"use client";

import { useSearchParams, useRouter } from "next/navigation";
import { Suspense, useEffect, useState } from "react";
import { LoginForm } from "@/components/auth/login-form";
import { useLanguage } from "@/components/language-provider";

interface Application {
  client_id: string;
  name: string;
  redirect_uris: string[];
}

interface ConsentData {
  application: Application;
  scopes: string[];
  login_url: string;
}

function ConsentContent() {
  const searchParams = useSearchParams();
  const router = useRouter();
  const { lang, dir } = useLanguage();

  const client_id = searchParams.get("client_id") || "";
  const redirect_uri = searchParams.get("redirect_uri") || "";
  const scope = searchParams.get("scope") || "openid";
  const state = searchParams.get("state") || "";
  const nonce = searchParams.get("nonce") || "";
  const code_challenge = searchParams.get("code_challenge") || "";
  const code_challenge_method = searchParams.get("code_challenge_method") || "plain";

  const [consentData, setConsentData] = useState<ConsentData | null>(null);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [token, setToken] = useState<string | null>(null);

  const t = (fa: string, en: string) => (lang === "fa" ? fa : en);

  const fetchConsent = async () => {
    try {
      const storedToken = localStorage.getItem("access_token");
      if (storedToken) {
        setToken(storedToken);
      }

      const params = new URLSearchParams({
        client_id,
        redirect_uri,
        response_type: "code",
        scope,
        state,
        nonce,
        code_challenge,
        code_challenge_method,
      });

      const headers: Record<string, string> = {};
      if (storedToken) {
        headers["Authorization"] = `Bearer ${storedToken}`;
      }

      const res = await fetch(
        `${process.env.NEXT_PUBLIC_API_URL}/oauth/authorize?${params.toString()}`,
        { headers }
      );

      if (res.status === 401) {
        const data = await res.json();
        setConsentData({
          application: data.application || { client_id, name: "", redirect_uris: [redirect_uri] },
          scopes: data.scopes || scope.split(" "),
          login_url: data.login_url,
        });
        setToken(null);
      } else if (res.ok) {
        const data = await res.json();
        setConsentData({
          application: data.application || { client_id, name: "", redirect_uris: [redirect_uri] },
          scopes: data.scopes || scope.split(" "),
          login_url: "",
        });
      }
    } catch (e) {
      setError("خطا در بارگذاری اطلاعات برنامه");
    } finally {
      setLoading(false);
    }
  };

  useEffect(() => {
    fetchConsent();
  }, []);

  const handleConsent = async () => {
    if (!token) return;

    const params = new URLSearchParams({
      client_id,
      redirect_uri,
      response_type: "code",
      scope,
      state,
      nonce,
      code_challenge,
      code_challenge_method,
    });

    const res = await fetch(
      `${process.env.NEXT_PUBLIC_API_URL}/oauth/authorize?${params.toString()}`,
      {
        headers: { Authorization: `Bearer ${token}` },
      }
    );

    if (res.ok) {
      const data = await res.json();
      const code = data.code;
      const redirectParams = new URLSearchParams();
      redirectParams.set("code", code);
      if (state) redirectParams.set("state", state);

      window.location.href = `${redirect_uri}?${redirectParams.toString()}`;
    }
  };

  const handleLogin = (access: string) => {
    setToken(access);
    handleConsent();
  };

  if (loading) {
    return (
      <div className="flex items-center justify-center min-h-screen bg-ink">
        <div className="text-center">
          <div className="animate-spin rounded-full h-8 w-8 border-b-2 border-brand-400 mx-auto"></div>
          <p className="mt-4 text-slate-400">{t("در حال بارگذاری...", "Loading...")}</p>
        </div>
      </div>
    );
  }

  return (
    <div className="min-h-screen bg-ink flex items-center justify-center p-4">
      <div className="w-full max-w-md">
        <div className="rounded-xl border border-white/10 bg-white/[0.02] p-6">
          <h2 className="text-xl font-bold text-white mb-4">
            {t("تایید دسترسی", "Authorize Application")}
          </h2>

          {error && (
            <div className="mb-4 text-sm text-rose-400">{error}</div>
          )}

          {consentData && (
            <div className="space-y-4">
              <div>
                <p className="text-sm text-slate-400">
                  {t("برنامه درخواست دسترسی به:", "This application requests access to:")}
                </p>
                <div className="mt-2 flex items-center gap-3">
                  <span className="flex h-9 w-9 items-center justify-center rounded-full bg-brand-gradient text-xs font-bold text-white">
                    {consentData.application?.name?.charAt(0) || "App"}
                  </span>
                  <div>
                    <div className="font-medium text-white">
                      {consentData.application?.name || client_id}
                    </div>
                    <div className="text-xs text-slate-500">{client_id}</div>
                  </div>
                </div>
              </div>

              <div>
                <p className="text-sm text-slate-400">
                  {t("دسترسی‌های درخواستی:", "Requested permissions:")}
                </p>
                <ul className="mt-2 space-y-1">
                  {consentData.scopes.map((s: string) => (
                    <li key={s} className="text-sm text-slate-300">
                      {s}
                    </li>
                  ))}
                </ul>
              </div>

              {!token ? (
                <LoginForm
                  onSuccess={handleLogin}
                  redirectUri={redirect_uri}
                  state={state}
                />
              ) : (
                <div className="flex gap-3">
                  <button
                    onClick={() => window.location.href = "/"}
                    className="flex-1 rounded-lg border border-white/10 px-4 py-2 text-sm text-slate-300 hover:bg-white/5"
                  >
                    {t("لغو", "Cancel")}
                  </button>
                  <button
                    onClick={handleConsent}
                    className="flex-1 rounded-lg bg-brand-gradient px-4 py-2 text-sm font-medium text-white hover:brightness-110"
                  >
                    {t("تایید", "Authorize")}
                  </button>
                </div>
              )}
            </div>
          )}
        </div>
      </div>
    </div>
  );
}

export default function ConsentPage() {
  return (
    <Suspense fallback={<div className="flex items-center justify-center min-h-screen bg-ink"><div className="text-slate-400">Loading...</div></div>}>
      <ConsentContent />
    </Suspense>
  );
}