"use client";

import { Suspense, useState, FormEvent, useEffect } from "react";
import { useAuth } from "@/lib/AuthContext";
import { useRouter, useSearchParams } from "next/navigation";
import { Mail, ArrowLeft } from "lucide-react";

type AuthMode = "login" | "register";
type PageState = "select" | "email-form";

/** Inline Google SVG logo */
function GoogleLogo({ className }: { className?: string }) {
  return (
    <svg className={className} viewBox="0 0 24 24" fill="none">
      <path
        d="M22.56 12.25c0-.78-.07-1.53-.2-2.25H12v4.26h5.92a5.06 5.06 0 0 1-2.2 3.32v2.77h3.57c2.08-1.92 3.28-4.74 3.28-8.1z"
        fill="#4285F4"
      />
      <path
        d="M12 23c2.97 0 5.46-.98 7.28-2.66l-3.57-2.77c-.98.66-2.23 1.06-3.71 1.06-2.86 0-5.29-1.93-6.16-4.53H2.18v2.84C3.99 20.53 7.7 23 12 23z"
        fill="#34A853"
      />
      <path
        d="M5.84 14.09c-.22-.66-.35-1.36-.35-2.09s.13-1.43.35-2.09V7.07H2.18C1.43 8.55 1 10.22 1 12s.43 3.45 1.18 4.93l2.85-2.22.81-.62z"
        fill="#FBBC05"
      />
      <path
        d="M12 5.38c1.62 0 3.06.56 4.21 1.64l3.15-3.15C17.45 2.09 14.97 1 12 1 7.7 1 3.99 3.47 2.18 7.07l3.66 2.84c.87-2.6 3.3-4.53 6.16-4.53z"
        fill="#EA4335"
      />
    </svg>
  );
}

/** Inline GitHub SVG logo */
function GitHubLogo({ className }: { className?: string }) {
  return (
    <svg className={className} viewBox="0 0 24 24" fill="currentColor">
      <path d="M12 0C5.37 0 0 5.37 0 12c0 5.31 3.435 9.795 8.205 11.385.6.105.825-.255.825-.57 0-.285-.015-1.23-.015-2.235-3.015.555-3.795-.735-4.035-1.41-.135-.345-.72-1.41-1.23-1.695-.42-.225-1.02-.78-.015-.795.945-.015 1.62.87 1.845 1.23 1.08 1.815 2.805 1.305 3.495.99.105-.78.42-1.305.765-1.605-2.67-.3-5.46-1.335-5.46-5.925 0-1.305.465-2.385 1.23-3.225-.12-.3-.54-1.53.12-3.18 0 0 1.005-.315 3.3 1.23.96-.27 1.98-.405 3-.405s2.04.135 3 .405c2.295-1.56 3.3-1.23 3.3-1.23.66 1.65.24 2.88.12 3.18.765.84 1.23 1.905 1.23 3.225 0 4.605-2.805 5.625-5.475 5.925.435.375.81 1.095.81 2.22 0 1.605-.015 2.895-.015 3.3 0 .315.225.69.825.57A12.02 12.02 0 0 0 24 12c0-6.63-5.37-12-12-12z" />
    </svg>
  );
}

function AuthPageInner() {
  const { user, login, register, oauthLogin, loading: authLoading } = useAuth();
  const router = useRouter();
  const searchParams = useSearchParams();
  const refCode = searchParams.get("ref");

  // Redirect to main page if already logged in (e.g. after OAuth popup completes)
  useEffect(() => {
    if (user) router.push("/");
  }, [user, router]);

  const [pageState, setPageState] = useState<PageState>("select");
  const [mode, setMode] = useState<AuthMode>("register");
  const [name, setName] = useState("");
  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  const [error, setError] = useState("");
  const [submitting, setSubmitting] = useState(false);

  const handleProviderClick = (provider: string) => {
    setError("");
    oauthLogin(provider);
  };

  const handleEmailClick = () => {
    setError("");
    setPageState("email-form");
  };

  const toggleMode = () => {
    setMode((m) => (m === "login" ? "register" : "login"));
    setError("");
  };

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

    if (!email.trim() || !password.trim()) {
      setError("Please fill in all fields");
      return;
    }
    if (mode === "register" && !name.trim()) {
      setError("Please enter your name");
      return;
    }
    if (mode === "register" && password.length < 6) {
      setError("Password must be at least 6 characters");
      return;
    }

    setSubmitting(true);
    try {
      if (mode === "login") {
        await login(email.trim(), password);
      } else {
        await register(email.trim(), name.trim(), password, refCode || undefined);
      }
      router.push("/");
    } catch (err: unknown) {
      const message =
        err instanceof Error ? err.message : "Something went wrong. Please try again.";
      setError(message);
    } finally {
      setSubmitting(false);
    }
  };

  // ── Select State ──────────────────────────────────────────────────────────
  if (pageState === "select") {
    return (
      <div className="min-h-dvh bg-[#0a0a0f] flex flex-col items-center justify-center px-5">
        <div className="w-full max-w-sm">
          {/* Logo / Brand */}
          <div className="text-center mb-8">
            <div className="w-16 h-16 rounded-2xl bg-gradient-to-br from-[#D4AF37]/20 to-[#D4AF37]/5 border border-[#D4AF37]/30 flex items-center justify-center mx-auto mb-4">
              <span className="text-3xl">☪️</span>
            </div>
            <h1 className="text-2xl font-bold text-white">Welcome to Falah</h1>
            <p className="text-sm text-gray-500 mt-1">
              Your Islamic lifestyle companion
            </p>
          </div>

          {/* SSO Buttons */}
          <div className="space-y-3">
            {/* Google */}
            <button
              onClick={() => handleProviderClick("google")}
              disabled={authLoading}
              className="w-full flex items-center gap-4 px-5 py-4 rounded-2xl bg-[#111118] border border-gray-800/60 active:bg-[#1a1a24] disabled:opacity-50 transition-all touch-manipulation"
            >
              <GoogleLogo className="w-6 h-6 shrink-0" />
              <span className="text-sm font-medium text-white">
                Continue with Google
              </span>
            </button>

            {/* GitHub */}
            <button
              onClick={() => handleProviderClick("github")}
              disabled={authLoading}
              className="w-full flex items-center gap-4 px-5 py-4 rounded-2xl bg-[#111118] border border-gray-800/60 active:bg-[#1a1a24] disabled:opacity-50 transition-all touch-manipulation"
            >
              <GitHubLogo className="w-6 h-6 shrink-0 text-white" />
              <span className="text-sm font-medium text-white">
                Continue with GitHub
              </span>
            </button>

            {/* Divider */}
            <div className="flex items-center gap-3 py-2">
              <div className="flex-1 h-px bg-gray-800/60" />
              <span className="text-xs text-gray-600">or</span>
              <div className="flex-1 h-px bg-gray-800/60" />
            </div>

            {/* Email */}
            <button
              onClick={handleEmailClick}
              disabled={authLoading}
              className="w-full flex items-center gap-4 px-5 py-4 rounded-2xl bg-[#D4AF37]/10 border border-[#D4AF37]/25 active:bg-[#D4AF37]/20 disabled:opacity-50 transition-all touch-manipulation"
            >
              <div className="w-6 h-6 shrink-0 flex items-center justify-center">
                <Mail size={22} className="text-[#D4AF37]" />
              </div>
              <span className="text-sm font-medium text-[#D4AF37]">
                Continue with Email
              </span>
            </button>
          </div>

          {/* Demo Credentials */}
          <div className="mt-8 rounded-2xl bg-[#111118] border border-gray-800/60 p-4 text-center">
            <p className="text-xs text-gray-600 uppercase tracking-wider mb-1.5">
              Demo Account
            </p>
            <p className="text-xs text-gray-500">
              Email:{" "}
              <span className="text-gray-300 font-mono">demo@falahos.my</span>
            </p>
            <p className="text-xs text-gray-500">
              Password:{" "}
              <span className="text-gray-300 font-mono">password123</span>
            </p>
          </div>
        </div>
      </div>
    );
  }

  // ── Email Form State ──────────────────────────────────────────────────────
  return (
    <div className="min-h-dvh bg-[#0a0a0f] flex flex-col items-center justify-center px-5">
      <div className="w-full max-w-sm">
        {/* Back button */}
        <button
          onClick={() => setPageState("select")}
          className="flex items-center gap-1.5 text-xs text-gray-500 mb-6 active:text-gray-300 transition-colors touch-manipulation"
        >
          <ArrowLeft size={16} />
          All sign-in methods
        </button>

        {/* Header */}
        <div className="text-center mb-7">
          <div className="w-14 h-14 rounded-2xl bg-gradient-to-br from-[#D4AF37]/20 to-[#D4AF37]/5 border border-[#D4AF37]/30 flex items-center justify-center mx-auto mb-3">
            <Mail size={22} className="text-[#D4AF37]" />
          </div>
          <h1 className="text-xl font-bold text-white">
            {mode === "login" ? "Sign In" : "Create Account"}
          </h1>
          <p className="text-sm text-gray-500 mt-1">
            {mode === "login"
              ? "Welcome back! Sign in to continue"
              : "Start your Islamic lifestyle journey"}
          </p>
        </div>

        {/* Error */}
        {error && (
          <div className="mb-4 p-3 rounded-xl bg-red-900/20 border border-red-800/40 text-red-400 text-sm text-center">
            {error}
          </div>
        )}

        {/* Form */}
        <form onSubmit={handleSubmit} className="space-y-4">
          {/* Name field (register only) */}
          {mode === "register" && (
            <div>
              <label
                htmlFor="auth-name"
                className="block text-xs font-medium text-gray-500 mb-1.5 uppercase tracking-wider"
              >
                Name
              </label>
              <input
                id="auth-name"
                type="text"
                value={name}
                onChange={(e) => setName(e.target.value)}
                placeholder="Your name"
                autoComplete="name"
                className="w-full bg-[#111118] border border-gray-800/60 rounded-xl px-4 py-3.5 text-white placeholder-gray-600 focus:outline-none focus:border-[#D4AF37]/50 focus:ring-1 focus:ring-[#D4AF37]/30 transition text-sm"
              />
            </div>
          )}

          {/* Email */}
          <div>
            <label
              htmlFor="auth-email"
              className="block text-xs font-medium text-gray-500 mb-1.5 uppercase tracking-wider"
            >
              Email
            </label>
            <input
              id="auth-email"
              type="email"
              value={email}
              onChange={(e) => setEmail(e.target.value)}
              placeholder="you@example.com"
              autoComplete="email"
              autoFocus
              className="w-full bg-[#111118] border border-gray-800/60 rounded-xl px-4 py-3.5 text-white placeholder-gray-600 focus:outline-none focus:border-[#D4AF37]/50 focus:ring-1 focus:ring-[#D4AF37]/30 transition text-sm"
            />
          </div>

          {/* Password */}
          <div>
            <label
              htmlFor="auth-password"
              className="block text-xs font-medium text-gray-500 mb-1.5 uppercase tracking-wider"
            >
              Password
            </label>
            <input
              id="auth-password"
              type="password"
              value={password}
              onChange={(e) => setPassword(e.target.value)}
              placeholder={mode === "register" ? "At least 6 characters" : "••••••••"}
              autoComplete={mode === "login" ? "current-password" : "new-password"}
              className="w-full bg-[#111118] border border-gray-800/60 rounded-xl px-4 py-3.5 text-white placeholder-gray-600 focus:outline-none focus:border-[#D4AF37]/50 focus:ring-1 focus:ring-[#D4AF37]/30 transition text-sm"
            />
          </div>

          {/* Submit */}
          <button
            type="submit"
            disabled={submitting}
            className="w-full py-3.5 rounded-xl bg-[#D4AF37] text-[#0a0a0f] font-semibold text-sm active:opacity-80 disabled:opacity-50 transition touch-manipulation"
          >
            {submitting ? (
              <span className="flex items-center justify-center gap-2">
                <span className="w-4 h-4 rounded-full border-2 border-[#0a0a0f]/30 border-t-[#0a0a0f] animate-spin" />
                {mode === "login" ? "Signing in..." : "Creating account..."}
              </span>
            ) : mode === "login" ? (
              "Sign In"
            ) : (
              "Create Account"
            )}
          </button>
        </form>

        {/* Toggle mode */}
        <div className="text-center mt-6">
          <p className="text-xs text-gray-600">
            {mode === "login" ? (
              <>
                Don&apos;t have an account?{" "}
                <button
                  type="button"
                  onClick={toggleMode}
                  className="text-[#D4AF37] font-medium hover:underline touch-manipulation"
                >
                  Create one
                </button>
              </>
            ) : (
              <>
                Already have an account?{" "}
                <button
                  type="button"
                  onClick={toggleMode}
                  className="text-[#D4AF37] font-medium hover:underline touch-manipulation"
                >
                  Sign in
                </button>
              </>
            )}
          </p>
        </div>

        {/* New Member Bonus (register only) */}
        {mode === "register" && (
          <div className="mt-6 rounded-xl bg-[#111118] border border-gray-800/60 p-3 text-center">
            <p className="text-xs text-gray-600 uppercase tracking-wider mb-1">
              New Member Bonus
            </p>
            <p className="text-xs text-gray-500">
              Get <span className="text-[#D4AF37] font-semibold">5,000 FLH</span>{" "}
              free on sign up + 7-day premium trial
              {refCode && (
                <>
                  {" "}+{" "}
                  <span className="text-emerald-400 font-semibold">1,000 FLH</span>{" "}
                  referral bonus
                </>
              )}
            </p>
          </div>
        )}

        {/* Demo credentials (subtle) */}
        <div className="mt-6 rounded-xl bg-[#111118]/60 border border-gray-800/40 p-3 text-center">
          <p className="text-xs text-gray-600">
            Demo:{" "}
            <span className="text-gray-500 font-mono">demo@falahos.my</span>{" "}
            <span className="text-gray-600">/</span>{" "}
            <span className="text-gray-500 font-mono">password123</span>
          </p>
        </div>
      </div>
    </div>
  );
}

export default function AuthPage() {
  return (
    <Suspense fallback={
      <div className="min-h-dvh bg-[#0a0a0f] flex items-center justify-center">
        <div className="w-8 h-8 rounded-full border-2 border-[#D4AF37]/30 border-t-[#D4AF37] animate-spin" />
      </div>
    }>
      <AuthPageInner />
    </Suspense>
  );
}