import { useEffect, useMemo, useState } from 'react';
import { Link, useParams } from '@tanstack/react-router';
import { ArrowLeft, Shirt } from 'lucide-react';
import { Card, CardBody, CardHeader } from '@/components/ui/Card';
import { WinProbBar } from '@/components/WinProbBar';
import { FormChips } from '@/components/FormChips';
import { teamFlag } from '@/lib/teams';
import { kickoffDay, kickoffTime } from '@/lib/format';
import { inPlayProbs } from '@/lib/model/inplay';
import { useTournamentStore } from '@/stores/tournamentStore';
import type { Fixture, KeyPlayer, MatchPreview } from '@/lib/types';

const STAGE: Record<string, string> = {
  group: 'Group', r32: 'Round of 32', r16: 'Round of 16', qf: 'Quarter-final', sf: 'Semi-final', third: 'Third place', final: 'Final',
};
const STAT_ROWS: [string, string][] = [
  ['possessionPct', 'Possession'],
  ['totalShots', 'Shots'],
  ['shotsOnTarget', 'On target'],
  ['wonCorners', 'Corners'],
  ['foulsCommitted', 'Fouls'],
  ['saves', 'Saves'],
];
const num = (s: string | undefined) => (s ? Number(s.replace('%', '')) || 0 : 0);

function eventIcon(type: string): string {
  const t = type.toLowerCase();
  if (t.includes('goal') || t.includes('penalty - scored')) return '⚽';
  if (t.includes('yellow')) return '🟨';
  if (t.includes('red')) return '🟥';
  if (t.includes('substitution')) return '🔁';
  return '•';
}

function LiveStatRow({ label, home, away }: { label: string; home: number; away: number }) {
  const total = home + away || 1;
  return (
    <div>
      <div className="flex items-center justify-between text-sm">
        <span className="tnum font-bold text-accent">{home}</span>
        <span className="text-xs uppercase tracking-wide text-faint">{label}</span>
        <span className="tnum font-bold text-info">{away}</span>
      </div>
      <div className="mt-1 flex h-1.5 overflow-hidden rounded-full bg-elevated">
        <div className="bg-accent" style={{ width: `${(home / total) * 100}%` }} />
        <div className="ml-auto bg-info" style={{ width: `${(away / total) * 100}%` }} />
      </div>
    </div>
  );
}

function ScorerList({ team, players }: { team: string; players: KeyPlayer[] }) {
  return (
    <div>
      <div className="mb-2 flex items-center gap-2 text-sm font-semibold text-ink"><span aria-hidden>{teamFlag(team)}</span> {team}</div>
      {players.length ? (
        <ul className="space-y-1">
          {players.slice(0, 6).map((p) => (
            <li key={p.name} className="flex items-center justify-between text-sm">
              <span className="truncate text-ink-soft">{p.name}</span>
              <span className="tnum shrink-0 text-faint">{p.goals}{p.pens ? ` (${p.pens}p)` : ''}</span>
            </li>
          ))}
        </ul>
      ) : <p className="text-xs text-faint">no data</p>}
    </div>
  );
}

function LineupCol({ team, players }: { team: string; players: { name: string; position: string | null; number: number | null; starter: boolean }[] }) {
  const starters = players.filter((p) => p.starter);
  const list = starters.length ? starters : players;
  return (
    <div>
      <div className="mb-2 text-sm font-semibold text-ink">{team}</div>
      <ul className="space-y-0.5 text-sm">
        {list.map((p) => (
          <li key={p.name} className="flex items-center gap-2 text-ink-soft">
            <span className="tnum w-5 text-right text-xs text-faint">{p.number ?? ''}</span>
            <span className="truncate">{p.name}</span>
            <span className="ml-auto text-[11px] text-faint">{p.position}</span>
          </li>
        ))}
      </ul>
    </div>
  );
}

export function MatchPreviewPage() {
  const { num: numParam } = useParams({ strict: false }) as { num: string };
  const [preview, setPreview] = useState<MatchPreview | null>(null);
  const [failed, setFailed] = useState(false);

  // Live score/minute arrive over the WebSocket snapshot — overlay them on the
  // (less-frequently-fetched) preview.
  const liveFixture = useTournamentStore((s) => s.snapshot?.fixtures.find((f) => f.num === Number(numParam)));
  const isLive = (liveFixture?.status ?? preview?.fixture.status) === 'live';

  useEffect(() => {
    let alive = true;
    setPreview(null);
    setFailed(false);
    const load = () =>
      fetch(`/api/preview/${numParam}`)
        .then((r) => (r.ok ? r.json() : Promise.reject()))
        .then((d: MatchPreview) => alive && setPreview(d))
        .catch(() => alive && setFailed(true));
    void load();
    const id = setInterval(() => { if (useTournamentStore.getState().snapshot?.fixtures.find((f) => f.num === Number(numParam))?.status === 'live') void load(); }, 10_000);
    return () => { alive = false; clearInterval(id); };
  }, [numParam]);

  const f: Fixture | undefined = liveFixture ?? preview?.fixture;

  const inPlay = useMemo(() => {
    if (!preview?.prediction || !f || f.status !== 'live' || f.homeScore == null || f.awayScore == null) return null;
    return inPlayProbs(preview.prediction.lambdaHome, preview.prediction.lambdaAway, f.minute ?? 0, f.homeScore, f.awayScore);
  }, [preview, f]);

  if (failed) return <div className="py-16 text-center text-muted">Couldn&apos;t load that match. <Link to="/" className="text-accent">Back to Live</Link></div>;
  if (!preview || !f) return <div className="h-96 animate-pulse rounded-xl border border-line bg-panel" />;

  const hasScore = f.status === 'live' || f.status === 'finished';
  const homeName = f.home.label;
  const awayName = f.away.label;
  const finished = f.status === 'finished';

  return (
    <div className="space-y-5">
      <Link to="/" className="inline-flex items-center gap-1.5 text-sm text-muted hover:text-ink"><ArrowLeft size={15} /> Back</Link>

      {/* hero */}
      <Card className={isLive ? 'border-live/40 ring-1 ring-live/30' : ''}>
        <CardBody>
          <div className="mb-3 text-center text-xs uppercase tracking-wide text-faint">
            {f.group ? `Group ${f.group}` : STAGE[f.stage]} · {kickoffDay(f.kickoff)} · {kickoffTime(f.kickoff)} · {preview.venue}
          </div>
          <div className="grid grid-cols-[1fr_auto_1fr] items-center gap-3">
            <Link to="/team/$name" params={{ name: f.home.team ?? '' }} className="flex flex-col items-center gap-1 hover:opacity-80">
              <span aria-hidden className="text-4xl">{f.home.team ? teamFlag(f.home.team) : '⚽'}</span>
              <span className="text-center text-sm font-semibold text-ink">{homeName}</span>
            </Link>
            <div className="text-center">
              {hasScore ? <div className="tnum text-3xl font-extrabold text-ink">{f.homeScore ?? 0}–{f.awayScore ?? 0}</div> : <div className="tnum text-lg font-bold text-muted">{kickoffTime(f.kickoff)}</div>}
              {isLive && <div className="inline-flex items-center gap-1 text-[11px] font-bold uppercase text-live"><span className="live-dot h-1.5 w-1.5 rounded-full bg-live" />{f.minute ? `${f.minute}'` : 'Live'}</div>}
              {finished && <div className="text-[11px] font-bold uppercase text-faint">Full time</div>}
            </div>
            <Link to="/team/$name" params={{ name: f.away.team ?? '' }} className="flex flex-col items-center gap-1 hover:opacity-80">
              <span aria-hidden className="text-4xl">{f.away.team ? teamFlag(f.away.team) : '⚽'}</span>
              <span className="text-center text-sm font-semibold text-ink">{awayName}</span>
            </Link>
          </div>
        </CardBody>
      </Card>

      {/* LIVE: in-play win probability */}
      {inPlay && preview.prediction && (
        <Card className="border-live/30">
          <CardHeader className="flex items-center gap-2">
            <span className="live-dot h-2 w-2 rounded-full bg-live" />
            <span className="font-display font-bold text-ink">Live win probability</span>
          </CardHeader>
          <CardBody>
            <WinProbBar home={homeName} away={awayName} probs={inPlay} />
            <p className="mt-2 text-xs text-faint">Updates with the score and clock — remaining goals modelled from each side&apos;s pre-match expectation.</p>
          </CardBody>
        </Card>
      )}

      {/* LIVE/FT: stats */}
      {preview.liveStats && (
        <Card>
          <CardHeader><span className="font-display font-bold text-ink">Match stats</span></CardHeader>
          <CardBody className="space-y-3">
            {STAT_ROWS.filter(([k]) => preview.liveStats!.home[k] != null || preview.liveStats!.away[k] != null).map(([k, label]) => (
              <LiveStatRow key={k} label={label} home={num(preview.liveStats!.home[k])} away={num(preview.liveStats!.away[k])} />
            ))}
          </CardBody>
        </Card>
      )}

      {/* LIVE/FT: timeline */}
      {preview.events.length > 0 && (
        <Card>
          <CardHeader><span className="font-display font-bold text-ink">Timeline</span></CardHeader>
          <CardBody>
            <ul className="space-y-1.5">
              {preview.events.map((e, i) => (
                <li key={i} className={`flex items-center gap-2 text-sm ${e.team === 'away' ? 'flex-row-reverse text-right' : ''}`}>
                  <span className="tnum w-8 shrink-0 text-xs text-faint">{e.minute != null ? `${e.minute}'` : ''}</span>
                  <span aria-hidden>{eventIcon(e.type)}</span>
                  <span className="truncate text-ink-soft">{e.text || e.type}</span>
                </li>
              ))}
            </ul>
          </CardBody>
        </Card>
      )}

      {/* model expectation */}
      {preview.prediction && (
        <Card>
          <CardHeader><span className="font-display font-bold text-ink">{hasScore ? 'Pre-match model' : 'Model expectation'}</span></CardHeader>
          <CardBody className="space-y-2">
            <WinProbBar home={preview.prediction.home} away={preview.prediction.away} probs={preview.prediction.probs} topScore={preview.prediction.topScore} />
            <p className="text-xs text-faint">Expected goals: {preview.prediction.lambdaHome.toFixed(2)} – {preview.prediction.lambdaAway.toFixed(2)} · model odds, not betting advice</p>
          </CardBody>
        </Card>
      )}

      {/* form */}
      {(preview.form.home.length > 0 || preview.form.away.length > 0) && (
        <Card>
          <CardHeader><span className="font-display font-bold text-ink">Recent form</span></CardHeader>
          <CardBody className="space-y-3">
            <div className="flex items-center justify-between"><span className="flex items-center gap-2 text-sm font-medium text-ink">{f.home.team && teamFlag(f.home.team)} {homeName}</span><FormChips form={preview.form.home} /></div>
            <div className="flex items-center justify-between"><span className="flex items-center gap-2 text-sm font-medium text-ink">{f.away.team && teamFlag(f.away.team)} {awayName}</span><FormChips form={preview.form.away} /></div>
          </CardBody>
        </Card>
      )}

      {/* head to head */}
      {preview.h2h && (
        <Card>
          <CardHeader><span className="font-display font-bold text-ink">Head to head</span></CardHeader>
          <CardBody>
            <div className="mb-3 grid grid-cols-3 items-center text-center">
              <div><div className="tnum text-2xl font-extrabold text-accent">{preview.h2h.homeWins}</div><div className="text-[11px] text-faint">{homeName} wins</div></div>
              <div><div className="tnum text-2xl font-extrabold text-muted">{preview.h2h.draws}</div><div className="text-[11px] text-faint">draws · {preview.h2h.games} total</div></div>
              <div><div className="tnum text-2xl font-extrabold text-info">{preview.h2h.awayWins}</div><div className="text-[11px] text-faint">{awayName} wins</div></div>
            </div>
            <div className="border-t border-line pt-2">
              <div className="mb-1 text-[11px] uppercase tracking-wide text-faint">Recent meetings</div>
              <ul className="space-y-1 text-sm">
                {preview.h2h.last.map((m, i) => (
                  <li key={i} className="flex items-center justify-between text-ink-soft"><span className="text-faint">{m.date.slice(0, 10)}</span><span>{m.home} <span className="tnum font-semibold text-ink">{m.homeScore}–{m.awayScore}</span> {m.away}</span></li>
                ))}
              </ul>
            </div>
          </CardBody>
        </Card>
      )}

      {/* lineups or key players */}
      <Card>
        <CardHeader className="flex items-center gap-2"><Shirt size={16} className="text-accent" /><span className="font-display font-bold text-ink">{preview.lineups ? 'Lineups' : 'Key players (all-time scorers)'}</span></CardHeader>
        <CardBody className="grid grid-cols-2 gap-6">
          {preview.lineups ? (
            <><LineupCol team={homeName} players={preview.lineups.home} /><LineupCol team={awayName} players={preview.lineups.away} /></>
          ) : (
            <><ScorerList team={homeName} players={preview.keyPlayers.home} /><ScorerList team={awayName} players={preview.keyPlayers.away} /></>
          )}
        </CardBody>
      </Card>

      <p className="text-center text-xs text-faint">{preview.dataNote}</p>
    </div>
  );
}
