r.done) return { ok: false, error: 'Runde ungueltig' };
  const elapsed = Date.now() - r.start;
  const current = crashMultAt(elapsed);
  r.done = true;
  rounds.delete(roundId);
  if (current >= r.crashPoint) {
    const bal = settle(userId, 'crash', r.bet, 0, { crashPoint: r.crashPoint, cashoutAt: current });
    return { ok: true, crashed: true, crashPoint: r.crashPoint, balance: bal };
  }
  const payout = round(r.bet * current);
  credit(userId, payout);
  const bal = settle(userId, 'crash', r.bet, payout, { multiplier: current, crashPoint: r.crashPoint });
  return { ok: true, crashed: false, multiplier: current, payout, balance: bal };
}

// Status-Abfrage fuer die Crash-Animation (autoritativ).
export function crashStatus(userId, roundId) {
  const r = rounds.get(roundId);
  if (!r || r.type !== 'crash' || r.userId !== userId) return { ok: false, error: 'Runde ungueltig' };
  const elapsed = Date.now() - r.start;
  const current = crashMultAt(elapsed);
  if (current >= r.crashPoint && !r.done) {
    r.done = true;
    rounds.delete(roundId);
    settle(userId, 'crash', r.bet, 0, { crashPoint: r.crashPoint, busted: true });
    return { ok: true, crashed: true, crashPoint: r.crashPoint, multiplier: r.crashPoint };
  }
  return { ok: true, crashed: false, multiplier: current };
}