// frontend/src/components/Bracket/BracketView.jsx

import { useEffect, useRef, useState } from 'react';
import MatchCard from "./MatchCard";
import Podium from "../Tournament/Podium";

export default function BracketView({ matches, onMatchClick }) {
    const containerRef = useRef(null);
    const [lines, setLines] = useState([]);

    useEffect(() => {
        const draw = () => {
            if (!containerRef.current) return;
            const container = containerRef.current.getBoundingClientRect();
            const newLines = [];

            matches.forEach(m => {
                if (m.winner_next_match_id) {
                    const sEl = document.getElementById(`match-${m.id}`);
                    const eEl = document.getElementById(`match-${m.winner_next_match_id}`);
                    if (sEl && eEl) {
                        const r1 = sEl.getBoundingClientRect(), r2 = eEl.getBoundingClientRect();
                        const sx = r1.right - container.left, sy = r1.top + r1.height / 2 - container.top;
                        const ex = r2.left - container.left, ey = r2.top + r2.height / 2 - container.top;
                        const c1 = sx + (ex - sx) / 2;
                        newLines.push(
                            <path key={`w-${m.id}`} d={`M ${sx} ${sy} C ${c1} ${sy}, ${c1} ${ey}, ${ex} ${ey}`} className="stroke-zinc-400/70 dark:stroke-zinc-700/70 print:!stroke-zinc-400 fill-none stroke-[2px]" />
                        );
                    }
                }

                if (m.loser_next_match_id) {
                    const targetMatch = matches.find(x => x.id === m.loser_next_match_id);
                    if (targetMatch && targetMatch.bracket === 'Finals') {
                        const sEl = document.getElementById(`match-${m.id}`);
                        const eEl = document.getElementById(`match-${targetMatch.id}`);
                        if (sEl && eEl) {
                            const r1 = sEl.getBoundingClientRect(), r2 = eEl.getBoundingClientRect();
                            const sx = r1.right - container.left, sy = r1.top + r1.height / 2 - container.top;
                            const ex = r2.left - container.left, ey = r2.top + r2.height / 2 - container.top;
                            const c1 = sx + (ex - sx) / 2;
                            newLines.push(
                                <path key={`l-${m.id}`} strokeDasharray="6 6" d={`M ${sx} ${sy} C ${c1} ${sy}, ${c1} ${ey}, ${ex} ${ey}`} className="stroke-zinc-300 dark:stroke-zinc-700 print:!stroke-zinc-400 fill-none stroke-[1.5px]" />
                            );
                        }
                    }
                }
            });
            setLines(newLines);
        };

        const t = setTimeout(draw, 100);
        window.addEventListener('resize', draw);

        const handlePrint = () => { draw(); setTimeout(draw, 100); };
        const mql = window.matchMedia('print');
        mql.addEventListener('change', handlePrint);
        window.addEventListener('beforeprint', handlePrint);
        window.addEventListener('afterprint', draw);

        return () => {
            clearTimeout(t);
            window.removeEventListener('resize', draw);
            mql.removeEventListener('change', handlePrint);
            window.removeEventListener('beforeprint', handlePrint);
            window.removeEventListener('afterprint', draw);
        };
    }, [matches]);

    const renderRound = (list) => {
        const rounds = {};
        list.forEach(m => (rounds[m.round] = rounds[m.round] || []).push(m));
        const roundKeys = Object.keys(rounds).sort((a, b) => Number(a) - Number(b));
        return roundKeys.map((r) => {
            let matchesInRound = rounds[r];
            matchesInRound.sort((a, b) => a.number - b.number);
            return (
                <div key={r} className="flex flex-col gap-10 z-10 w-64 shrink-0 justify-around">
                    {matchesInRound.map(m => <MatchCard key={m.id} match={m} onClick={onMatchClick} />)}
                </div>
            );
        });
    };

    const isDoubleElim = matches.some(m => m.bracket === 'Loser');
    const wb = matches.filter(m => m.bracket === 'Winner');
    const lb = matches.filter(m => m.bracket === 'Loser');
    const finals = matches.filter(m => m.bracket === 'Finals');

    let displayWb = [...wb];
    let displayFinals = [...finals];

    if (!isDoubleElim && displayWb.length > 0) {
        const maxRound = Math.max(...displayWb.map(m => m.round));
        const gfIndex = displayWb.findIndex(m => m.round === maxRound);

        if (gfIndex !== -1) {
            const gfMatch = displayWb.splice(gfIndex, 1)[0];
            displayFinals.unshift(gfMatch);
        }
    }

    return (
        <div className="transition-colors w-full h-full overflow-auto print:overflow-visible print:h-auto print:w-auto bg-zinc-50 dark:bg-zinc-950 bg-[radial-gradient(theme(colors.zinc.300)_1px,transparent_1px)] dark:bg-[radial-gradient(theme(colors.zinc.800)_1px,transparent_1px)] [background-size:20px_20px] print:!bg-white print:!bg-none">
            <style>
                {`@media print { 
                    @page { size: landscape; margin: 0.5cm; }
                    body { -webkit-print-color-adjust: exact; print-color-adjust: exact; background: white !important; }
                }`}
            </style>

            <div ref={containerRef} className="relative min-w-max min-h-full p-12 flex gap-20 items-center">
                <svg className="absolute inset-0 w-full h-full pointer-events-none z-0 print:overflow-visible">
                    {lines}
                </svg>

                <div className="flex flex-col gap-24">
                    <div className="relative">
                        <div className="absolute -top-8 left-0 text-[10px] font-black uppercase tracking-[0.2em] text-zinc-400 print:!text-black">Winners Bracket</div>
                        <div className="flex gap-20">{renderRound(displayWb)}</div>
                    </div>
                    {isDoubleElim && (
                        <div className="relative pt-8 border-t border-dashed border-zinc-300 dark:border-zinc-800 print:!border-zinc-400">
                            <div className="absolute top-4 left-0 text-[10px] font-black uppercase tracking-[0.2em] text-zinc-400 print:!text-black">Losers Bracket</div>
                            <div className="flex gap-20 mt-4">{renderRound(lb)}</div>
                        </div>
                    )}
                </div>

                <div className="flex flex-col justify-center gap-6 z-10">
                    {displayFinals.length > 0 && (
                        <div className="relative flex flex-col gap-6">
                            <div className="absolute -top-10 left-1/2 -translate-x-1/2 text-[10px] font-black uppercase bg-orange-100 dark:bg-orange-900/30 text-orange-600 print:!bg-transparent print:!border-black print:!text-black px-4 py-1.5 rounded-full border border-orange-200 dark:border-orange-800 shadow-sm whitespace-nowrap">
                                Championship
                            </div>
                            {displayFinals.map(m => <MatchCard key={m.id} match={m} onClick={onMatchClick} />)}
                        </div>
                    )}
                </div>
                <div className="flex flex-col justify-center gap-6 z-10">
                    <Podium matches={matches} />
                </div>
            </div>
        </div>
    );
}