"use client";

import {
  CircleAlert,
  ExternalLink,
  KeyRound,
  LoaderCircle,
  Lock,
  LogIn,
  RefreshCw,
  Trash2,
  TriangleAlert,
} from "lucide-react";
import Link from "next/link";
import { useEffect, useRef, useState } from "react";
import type { CameraSummary } from "@/lib/camera-registry";
import {
  useCameraInfo,
  useCameraSnapshot,
  useClearCredentials,
  useCredentialStatus,
  useResetCamera,
  useSaveCredentials,
  type CameraProblem,
} from "./camera-queries";
import { cameraStatus, StatusBadge } from "./camera-status";
import { deviceLine, streamSummary } from "./camera-summary";

const DEFAULT_USERNAME = "camera";

/** The camera's own web interface; it can't be framed (X-Frame-Options: SAMEORIGIN). */
function webUiUrl(cam: CameraSummary) {
  return `http://${cam.host}${cam.port === 80 ? "" : `:${cam.port}`}/`;
}

function WebUiLink({ cam, children }: { cam: CameraSummary; children: React.ReactNode }) {
  return (
    <a href={webUiUrl(cam)} target="_blank" rel="noopener noreferrer" className="underline">
      {children}
      <ExternalLink aria-hidden className="ml-0.5 inline size-3 align-[-0.1em]" />
    </a>
  );
}

function SetupPanel({ cam, onCheckAgain }: { cam: CameraSummary; onCheckAgain: () => void }) {
  return (
    <div className="flex flex-col gap-2 rounded border border-amber-400/60 p-3 text-sm">
      <div className="flex items-center gap-1.5 font-medium">
        <TriangleAlert aria-hidden className="size-4 shrink-0 text-amber-600 dark:text-amber-400" />
        Setup required: camera not activated
      </div>
      <ol className="list-decimal space-y-1 pl-5 text-zinc-700 dark:text-zinc-300">
        <li>
          <WebUiLink cam={cam}>Open the camera&apos;s web page</WebUiLink> and activate it by
          choosing an admin password. Save it in your password manager; this app never stores
          it.
        </li>
        <li>
          Enable ONVIF (usually Configuration → Network → Advanced Settings → Integration
          Protocol).
        </li>
        <li>
          On the same page, add an ONVIF user named <code>{DEFAULT_USERNAME}</code> with the{" "}
          <strong>Operator</strong> level.
        </li>
        <li>Come back here and click Check again, then enter that user&apos;s login.</li>
      </ol>
      <div>
        <button
          onClick={onCheckAgain}
          className="inline-flex items-center gap-1.5 rounded bg-black px-3 py-1 text-white dark:bg-white dark:text-black"
        >
          <RefreshCw aria-hidden className="size-4" />
          Check again
        </button>
      </div>
    </div>
  );
}

/** Shows the latest frame; polling itself lives in useCameraSnapshot. */
function Snapshot({ cam, frame, paused }: { cam: CameraSummary; frame?: Blob; paused: boolean }) {
  const imgRef = useRef<HTMLImageElement>(null);

  // Each frame gets one object URL, created and revoked in the same effect so it is freed
  // exactly once, including under Strict Mode's double rendering.
  useEffect(() => {
    const img = imgRef.current;
    if (!frame || !img) return;
    const url = URL.createObjectURL(frame);
    img.src = url;
    return () => URL.revokeObjectURL(url);
  }, [frame]);

  return (
    <div className="relative aspect-video overflow-hidden rounded bg-zinc-100 dark:bg-zinc-900">
      {frame && (
        // eslint-disable-next-line @next/next/no-img-element -- live frames, not optimizable
        <img
          ref={imgRef}
          alt={cam.name ?? cam.host}
          className={`h-full w-full object-contain ${paused ? "opacity-40" : ""}`}
        />
      )}
      {!frame && !paused && (
        <div className="absolute inset-0 flex items-center justify-center text-sm text-zinc-500">
          Loading…
        </div>
      )}
    </div>
  );
}

function CredentialsForm({
  cam,
  reason,
  onSaved,
  onCancel,
}: {
  cam: CameraSummary;
  reason?: string;
  /** Called after a save or clear; the camera's queries have already been reset. */
  onSaved: () => void;
  onCancel?: () => void;
}) {
  const status = useCredentialStatus(cam.id);
  const save = useSaveCredentials(cam.id);
  const clear = useClearCredentials(cam.id);
  // null until the user types, so the saved username (never the password) can prefill it.
  const [typedUsername, setTypedUsername] = useState<string | null>(null);
  const [password, setPassword] = useState("");
  const username = typedUsername ?? status.data?.username ?? DEFAULT_USERNAME;

  function submit(e: React.FormEvent) {
    e.preventDefault();
    save.mutate(
      { username, password },
      {
        onSuccess: () => {
          setPassword("");
          onSaved();
        },
      },
    );
  }

  const error = save.error ?? clear.error;
  const busy = save.isPending || clear.isPending;

  return (
    <form onSubmit={submit} className="flex flex-col gap-2 rounded border border-amber-400/60 p-3 text-sm">
      <div className="flex items-center gap-1.5 font-medium">
        <KeyRound aria-hidden className="size-4 shrink-0" />
        Camera login
      </div>
      {reason && <div className="text-xs text-zinc-500">{reason}</div>}
      <div className="text-xs text-zinc-500">
        Use the ONVIF user you created on the camera (
        <WebUiLink cam={cam}>camera web page</WebUiLink>).
      </div>
      <input
        value={username}
        onChange={(e) => setTypedUsername(e.target.value)}
        placeholder="Username"
        autoComplete="off"
        required
        className="rounded border border-zinc-300 bg-transparent px-2 py-1 dark:border-zinc-700"
      />
      <input
        type="password"
        value={password}
        onChange={(e) => setPassword(e.target.value)}
        placeholder="Password"
        autoComplete="new-password"
        className="rounded border border-zinc-300 bg-transparent px-2 py-1 dark:border-zinc-700"
      />
      {error && (
        <div className="flex items-center gap-1.5 text-red-600">
          <CircleAlert aria-hidden className="size-4 shrink-0" />
          {error === save.error && error.kind === "auth" ? "Camera rejected that login." : error.message}
        </div>
      )}
      <div className="flex gap-2">
        <button
          type="submit"
          disabled={busy}
          className="inline-flex items-center gap-1.5 rounded bg-black px-3 py-1 text-white disabled:opacity-50 dark:bg-white dark:text-black"
        >
          {save.isPending ? (
            <LoaderCircle aria-hidden className="size-4 animate-spin motion-reduce:animate-none" />
          ) : (
            <Lock aria-hidden className="size-4" />
          )}
          {save.isPending ? "Checking…" : "Save"}
        </button>
        {status.data?.source === "stored" && (
          <button
            type="button"
            disabled={busy}
            onClick={() => clear.mutate(undefined, { onSuccess: onSaved })}
            className="inline-flex items-center gap-1.5 rounded px-3 py-1 underline disabled:opacity-50"
          >
            <Trash2 aria-hidden className="size-4" />
            Forget saved login
          </button>
        )}
        {onCancel && (
          <button type="button" onClick={onCancel} className="rounded px-3 py-1 underline">
            Cancel
          </button>
        )}
      </div>
    </form>
  );
}

export default function CameraCard({
  cam,
  intervalMs,
}: {
  cam: CameraSummary;
  intervalMs: number;
}) {
  const info = useCameraInfo(cam.id);
  const snapshot = useCameraSnapshot(cam.id, intervalMs, info.isSuccess);
  const resetCamera = useResetCamera(cam.id);
  const [editingLogin, setEditingLogin] = useState(false);
  const problem: CameraProblem | null = info.error ?? snapshot.error;

  function retry() {
    setEditingLogin(false);
    resetCamera();
  }

  const device = info.data ? deviceLine(info.data) : null;
  const summary = info.data ? streamSummary(info.data.profiles) : null;

  const showSetup = problem?.kind === "inactive";
  const showLogin = !showSetup && (problem?.kind === "auth" || editingLogin);

  return (
    <li className="flex flex-col gap-3 rounded-lg border border-zinc-200 p-4 dark:border-zinc-800">
      <Snapshot cam={cam} frame={snapshot.data} paused={problem !== null || !info.isSuccess} />

      <div>
        <div className="flex items-center justify-between gap-2">
          <Link href={`/cameras/${cam.id}`} className="font-medium hover:underline">
            {cam.name ?? info.data?.model ?? "Unnamed camera"}
          </Link>
          <StatusBadge
            status={cameraStatus({ problem: problem?.kind ?? null, hasFrame: snapshot.data !== undefined })}
          />
        </div>
        <div className="flex items-center justify-between gap-2">
          <span className="font-mono text-sm">
            {cam.host}:{cam.port}
          </span>
          <span className="flex gap-3 text-xs">
            <WebUiLink cam={cam}>Web page</WebUiLink>
            {!showLogin && !showSetup && (
              <button
                onClick={() => setEditingLogin(true)}
                className="inline-flex items-center gap-1 underline"
              >
                <KeyRound aria-hidden className="size-3.5" />
                Change login
              </button>
            )}
          </span>
        </div>
        {device && <div className="text-sm text-zinc-600 dark:text-zinc-400">{device}</div>}
        {summary && <div className="text-sm text-zinc-600 dark:text-zinc-400">{summary}</div>}
        {cam.location && (
          <div className="text-sm text-zinc-600 dark:text-zinc-400">{cam.location}</div>
        )}
      </div>

      {showSetup && <SetupPanel cam={cam} onCheckAgain={retry} />}

      {showLogin && (
        <CredentialsForm
          cam={cam}
          reason={problem?.kind === "auth" ? problem.message : undefined}
          onSaved={() => setEditingLogin(false)}
          onCancel={problem?.kind === "auth" ? undefined : () => setEditingLogin(false)}
        />
      )}

      {problem?.kind === "signed-out" && (
        <div className="flex items-center justify-between gap-2 text-sm text-red-600">
          <span className="inline-flex items-center gap-1.5">
            <CircleAlert aria-hidden className="size-4 shrink-0" />
            Your session has ended.
          </span>
          <a href="/login" className="inline-flex items-center gap-1 underline">
            <LogIn aria-hidden className="size-4" />
            Sign in again
          </a>
        </div>
      )}

      {problem?.kind === "error" && (
        <div className="flex items-center justify-between gap-2 text-sm text-red-600">
          <span className="inline-flex items-center gap-1.5">
            <CircleAlert aria-hidden className="size-4 shrink-0" />
            Stopped: {problem.message}
          </span>
          <button onClick={retry} className="inline-flex items-center gap-1 underline">
            <RefreshCw aria-hidden className="size-4" />
            Retry
          </button>
        </div>
      )}

      {info.data && info.data.profiles.length > 0 && (
        <table className="text-xs">
          <thead className="text-left text-zinc-500">
            <tr>
              <th className="font-normal">Profile</th>
              <th className="font-normal">Codec</th>
              <th className="font-normal">Resolution</th>
              <th className="font-normal">FPS</th>
            </tr>
          </thead>
          <tbody className="font-mono">
            {info.data.profiles.map((p) => (
              <tr key={p.token}>
                <td>{p.name ?? p.token}</td>
                <td>{p.encoding ?? "?"}</td>
                <td>{p.width && p.height ? `${p.width}×${p.height}` : "?"}</td>
                <td>{p.fps ?? "?"}</td>
              </tr>
            ))}
          </tbody>
        </table>
      )}
    </li>
  );
}