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

/**
 * Farm health: who is up, what is waiting, and who is running an old worker.
 *
 * The version row is not trivia — a worker's version is what decides whether
 * it has a given fix, and a machine that quietly stayed behind keeps producing
 * the bug everyone else has stopped seeing.
 */
export function FarmStrip({ farm }: { farm: FarmStatus }) {
  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">
          {farm.online} of {farm.total} online
        </h3>
        <Link href="/pipeline/machines" className="text-xs text-zinc-400 hover:text-amber-400">
          Machines →
        </Link>
      </div>

      {farm.machines.length === 0 ? (
        <p className="px-4 py-8 text-center text-sm text-zinc-500">
          No machines have registered yet.
        </p>
      ) : (
        farm.machines.map((m) => (
          <div
            key={m.id}
            className="flex items-center gap-3 border-b border-zinc-800/60 px-4 py-2.5 last:border-b-0"
          >
            <span
              className={cn(
                "h-2 w-2 shrink-0 rounded-full",
                m.status === "ONLINE"
                  ? "bg-green-500 ring-4 ring-green-500/15"
                  : m.status === "DISABLED"
                    ? "bg-zinc-600"
                    : "bg-zinc-500"
              )}
              title={m.status}
            />
            <span className="w-24 shrink-0 font-mono text-[12.5px] text-white">{m.name}</span>
            <span className="min-w-0 flex-1 truncate text-[12.5px] text-zinc-400">
              {m.currentJob
                ? `${m.currentJob.shotCode ?? "job"} ${m.currentJob.versionString ?? ""} · ${Math.round(
                    (m.currentJob.progress ?? 0) * 100
                  )}% · ETA ${formatEta(m.currentJob.etaSeconds)}`
                : m.status === "ONLINE"
                  ? "Idle"
                  : m.lastSeenAt
                    ? `Offline · last seen ${formatDistanceToNowStrict(new Date(m.lastSeenAt))} ago`
                    : "Never seen"}
            </span>
            <span
              className={cn(
                "shrink-0 font-mono text-[11.5px]",
                farm.latestWorkerVersion && m.workerVersion !== farm.latestWorkerVersion
                  ? "text-amber-400"
                  : "text-zinc-500"
              )}
            >
              {m.workerVersion ?? "—"}
            </span>
          </div>
        ))
      )}

      <div className="grid grid-cols-3 border-t border-zinc-800/60">
        <div className="border-r border-zinc-800/60 px-4 py-2.5">
          <b className="block font-mono text-lg font-semibold leading-tight text-white">
            {farm.queued.render}
          </b>
          <small className="text-xs text-zinc-500">renders queued</small>
        </div>
        <div className="border-r border-zinc-800/60 px-4 py-2.5">
          <b className="block font-mono text-lg font-semibold leading-tight text-white">
            {farm.queued.preview}
          </b>
          <small className="text-xs text-zinc-500">previews queued</small>
        </div>
        <div className="px-4 py-2.5">
          <b className="block font-mono text-lg font-semibold leading-tight text-white">
            {farm.oldestQueuedMs == null
              ? "—"
              : formatDistanceToNowStrict(new Date(Date.now() - farm.oldestQueuedMs))}
          </b>
          <small className="text-xs text-zinc-500">oldest wait</small>
        </div>
      </div>

      {farm.behindMachines.length > 0 && (
        <div className="flex gap-2 border-t border-amber-500/20 bg-amber-500/[0.07] px-4 py-2.5 text-xs text-amber-400">
          <span aria-hidden="true">▲</span>
          <span>
            {farm.behindMachines.length} machine
            {farm.behindMachines.length === 1 ? " is" : "s are"} behind{" "}
            <span className="font-mono">{farm.latestWorkerVersion}</span> —{" "}
            {farm.behindMachines
              .map((m) => `${m.name} (${m.workerVersion ?? "unknown"})`)
              .join(", ")}
          </span>
        </div>
      )}
    </div>
  );
}