import Link from "next/link";
import { formatDistanceToNowStrict } from "date-fns";
import { cn } from "@/lib/utils";
import { EXPORT_STATUS_STYLES, statusLabel } from "@/app/(dashboard)/pipeline/status-colors";
import type { BlockedExport } from "@/lib/dashboard/ops";

/**
 * The exception list: exports that have stopped moving and need a person.
 *
 * Read by scanning down the left edge — the severity rail says which rows are
 * dead in the water (a failed state, which nothing retries) versus merely
 * overdue (still nominally in flight, or waiting on a QC pass). The reason
 * column exists so the answer to "what happened" doesn't require opening
 * anything.
 */
export function BlockedQueue({ blocked }: { blocked: BlockedExport[] }) {
  const critical = blocked.filter((b) => b.severity === "critical").length;

  return (
    <div className="rounded-lg border border-zinc-800 bg-card overflow-hidden">
      <div className="flex items-center justify-between gap-3 border-b border-zinc-800/60 px-4 py-3">
        <h3 className="text-sm font-semibold text-white">
          {blocked.length === 0
            ? "Nothing blocked"
            : `${blocked.length} export${blocked.length === 1 ? "" : "s"} stalled`}
          {critical > 0 && (
            <span className="ml-2 text-xs font-normal text-red-400">{critical} failed</span>
          )}
        </h3>
        <Link href="/pipeline" className="text-xs text-zinc-400 hover:text-amber-400">
          Open render queue →
        </Link>
      </div>

      {blocked.length === 0 ? (
        <p className="px-4 py-10 text-center text-sm text-zinc-500">
          Every export is either moving or done.
        </p>
      ) : (
        <div className="overflow-x-auto">
          <table className="w-full text-sm">
            <thead>
              <tr className="border-b border-zinc-800 bg-zinc-900/60 text-left text-xs text-zinc-400">
                <th className="w-[3px] p-0" />
                <th className="px-4 py-2.5 font-medium">Shot</th>
                <th className="px-4 py-2.5 font-medium">Status</th>
                <th className="px-4 py-2.5 font-medium whitespace-nowrap">Stuck</th>
                <th className="px-4 py-2.5 font-medium">Why</th>
                <th className="px-4 py-2.5 font-medium">Artist</th>
              </tr>
            </thead>
            <tbody>
              {blocked.map((b) => (
                <tr key={b.exportId} className="border-b border-zinc-800/60 hover:bg-zinc-900/40">
                  <td className="w-[3px] p-0">
                    <div
                      className={cn(
                        "h-9 w-[3px]",
                        b.severity === "critical" ? "bg-red-500" : "bg-amber-500"
                      )}
                    />
                  </td>
                  <td className="px-4 py-2.5">
                    <Link
                      href={`/pipeline/exports/${b.exportId}`}
                      className="font-mono text-[13px] font-medium text-white hover:text-amber-400"
                    >
                      {b.shotCode}{" "}
                      <span className="text-zinc-500">{b.versionString}</span>
                    </Link>
                    <div className="text-xs text-zinc-500">
                      {b.projectCode}
                      {b.episode ? ` · ep ${b.episode}` : ""}
                    </div>
                  </td>
                  <td className="px-4 py-2.5">
                    <span
                      className={cn(
                        "inline-block rounded-full border px-2 py-0.5 text-xs whitespace-nowrap",
                        EXPORT_STATUS_STYLES[b.status] ?? "bg-zinc-500/15 text-zinc-300 border-zinc-500/30"
                      )}
                    >
                      {statusLabel(b.status)}
                    </span>
                  </td>
                  <td
                    className={cn(
                      "px-4 py-2.5 tabular-nums whitespace-nowrap",
                      b.severity === "critical" ? "text-red-400" : "text-zinc-300"
                    )}
                  >
                    {formatDistanceToNowStrict(b.since)}
                  </td>
                  {/* The reason can be an aerender error several lines long;
                      it is clamped here and given in full on hover. */}
                  <td className="px-4 py-2.5 text-zinc-400 max-w-md" title={b.reason}>
                    <span className="line-clamp-2">{b.reason}</span>
                  </td>
                  <td className="px-4 py-2.5 text-zinc-300 whitespace-nowrap">
                    {b.artistName ?? "—"}
                  </td>
                </tr>
              ))}
            </tbody>
          </table>
        </div>
      )}
    </div>
  );
}