import { useMemo } from "react";
import {
  Table,
  TableBody,
  TableCell,
  TableHead,
  TableHeader,
  TableRow,
} from "~/components/ui/table";
import { Badge } from "~/components/ui/badge";
import { TrendingUp, TrendingDown, Minus, Trophy, Medal, Award } from "lucide-react";
import { buildTiedRankChecker } from "~/lib/standings-display";

export interface StandingsRow {
  teamId: string;
  teamName: string;
  totalPoints: number;
  currentRank: number;
  previousRank?: number | null;
  firstPlaceCount: number;
  secondPlaceCount: number;
  thirdPlaceCount: number;
  fourthPlaceCount: number;
  fifthPlaceCount: number;
  sixthPlaceCount: number;
  seventhPlaceCount: number;
  eighthPlaceCount: number;
  participantsRemaining: number;
}

interface StandingsTableProps {
  standings: StandingsRow[];
  showMovement?: boolean;
  showPlacementBreakdown?: boolean;
}

function getRankBadge(rank: number, isTied?: boolean) {
  const t = isTied ? "T" : "";
  if (rank === 1) {
    return (
      <div className="flex items-center gap-2">
        <Trophy className="h-5 w-5 text-yellow-500" />
        <span className="font-bold text-lg">{t}{rank}</span>
      </div>
    );
  } else if (rank === 2) {
    return (
      <div className="flex items-center gap-2">
        <Medal className="h-5 w-5 text-gray-400" />
        <span className="font-semibold">{t}{rank}</span>
      </div>
    );
  } else if (rank === 3) {
    return (
      <div className="flex items-center gap-2">
        <Award className="h-5 w-5 text-amber-700" />
        <span className="font-semibold">{t}{rank}</span>
      </div>
    );
  } else {
    return <span className="font-medium">{t}{rank}</span>;
  }
}

export function StandingsTable({
  standings,
  showMovement = true,
  showPlacementBreakdown = false,
}: StandingsTableProps) {
  const isTied = useMemo(
    () => buildTiedRankChecker(standings.map((s) => s.currentRank)),
    [standings]
  );
  const getMovementIndicator = (current: number, previous?: number | null) => {
    if (!showMovement || !previous) return null;

    const change = previous - current; // Positive means moved up

    if (change > 0) {
      return (
        <div className="flex items-center gap-1 text-emerald-400">
          <TrendingUp className="h-3 w-3" aria-hidden="true" />
          <span className="text-xs">+{change}</span>
        </div>
      );
    } else if (change < 0) {
      return (
        <div className="flex items-center gap-1 text-coral-accent">
          <TrendingDown className="h-3 w-3" aria-hidden="true" />
          <span className="text-xs">{change}</span>
        </div>
      );
    } else {
      return (
        <div className="flex items-center gap-1 text-muted-foreground">
          <Minus className="h-3 w-3" aria-hidden="true" />
          <span className="text-xs">-</span>
        </div>
      );
    }
  };

  return (
    <Table aria-label="Standings">
      <TableHeader>
        <TableRow>
          <TableHead scope="col" className="w-16">Rank</TableHead>
          {showMovement && <TableHead scope="col" className="w-20">Change</TableHead>}
          <TableHead scope="col">Team</TableHead>
          <TableHead scope="col" className="text-right">Total Points</TableHead>
          {showPlacementBreakdown && (
            <>
              <TableHead scope="col" aria-label="1st place finishes" className="text-center w-12"><span aria-hidden="true">🥇</span></TableHead>
              <TableHead scope="col" aria-label="2nd place finishes" className="text-center w-12"><span aria-hidden="true">🥈</span></TableHead>
              <TableHead scope="col" aria-label="3rd place finishes" className="text-center w-12"><span aria-hidden="true">🥉</span></TableHead>
              <TableHead scope="col" className="text-center w-12">4th</TableHead>
              <TableHead scope="col" className="text-center w-12">5th</TableHead>
              <TableHead scope="col" className="text-center w-12">6th</TableHead>
              <TableHead scope="col" className="text-center w-12">7th</TableHead>
              <TableHead scope="col" className="text-center w-12">8th</TableHead>
            </>
          )}
          <TableHead scope="col" className="text-right">Remaining</TableHead>
        </TableRow>
      </TableHeader>
      <TableBody>
        {standings.length === 0 ? (
          <TableRow>
            <TableCell colSpan={showPlacementBreakdown ? 13 : 5} className="text-center text-muted-foreground">
              No standings data available yet
            </TableCell>
          </TableRow>
        ) : (
          standings.map((row) => (
            <TableRow key={row.teamId} className={row.currentRank <= 3 ? "bg-muted/30" : undefined}>
              <TableCell>
                {getRankBadge(row.currentRank, isTied(row.currentRank))}
              </TableCell>
              {showMovement && (
                <TableCell>
                  {getMovementIndicator(row.currentRank, row.previousRank)}
                </TableCell>
              )}
              <TableCell className="font-medium">{row.teamName}</TableCell>
              <TableCell className="text-right font-semibold">
                {row.totalPoints.toFixed(2)}
              </TableCell>
              {showPlacementBreakdown && (
                <>
                  <TableCell className="text-center">{row.firstPlaceCount || "-"}</TableCell>
                  <TableCell className="text-center">{row.secondPlaceCount || "-"}</TableCell>
                  <TableCell className="text-center">{row.thirdPlaceCount || "-"}</TableCell>
                  <TableCell className="text-center">{row.fourthPlaceCount || "-"}</TableCell>
                  <TableCell className="text-center">{row.fifthPlaceCount || "-"}</TableCell>
                  <TableCell className="text-center">{row.sixthPlaceCount || "-"}</TableCell>
                  <TableCell className="text-center">{row.seventhPlaceCount || "-"}</TableCell>
                  <TableCell className="text-center">{row.eighthPlaceCount || "-"}</TableCell>
                </>
              )}
              <TableCell className="text-right">
                {row.participantsRemaining > 0 ? (
                  <Badge variant="secondary">{row.participantsRemaining}</Badge>
                ) : (
                  <span className="text-muted-foreground">-</span>
                )}
              </TableCell>
            </TableRow>
          ))
        )}
      </TableBody>
    </Table>
  );
}