import { formatDistanceToNow } from "date-fns";
import { Link } from "react-router";
import { Button } from "~/components/ui/button";
import { LeagueAvatar } from "./LeagueAvatar";

export interface LeagueRowProps {
  leagueId: string;
  leagueName: string;
  numSports: number;
  status: "draft" | "active" | "pre_draft" | "completed";
  seasonId?: string;
  currentRank?: number;
  totalPoints?: number;
  previousRank?: number;
  completionPercentage?: number;
  draftDateTime?: string | null;
  picksUntilMyTurn?: number;
  draftPosition?: number;
}

// ─── Helpers ──────────────────────────────────────────────────────────────────

function ordinal(n: number): string {
  const v = n % 100;
  // 11–13 are always "th" (e.g. 11th, 12th, 13th)
  if (v >= 11 && v <= 13) return `${n}th`;
  const s = ["th", "st", "nd", "rd"];
  return `${n}${s[n % 10] ?? "th"}`;
}


// ─── Shared stat column ───────────────────────────────────────────────────────

function StatColumn({
  label,
  children,
}: {
  label: string;
  children: React.ReactNode;
}) {
  return (
    <div className="text-right shrink-0 flex-1 sm:flex-none">
      <p className="text-xs font-semibold uppercase tracking-wide text-muted-foreground">
        {label}
      </p>
      <div className="flex items-baseline justify-end gap-1">{children}</div>
    </div>
  );
}

function StatDivider() {
  return <div className="h-8 w-px bg-border shrink-0 self-center" />;
}

// ─── Season progress bar ──────────────────────────────────────────────────────

function SeasonProgress({ pct, status }: { pct: number; status: "active" | "completed" }) {
  const label = status === "completed" ? "100% Complete" : `${pct}% Complete`;
  const fill = status === "completed" ? 100 : pct;
  return (
    <div className="flex items-center gap-1.5 mt-1.5 w-40">
      <div className="flex-1 h-1 rounded-full bg-white/10 overflow-hidden">
        <div
          className="h-full rounded-full bg-electric transition-all"
          style={{ width: `${fill}%` }}
        />
      </div>
      <span className="text-xs text-muted-foreground shrink-0">{label}</span>
    </div>
  );
}

// ─── Rank change indicator ────────────────────────────────────────────────────

function RankChange({ current, previous }: { current: number; previous: number | undefined }) {
  if (previous === undefined || previous === current) return null;
  const delta = previous - current;
  if (delta > 0) {
    return <span className="text-xs font-semibold text-primary" aria-label={`ranked up ${delta}`}>▲{delta}</span>;
  }
  return (
    <span className="text-xs font-semibold" style={{ color: "var(--coral-accent, #ef4444)" }} aria-label={`ranked down ${Math.abs(delta)}`}>
      ▼{Math.abs(delta)}
    </span>
  );
}

// ─── Row variants ─────────────────────────────────────────────────────────────

function DraftRow({ leagueId, leagueName, seasonId, picksUntilMyTurn }: LeagueRowProps) {
  const draftUrl = `/leagues/${leagueId}/draft/${seasonId}`;
  const picksLabel =
    picksUntilMyTurn === 0
      ? "You're on the clock!"
      : picksUntilMyTurn !== undefined
      ? `Up in ${picksUntilMyTurn} pick${picksUntilMyTurn === 1 ? "" : "s"}`
      : null;

  return (
    <div className="flex items-start gap-3 rounded-lg border border-primary/40 bg-primary/10 px-3 py-3 sm:px-5 sm:py-4">
      <LeagueAvatar leagueId={leagueId} leagueName={leagueName} />
      <div className="flex-1 min-w-0">
        <p className="font-semibold leading-tight truncate">{leagueName}</p>
        <div className="flex items-center gap-2 mt-0.5 flex-wrap">
          <div className="flex items-center gap-1.5">
            <span className="h-1.5 w-1.5 animate-pulse rounded-full bg-electric" />
            <span className="text-xs font-semibold tracking-wide text-electric uppercase">
              Draft in Progress
            </span>
          </div>
          {picksLabel && (
            <span className="text-xs text-muted-foreground">{picksLabel}</span>
          )}
        </div>
        {seasonId && (
          <Button asChild size="sm" className="mt-3 sm:hidden">
            <Link to={draftUrl}>Enter Draft</Link>
          </Button>
        )}
      </div>
      {seasonId && (
        <Button asChild size="sm" className="shrink-0 hidden sm:inline-flex">
          <Link to={draftUrl}>Enter Draft</Link>
        </Button>
      )}
    </div>
  );
}

function ActiveRow({
  leagueId,
  leagueName,
  currentRank,
  totalPoints,
  previousRank,
  completionPercentage = 0,
}: LeagueRowProps) {
  const showStats = currentRank !== undefined || totalPoints !== undefined;

  return (
    <Link
      to={`/leagues/${leagueId}`}
      className="flex flex-col sm:flex-row sm:items-center gap-3 rounded-lg bg-card px-3 py-3 sm:px-5 sm:py-4 hover:bg-white/[0.06] transition-colors"
    >
      {/* Avatar + name */}
      <div className="flex items-center gap-3 min-w-0 flex-1">
        <LeagueAvatar leagueId={leagueId} leagueName={leagueName} />
        <div className="min-w-0">
          <p className="font-semibold leading-tight truncate">{leagueName}</p>
          <SeasonProgress pct={completionPercentage} status="active" />
        </div>
      </div>
      {/* Stats — second row on mobile, right side on desktop */}
      {showStats && (
        <div className="flex items-center gap-4 border-t border-border/50 pt-2 sm:border-0 sm:pt-0 sm:shrink-0">
          {currentRank !== undefined && (
            <StatColumn label="Ranking">
              <span className="text-2xl font-bold leading-none">#{currentRank}</span>
              <RankChange current={currentRank} previous={previousRank} />
            </StatColumn>
          )}
          {currentRank !== undefined && totalPoints !== undefined && <StatDivider />}
          {totalPoints !== undefined && (
            <StatColumn label="Points">
              <span className="text-2xl font-bold leading-none text-electric">
                {Math.round(totalPoints).toLocaleString("en-US")}
              </span>
            </StatColumn>
          )}
        </div>
      )}
    </Link>
  );
}

function PreDraftRow({
  leagueId,
  leagueName,
  draftDateTime,
  draftPosition,
}: LeagueRowProps) {
  let draftTimeValue = "Not scheduled";
  if (draftDateTime) {
    const draftDate = new Date(draftDateTime);
    draftTimeValue =
      draftDate > new Date()
        ? formatDistanceToNow(draftDate, { addSuffix: true })
        : "Starting soon";
  }

  return (
    <Link
      to={`/leagues/${leagueId}`}
      className="flex flex-col sm:flex-row sm:items-center gap-3 rounded-lg bg-card px-3 py-3 sm:px-5 sm:py-4 hover:bg-white/[0.06] transition-colors"
    >
      {/* Avatar + name */}
      <div className="flex items-center gap-3 min-w-0 flex-1">
        <LeagueAvatar leagueId={leagueId} leagueName={leagueName} />
        <div className="min-w-0">
          <p className="font-semibold leading-tight truncate">{leagueName}</p>
          <p className="text-xs text-muted-foreground mt-0.5">Pre-Draft</p>
        </div>
      </div>
      {/* Stats — second row on mobile, right side on desktop */}
      <div className="flex items-center gap-4 border-t border-border/50 pt-2 sm:border-0 sm:pt-0 sm:shrink-0">
        <StatColumn label="Draft">
          <span className="text-2xl font-bold leading-none">{draftTimeValue}</span>
        </StatColumn>
        {draftPosition !== undefined && (
          <>
            <StatDivider />
            <StatColumn label="Position">
              <span className="text-2xl font-bold leading-none">
                {ordinal(draftPosition)}
              </span>
            </StatColumn>
          </>
        )}
      </div>
    </Link>
  );
}

function CompletedRow({
  leagueId,
  leagueName,
  completionPercentage = 0,
}: LeagueRowProps) {
  return (
    <Link
      to={`/leagues/${leagueId}`}
      className="flex items-center gap-3 rounded-lg bg-card px-3 py-3 sm:px-5 sm:py-4 hover:bg-white/[0.06] transition-colors"
    >
      <LeagueAvatar leagueId={leagueId} leagueName={leagueName} />
      <div className="flex-1 min-w-0">
        <p className="font-semibold leading-tight truncate">{leagueName}</p>
        <SeasonProgress pct={completionPercentage} status="completed" />
      </div>
    </Link>
  );
}

// ─── Public export ────────────────────────────────────────────────────────────

export function LeagueRow(props: LeagueRowProps) {
  if (props.status === "draft") return <DraftRow {...props} />;
  if (props.status === "active") return <ActiveRow {...props} />;
  if (props.status === "pre_draft") return <PreDraftRow {...props} />;
  return <CompletedRow {...props} />;
}