"use client";

import Link from "next/link";
import { useRouter, useSearchParams } from "next/navigation";
import { Suspense, useState } from "react";
import { PageSchema } from "../../components/page-schema";
import { SiteFooter } from "../../components/site-footer";
import { SiteHeader } from "../../components/site-header";
import { defaultFaqs } from "../../data/faq";
import { siteInfo } from "../../data/site";
import { storeAuthTokens } from "@/lib/api";

type ApiResponse<T> = {
  data: T;
  meta: { timestamp: string; version: "v1" };
  error: null | { message: string; code?: string };
};

type AuthData = {
  user: { id: string; email: string; fullName?: string; emailVerified?: boolean };
  accessToken: string;
  refreshToken: string;
  requiresTwoFactor?: boolean;
};

function LoginForm() {
  const router = useRouter();
  const searchParams = useSearchParams();
  const nextPath = searchParams.get("next") ?? "/app";

  const [email, setEmail] = useState("");
  const [password, setPassword] = useState("");
  const [totpToken, setTotpToken] = useState("");
  const [requiresTwoFactor, setRequiresTwoFactor] = useState(false);
  const [status, setStatus] = useState<string>("");
  const [isError, setIsError] = useState(false);

  const onSubmit = async (event: React.FormEvent) => {
    event.preventDefault();
    setStatus("Signing in...");
    setIsError(false);
    try {
      const res = await fetch("/api/auth/login", {
        method: "POST",
        headers: { "Content-Type": "application/json" },
        body: JSON.stringify({ email, password, ...(requiresTwoFactor ? { totpToken } : {}) }),
      });
      const payload = (await res.json()) as ApiResponse<AuthData>;
      if (!res.ok || payload.error) {
        setStatus(payload.error?.message ?? "Login failed.");
        setIsError(true);
        return;
      }

      if (payload.data.requiresTwoFactor) {
        setRequiresTwoFactor(true);
        setStatus("Enter the code from your authenticator app.");
        return;
      }

      storeAuthTokens({
        accessToken: payload.data.accessToken,
        refreshToken: payload.data.refreshToken,
        user: payload.data.user,
      });
      setStatus(`Welcome back, ${payload.data.user.email}`);
      router.push(nextPath);
    } catch {
      setStatus("Login failed. Please try again.");
      setIsError(true);
    }
  };

  return (
    <form className="space-y-6" onSubmit={onSubmit}>
      <div>
        <label htmlFor="email" className="block text-sm font-medium text-foreground">
          Email address
        </label>
        <div className="mt-1">
          <input
            id="email" name="email" type="email" autoComplete="email" required
            value={email} onChange={(e) => setEmail(e.target.value)}
            className="block w-full appearance-none rounded-lg border border-border bg-background/50 px-3 py-2 placeholder-muted-foreground shadow-sm focus:border-primary focus:outline-none focus:ring-primary sm:text-sm transition-all"
          />
        </div>
      </div>

      <div>
        <label htmlFor="password" className="block text-sm font-medium text-foreground">
          Password
        </label>
        <div className="mt-1">
          <input
            id="password" name="password" type="password" autoComplete="current-password" required
            value={password} onChange={(e) => setPassword(e.target.value)}
            className="block w-full appearance-none rounded-lg border border-border bg-background/50 px-3 py-2 placeholder-muted-foreground shadow-sm focus:border-primary focus:outline-none focus:ring-primary sm:text-sm transition-all"
          />
        </div>
      </div>

      {requiresTwoFactor && (
        <div>
          <label htmlFor="totp" className="block text-sm font-medium text-foreground">
            Authenticator Code
          </label>
          <div className="mt-1">
            <input
              id="totp" name="totp" type="text" inputMode="numeric" maxLength={6}
              placeholder="6-digit code" autoComplete="one-time-code" required
              value={totpToken} onChange={(e) => setTotpToken(e.target.value.replace(/\D/g, ""))}
              className="block w-full appearance-none rounded-lg border border-border bg-background/50 px-3 py-2 placeholder-muted-foreground shadow-sm focus:border-primary focus:outline-none focus:ring-primary sm:text-sm transition-all tracking-widest text-center"
            />
          </div>
        </div>
      )}

      <div>
        <button
          type="submit"
          className="flex w-full justify-center rounded-lg border border-transparent bg-primary py-2.5 px-4 text-sm font-bold text-primary-foreground shadow-sm hover:bg-primary/90 focus:outline-none focus:ring-2 focus:ring-primary focus:ring-offset-2 transition-all hover:-translate-y-0.5"
        >
          {requiresTwoFactor ? "Verify" : "Sign in"}
        </button>
      </div>

      <div className="text-center">
        <Link href="/forgot-password" className="text-sm text-muted-foreground hover:text-primary transition-colors">
          Forgot your password?
        </Link>
      </div>

      {status && (
        <div className={`mt-4 rounded-lg p-4 ${isError ? "bg-red-500/10 border border-red-500/20" : "bg-accent/10 border border-accent/20"}`}>
          <p className="text-sm font-medium text-center">{status}</p>
        </div>
      )}
    </form>
  );
}

export default function LoginPage() {
  const schema = [
    {
      "@context": "https://schema.org",
      "@type": "WebPage",
      name: "LedgerOne Login",
      description: "Sign in to LedgerOne to access your audit-ready ledger.",
      url: `${siteInfo.url}/login`,
    },
    {
      "@context": "https://schema.org",
      "@type": "FAQPage",
      mainEntity: defaultFaqs.map((item) => ({
        "@type": "Question",
        name: item.question,
        acceptedAnswer: { "@type": "Answer", text: item.answer },
      })),
    },
  ];

  return (
    <div className="min-h-screen bg-background font-sans text-foreground">
      <SiteHeader />
      <div className="flex min-h-full flex-col justify-center py-12 sm:px-6 lg:px-8 mt-16 relative">
        <div className="absolute inset-0 mesh-gradient -z-10 opacity-30" />
        <div className="sm:mx-auto sm:w-full sm:max-w-md">
          <div className="flex justify-center">
            <div className="h-12 w-12 rounded-xl bg-primary flex items-center justify-center text-primary-foreground font-bold text-xl shadow-glow-teal">
              L1
            </div>
          </div>
          <h2 className="mt-6 text-center text-3xl font-bold tracking-tight text-foreground">
            Sign in to your account
          </h2>
          <p className="mt-2 text-center text-sm text-muted-foreground">
            Or{" "}
            <Link href="/register" className="font-medium text-primary hover:text-primary/80 transition-colors">
              start your 14-day free trial
            </Link>
          </p>
        </div>
        <div className="mt-8 sm:mx-auto sm:w-full sm:max-w-md">
          <div className="glass-panel py-8 px-4 shadow-xl sm:rounded-xl sm:px-10">
            <Suspense fallback={null}>
              <LoginForm />
            </Suspense>
          </div>
        </div>
      </div>
      <SiteFooter />
      <PageSchema schema={schema} />
    </div>
  );
}
