"use client";

import { useEffect, useState } from "react";
import { useParams, useRouter } from "next/navigation";
import { doc, onSnapshot } from "firebase/firestore";
import { db } from "@/lib/firebase";
import { useSystems } from "@/lib/useSystems";
import { useCalls } from "@/lib/useCalls";
import { StatusBadge } from "@/components/StatusBadge";
import { NodeConfigModal } from "@/components/NodeConfigModal";
import { SdrSettings } from "@/components/SdrSettings";
import { RadioChannels } from "@/components/RadioChannels";
import { NodeDiscordRadio } from "@/components/NodeDiscordRadio";
import { CallRow } from "@/components/CallRow";
import { MachineOutputNotice } from "@/components/ui/MachineOutputNotice";
import { useAuth } from "@/components/AuthProvider";
import { c2api } from "@/lib/c2api";
import { errorMessage } from "@/lib/c2error";
import { diskState, DISK_TEXT_CLASS } from "@/lib/nodeDisk";
import type { NodeRecord } from "@/lib/types";

function ApprovalBadge({ status }: { status: string | null }) {
  if (status === "approved") return (
    <span className="text-xs text-green-400 bg-green-400/10 px-2 py-0.5 rounded font-mono">Approved</span>
  );
  if (status === "rejected") return (
    <span className="text-xs text-red-400 bg-red-400/10 px-2 py-0.5 rounded font-mono">Rejected</span>
  );
  return (
    <span className="text-xs text-yellow-400 bg-yellow-400/10 px-2 py-0.5 rounded font-mono">Pending approval</span>
  );
}

export default function NodeDetailPage() {
  const { id } = useParams<{ id: string }>();
  const router = useRouter();
  const [node, setNode] = useState<NodeRecord | null>(null);
  const [showConfig, setShowConfig] = useState(false);
  const [sending, setSending] = useState(false);
  const [approving, setApproving] = useState(false);
  const [deleting, setDeleting] = useState(false);
  const { systems } = useSystems();
  // TODO(server-26#109 item5): server-side node_id filter. A where("node_id","==",id)
  // alongside the existing org_id equality + started_at orderBy needs a brand-new
  // composite index, so for now pull a wider window and filter client-side.
  const { calls } = useCalls(200);
  const { isAdmin } = useAuth();

  const systemMap = Object.fromEntries(systems.map((s) => [s.system_id, s]));
  const nodeCalls = calls.filter((c) => c.node_id === id);

  useEffect(() => {
    const unsub = onSnapshot(doc(db, "nodes", id), (snap) => {
      setNode(snap.exists() ? (snap.data() as NodeRecord) : null);
    });
    return unsub;
  }, [id]);

  async function sendCommand(action: string, label: string) {
    setSending(true);
    try {
      await c2api.sendCommand(id, { action });
      alert(`${label} sent to the node.`);
    } catch (e) {
      // Was try/finally only: an unhandled rejection and no feedback (server-26#284).
      alert(`Couldn't send ${label.toLowerCase()}: ${errorMessage(e)}`);
    } finally {
      setSending(false);
    }
  }

  async function handleRequestUpdate() {
    if (
      !confirm(
        "Update this node's software?\n\n" +
          "The node pulls the latest release it was installed to track and recreates its containers " +
          "(radio capture pauses for about a minute). An online node starts within seconds; an offline " +
          "or locked-out node picks it up on its next check-in (up to ~15 minutes). Nodes installed " +
          "before the host updater existed need install.sh re-run once.",
      )
    )
      return;
    setSending(true);
    try {
      const r = await c2api.requestNodeUpdate(id);
      alert(
        r.mqtt_sent
          ? "Update requested. The node should restart within a minute."
          : "Update requested. The node is not reachable over MQTT right now; it will update on its next HTTPS check-in.",
      );
    } catch (err) {
      alert(err instanceof Error ? err.message : "Update request failed.");
    } finally {
      setSending(false);
    }
  }

  async function handleApprove() {
    setApproving(true);
    try {
      await c2api.approveNode(id);
    } catch (err) {
      alert(err instanceof Error ? err.message : "Approval failed.");
    } finally {
      setApproving(false);
    }
  }

  async function handleDelete() {
    if (!confirm(`Permanently delete node "${node?.name ?? id}"? This cannot be undone.`)) return;
    setDeleting(true);
    try {
      await c2api.deleteNode(id);
      router.push("/nodes");
    } catch (err) {
      alert(err instanceof Error ? err.message : "Delete failed.");
      setDeleting(false);
    }
  }

  async function handleReject() {
    if (!confirm("Reject this node? Any MQTT login and API key it holds are revoked, so it cannot connect or upload. Re-approving later issues a new key.")) return;
    setApproving(true);
    try {
      await c2api.rejectNode(id);
    } catch (err) {
      alert(err instanceof Error ? err.message : "Rejection failed.");
    } finally {
      setApproving(false);
    }
  }

  if (!node) {
    return <p className="text-ink-muted font-mono text-sm">Loading node…</p>;
  }

  const system = systemMap[node.assigned_system_id ?? ""];

  return (
    <div className="space-y-6 max-w-3xl">
      <div className="flex items-start justify-between">
        <div>
          <h1 className="text-xl font-bold text-white font-mono">{node.name}</h1>
          <p className="text-ink-muted text-sm font-mono">{node.node_id}</p>
        </div>
        <StatusBadge status={node.status} />
      </div>

      {/* Override Warning */}
      {node.is_overridden && (
        <div className="bg-yellow-950/40 border border-yellow-800/60 rounded-lg p-4 font-mono text-sm space-y-3">
          <div className="flex items-center gap-2 text-yellow-400 font-semibold">
            <span className="text-base">⚠</span>
            <span>Local System Override Active</span>
          </div>
          <p className="text-ink-2 text-xs leading-relaxed">
            This node is operating on a local system override. 
            {node.override_timeout_at ? (
              <> Resets automatically on: <span className="text-white font-bold">{new Date(node.override_timeout_at).toLocaleString()}</span>.</>
            ) : (
              <> No timeout is currently enforced (permanent override).</>
            )}
          </p>
          {/* Override routes are require_service_key_or_admin (server-26#222). */}
          {isAdmin && <div className="flex gap-2">
            {node.override_timeout_at && (
              <button
                onClick={async () => {
                  try {
                    await c2api.ackOverride(id, 1440);
                  } catch (e) {
                    alert("Failed to extend timer.");
                  }
                }}
                className="px-3 py-1 bg-yellow-800 hover:bg-yellow-700 text-white rounded text-xs transition-colors"
              >
                Ack (Reset 24h Timer)
              </button>
            )}
            <button
              onClick={async () => {
                if (confirm("Force this node to revert back to its assigned system config?")) {
                  try {
                    await c2api.resetOverride(id);
                  } catch (e) {
                    alert("Failed to reset override.");
                  }
                }
              }}
              className="px-3 py-1 bg-red-900 hover:bg-red-800 text-red-200 rounded text-xs transition-colors"
            >
              Force Revert Config
            </button>
          </div>}
        </div>
      )}

      {/* Info */}
      <div className="bg-surface border border-line rounded-lg divide-y divide-line font-mono text-sm">
        {[
          ["System",    system?.name ?? "Unassigned"],
          ["Location",  `${node.lat}, ${node.lon}`],
          ["Last Seen", node.last_seen ? new Date(node.last_seen).toLocaleString() : "never"],
          ["Updater Check-in", node.updater_last_check_at ? new Date(node.updater_last_check_at).toLocaleString() : "never"],
          ...(node.update_requested_at
            ? [[
                "Last Update",
                node.update_applied_at && node.update_applied_at >= node.update_requested_at
                  ? `${node.update_result === "failed" ? "FAILED" : "applied"} ${new Date(node.update_applied_at).toLocaleString()}`
                  : `requested ${new Date(node.update_requested_at).toLocaleString()} — pending`,
              ]]
            : []),
          ["Configured", node.configured ? "Yes" : "No"],
          ["Node Type", node.node_type ?? "fixed"],
          ...(node.node_type !== "portable" ? [["Enforce Timeout", node.enforce_override_timeout ? "Yes" : "No"]] : []),
        ].map(([label, value]) => (
          <div key={label} className="flex justify-between px-4 py-2.5">
            <span className="text-ink-muted">{label}</span>
            <span className="text-ink">{value}</span>
          </div>
        ))}
        {(() => {
          const disk = diskState(node);
          return (
            <div className="flex justify-between px-4 py-2.5">
              <span className="text-ink-muted">Disk</span>
              <span className={disk ? DISK_TEXT_CLASS[disk.level] : "text-ink-muted"}>
                {disk ? `${disk.level !== "ok" ? "⚠ " : ""}${disk.label}` : "not reported (node software too old)"}
              </span>
            </div>
          );
        })()}
        <div className="flex justify-between px-4 py-2.5">
          <span className="text-ink-muted">Approval</span>
          <ApprovalBadge status={node.approval_status ?? null} />
        </div>
      </div>

      {/* Admin approval actions */}
      {isAdmin && node.approval_status === "pending" && (
        <div className="flex gap-3 items-center">
          <span className="text-sm text-yellow-400 font-mono">This node is awaiting approval.</span>
          <button
            onClick={handleApprove}
            disabled={approving}
            className="px-4 py-2 bg-green-700 hover:bg-green-600 disabled:opacity-50 text-white rounded-lg text-sm font-mono transition-colors"
          >
            {approving ? "…" : "Approve"}
          </button>
          <button
            onClick={handleReject}
            disabled={approving}
            className="px-4 py-2 bg-red-900 hover:bg-red-800 disabled:opacity-50 text-ink-2 rounded-lg text-sm font-mono transition-colors"
          >
            Reject
          </button>
        </div>
      )}

      {/* Actions */}
      {/* Configure and Restart are admin-only on the server (server-26#222);
          non-admins get a note instead of a button that 403s. */}
      {!isAdmin && !node.configured && (
        <p className="text-sm text-ink-2">This node isn&apos;t configured yet. An admin needs to assign it a radio system.</p>
      )}
      <div className="flex flex-wrap gap-3">
        {isAdmin && (
          <button
            onClick={() => setShowConfig(true)}
            className="px-4 py-2 bg-indigo-700 hover:bg-indigo-600 text-white rounded-lg text-sm font-mono transition-colors"
          >
            {node.configured ? "Reassign System" : "Configure"}
          </button>
        )}
        {isAdmin && (
          <button
            disabled={sending}
            onClick={() => sendCommand("op25_restart", "Restart OP25")}
            className="px-4 py-2 bg-raised hover:bg-gray-700 text-ink-2 rounded-lg text-sm font-mono transition-colors disabled:opacity-50"
          >
            Restart OP25
          </button>
        )}
        {isAdmin && (
          <button
            disabled={sending}
            onClick={handleRequestUpdate}
            className="px-4 py-2 bg-raised hover:bg-gray-700 text-ink-2 rounded-lg text-sm font-mono transition-colors disabled:opacity-50"
          >
            Update Node Software
          </button>
        )}
        {isAdmin && (
          <button
            disabled={deleting}
            onClick={handleDelete}
            className="px-4 py-2 bg-red-900 hover:bg-red-800 disabled:opacity-50 text-red-300 rounded-lg text-sm font-mono transition-colors ml-auto"
          >
            {deleting ? "Deleting…" : "Delete Node"}
          </button>
        )}
      </div>

      {/* server-26#213 item 3: picker over the org's linked servers, not raw IDs. */}
      <NodeDiscordRadio nodeId={id} />

      <RadioChannels channels={node.radio_channels} />

      <SdrSettings node={node} canEdit={isAdmin} />

      {/* Recent calls */}
      <section>
        <h2 className="text-sm font-semibold text-ink-2 uppercase tracking-wider mb-3">Recent Calls</h2>
        {/* Gate A / A2 (server-26#46) — each row expands to a transcript. */}
        {nodeCalls.length > 0 && <MachineOutputNotice variant="inline" className="mb-3" />}
        {nodeCalls.length === 0 ? (
          <p className="text-ink-muted text-sm font-mono">No calls recorded from this node.</p>
        ) : (
          <div className="overflow-x-auto">
            <table className="w-full text-sm">
              <thead>
                <tr className="text-xs text-ink-muted uppercase tracking-wider border-b border-line">
                  <th className="px-4 py-2 text-left">Time</th>
                  <th className="px-4 py-2 text-left">Talkgroup</th>
                  <th className="px-4 py-2 text-left">System</th>
                  <th className="px-4 py-2 text-left">Node</th>
                  <th className="px-4 py-2 text-left">Duration</th>
                  <th className="px-4 py-2 text-left">Audio</th>
                </tr>
              </thead>
              <tbody>
                {nodeCalls.map((c) => (
                  <CallRow key={c.call_id} call={c} systemName={system?.name} />
                ))}
              </tbody>
            </table>
          </div>
        )}
      </section>

      {showConfig && (
        <NodeConfigModal
          node={node}
          systems={systems}
          onClose={() => setShowConfig(false)}
        />
      )}

    </div>
  );
}