"use client";
import { useCallback, useEffect, useRef, useState } from "react";
import { useRouter } from "next/navigation";
import {
  Maximize2,
  Minimize2,
  MousePointer2,
  Move,
  MapPin,
} from "lucide-react";
import { Brand } from "./Brand";
import { Panorama } from "./Panorama";
import { GuessMap, type Pin } from "./GuessMap";
import { api } from "./StartGame";
import { difficulties, type Difficulty, type Bounds } from "@/shared/protocol";
import { roundClock } from "@/shared/round-clock";
import { ReportContent } from "./ReportContent";
export type RoundResult = {
  score: number;
  distance: number | null;
  timedOut: boolean;
  actual: Pin;
  guess: Pin | null;
};
export type SessionView = {
  id: string;
  name: string;
  difficulty: Difficulty;
  round: number;
  bounds: Bounds;
  map: string;
  serverNow: number;
  rounds: {
    number: number;
    faces: string[];
    deadline: string | null;
    result: RoundResult | null;
  }[];
};
export function Game({ id }: { id: string }) {
  const router = useRouter(),
    [session, setSession] = useState<SessionView | null>(null),
    [pin, setPin] = useState<Pin | null>(null),
    [expanded, setExpanded] = useState(false),
    [loaded, setLoaded] = useState({ panorama: false, map: false }),
    [error, setError] = useState(""),
    [busy, setBusy] = useState(false),
    [result, setResult] = useState<RoundResult | null>(null),
    [remaining, setRemaining] = useState(0);
  const clock = useRef<ReturnType<typeof roundClock> | null>(null),
    loadVersion = useRef(0),
    guessing = useRef(false),
    activating = useRef(false),
    timingOut = useRef(false);
  const load = useCallback(async () => {
    const version = ++loadVersion.current;
    const sentAt = performance.now();
    try {
      const s = await api<SessionView>("sessions/" + id);
      if (version !== loadVersion.current) return;
      clock.current = roundClock(s.serverNow, sentAt, performance.now());
      if (s.round >= 5) {
        router.replace("/results/" + id);
        return;
      }
      setSession(s);
      setRemaining(
        s.rounds[s.round].deadline
          ? clock.current.remaining(
              s.rounds[s.round].deadline!,
              performance.now(),
            )
          : difficulties[s.difficulty].seconds,
      );
    } catch (e) {
      if (version === loadVersion.current) setError((e as Error).message);
    }
  }, [id, router]);
  useEffect(() => {
    load();
    return () => {
      loadVersion.current++;
    };
  }, [load]);
  useEffect(() => {
    if (
      !session ||
      !loaded.panorama ||
      !loaded.map ||
      error ||
      result ||
      activating.current
    )
      return;
    const r = session.rounds[session.round];
    if (r.deadline) return;
    activating.current = true;
    const round = session.round;
    const sentAt = performance.now();
    api<{ deadline: string; serverNow: number }>(`sessions/${id}/activate`, {
      round: session.round,
    })
      .then((d) => {
        clock.current = roundClock(d.serverNow, sentAt, performance.now());
        setSession((s) =>
          s && s.round === round
            ? {
                ...s,
                rounds: s.rounds.map((r) =>
                  r.number === s.round ? { ...r, deadline: d.deadline } : r,
                ),
              }
            : s,
        );
      })
      .catch((e) => setError(e.message))
      .finally(() => (activating.current = false));
  }, [loaded, session, id, result, error]);
  const guess = useCallback(
    async (timeout = false) => {
      if (!session || guessing.current || result || (!pin && !timeout)) return;
      guessing.current = true;
      setBusy(true);
      setError("");
      try {
        const r = await api<RoundResult>(`sessions/${id}/guess`, {
          round: session.round,
          ...(!timeout && pin ? pin : {}),
        });
        setResult(r);
        setSession((s) =>
          s
            ? {
                ...s,
                rounds: s.rounds.map((round) =>
                  round.number === session.round
                    ? { ...round, result: r }
                    : round,
                ),
              }
            : s,
        );
      } catch (e) {
        setError((e as Error).message);
        timingOut.current = false;
      } finally {
        guessing.current = false;
        setBusy(false);
      }
    },
    [session, result, pin, id],
  );
  useEffect(() => {
    if (!session || result || error) return;
    const deadline = session.rounds[session.round].deadline;
    if (!deadline) return;
    const tick = () => {
      const left = clock.current?.remaining(deadline, performance.now()) ?? 0;
      setRemaining(left);
      if (left === 0 && !timingOut.current && !guessing.current) {
        timingOut.current = true;
        guess(true);
      }
    };
    tick();
    const timer = setInterval(tick, 250);
    return () => clearInterval(timer);
  }, [session, result, guess, error]);
  async function next() {
    if (!session) return;
    setSession(null);
    setResult(null);
    setPin(null);
    setLoaded({ panorama: false, map: false });
    timingOut.current = false;
    setError("");
    await load();
  }
  const ready = useCallback(
      () => setLoaded((s) => ({ ...s, panorama: true })),
      [],
    ),
    mapReady = useCallback(() => setLoaded((s) => ({ ...s, map: true })), []);
  const onError = useCallback((e: string) => setError(e), []);
  const current = session?.rounds[session.round];
  const total =
    session?.rounds.reduce((n, r) => n + (r.result?.score || 0), 0) || 0;
  return (
    <main className="game-page">
      {session && current && (
        <Panorama
          key={session.round}
          urls={current.faces}
          zoom={difficulties[session.difficulty].zoom}
          onReady={ready}
          onError={onError}
        />
      )}
      <div className="game-header">
        <Brand />
        {session && (
          <ReportContent
            key={session.round}
            sessionId={id}
            round={session.round}
          />
        )}
        <div className="game-info">
          <div>
            <small>ROUND</small>
            <strong>{session ? session.round + 1 : "—"} / 5</strong>
          </div>
          <div>
            <small>TIME LEFT</small>
            <strong className={remaining <= 10 ? "urgent" : ""}>
              {Math.floor(remaining / 60)}:
              {String(remaining % 60).padStart(2, "0")}
            </strong>
          </div>
          <div>
            <small>POINTS</small>
            <strong>{total.toLocaleString()}</strong>
          </div>
        </div>
      </div>
      {session && (
        <div className={"game-map " + (expanded ? "expanded" : "")}>
          <div className="map-topline">
            <span>↑ N · PLACE YOUR GUESS</span>
            <button
              aria-label={expanded ? "Collapse map" : "Expand map"}
              onClick={() => setExpanded((v) => !v)}
            >
              {expanded ? <Minimize2 size={15} /> : <Maximize2 size={15} />}
            </button>
          </div>
          <GuessMap
            key={"map-" + session.round}
            bounds={session.bounds}
            image={session.map}
            pin={result ? result.guess : pin}
            actual={result?.actual}
            onPin={setPin}
            onReady={mapReady}
            onError={onError}
            disabled={!!result || busy}
          />
          <div className="map-actions">
            <small>
              {pin
                ? `X ${Math.round(pin.x)} · Z ${Math.round(pin.z)}`
                : "Click the map to drop a pin"}
            </small>
            <button
              className="button primary full"
              disabled={!pin || busy || !!result || !current?.deadline}
              onClick={() => guess()}
            >
              <MapPin size={15} />
              {busy ? "Checking your guess…" : "Submit guess"}
            </button>
          </div>
        </div>
      )}
      <div className="look-help">
        <span>
          <Move size={12} /> DRAG TO LOOK AROUND
        </span>
        <span>
          <MousePointer2 size={12} />{" "}
          {session?.difficulty === "hard" ? "NO ZOOM" : "SCROLL TO ZOOM"}
        </span>
      </div>
      {(!session || !loaded.panorama || !loaded.map) && !error && (
        <div className="game-loading">
          <div className="loading-cube" />
          <h2>Preparing your expedition.</h2>
          <p>Loading panorama and surface map…</p>
        </div>
      )}
      {error && (
        <div className="round-result" role="alert">
          <h2>Connection interrupted.</h2>
          <p>{error}</p>
          <button
            className="button primary"
            onClick={() => window.location.reload()}
          >
            Reconnect
          </button>
        </div>
      )}
      {result && !error && (
        <div className="round-result">
          <span className="eyebrow">
            ROUND {(session?.round || 0) + 1} COMPLETE
          </span>
          <h2>
            {result.timedOut
              ? "Time slipped away."
              : result.score === 5000
                ? "Right on the block!"
                : result.score > 3000
                  ? "You know your way around."
                  : "A little off the beaten block."}
          </h2>
          <div className="score">
            {result.score.toLocaleString()}
            <small> / 5,000</small>
          </div>
          <p>
            {result.timedOut
              ? "The clock ran out. This round scores zero."
              : `${Math.round(result.distance || 0).toLocaleString()} blocks from the actual location.`}
          </p>
          <button className="button primary full" onClick={next}>
            {session?.round === 4 ? "See expedition results" : "Next round"} →
          </button>
        </div>
      )}
    </main>
  );
}