import { useState, useRef, useCallback, useEffect } from "react";
import { useQuery, useMutation, useQueryClient } from "@tanstack/react-query";
import { motion, AnimatePresence } from "framer-motion";
import {
  Video, Loader2, Download, Trash2, Sparkles, Lock, Globe, Play,
  Upload, X, ImagePlus, CheckCircle2, AlertCircle, Clock,
} from "lucide-react";
import { Button } from "@/components/ui/button";
import { Textarea } from "@/components/ui/textarea";
import { Badge } from "@/components/ui/badge";
import { Progress } from "@/components/ui/progress";
import { useToast } from "@/hooks/use-toast";
import { useLang } from "@/contexts/LanguageContext";
import { useAuth } from "@/contexts/AuthContext";
import {
  AlertDialog, AlertDialogAction, AlertDialogCancel, AlertDialogContent,
  AlertDialogDescription, AlertDialogFooter, AlertDialogHeader, AlertDialogTitle,
  AlertDialogTrigger,
} from "@/components/ui/alert-dialog";

const BASE = import.meta.env.BASE_URL.replace(/\/$/, "");

// ── Types ─────────────────────────────────────────────────────────────────────
interface VideoRecord {
  id: number;
  videoUrl: string;
  thumbnailUrl: string | null;
  prompt: string;
  negativePrompt: string | null;
  model: string;
  aspectRatio: string;
  resolution: string;
  duration: number;
  hasRefImage: boolean;
  isPrivate: boolean;
  userId: number | null;
  createdAt: string;
}

interface RefImage { base64: string; mime: string; preview: string }

type VideoModel = "grok-3" | "veo-3-fast";

interface VideoOptions {
  model: VideoModel;
  aspectRatio: string;
  resolution: string;
  duration: number;
  negativePrompt: string;
  enhancePrompt: boolean;
}

type GenPhase =
  | "idle"
  | "submitting"       // POSTing to /generate
  | "turnstile"        // fetching turnstile token
  | "connecting"       // connecting to geminigen.ai
  | "generating"       // AI generating (status 1 events)
  | "done"
  | "error";

interface GenState {
  phase: GenPhase;
  message: string;
  elapsedMs: number;
  progress: number | null;  // 0-100 from geminigen.ai
  result: VideoRecord | null;
  errorMsg: string | null;
}

// ── API helpers ───────────────────────────────────────────────────────────────
async function initiateVideoGeneration(
  prompt: string,
  isPrivate: boolean,
  videoOpts: VideoOptions,
  refImageBase64?: string,
  refImageMime?: string,
): Promise<{ taskId: string }> {
  const resp = await fetch(`${BASE}/api/videos/generate`, {
    method: "POST",
    headers: { "Content-Type": "application/json" },
    credentials: "include",
    body: JSON.stringify({
      prompt, isPrivate,
      model: videoOpts.model,
      aspectRatio: videoOpts.aspectRatio,
      resolution: videoOpts.resolution,
      duration: videoOpts.duration,
      negativePrompt: videoOpts.negativePrompt || undefined,
      enhancePrompt: videoOpts.enhancePrompt,
      referenceImageBase64: refImageBase64,
      referenceImageMime: refImageMime,
    }),
  });
  if (!resp.ok) {
    const err = await resp.json().catch(() => ({ message: `HTTP ${resp.status}` }));
    throw new Error(err.message || `HTTP ${resp.status}`);
  }
  return resp.json();
}

async function fetchVideoHistory(): Promise<{ videos: VideoRecord[] }> {
  const resp = await fetch(`${BASE}/api/videos/history?limit=50`, { credentials: "include" });
  if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
  return resp.json();
}

async function deleteVideo(id: number): Promise<void> {
  const resp = await fetch(`${BASE}/api/videos/${id}`, { method: "DELETE", credentials: "include" });
  if (!resp.ok) throw new Error(`HTTP ${resp.status}`);
}

// ── useVideoGeneration hook ───────────────────────────────────────────────────
function useVideoGeneration(onSuccess: (v: VideoRecord) => void) {
  const { t } = useLang();
  const [state, setState] = useState<GenState>({
    phase: "idle", message: "", elapsedMs: 0, progress: null, result: null, errorMsg: null,
  });

  const esRef = useRef<EventSource | null>(null);
  const timerRef = useRef<ReturnType<typeof setInterval> | null>(null);
  const startTimeRef = useRef<number>(0);
  // Track whether an error was already received via onmessage, so onerror doesn't override it
  const terminalPhaseRef = useRef<boolean>(false);

  const stopTimer = useCallback(() => {
    if (timerRef.current) { clearInterval(timerRef.current); timerRef.current = null; }
  }, []);

  const stopSSE = useCallback(() => {
    if (esRef.current) { esRef.current.close(); esRef.current = null; }
    stopTimer();
  }, [stopTimer]);

  const startTimer = useCallback(() => {
    startTimeRef.current = Date.now();
    timerRef.current = setInterval(() => {
      setState((s) => ({ ...s, elapsedMs: Date.now() - startTimeRef.current }));
    }, 1000);
  }, []);

  const generate = useCallback(async (
    prompt: string,
    isPrivate: boolean,
    videoOpts: VideoOptions,
    refImageBase64?: string,
    refImageMime?: string,
  ) => {
    stopSSE();
    terminalPhaseRef.current = false;
    setState({ phase: "submitting", message: t.videoPhaseSubmitting, elapsedMs: 0, progress: null, result: null, errorMsg: null });
    startTimer();

    let taskId: string;
    try {
      const result = await initiateVideoGeneration(prompt, isPrivate, videoOpts, refImageBase64, refImageMime);
      taskId = result.taskId;
    } catch (err) {
      stopTimer();
      setState((s) => ({
        ...s,
        phase: "error",
        message: "",
        errorMsg: err instanceof Error ? err.message : String(err),
      }));
      return;
    }

    // Open SSE connection to /progress/:taskId
    const es = new EventSource(`${BASE}/api/videos/progress/${taskId}`, { withCredentials: true });
    esRef.current = es;

    es.onmessage = (ev) => {
      try {
        const data = JSON.parse(ev.data) as {
          type: string;
          message?: string;
          status?: number;
          progress?: number;
          video?: VideoRecord;
          errorCode?: string;
        };

        if (data.type === "start") {
          setState((s) => ({
            ...s,
            phase: data.message?.includes("Turnstile") ? "turnstile"
              : (data.message?.includes("連接") || data.message?.includes("connect")) ? "connecting"
              : "submitting",
            message: data.message || "",
          }));
        } else if (data.type === "progress") {
          setState((s) => ({
            ...s,
            phase: "generating",
            message: data.message || t.videoPhaseGenerating,
            progress: typeof data.progress === "number" ? data.progress : s.progress,
          }));
        } else if (data.type === "complete" && data.video) {
          terminalPhaseRef.current = true;
          stopSSE();
          setState((s) => ({
            ...s,
            phase: "done",
            message: t.videoDone,
            result: data.video!,
          }));
          onSuccess(data.video);
        } else if (data.type === "error") {
          terminalPhaseRef.current = true;
          stopSSE();
          setState((s) => ({
            ...s,
            phase: "error",
            message: "",
            errorMsg: data.message || t.videoGenFailed,
          }));
        } else if (data.type === "done") {
          // stream closed by server (task was already in terminal state)
          es.close();
        }
      } catch { /* ignore parse errors */ }
    };

    es.onerror = () => {
      if (esRef.current === es) {
        // If we already received a terminal event (error/complete) via onmessage,
        // don't overwrite the state with the generic "stream disconnected" message.
        if (terminalPhaseRef.current) {
          stopSSE();
          return;
        }
        stopSSE();
        setState((s) => {
          if (s.phase !== "done" && s.phase !== "error") {
            return {
              ...s,
              phase: "error",
              message: "",
              errorMsg: t.videoConnectionFailed,
            };
          }
          return s;
        });
      }
    };
  }, [stopSSE, startTimer, stopTimer, onSuccess, t]);

  const reset = useCallback(() => {
    stopSSE();
    setState({ phase: "idle", message: "", elapsedMs: 0, progress: null, result: null, errorMsg: null });
  }, [stopSSE]);

  // Cleanup on unmount
  useEffect(() => () => { stopSSE(); }, [stopSSE]);

  return { state, generate, reset };
}

// ── ElapsedTimer component ────────────────────────────────────────────────────
function formatMs(ms: number): string {
  const s = Math.floor(ms / 1000);
  const m = Math.floor(s / 60);
  const sec = s % 60;
  return m > 0 ? `${m}m ${sec}s` : `${sec}s`;
}

// ── VideoCard component ───────────────────────────────────────────────────────
function VideoCard({ vid, onDelete }: { vid: VideoRecord; onDelete: (id: number) => void }) {
  const { t } = useLang();
  return (
    <motion.div
      layout
      initial={{ opacity: 0, scale: 0.95 }}
      animate={{ opacity: 1, scale: 1 }}
      exit={{ opacity: 0, scale: 0.9 }}
      transition={{ duration: 0.25 }}
      className="bg-card/60 border border-border/50 rounded-xl overflow-hidden"
    >
      <div className="relative aspect-video bg-black/40">
        <video
          src={vid.videoUrl.startsWith("/") ? `${BASE}${vid.videoUrl}` : vid.videoUrl}
          poster={vid.thumbnailUrl
            ? (vid.thumbnailUrl.startsWith("/") ? `${BASE}${vid.thumbnailUrl}` : vid.thumbnailUrl)
            : undefined}
          className="w-full h-full object-cover"
          controls
          preload="metadata"
          playsInline
        />
        <div className="absolute top-2 left-2 flex gap-1">
          {vid.hasRefImage && (
            <Badge variant="outline" className="text-[10px] bg-black/60 border-violet-400/40 text-violet-300 backdrop-blur-sm">
              <ImagePlus className="w-2.5 h-2.5 mr-1" />{t.videoModeImage}
            </Badge>
          )}
        </div>
        <div className="absolute top-2 right-2">
          <Badge variant="outline" className="text-[10px] bg-black/60 border-white/20 text-white/80 backdrop-blur-sm">
            {vid.isPrivate
              ? <><Lock className="w-2.5 h-2.5 mr-1" />{t.videoPrivateLabel}</>
              : <><Globe className="w-2.5 h-2.5 mr-1" />{t.videoPublicLabel}</>
            }
          </Badge>
        </div>
      </div>
      <div className="p-3">
        <p className="text-xs text-muted-foreground line-clamp-2 mb-3">{vid.prompt}</p>
        <div className="flex items-center gap-1.5">
          <Badge variant="secondary" className="text-[10px]">{vid.model}</Badge>
          <Badge variant="outline" className="text-[10px]">{vid.duration}s</Badge>
          {vid.aspectRatio && <Badge variant="outline" className="text-[10px]">{vid.aspectRatio}</Badge>}
          {vid.resolution && <Badge variant="outline" className="text-[10px] text-sky-400 border-sky-400/30">{vid.resolution}</Badge>}
          <div className="flex-1" />
          <Button
            size="icon" variant="ghost" className="h-7 w-7"
            onClick={() => { const a = document.createElement("a"); a.href = vid.videoUrl.startsWith("/") ? `${BASE}${vid.videoUrl}` : vid.videoUrl; a.download = `starforge-video-${vid.id}.mp4`; a.click(); }}
            title={t.videoDownload}
          >
            <Download className="w-3.5 h-3.5" />
          </Button>
          <AlertDialog>
            <AlertDialogTrigger asChild>
              <Button size="icon" variant="ghost" className="h-7 w-7 text-destructive hover:text-destructive" title={t.videoDelete}>
                <Trash2 className="w-3.5 h-3.5" />
              </Button>
            </AlertDialogTrigger>
            <AlertDialogContent>
              <AlertDialogHeader>
                <AlertDialogTitle>{t.videoDelete}</AlertDialogTitle>
                <AlertDialogDescription>{vid.prompt.slice(0, 100)}</AlertDialogDescription>
              </AlertDialogHeader>
              <AlertDialogFooter>
                <AlertDialogCancel>{t.poolCancel}</AlertDialogCancel>
                <AlertDialogAction onClick={() => onDelete(vid.id)} className="bg-destructive hover:bg-destructive/90">
                  {t.videoDelete}
                </AlertDialogAction>
              </AlertDialogFooter>
            </AlertDialogContent>
          </AlertDialog>
        </div>
      </div>
    </motion.div>
  );
}

// ── GeneratingPanel component ─────────────────────────────────────────────────
function GeneratingPanel({ state }: { state: GenState }) {
  const { t } = useLang();
  const phaseProgress: Record<GenPhase, number> = {
    idle: 0, submitting: 5, turnstile: 12, connecting: 20, generating: 25, done: 100, error: 0,
  };

  // When generating: map geminigen.ai's 0-100 into the 25-95 range of our UI bar
  // so early phases (submitting/connecting) stay visible before generation starts.
  let progress: number;
  if (state.phase === "generating" && state.progress !== null) {
    progress = 25 + Math.round(state.progress * 0.70); // 25%–95%
  } else {
    progress = phaseProgress[state.phase];
  }

  return (
    <motion.div
      key="generating"
      initial={{ opacity: 0, y: 10 }}
      animate={{ opacity: 1, y: 0 }}
      exit={{ opacity: 0 }}
      className="bg-card/40 border border-primary/20 rounded-xl p-6 mb-6"
    >
      <div className="flex items-center gap-3 mb-4">
        <div className="w-10 h-10 rounded-full bg-primary/10 border border-primary/20 flex items-center justify-center shrink-0">
          <Loader2 className="w-5 h-5 text-primary animate-spin" />
        </div>
        <div className="flex-1 min-w-0">
          <p className="font-medium text-foreground text-sm">
            {state.phase === "submitting" ? t.videoPhaseSubmitting :
             state.phase === "turnstile" ? t.videoPhaseGettingCaptcha :
             state.phase === "connecting" ? t.videoPhaseConnecting :
             state.phase === "generating" ? t.videoPhaseGenerating :
             t.videoPhaseProcessing}
          </p>
          {state.message && (
            <p className="text-xs text-muted-foreground mt-0.5 truncate">{state.message}</p>
          )}
        </div>
        {state.elapsedMs > 0 && (
          <div className="flex items-center gap-1 text-xs text-muted-foreground shrink-0">
            <Clock className="w-3 h-3" />
            {formatMs(state.elapsedMs)}
          </div>
        )}
      </div>

      <Progress value={progress} className="h-1.5 mb-3" />

      <div className="flex flex-wrap gap-2">
        {(["submitting", "turnstile", "connecting", "generating"] as GenPhase[]).map((ph) => {
          const labels: Record<string, string> = {
            submitting: t.videoPhaseSubmitLabel,
            turnstile: t.videoPhaseTurnstileLabel,
            connecting: t.videoPhaseConnectLabel,
            generating: t.videoPhaseGenerateLabel,
          };
          const passed = phaseProgress[state.phase] > phaseProgress[ph];
          const active = state.phase === ph;
          return (
            <div
              key={ph}
              className={`flex items-center gap-1 text-[10px] px-2 py-0.5 rounded-full border transition-colors ${
                active ? "bg-primary/20 border-primary/40 text-primary" :
                passed ? "bg-green-500/10 border-green-500/20 text-green-400" :
                "bg-muted/30 border-border/30 text-muted-foreground"
              }`}
            >
              {passed ? <CheckCircle2 className="w-2.5 h-2.5" /> :
               active ? <Loader2 className="w-2.5 h-2.5 animate-spin" /> :
               <div className="w-2.5 h-2.5 rounded-full border border-current opacity-40" />}
              {labels[ph]}
            </div>
          );
        })}
      </div>

      {state.phase === "generating" && (
        <p className="text-[11px] text-muted-foreground mt-3">
          {t.videoGeneratingHint}
        </p>
      )}
    </motion.div>
  );
}

// ── Main VideoPage ────────────────────────────────────────────────────────────
export function VideoPage() {
  const { t } = useLang();
  const { toast } = useToast();
  const queryClient = useQueryClient();
  const { isSignedIn } = useAuth();

  const [prompt, setPrompt] = useState("");
  const [isPrivate, setIsPrivate] = useState(false);
  const [referenceImage, setReferenceImage] = useState<RefImage | null>(null);
  const fileInputRef = useRef<HTMLInputElement>(null);

  // ── Model selection ──
  const [selectedModel, setSelectedModel] = useState<VideoModel>("grok-3");

  // ── Video generation options ──
  const [aspectRatio, setAspectRatio] = useState("16:9");
  const [resolution, setResolution] = useState("480p");
  const [duration, setDuration] = useState(6);
  const [negativePrompt, setNegativePrompt] = useState("");
  const [enhancePrompt, setEnhancePrompt] = useState(true);
  const [showAdvanced, setShowAdvanced] = useState(false);

  // When switching to Veo, enforce its constraints
  const handleModelChange = (model: VideoModel) => {
    setSelectedModel(model);
    if (model === "veo-3-fast") {
      setDuration(8);
      if (aspectRatio !== "16:9" && aspectRatio !== "9:16") setAspectRatio("16:9");
    } else {
      setDuration(6);
    }
  };

  const HISTORY_KEY = ["video-history"];

  const { data: historyData, isLoading: historyLoading } = useQuery({
    queryKey: HISTORY_KEY,
    queryFn: fetchVideoHistory,
    staleTime: 30_000,
  });

  const handleSuccess = useCallback((video: VideoRecord) => {
    toast({ title: t.videoGenSuccess });
    queryClient.invalidateQueries({ queryKey: HISTORY_KEY });
    setPrompt("");
    setReferenceImage(null);
  }, [toast, queryClient, t]);

  const { state: genState, generate, reset } = useVideoGeneration(handleSuccess);

  const isGenerating = genState.phase !== "idle" && genState.phase !== "done" && genState.phase !== "error";

  const handleFileUpload = useCallback((file: File) => {
    if (!file.type.startsWith("image/")) {
      toast({ title: t.errorFormatTitle, description: t.errorFormatDesc, variant: "destructive" });
      return;
    }
    const reader = new FileReader();
    reader.onload = (e) => {
      const dataUrl = e.target?.result as string;
      const base64 = dataUrl.split(",")[1];
      setReferenceImage({ base64, mime: file.type, preview: dataUrl });
    };
    reader.readAsDataURL(file);
  }, [t, toast]);

  const handleDrop = useCallback((e: React.DragEvent<HTMLDivElement>) => {
    e.preventDefault();
    const file = e.dataTransfer.files[0];
    if (file) handleFileUpload(file);
  }, [handleFileUpload]);

  const { mutate: removeVideo } = useMutation({
    mutationFn: deleteVideo,
    onSuccess: () => {
      toast({ title: t.videoDeleteSuccess });
      queryClient.invalidateQueries({ queryKey: HISTORY_KEY });
    },
    onError: () => { toast({ title: t.videoDeleteFailed, variant: "destructive" }); },
  });

  const videos = historyData?.videos ?? [];

  return (
    <div className="container mx-auto px-4 py-8 max-w-4xl">
      {/* Header */}
      <div className="mb-8">
        <div className="flex items-center gap-3 mb-2">
          <div className="w-9 h-9 rounded-lg bg-primary/20 border border-primary/30 flex items-center justify-center">
            <Video className="w-5 h-5 text-primary" />
          </div>
          <div>
            <h1 className="text-2xl font-bold tracking-tight">{t.videoTitle}</h1>
            <p className="text-sm text-muted-foreground">{t.videoSubtitle}</p>
          </div>
        </div>
      </div>

      {/* Generator Card */}
      <div className="bg-card/60 border border-border/50 rounded-xl p-5 mb-6 backdrop-blur-sm space-y-4">

        {/* ── Model Picker ── */}
        <div>
          <p className="text-xs text-muted-foreground mb-2">{t.videoModel}</p>
          <div className="flex flex-wrap gap-2">
            {([
              {
                value: "grok-3" as VideoModel,
                label: "Grok-3",
                sub: t.videoModelGrokSub,
                desc: t.videoModelGrokDesc,
                color: "text-violet-400",
                border: "border-violet-500/40",
                bg: "bg-violet-500/10",
              },
              {
                value: "veo-3-fast" as VideoModel,
                label: "Veo 3.1 Fast",
                sub: t.videoModelVeoSub,
                desc: t.videoModelVeoDesc,
                color: "text-sky-400",
                border: "border-sky-500/40",
                bg: "bg-sky-500/10",
              },
            ]).map((m) => {
              const active = selectedModel === m.value;
              return (
                <button
                  key={m.value}
                  onClick={() => !isGenerating && handleModelChange(m.value)}
                  disabled={isGenerating}
                  className={`flex flex-col items-start gap-0.5 px-3 py-2.5 rounded-lg border text-xs font-medium transition-all ${
                    active
                      ? `${m.border} ${m.bg} ${m.color}`
                      : "border-border/50 hover:border-border text-muted-foreground hover:text-foreground"
                  }`}
                >
                  <div className="flex items-center gap-1.5">
                    <Sparkles className={`w-3 h-3 ${active ? m.color : ""}`} />
                    <span className="font-semibold">{m.label}</span>
                    <span className={`text-[10px] opacity-70 font-normal ${active ? "" : ""}`}>{m.sub}</span>
                  </div>
                  <span className={`text-[10px] opacity-60 ml-5 ${active ? m.color : "text-muted-foreground"}`}>{m.desc}</span>
                </button>
              );
            })}
          </div>
          {selectedModel === "veo-3-fast" && (
            <p className="mt-2 text-[11px] text-sky-400/80 flex items-center gap-1">
              <span>⏱</span> {t.videoVeoTimingNote}
            </p>
          )}
        </div>

        {referenceImage && (
          <Badge className="text-xs gap-1 bg-violet-500/20 text-violet-300 border-violet-400/30">
            <ImagePlus className="w-3 h-3" />{t.videoModeImage}
          </Badge>
        )}

        <Textarea
          value={prompt}
          onChange={(e) => setPrompt(e.target.value)}
          placeholder={t.videoPromptPlaceholder}
          className="min-h-[90px] resize-none bg-background/50"
          disabled={isGenerating}
        />

        {/* ── Aspect Ratio ── */}
        <div>
          <p className="text-xs text-muted-foreground mb-1.5">{t.ratioLabel}</p>
          <div className="flex flex-wrap gap-2">
            {([
              { value: "16:9",  label: "16:9",  tw: "w-[48px] h-[27px]" },
              { value: "9:16",  label: "9:16",  tw: "w-[19px] h-[34px]" },
              { value: "1:1",   label: "1:1",   tw: "w-[30px] h-[30px]", veoLimited: true },
              { value: "4:3",   label: "4:3",   tw: "w-[38px] h-[28px]", veoLimited: true },
              { value: "3:4",   label: "3:4",   tw: "w-[28px] h-[37px]", veoLimited: true },
            ] as const).map(({ value, label, tw, veoLimited }) => {
              const isLimited = selectedModel === "veo-3-fast" && veoLimited;
              return (
                <div key={value} className="relative group">
                  <button
                    onClick={() => !isLimited && setAspectRatio(value)}
                    disabled={isGenerating || isLimited}
                    className={`flex flex-col items-center gap-1 px-2.5 py-2 rounded-lg border text-[11px] font-medium transition-all ${
                      isLimited
                        ? "border-border/20 text-muted-foreground/30 cursor-not-allowed opacity-40 line-through"
                        : aspectRatio === value
                          ? "border-primary/60 bg-primary/10 text-primary"
                          : "border-border/50 hover:border-border text-muted-foreground hover:text-foreground"
                    }`}
                  >
                    <div className={`${tw} rounded-sm border-2 ${
                      isLimited ? "border-muted-foreground/20" :
                      aspectRatio === value ? "border-primary/70 bg-primary/20" : "border-muted-foreground/40"
                    }`} />
                    {label}
                  </button>
                  {isLimited && (
                    <div className="absolute bottom-full left-1/2 -translate-x-1/2 mb-1.5 hidden group-hover:block z-10 pointer-events-none">
                      <div className="bg-popover border border-border text-[10px] text-muted-foreground px-2 py-1 rounded-md whitespace-nowrap shadow-lg">
                        {t.videoVeoNotSupported}
                      </div>
                    </div>
                  )}
                </div>
              );
            })}
          </div>
        </div>

        {/* ── Resolution & Duration ── */}
        <div className="flex flex-wrap gap-5">
          {/* Resolution: Veo ignores resolution (server-side), Grok max 720p */}
          {selectedModel === "grok-3" && (
            <div>
              <p className="text-xs text-muted-foreground mb-1.5">
                {t.resolutionLabel}
                <span className="ml-1.5 text-amber-400/80 text-[10px]">{t.videoGrokMaxRes}</span>
              </p>
              <div className="flex gap-1.5">
                {([
                  { value: "480p",  label: "480p",  sub: "SD",  limited: false },
                  { value: "720p",  label: "720p",  sub: "HD",  limited: false },
                  { value: "1080p", label: "1080p", sub: "FHD", limited: true  },
                ] as const).map(({ value, label, sub, limited }) => (
                  <div key={value} className="relative group">
                    <button
                      onClick={() => !limited && setResolution(value)}
                      disabled={isGenerating || limited}
                      className={`px-3 py-1.5 rounded-lg border text-xs font-medium transition-all ${
                        limited
                          ? "border-border/20 text-muted-foreground/30 cursor-not-allowed opacity-40 line-through"
                          : resolution === value
                            ? "border-primary/60 bg-primary/10 text-primary"
                            : "border-border/50 hover:border-border text-muted-foreground hover:text-foreground"
                      }`}
                    >
                      {label} <span className="opacity-60 ml-0.5">{sub}</span>
                    </button>
                    {limited && (
                      <div className="absolute bottom-full left-1/2 -translate-x-1/2 mb-1.5 hidden group-hover:block z-10 pointer-events-none">
                        <div className="bg-popover border border-border text-[10px] text-muted-foreground px-2 py-1 rounded-md whitespace-nowrap shadow-lg">
                          {t.videoGrokNotSupported}
                        </div>
                      </div>
                    )}
                  </div>
                ))}
              </div>
            </div>
          )}

          {/* Duration */}
          <div>
            <p className="text-xs text-muted-foreground mb-1.5">
              {t.videoDuration}
              {selectedModel === "grok-3" && (
                <span className="ml-1.5 text-amber-400/80 text-[10px]">{t.videoGrokMaxTime}</span>
              )}
              {selectedModel === "veo-3-fast" && (
                <span className="ml-1.5 text-sky-400/80 text-[10px]">{t.videoVeoFixedTime}</span>
              )}
            </p>
            <div className="flex gap-1.5">
              {([5, 6, 8, 10] as const).map((d) => {
                const isGrok3Limited  = selectedModel === "grok-3" && d > 6;
                const isVeoLocked     = selectedModel === "veo-3-fast" && d !== 8;
                const isLimited = isGrok3Limited || isVeoLocked;
                const tooltipMsg = isGrok3Limited ? t.videoGrokMaxTime : isVeoLocked ? t.videoVeoFixedTime : "";
                return (
                  <div key={d} className="relative group">
                    <button
                      onClick={() => !isLimited && setDuration(d)}
                      disabled={isGenerating || isLimited}
                      className={`px-3 py-1.5 rounded-lg border text-xs font-medium transition-all ${
                        isLimited
                          ? "border-border/20 text-muted-foreground/30 cursor-not-allowed opacity-40 line-through"
                          : duration === d
                            ? "border-primary/60 bg-primary/10 text-primary"
                            : "border-border/50 hover:border-border text-muted-foreground hover:text-foreground"
                      }`}
                    >
                      {d}s
                    </button>
                    {isLimited && tooltipMsg && (
                      <div className="absolute bottom-full left-1/2 -translate-x-1/2 mb-1.5 hidden group-hover:block z-10 pointer-events-none">
                        <div className="bg-popover border border-border text-[10px] text-muted-foreground px-2 py-1 rounded-md whitespace-nowrap shadow-lg">
                          {tooltipMsg}
                        </div>
                      </div>
                    )}
                  </div>
                );
              })}
            </div>
          </div>
        </div>

        {/* ── Advanced ── */}
        <div>
          <button
            onClick={() => setShowAdvanced((v) => !v)}
            className="flex items-center gap-1 text-xs text-muted-foreground hover:text-foreground transition-colors"
          >
            <span className={`transition-transform ${showAdvanced ? "rotate-90" : ""}`}>▶</span>
            {t.videoAdvanced}
          </button>
          {showAdvanced && (
            <div className="mt-3 space-y-3 pl-3 border-l border-border/40">
              <div>
                <p className="text-xs text-muted-foreground mb-1">{t.videoNegativePrompt}</p>
                <Textarea
                  value={negativePrompt}
                  onChange={(e) => setNegativePrompt(e.target.value)}
                  placeholder="blurry, distorted, low quality..."
                  className="min-h-[60px] resize-none bg-background/50 text-xs"
                  disabled={isGenerating}
                />
              </div>
              <label className="flex items-center gap-2 cursor-pointer">
                <input
                  type="checkbox"
                  checked={enhancePrompt}
                  onChange={(e) => setEnhancePrompt(e.target.checked)}
                  disabled={isGenerating}
                  className="w-3.5 h-3.5 accent-primary"
                />
                <span className="text-xs text-muted-foreground">{t.videoEnhancePrompt}</span>
              </label>
            </div>
          )}
        </div>

        {/* Reference Image */}
        <div>
          <div className="flex items-center gap-2 mb-2">
            <span className="text-sm font-medium">{t.videoRefImageLabel}</span>
            <Badge variant="outline" className="text-[10px] px-1.5 py-0 h-4 border-violet-400/40 text-violet-400">
              {t.videoRefImageBadge}
            </Badge>
          </div>
          {referenceImage ? (
            <div className="relative rounded-lg overflow-hidden border border-border/50 bg-background/30">
              <img src={referenceImage.preview} alt="reference" className="w-full max-h-48 object-contain" />
              <button
                onClick={() => setReferenceImage(null)}
                className="absolute top-2 right-2 p-1 rounded-full bg-black/60 hover:bg-black/80 text-white transition-colors"
              >
                <X className="w-3.5 h-3.5" />
              </button>
            </div>
          ) : (
            <div
              onDrop={handleDrop}
              onDragOver={(e) => e.preventDefault()}
              onClick={() => !isGenerating && fileInputRef.current?.click()}
              className="border-2 border-dashed border-border/60 rounded-lg p-6 text-center cursor-pointer hover:border-primary/50 hover:bg-primary/5 transition-colors"
            >
              <Upload className="w-6 h-6 mx-auto mb-2 text-muted-foreground" />
              <p className="text-xs text-muted-foreground">{t.videoRefImageDrop}</p>
              <p className="text-[11px] text-muted-foreground/60 mt-0.5">{t.videoRefImageFormats}</p>
            </div>
          )}
          <input ref={fileInputRef} type="file" accept="image/*" className="hidden"
            onChange={(e) => { const f = e.target.files?.[0]; if (f) handleFileUpload(f); }}
          />
        </div>

        <div className="flex items-center justify-between gap-3 pt-1">
          {isSignedIn && (
            <button
              onClick={() => setIsPrivate((v) => !v)}
              className="flex items-center gap-1.5 px-3 py-1.5 rounded-md text-xs border border-border/60 text-muted-foreground hover:text-foreground transition-colors"
            >
              {isPrivate
                ? <><Lock className="w-3.5 h-3.5 text-yellow-400" />{t.videoPrivateLabel}</>
                : <><Globe className="w-3.5 h-3.5" />{t.videoPublicLabel}</>
              }
            </button>
          )}
          <div className="flex-1" />
          <Button
            onClick={() => generate(prompt.trim(), isPrivate, { model: selectedModel, aspectRatio, resolution, duration, negativePrompt, enhancePrompt }, referenceImage?.base64, referenceImage?.mime)}
            disabled={isGenerating || !prompt.trim()}
            className="gap-2 min-w-[140px]"
          >
            {isGenerating
              ? <><Loader2 className="w-4 h-4 animate-spin" />{t.videoBtnGenerating}</>
              : <><Play className="w-4 h-4" />{t.videoBtnGenerate}</>
            }
          </Button>
        </div>
      </div>

      {/* Progress / Result / Error panels */}
      <AnimatePresence mode="wait">
        {isGenerating && (
          <GeneratingPanel key="generating" state={genState} />
        )}

        {genState.phase === "error" && (
          <motion.div
            key="error"
            initial={{ opacity: 0, y: 10 }}
            animate={{ opacity: 1, y: 0 }}
            exit={{ opacity: 0 }}
            className="bg-destructive/10 border border-destructive/30 rounded-xl p-5 mb-6"
          >
            <div className="flex items-start gap-3">
              <AlertCircle className="w-5 h-5 text-destructive shrink-0 mt-0.5" />
              <div className="flex-1">
                <p className="font-medium text-destructive text-sm">{t.videoGenFailed}</p>
                {genState.errorMsg && (
                  <p className="text-xs text-muted-foreground mt-1">{genState.errorMsg}</p>
                )}
              </div>
              <Button size="sm" variant="outline" onClick={reset} className="text-xs h-7 shrink-0">
                {t.poolCancel}
              </Button>
            </div>
          </motion.div>
        )}

        {genState.phase === "done" && genState.result && (
          <motion.div
            key="result"
            initial={{ opacity: 0, scale: 0.97 }}
            animate={{ opacity: 1, scale: 1 }}
            exit={{ opacity: 0 }}
            className="mb-6"
          >
            <div className="flex items-center gap-2 mb-2">
              <CheckCircle2 className="w-4 h-4 text-green-400" />
              <span className="text-sm font-medium text-green-400">{t.videoComplete}</span>
              {genState.elapsedMs > 0 && (
                <span className="text-xs text-muted-foreground ml-auto">{t.videoElapsed} {formatMs(genState.elapsedMs)}</span>
              )}
            </div>
            <div className="bg-card/60 border border-primary/30 rounded-xl overflow-hidden">
              <div className="relative aspect-video bg-black">
                <video
                  src={genState.result.videoUrl.startsWith("/") ? `${BASE}${genState.result.videoUrl}` : genState.result.videoUrl}
                  poster={genState.result.thumbnailUrl
                    ? (genState.result.thumbnailUrl.startsWith("/") ? `${BASE}${genState.result.thumbnailUrl}` : genState.result.thumbnailUrl)
                    : undefined}
                  className="w-full h-full object-contain"
                  controls
                  autoPlay
                  playsInline
                />
                {genState.result.hasRefImage && (
                  <div className="absolute top-2 left-2">
                    <Badge className="text-[10px] bg-violet-500/80 text-white border-0">
                      <ImagePlus className="w-2.5 h-2.5 mr-1" />{t.videoModeImage}
                    </Badge>
                  </div>
                )}
              </div>
              <div className="p-3 flex items-center justify-between gap-2">
                <p className="text-xs text-muted-foreground line-clamp-1 flex-1">{genState.result.prompt}</p>
                <Button
                  size="sm" variant="outline" className="gap-1.5 text-xs h-7 shrink-0"
                  onClick={() => { const a = document.createElement("a"); const url = genState.result!.videoUrl; a.href = url.startsWith("/") ? `${BASE}${url}` : url; a.download = `starforge-video-${genState.result!.id}.mp4`; a.click(); }}
                >
                  <Download className="w-3.5 h-3.5" />{t.videoDownload}
                </Button>
              </div>
            </div>
          </motion.div>
        )}
      </AnimatePresence>

      {/* History */}
      <div>
        <h2 className="text-base font-semibold mb-4 flex items-center gap-2">
          <Video className="w-4 h-4 text-muted-foreground" />
          {t.videoHistoryTitle}
        </h2>
        {historyLoading ? (
          <div className="flex items-center justify-center py-12">
            <Loader2 className="w-6 h-6 text-muted-foreground animate-spin" />
          </div>
        ) : videos.length === 0 ? (
          <div className="text-center py-12 text-muted-foreground">
            <Video className="w-10 h-10 mx-auto mb-3 opacity-30" />
            <p className="text-sm">{t.videoHistoryEmpty}</p>
          </div>
        ) : (
          <motion.div layout className="grid grid-cols-1 sm:grid-cols-2 gap-4">
            <AnimatePresence mode="popLayout">
              {videos.map((v) => (
                <VideoCard key={v.id} vid={v} onDelete={removeVideo} />
              ))}
            </AnimatePresence>
          </motion.div>
        )}
      </div>
    </div>
  );
}