import React, { useState, useEffect } from "react";
import { Sparkles, Mail, Lock, User, PawPrint, ArrowLeft } from "lucide-react";
import { useAuth } from "../context/AuthContext";

interface AuthPageProps {
  initialMode?: "login" | "register";
  onBack?: () => void;
}

export const AuthPage: React.FC<AuthPageProps> = ({ initialMode = "login", onBack }) => {
  const { login, register } = useAuth();
  const [isRegistering, setIsRegistering] = useState(initialMode === "register");
  const [username, setUsername] = useState("");
  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  const [error, setError] = useState("");
  const [loading, setLoading] = useState(false);

  // Sync with initialMode if it changes externally
  useEffect(() => {
    setIsRegistering(initialMode === "register");
  }, [initialMode]);

  const handleSubmit = async (e: React.FormEvent) => {
    e.preventDefault();
    setError("");
    setLoading(true);

    try {
      if (isRegistering) {
        await register(username, email, password);
      } else {
        await login(email, password);
      }
    } catch (err: any) {
      setError(err.message || "Something went wrong");
    } finally {
      setLoading(false);
    }
  };

  return (
    <div className="min-h-screen bg-[#F9F7F2] flex items-center justify-center px-4">
      <div className="w-full max-w-md">
        {/* Back button */}
        {onBack && (
          <button
            onClick={onBack}
            className="mb-4 flex items-center gap-2 text-sm text-[#5A6E85] hover:text-[#1A2A40] transition-colors cursor-pointer"
          >
            <ArrowLeft className="w-4 h-4" />
            Back to PetTAlk
          </button>
        )}

        {/* Logo */}
        <div className="text-center mb-8">
          <div className="inline-flex items-center justify-center w-16 h-16 rounded-2xl bg-[#1A2A40] text-[#F9F7F2] shadow-lg mb-4">
            <Sparkles className="w-8 h-8 text-[#F08C7D]" />
          </div>
          <h1 className="font-serif text-3xl font-bold text-[#1A2A40] tracking-tight">
            PetTalk
          </h1>
          <p className="text-[#5A6E85] text-sm mt-1">
            Understanding pet intent softly
          </p>
        </div>

        {/* Form Card */}
        <div className="bg-white rounded-3xl border border-[#E5DFD3] shadow-2xs p-8">
          <div className="flex items-center justify-center gap-2 mb-6">
            <PawPrint className="w-5 h-5 text-[#F08C7D]" />
            <h2 className="font-serif text-xl font-bold text-[#1A2A40]">
              {isRegistering ? "Create Account" : "Welcome Back"}
            </h2>
          </div>

          {error && (
            <div className="mb-4 p-3 rounded-xl bg-red-50 border border-red-200 text-red-700 text-sm">
              {error}
            </div>
          )}

          <form onSubmit={handleSubmit} className="space-y-4">
            {isRegistering && (
              <div>
                <label className="block text-xs font-semibold text-[#4A5D78] mb-1.5">
                  Username
                </label>
                <div className="relative">
                  <User className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-[#5A6E85]" />
                  <input
                    type="text"
                    value={username}
                    onChange={(e) => setUsername(e.target.value)}
                    placeholder="Your name"
                    required
                    className="w-full pl-10 pr-4 py-2.5 rounded-xl border border-[#E5DFD3] bg-[#F9F7F2] text-[#1A2A40] text-sm placeholder:text-[#5A6E85] focus:outline-none focus:ring-2 focus:ring-[#F08C7D]/40 focus:border-[#F08C7D]/50 transition-all"
                  />
                </div>
              </div>
            )}

            <div>
              <label className="block text-xs font-semibold text-[#4A5D78] mb-1.5">
                Email
              </label>
              <div className="relative">
                <Mail className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-[#5A6E85]" />
                <input
                  type="email"
                  value={email}
                  onChange={(e) => setEmail(e.target.value)}
                  placeholder="you@example.com"
                  required
                  className="w-full pl-10 pr-4 py-2.5 rounded-xl border border-[#E5DFD3] bg-[#F9F7F2] text-[#1A2A40] text-sm placeholder:text-[#5A6E85] focus:outline-none focus:ring-2 focus:ring-[#F08C7D]/40 focus:border-[#F08C7D]/50 transition-all"
                />
              </div>
            </div>

            <div>
              <label className="block text-xs font-semibold text-[#4A5D78] mb-1.5">
                Password
              </label>
              <div className="relative">
                <Lock className="absolute left-3 top-1/2 -translate-y-1/2 w-4 h-4 text-[#5A6E85]" />
                <input
                  type="password"
                  value={password}
                  onChange={(e) => setPassword(e.target.value)}
                  placeholder="Min 6 characters"
                  required
                  minLength={6}
                  className="w-full pl-10 pr-4 py-2.5 rounded-xl border border-[#E5DFD3] bg-[#F9F7F2] text-[#1A2A40] text-sm placeholder:text-[#5A6E85] focus:outline-none focus:ring-2 focus:ring-[#F08C7D]/40 focus:border-[#F08C7D]/50 transition-all"
                />
              </div>
            </div>

            <button
              type="submit"
              disabled={loading}
              className="w-full py-3 rounded-2xl bg-[#F08C7D] hover:bg-[#E57B6C] text-white font-semibold text-sm flex items-center justify-center gap-2 transition-all disabled:opacity-50 cursor-pointer"
            >
              {loading ? (
                <span className="animate-pulse">Please wait...</span>
              ) : isRegistering ? (
                "Create Account"
              ) : (
                "Sign In"
              )}
            </button>
          </form>

          <div className="mt-6 text-center">
            <button
              onClick={() => {
                setIsRegistering(!isRegistering);
                setError("");
              }}
              className="text-sm text-[#5A6E85] hover:text-[#1A2A40] underline underline-offset-2 cursor-pointer transition-colors"
            >
              {isRegistering
                ? "Already have an account? Sign in"
                : "Don't have an account? Create one"}
            </button>
          </div>
        </div>

        {/* Footer */}
        <p className="text-center text-[10px] text-[#5A6E85] mt-6">
          PetTalk AI · Probabilistic Pet Behavioral Interpretation
        </p>
      </div>
    </div>
  );
};