import { useState } from "react";
import { Dialog, DialogContent, DialogHeader, DialogTitle } from "@/components/ui/dialog";
import { Button } from "@/components/ui/button";
import { Input } from "@/components/ui/input";
import { Label } from "@/components/ui/label";
import { Sparkles, Loader2, Eye, EyeOff } from "lucide-react";
import { useAuth } from "@/contexts/AuthContext";
import { useLang } from "@/contexts/LanguageContext";

interface AuthModalProps {
  open: boolean;
  onOpenChange: (open: boolean) => void;
  defaultTab?: "signin" | "signup";
}

export function AuthModal({ open, onOpenChange, defaultTab = "signin" }: AuthModalProps) {
  const { t } = useLang();
  const { signIn, signUp } = useAuth();
  const [tab, setTab] = useState<"signin" | "signup">(defaultTab);
  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  const [displayName, setDisplayName] = useState("");
  const [showPassword, setShowPassword] = useState(false);
  const [loading, setLoading] = useState(false);
  const [error, setError] = useState("");

  const reset = () => {
    setEmail("");
    setPassword("");
    setDisplayName("");
    setError("");
    setShowPassword(false);
  };

  const switchTab = (next: "signin" | "signup") => {
    setTab(next);
    setError("");
  };

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setError("");
    setLoading(true);
    try {
      if (tab === "signin") {
        await signIn(email, password);
      } else {
        await signUp(email, password, displayName);
      }
      reset();
      onOpenChange(false);
    } catch (err: unknown) {
      setError(err instanceof Error ? err.message : t.authError);
    } finally {
      setLoading(false);
    }
  };

  const handleOpenChange = (next: boolean) => {
    if (!next) reset();
    onOpenChange(next);
  };

  return (
    <Dialog open={open} onOpenChange={handleOpenChange}>
      <DialogContent className="sm:max-w-[400px] bg-card border-border">
        <DialogHeader>
          <DialogTitle className="flex items-center gap-2 text-foreground">
            <div className="w-7 h-7 rounded-lg bg-primary/15 border border-primary/30 flex items-center justify-center">
              <Sparkles className="w-4 h-4 text-primary" />
            </div>
            {t.appName}
          </DialogTitle>
        </DialogHeader>

        <div className="flex rounded-lg overflow-hidden border border-border/60 mb-4">
          {(["signin", "signup"] as const).map((t_) => (
            <button
              key={t_}
              type="button"
              onClick={() => switchTab(t_)}
              className={`flex-1 py-2 text-sm font-medium transition-colors ${
                tab === t_
                  ? "bg-primary text-primary-foreground"
                  : "text-muted-foreground hover:text-foreground hover:bg-secondary"
              }`}
            >
              {t_ === "signin" ? t.authSignIn : t.authSignUp}
            </button>
          ))}
        </div>

        <form onSubmit={handleSubmit} className="space-y-4">
          {tab === "signup" && (
            <div className="space-y-1.5">
              <Label className="text-sm text-muted-foreground">{t.authDisplayName}</Label>
              <Input
                value={displayName}
                onChange={(e) => setDisplayName(e.target.value)}
                placeholder={t.authDisplayNamePlaceholder}
                className="bg-background/50"
                maxLength={50}
              />
            </div>
          )}

          <div className="space-y-1.5">
            <Label className="text-sm text-muted-foreground">{t.authEmail}</Label>
            <Input
              type="email"
              value={email}
              onChange={(e) => setEmail(e.target.value)}
              placeholder={t.authEmailPlaceholder}
              className="bg-background/50"
              required
              autoFocus
            />
          </div>

          <div className="space-y-1.5">
            <Label className="text-sm text-muted-foreground">{t.authPassword}</Label>
            <div className="relative">
              <Input
                type={showPassword ? "text" : "password"}
                value={password}
                onChange={(e) => setPassword(e.target.value)}
                placeholder={tab === "signup" ? t.authPasswordMinHint : t.authPasswordPlaceholder}
                className="bg-background/50 pr-10"
                required
                minLength={tab === "signup" ? 6 : undefined}
              />
              <button
                type="button"
                tabIndex={-1}
                onClick={() => setShowPassword((v) => !v)}
                className="absolute right-3 top-1/2 -translate-y-1/2 text-muted-foreground hover:text-foreground"
              >
                {showPassword ? <EyeOff className="w-4 h-4" /> : <Eye className="w-4 h-4" />}
              </button>
            </div>
          </div>

          {error && (
            <p className="text-sm text-destructive bg-destructive/10 rounded-lg px-3 py-2">{error}</p>
          )}

          <Button type="submit" className="w-full" disabled={loading}>
            {loading ? (
              <><Loader2 className="mr-2 h-4 w-4 animate-spin" />{t.authLoading}</>
            ) : (
              tab === "signin" ? t.authSignIn : t.authSignUp
            )}
          </Button>

          <p className="text-center text-xs text-muted-foreground">
            {tab === "signin" ? (
              <>{t.authNoAccount}{" "}
                <button type="button" onClick={() => switchTab("signup")} className="text-primary hover:underline font-medium">
                  {t.authSignUp}
                </button>
              </>
            ) : (
              <>{t.authHasAccount}{" "}
                <button type="button" onClick={() => switchTab("signin")} className="text-primary hover:underline font-medium">
                  {t.authSignIn}
                </button>
              </>
            )}
          </p>
        </form>
      </DialogContent>
    </Dialog>
  );
}