"use client";

import Link from "next/link";
import { useEffect, useState } from "react";
import { todayISO } from "@/lib/rng";
import { GAME_META, GAMES, GameId } from "@/lib/levels";
import { allStats, GameStats } from "@/lib/progress";
import { loadStats, updateRitualStreak, getRitualStreak, RitualStats } from "@/lib/stats";
import { PlayMode, getPlayMode, savePlayMode, getSessionOrder } from "@/lib/session";

// ── Other helpers ─────────────────────────────────────────────────────────────

function fmt(s: number): string {
  return `${String(Math.floor(s / 60)).padStart(2, "0")}:${String(s % 60).padStart(2, "0")}`;
}

function isDailySolved(game: GameId, date: string): boolean {
  if (typeof window === "undefined") return false;
  try {
    const stats = localStorage.getItem(`stats-${game}`);
    if (!stats) return false;
    return JSON.parse(stats)?.lastDate === date;
  } catch { return false; }
}

function isNewUser(): boolean {
  if (typeof window === "undefined") return true;
  return GAMES.every(g => !localStorage.getItem(`stats-${g}`));
}

// ── Onboarding screen ─────────────────────────────────────────────────────────

function OnboardingScreen() {
  return (
    <div className="flex flex-col items-center justify-center min-h-[70vh] gap-8 text-center px-6">
      <div className="flex flex-col items-center gap-4">
        <div className="w-20 h-20 rounded-3xl bg-gray-900 flex items-center justify-center shadow-xl">
          <span className="text-4xl" aria-hidden>🧩</span>
        </div>
        <div>
          <h1 className="text-3xl font-black text-gray-900 tracking-tight">Puzzle Trainer</h1>
          <p className="text-gray-500 mt-2 text-base">5 puzzles logiques, chaque jour.</p>
        </div>
      </div>

      <div className="flex flex-col gap-3 text-sm text-gray-500 max-w-[260px]">
        <div className="flex items-center gap-2.5 text-left">
          <span className="w-6 h-6 rounded-full bg-gray-100 flex items-center justify-center text-base shrink-0">🔓</span>
          <span>Pas de compte, pas de pub</span>
        </div>
        <div className="flex items-center gap-2.5 text-left">
          <span className="w-6 h-6 rounded-full bg-gray-100 flex items-center justify-center text-base shrink-0">📱</span>
          <span>Tout dans le navigateur</span>
        </div>
        <div className="flex items-center gap-2.5 text-left">
          <span className="w-6 h-6 rounded-full bg-gray-100 flex items-center justify-center text-base shrink-0">⏱</span>
          <span>2 à 4 minutes par puzzle</span>
        </div>
      </div>

      <Link
        href="/tango"
        className="flex items-center gap-2 px-8 py-4 rounded-2xl bg-gray-900 text-white font-bold text-base hover:bg-gray-700 transition-colors shadow-lg"
      >
        Commencer
        <svg width="18" height="18" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2.5} strokeLinecap="round"><polyline points="9 18 15 12 9 6"/></svg>
      </Link>

      <p className="text-xs text-gray-300 -mt-2">Commence avec Tango — le plus facile à apprendre</p>
    </div>
  );
}

// ── Mode toggle ───────────────────────────────────────────────────────────────

function ModeToggle({ mode, onChange }: { mode: PlayMode; onChange: (m: PlayMode) => void }) {
  return (
    <div className="flex items-center gap-1 p-1 bg-gray-100 rounded-xl text-xs font-semibold">
      <button
        onClick={() => onChange("free")}
        className={`px-3 py-1.5 rounded-lg transition-all ${
          mode === "free"
            ? "bg-white text-gray-900 shadow-sm"
            : "text-gray-400 hover:text-gray-600"
        }`}
      >
        Libre
      </button>
      <button
        onClick={() => onChange("session")}
        className={`px-3 py-1.5 rounded-lg transition-all flex items-center gap-1 ${
          mode === "session"
            ? "bg-white text-gray-900 shadow-sm"
            : "text-gray-400 hover:text-gray-600"
        }`}
      >
        Session
        <span className="text-[10px] text-gray-400 font-normal">5 à la suite</span>
      </button>
    </div>
  );
}

// ── Streak banner ─────────────────────────────────────────────────────────────

function StreakBanner({ ritual, today }: { ritual: RitualStats; today: string }) {
  if (ritual.streak === 0) return null;
  const isAliveToday = ritual.lastDate === today;
  return (
    <div className="w-full flex items-center gap-3 px-4 py-3 bg-amber-50 border border-amber-200 rounded-2xl">
      <span className="text-xl" aria-hidden>🔥</span>
      <div className="flex-1 min-w-0">
        <p className="text-sm font-bold text-amber-800">
          {ritual.streak} jour{ritual.streak > 1 ? "s" : ""} de suite
        </p>
        <p className="text-xs text-amber-600">
          {isAliveToday
            ? "Tous les puzzles complétés aujourd'hui !"
            : "Complète les puzzles du jour pour continuer ta série"}
        </p>
      </div>
    </div>
  );
}

// ── Free mode: simple game row ────────────────────────────────────────────────

function FreeRow({ game, solved, lastTime }: {
  game: GameId;
  solved: boolean;
  lastTime: number;
}) {
  const { name, accent, subtitle, duration, symbol } = GAME_META[game];

  return (
    <Link
      href={`/${game}`}
      className={`group flex items-center gap-4 px-4 py-3.5 bg-white rounded-2xl border transition-all ${
        solved
          ? "border-green-200"
          : "border-gray-100 hover:border-gray-200 hover:shadow-sm"
      }`}
    >
      <span
        className="w-10 h-10 rounded-xl flex items-center justify-center text-lg font-bold shrink-0"
        style={{ background: solved ? "#dcfce7" : `${accent}18`, color: solved ? "#16a34a" : accent }}
        aria-hidden
      >
        {solved ? "✓" : symbol}
      </span>
      <div className="flex-1 min-w-0">
        <div className="flex items-baseline gap-2">
          <span className={`text-sm font-semibold ${solved ? "text-green-800" : "text-gray-800"}`}>
            {name}
          </span>
          {!solved && <span className="text-xs text-gray-400">{duration}</span>}
        </div>
        <p className="text-xs text-gray-400 truncate mt-0.5">
          {solved && lastTime > 0 ? `Résolu en ${fmt(lastTime)}` : subtitle}
        </p>
      </div>
      {solved ? (
        <span className="shrink-0 text-xs text-green-600 font-semibold bg-green-50 px-2.5 py-1 rounded-full border border-green-200">
          Rejouer
        </span>
      ) : (
        <span
          className="shrink-0 text-xs font-semibold px-3 py-1.5 rounded-full text-white transition-opacity group-hover:opacity-90"
          style={{ background: accent }}
        >
          Jouer
        </span>
      )}
    </Link>
  );
}

// ── Session mode: ordered list with progress ──────────────────────────────────

function SessionList({ order, solvedToday, lastTimes }: {
  order: GameId[];
  solvedToday: Record<GameId, boolean>;
  lastTimes: Record<GameId, number>;
}) {
  // Find the next game to play (first unsolved in order)
  const nextIdx = order.findIndex(g => !solvedToday[g]);
  const allDone = nextIdx === -1;
  const solvedCount = order.filter(g => solvedToday[g]).length;

  return (
    <div className="flex flex-col gap-2">
      {/* Progress bar */}
      <div className="flex items-center gap-3 mb-1">
        <div className="flex-1 h-1.5 bg-gray-100 rounded-full overflow-hidden">
          <div
            className="h-full rounded-full bg-gray-900 transition-all duration-500"
            style={{ width: `${(solvedCount / order.length) * 100}%` }}
          />
        </div>
        <span className="text-xs text-gray-400 shrink-0">{solvedCount}/{order.length}</span>
      </div>

      {order.map((game, idx) => {
        const solved = solvedToday[game];
        const isCurrent = !allDone && idx === nextIdx;
        const isPending = !solved && !isCurrent;
        const { name, accent, subtitle, duration, symbol } = GAME_META[game];

        return (
          <Link
            key={game}
            href={`/${game}`}
            className={`group flex items-center gap-4 px-4 py-3.5 rounded-2xl border transition-all ${
              solved
                ? "bg-white border-green-200"
                : isCurrent
                ? "bg-white border-2 shadow-sm"
                : "bg-white border-gray-100 opacity-50"
            }`}
            style={isCurrent ? { borderColor: accent } : undefined}
          >
            {/* Step number / status */}
            <div className="relative shrink-0">
              <span
                className="w-10 h-10 rounded-xl flex items-center justify-center text-lg font-bold"
                style={{
                  background: solved ? "#dcfce7" : isCurrent ? `${accent}18` : "#f1f5f9",
                  color: solved ? "#16a34a" : isCurrent ? accent : "#9ca3af",
                }}
                aria-hidden
              >
                {solved ? "✓" : isCurrent ? symbol : <span className="text-sm font-bold">{idx + 1}</span>}
              </span>
              {/* Connector line below (not last) */}
              {idx < order.length - 1 && (
                <div
                  className="absolute left-1/2 -translate-x-1/2 w-0.5 rounded-full"
                  style={{
                    top: "100%",
                    height: "10px",
                    marginTop: "2px",
                    background: solved ? "#bbf7d0" : "#e5e7eb",
                  }}
                />
              )}
            </div>

            <div className="flex-1 min-w-0">
              <div className="flex items-baseline gap-2">
                <span className={`text-sm font-semibold ${
                  solved ? "text-green-800" : isCurrent ? "text-gray-900" : "text-gray-500"
                }`}>
                  {name}
                </span>
                {!solved && isCurrent && (
                  <span className="text-xs text-gray-400">{duration}</span>
                )}
              </div>
              <p className="text-xs text-gray-400 truncate mt-0.5">
                {solved && lastTimes[game] > 0
                  ? `Résolu en ${fmt(lastTimes[game])}`
                  : isCurrent
                  ? subtitle
                  : ""}
              </p>
            </div>

            {/* CTA */}
            {solved ? (
              <span className="shrink-0 text-xs text-green-600 font-semibold bg-green-50 px-2.5 py-1 rounded-full border border-green-200">
                ✓
              </span>
            ) : isCurrent ? (
              <span
                className="shrink-0 text-sm font-bold px-4 py-2 rounded-full text-white flex items-center gap-1 transition-opacity group-hover:opacity-90"
                style={{ background: accent }}
              >
                Jouer
                <svg width="13" height="13" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2.5} strokeLinecap="round"><polyline points="9 18 15 12 9 6"/></svg>
              </span>
            ) : (
              <span className="shrink-0 w-8 h-8 rounded-full bg-gray-100 flex items-center justify-center">
                <svg width="12" height="12" viewBox="0 0 24 24" fill="none" stroke="#9ca3af" strokeWidth={2} strokeLinecap="round"><path d="M12 2a10 10 0 1 0 0 20 10 10 0 0 0 0-20z"/></svg>
              </span>
            )}
          </Link>
        );
      })}
    </div>
  );
}

// ── All done banner ────────────────────────────────────────────────────────────

function AllDoneBanner({ nextPuzzleIn }: { nextPuzzleIn: string }) {
  return (
    <div className="w-full flex flex-col items-center gap-2 px-4 py-5 bg-green-50 border border-green-200 rounded-2xl text-center">
      <span className="text-3xl" aria-hidden>🎉</span>
      <p className="text-sm font-bold text-green-800">Bravo ! Tous les puzzles du jour complétés.</p>
      <p className="text-xs text-green-600">Prochain puzzle dans {nextPuzzleIn}</p>
    </div>
  );
}

// ── Training row ──────────────────────────────────────────────────────────────

function TrainingRow({ game, stats }: { game: GameId; stats: GameStats | undefined }) {
  const { name, accent } = GAME_META[game];
  const pct = stats?.pct ?? 0;
  const label = !stats || stats.completed === 0 ? "Commencer" : `Niv. ${stats.nextLevel}`;

  return (
    <Link
      href={`/${game}/levels`}
      className="group flex items-center gap-3 px-4 py-3 bg-white rounded-xl border border-gray-100 hover:border-gray-200 hover:shadow-sm transition-all"
    >
      <span className="text-xs font-semibold text-gray-600 w-14 shrink-0">{name}</span>
      <div className="flex-1 min-w-0">
        <div className="h-1.5 bg-gray-100 rounded-full overflow-hidden">
          <div className="h-full rounded-full transition-all" style={{ width: `${pct}%`, background: accent }} />
        </div>
      </div>
      <span className="text-[11px] text-gray-400 shrink-0 w-14 text-right">{stats?.completed ?? 0}/100</span>
      <span
        className="shrink-0 text-xs font-semibold px-2.5 py-1 rounded-full whitespace-nowrap"
        style={{ background: `${accent}18`, color: accent }}
      >
        {label}
      </span>
    </Link>
  );
}

// ── Main page ─────────────────────────────────────────────────────────────────

export default function Home() {
  const today = todayISO();
  const [loaded, setLoaded] = useState(false);
  const [newUser, setNewUser] = useState(false);
  const [mode, setMode] = useState<PlayMode>("free");
  const [levelStats, setLevelStats] = useState<Record<GameId, GameStats> | null>(null);
  const [solvedToday, setSolvedToday] = useState<Record<GameId, boolean>>({} as Record<GameId, boolean>);
  const [lastTimes, setLastTimes] = useState<Record<GameId, number>>({} as Record<GameId, number>);
  const [ritual, setRitual] = useState<RitualStats>({ streak: 0, lastDate: "" });
  const [showTraining, setShowTraining] = useState(false);

  const handleModeChange = (m: PlayMode) => {
    setMode(m);
    savePlayMode(m);
  };

  useEffect(() => {
    const refresh = () => {
      setNewUser(isNewUser());
      setMode(getPlayMode());
      setLevelStats(allStats());

      const solved = {} as Record<GameId, boolean>;
      const times = {} as Record<GameId, number>;
      for (const g of GAMES) {
        solved[g] = isDailySolved(g, today);
        const s = loadStats(g);
        times[g] = s.lastDate === today ? s.lastTime : 0;
      }
      setSolvedToday(solved);
      setLastTimes(times);

      const allSolved = GAMES.every(g => solved[g]);
      const r = allSolved ? updateRitualStreak(today) : getRitualStreak();
      setRitual(r);
      setLoaded(true);
    };

    refresh();
    window.addEventListener("focus", refresh);
    document.addEventListener("visibilitychange", refresh);
    return () => {
      window.removeEventListener("focus", refresh);
      document.removeEventListener("visibilitychange", refresh);
    };
  }, [today]);

  if (!loaded) {
    return (
      <div className="flex flex-col gap-3 max-w-sm mx-auto py-4 px-4">
        {[...Array(5)].map((_, i) => (
          <div key={i} className="skeleton h-[68px] rounded-2xl" />
        ))}
      </div>
    );
  }

  if (newUser) return <OnboardingScreen />;

  const dateLabel = new Date(today + "T00:00:00").toLocaleDateString("fr-FR", {
    weekday: "long", day: "numeric", month: "long",
  });

  const sessionOrder = getSessionOrder(today);
  const totalSolvedToday = GAMES.filter(g => solvedToday[g]).length;
  const allSolvedToday = totalSolvedToday === GAMES.length;

  const now = new Date();
  const midnight = new Date(now);
  midnight.setDate(midnight.getDate() + 1);
  midnight.setHours(0, 0, 0, 0);
  const hoursLeft = Math.ceil((midnight.getTime() - now.getTime()) / 3600000);
  const nextPuzzleIn = `${hoursLeft}h`;

  return (
    <div className="flex flex-col gap-6 max-w-sm mx-auto py-4 px-4">

      {/* Header */}
      <div className="flex items-start justify-between">
        <div>
          <h1 className="text-2xl font-bold text-gray-900 tracking-tight">Puzzle Trainer</h1>
          <p className="text-gray-400 mt-0.5 text-sm capitalize">{dateLabel}</p>
        </div>
        <Link
          href="/stats"
          className="flex items-center gap-1 text-xs text-gray-400 hover:text-gray-700 mt-1 transition-colors"
        >
          <svg width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2} strokeLinecap="round" strokeLinejoin="round">
            <line x1="18" y1="20" x2="18" y2="10"/><line x1="12" y1="20" x2="12" y2="4"/><line x1="6" y1="20" x2="6" y2="14"/>
          </svg>
          Stats
        </Link>
      </div>

      {/* Streak */}
      <StreakBanner ritual={ritual} today={today} />

      {/* Daily puzzles */}
      <section>
        <div className="flex items-center justify-between mb-3">
          <h2 className="text-[11px] font-semibold text-gray-400 uppercase tracking-widest">
            Puzzles du jour
          </h2>
          <ModeToggle mode={mode} onChange={handleModeChange} />
        </div>

        {mode === "session" && (
          <p className="text-xs text-gray-400 mb-3 -mt-1">
            Joue les 5 puzzles à la suite — l&apos;ordre change chaque jour.
          </p>
        )}

        {allSolvedToday ? (
          <AllDoneBanner nextPuzzleIn={nextPuzzleIn} />
        ) : mode === "session" ? (
          <SessionList
            order={sessionOrder}
            solvedToday={solvedToday}
            lastTimes={lastTimes}
          />
        ) : (
          <div className="flex flex-col gap-2">
            {GAMES.map(game => (
              <FreeRow
                key={game}
                game={game}
                solved={solvedToday[game]}
                lastTime={lastTimes[game]}
              />
            ))}
          </div>
        )}
      </section>

      {/* Training */}
      <section>
        <button
          onClick={() => setShowTraining(v => !v)}
          className="w-full flex items-center justify-between text-[11px] font-semibold text-gray-400 uppercase tracking-widest mb-2 hover:text-gray-600 transition-colors"
        >
          <span>Entraînement</span>
          <svg
            width="14" height="14" viewBox="0 0 24 24" fill="none" stroke="currentColor" strokeWidth={2} strokeLinecap="round"
            style={{ transform: showTraining ? "rotate(180deg)" : "rotate(0deg)", transition: "transform 0.2s" }}
          >
            <polyline points="6 9 12 15 18 9"/>
          </svg>
        </button>
        {showTraining && (
          <div className="flex flex-col gap-2">
            {GAMES.map(game => (
              <TrainingRow key={game} game={game} stats={levelStats?.[game]} />
            ))}
          </div>
        )}
      </section>

      {/* Footer */}
      <div className="flex items-center gap-4 text-xs text-gray-300 pb-2">
        <Link href="/archive" className="hover:text-gray-500 transition-colors">Archives</Link>
        <span>·</span>
        <Link href="/stats" className="hover:text-gray-500 transition-colors">Statistiques</Link>
        <span>·</span>
        <Link href="/comment-jouer" className="hover:text-gray-500 transition-colors">Comment jouer</Link>
      </div>
    </div>
  );
}