frontend/src/utils/fplLogic.js

// src/utils/fplLogic.js

export const CHIP_CONFIG = {
  wc: {
    label: "Wildcard", short: "WC", desc: "Unlimited free transfers for 1 GW. FTs reset to max after.",
    dot: "bg-yellow-400", text: "text-yellow-400", activeBg: "bg-yellow-500 text-slate-950",
    inactiveBg: "bg-slate-800 text-slate-500 hover:bg-slate-700", border: "border-yellow-700/40", badge: "bg-yellow-500/20 text-yellow-300",
  },
  fh: {
    label: "Free Hit", short: "FH", desc: "Unlimited transfers for 1 GW. Squad reverts to original after.",
    dot: "bg-orange-400", text: "text-orange-400", activeBg: "bg-orange-500 text-slate-950",
    inactiveBg: "bg-slate-800 text-slate-500 hover:bg-slate-700", border: "border-orange-700/40", badge: "bg-orange-500/20 text-orange-300",
  },
  bb: {
    label: "Bench Boost", short: "BB", desc: "All 15 squad players score points this GW.",
    dot: "bg-emerald-400", text: "text-emerald-400", activeBg: "bg-emerald-500 text-slate-950",
    inactiveBg: "bg-slate-800 text-slate-500 hover:bg-slate-700", border: "border-emerald-700/40", badge: "bg-emerald-500/20 text-emerald-300",
  },
  tc: {
    label: "Triple Captain", short: "TC", desc: "Captain earns 3× points instead of 2× this GW.",
    dot: "bg-purple-400", text: "text-purple-400", activeBg: "bg-purple-500 text-white",
    inactiveBg: "bg-slate-800 text-slate-500 hover:bg-slate-700", border: "border-purple-700/40", badge: "bg-purple-500/20 text-purple-300",
  },
};

export const getPlayerPrice = (p) => {
  // 1. Exact FPL Calculation if we have both purchase_price and now_cost
  let pp = p.purchase_price !== undefined ? Number(p.purchase_price) : undefined;
  let nc = p.now_cost !== undefined ? Number(p.now_cost) : undefined;

  // FPL API sometimes sends prices multiplied by 10 (e.g., 43 for 4.3m)
  if (pp > 20) pp = pp / 10;
  if (nc > 20) nc = nc / 10;

  if (pp !== undefined && nc !== undefined) {
     if (nc > pp) {
         // Gain is 0.1m for every 0.2m increase. 
         // To avoid floating point errors, multiply by 10, floor the difference/2, and divide by 10.
         const diff = Math.round((nc - pp) * 10); 
         const gain = Math.floor(diff / 2); 
         return (Math.round(pp * 10) + gain) / 10; 
     } else {
         // FPL Rule: You take full losses on price drops.
         return nc;
     }
  }

  // 2. Fallbacks if purchase_price isn't explicitly available
  if (p.selling_price !== undefined && p.selling_price !== null) {
     const sp = Number(p.selling_price);
     return sp > 20 ? sp / 10 : sp;
  }
  if (p.sell_price !== undefined && p.sell_price !== null) {
     const sp = Number(p.sell_price);
     return sp > 20 ? sp / 10 : sp;
  }
  if (p.Price !== undefined) return Number(p.Price);
  if (nc !== undefined) return nc;

  return 0;
};

export function normalizeBenchGkFirst(teamData, gw) {
  if (!teamData.length || teamData.length < 15 || !gw) return teamData;
  const starters = teamData.slice(0, 11);
  const bench = teamData.slice(11, 15);
  const getEV = (p) => Number(p[`${gw}_Pts`]) || 0;
  const nonBlank = bench.filter((p) => !p.isBlank);
  const blanks = bench.filter((p) => p.isBlank);
  const gk = nonBlank.find((p) => p.Pos === "G");
  const outfield = nonBlank.filter((p) => p.Pos !== "G");
  outfield.sort((a, b) => getEV(b) - getEV(a));
  const ordered = gk ? [gk, ...outfield] : [...outfield];
  const newBench = [...ordered, ...blanks];
  while (newBench.length < 4) {
    newBench.push({
      ID: `blank_pad_${Date.now()}_${newBench.length}`,
      isBlank: true, Pos: "M", Name: "", Team: "", Price: 0,
    });
  }
  return [...starters, ...newBench.slice(0, 4)];
}

export function countSquadByPos(players) {
  const c = { G: 0, D: 0, M: 0, F: 0 };
  players.filter((p) => !p.isBlank && p.Pos).forEach((p) => {
    if (c[p.Pos] !== undefined) c[p.Pos] += 1;
  });
  return c;
}

export function isValidFplSquad(players) {
  const c = countSquadByPos(players);
  return c.G === 2 && c.D === 5 && c.M === 5 && c.F === 3;
}

export const getOptimalLayout = (players, gw) => {
  if (!players.length || !gw || players.some((p) => p.isBlank)) return null;
  const getEV = (p) => Number(p[`${gw}_Pts`]) || 0;

  let gks = players.filter((p) => p.Pos === "G").sort((a, b) => getEV(b) - getEV(a));
  let defs = players.filter((p) => p.Pos === "D").sort((a, b) => getEV(b) - getEV(a));
  let mids = players.filter((p) => p.Pos === "M").sort((a, b) => getEV(b) - getEV(a));
  let fwds = players.filter((p) => p.Pos === "F").sort((a, b) => getEV(b) - getEV(a));

  const starters = [];
  if (gks.length) starters.push(gks.shift());
  starters.push(...defs.splice(0, 3), ...mids.splice(0, 2), ...fwds.splice(0, 1));

  const remaining = [...defs, ...mids, ...fwds].sort((a, b) => getEV(b) - getEV(a));
  starters.push(...remaining.splice(0, 11 - starters.length));

  const finalStarters = [
    ...starters.filter((p) => p.Pos === "G"),
    ...starters.filter((p) => p.Pos === "D"),
    ...starters.filter((p) => p.Pos === "M"),
    ...starters.filter((p) => p.Pos === "F"),
  ];

  const benchGk = gks.length ? gks[0] : null;
  const benchRest = remaining.sort((a, b) => getEV(b) - getEV(a));
  const bench = benchGk ? [benchGk, ...benchRest] : benchRest;
  const topStarters = [...finalStarters].sort((a, b) => getEV(b) - getEV(a));

  return {
    optimalArray: [...finalStarters, ...bench],
    cap: topStarters[0]?.ID,
    vice: topStarters[1]?.ID,
  };
};