import { useState } from "react";
import { useQuery, useQueryClient } from "@tanstack/react-query";
import { RefreshCw, ArrowUpCircle, CheckCircle2, HelpCircle } from "lucide-react";
import { toast } from "sonner";
import { Button, Card, Spinner } from "@/components/ui";
import { HostHeader } from "@/components/hosts/HostHeader";
import { imagesApi, type ImageRow } from "@/api/images";
import { agentsApi } from "@/api/agents";
import { apiErrorMessage } from "@/api/client";
import { formatBytes, relativeTime } from "@/lib/utils";
import { useAuthStore } from "@/store/auth";
import type { Agent } from "@/types";

function UpdateBadge({ row }: { row: ImageRow }) {
  const u = row.update;
  if (!u) return <span className="inline-flex items-center gap-1 text-xs text-slate-400"><HelpCircle className="h-3.5 w-3.5" /> not checked</span>;
  if (u.error) return <span className="text-xs text-amber-500">⚠ {u.error}</span>;
  if (u.update_available)
    return (
      <span className="inline-flex items-center gap-1 text-xs font-medium text-amber-600 dark:text-amber-400">
        <ArrowUpCircle className="h-3.5 w-3.5" /> update available
      </span>
    );
  return (
    <span className="inline-flex items-center gap-1 text-xs text-green-600 dark:text-green-400">
      <CheckCircle2 className="h-3.5 w-3.5" /> up to date
    </span>
  );
}

export function Images() {
  const isAdmin = useAuthStore((s) => s.user?.role === "admin");
  const agents = useQuery({
    queryKey: ["agents"],
    queryFn: () => agentsApi.list(),
    refetchInterval: 15000,
  });
  const hasAgents = (agents.data?.length ?? 0) > 0;

  return (
    <div className="space-y-8">
      <ImagesSection isAdmin={isAdmin} showHostLabel={hasAgents} />
      {agents.data?.map((agent) => (
        <ImagesSection key={agent.id} agent={agent} isAdmin={isAdmin} showHostLabel />
      ))}
    </div>
  );
}

function ImagesSection({
  agent,
  isAdmin,
  showHostLabel,
}: {
  agent?: Agent;
  isAdmin: boolean;
  showHostLabel: boolean;
}) {
  const agentId = agent?.id;
  const online = !agent || agent.status === "online";
  const qc = useQueryClient();
  const [checking, setChecking] = useState(false);
  const { data, isLoading } = useQuery({
    queryKey: ["images", agentId ?? "local"],
    queryFn: () => imagesApi.list(agentId),
    enabled: online,
  });

  const check = async () => {
    setChecking(true);
    const t = toast.loading("Checking for updates…");
    try {
      await imagesApi.check(agentId);
      await qc.invalidateQueries({ queryKey: ["images", agentId ?? "local"] });
      toast.success("Update check complete", { id: t });
    } catch (e) {
      toast.error(apiErrorMessage(e), { id: t });
    } finally {
      setChecking(false);
    }
  };

  return (
    <section>
      {(showHostLabel || (isAdmin && online)) && (
        <HostHeader agent={agent}>
          {isAdmin && online && (
            <Button onClick={check} loading={checking}>
              <RefreshCw className="h-4 w-4" /> Check updates
            </Button>
          )}
        </HostHeader>
      )}

      {!online ? (
        <Card>
          <p className="text-sm text-slate-500">
            Host is {agent?.status}. Check it under Settings → Remote hosts.
          </p>
        </Card>
      ) : isLoading ? (
        <Spinner />
      ) : (
        <Card className="overflow-x-auto p-0">
          <table className="w-full text-sm">
            <thead className="border-b border-slate-200 text-left text-xs text-slate-500 dark:border-slate-700">
              <tr>
                <th className="p-3">Image</th>
                <th className="p-3">Used by</th>
                <th className="p-3">Size</th>
                <th className="p-3">Created</th>
                <th className="p-3">Status</th>
              </tr>
            </thead>
            <tbody>
              {data?.map((row) => (
                <tr key={row.tag} className="border-b border-slate-100 dark:border-slate-700/50">
                  <td className="p-3 font-mono text-xs">{row.tag}</td>
                  <td className="p-3 text-xs text-slate-500">
                    {row.stacks.length ? row.stacks.join(", ") : "—"}
                  </td>
                  <td className="p-3 text-xs">{formatBytes(row.size)}</td>
                  <td className="p-3 text-xs text-slate-500">
                    {row.created ? relativeTime(row.created) : "—"}
                  </td>
                  <td className="p-3"><UpdateBadge row={row} /></td>
                </tr>
              ))}
              {data?.length === 0 && (
                <tr>
                  <td colSpan={5} className="p-6 text-center text-sm text-slate-500">
                    No images.
                  </td>
                </tr>
              )}
            </tbody>
          </table>
        </Card>
      )}
    </section>
  );
}