"use client";

import { useSearchParams } from "next/navigation";
import { useRouter } from "next/navigation";
import { Suspense, useEffect, useState } from "react";
import Header from "@/components/Header";
import DestructibleAlert from "@/components/DestructibleAlert";
import BackgroundWrapper from "@/components/BackgroundWrapper";
import { API_URL } from "@/lib/auth";
import { Loader, RefreshCw } from "lucide-react";

interface Mock {
  id: string;
  title: string;
  rating: number;
}

function PaperPageContent() {
  const router = useRouter();
  const searchParams = useSearchParams();
  const name = searchParams.get("name") || "";

  const [questions, setQuestions] = useState<Mock[] | null>(null);
  const [errorMsg, setErrorMsg] = useState<string | null>(null);
  const [refreshing, setRefreshing] = useState<boolean>(false);

  async function fetchMocks() {
    try {
      const questionResponse = await fetch(`${API_URL}/mocks`, {
        method: "GET",
      });
      const fetchedQuestionData: Mock[] = await questionResponse.json();
      setQuestions(fetchedQuestionData);
    } catch (error) {
      setErrorMsg(error instanceof Error ? error.message : "An error occurred");
    }
  }

  useEffect(() => {
    if (name) {
      fetchMocks();
    }
  }, [name]);

  const onRefresh = async () => {
    setRefreshing(true);
    await fetchMocks();
  };

  if (errorMsg) {
    return (
      <BackgroundWrapper>
        <div className="min-h-screen">
          <Header displayTabTitle={name} />
          <div className="overflow-y-auto">
            <div className="mt-5 px-5">
              <DestructibleAlert text={errorMsg} extraStyles="" />
            </div>
            <div className="flex justify-center mt-4">
              <button
                onClick={onRefresh}
                disabled={refreshing}
                className="px-4 py-2 bg-blue-500 text-white rounded hover:bg-blue-600 disabled:opacity-50"
              >
                {refreshing ? <Loader /> : <RefreshCw />}
              </button>
            </div>
          </div>
          {/* <CustomBackHandler fallbackRoute="unit" /> */}
        </div>
      </BackgroundWrapper>
    );
  }

  return (
    <BackgroundWrapper>
      <div>
        <Header displayTabTitle={name} />
        <div className="mx-10 pt-10 overflow-y-auto">
          <div className="border border-[#c0dafc] flex flex-col gap-4 w-full rounded-[25px] p-4">
            {questions ? (
              questions.map((mock) => (
                <div key={mock.id}>
                  <button
                    onClick={() =>
                      router.push(
                        `/exam/pretest?unitname=${name}&id=${mock.id}&title=${mock.title}&rating=${mock.rating}`
                      )
                    }
                    className="w-full border-2 border-[#B0C2DA] py-4 rounded-[10px] px-6 gap-2 text-left hover:bg-gray-50 transition-colors"
                  >
                    <h3 className="text-xl font-medium">{mock.title}</h3>
                    <p className="text-md font-normal">
                      Rating: {mock.rating} / 10
                    </p>
                  </button>
                </div>
              ))
            ) : (
              <div className="flex flex-col items-center justify-center">
                <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-blue-500 mb-4"></div>
                <p className="text-xl font-medium text-center">Loading...</p>
              </div>
            )}
          </div>
          <div className="flex justify-center mt-4">
            <button
              onClick={onRefresh}
              disabled={refreshing}
              className="p-2 bg-blue-500 text-white hover:bg-blue-600 disabled:opacity-50 rounded-full"
            >
              {refreshing ? <Loader /> : <RefreshCw />}
            </button>
          </div>
        </div>
      </div>
      {/* <CustomBackHandler fallbackRoute="unit" useCustomHandler={false} /> */}
    </BackgroundWrapper>
  );
}

export default function PaperScreen() {
  <Suspense
    fallback={
      <BackgroundWrapper>
        <div className="min-h-screen">
          <div className="mx-10 mt-10 flex flex-col justify-center items-center">
            <div className="animate-spin rounded-full h-12 w-12 border-b-2 border-blue-900 mb-4"></div>
            <p className="text-lg font-medium text-gray-900">Loading...</p>
          </div>
        </div>
      </BackgroundWrapper>
    }
  >
    <PaperPageContent />
  </Suspense>;
}