import React, { useState, useEffect } from "react";
import { apiFetch } from "../utils/apiFetch";

interface UserInfo {
  connected: boolean;
  username: string | null;
}

interface CountResponse {
  name: string;
  count: number;
}

const Counter: React.FC = () => {
  const [userInfo, setUserInfo] = useState<UserInfo | null>(null);
  const [count, setCount] = useState<number>(0);
  const [loading, setLoading] = useState(true);
  const [error, setError] = useState<string | null>(null);
  const [incrementing, setIncrementing] = useState(false);

  useEffect(() => {
    const fetchUserInfo = async () => {
      try {
        setLoading(true);
        const response = await apiFetch("/api/user");
        if (!response.ok) {
          throw new Error(`HTTP error! status: ${response.status}`);
        }
        const data: UserInfo = await response.json();
        setUserInfo(data);
        setError(null);

        // If user is logged in, fetch their count
        if (data.connected) {
          await fetchUserCount();
        }
      } catch (err) {
        setError(
          err instanceof Error ? err.message : "Failed to fetch user info",
        );
        setUserInfo(null);
      } finally {
        setLoading(false);
      }
    };

    fetchUserInfo();
  }, []);

  const fetchUserCount = async () => {
    try {
      const response = await apiFetch("/api/user/count");
      if (!response.ok) {
        throw new Error(`HTTP error! status: ${response.status}`);
      }
      const data: CountResponse = await response.json();
      setCount(data.count);
    } catch (err) {
      console.error("Failed to fetch user count:", err);
      setCount(0);
    }
  };

  const handleIncrement = async () => {
    if (!userInfo?.connected) {
      setError("You must be logged in to increment the counter");
      return;
    }

    try {
      setIncrementing(true);
      setError(null);

      const response = await apiFetch("/api/user/count/increment", {
        method: "POST",
      });

      if (!response.ok) {
        throw new Error(`HTTP error! status: ${response.status}`);
      }

      const data: CountResponse = await response.json();
      setCount(data.count);
    } catch (err) {
      setError(
        err instanceof Error ? err.message : "Failed to increment counter",
      );
    } finally {
      setIncrementing(false);
    }
  };

  // Loading state
  if (loading) {
    return (
      <div className="flex items-center justify-center">
        <div className="animate-spin rounded-full h-4 w-4 border-b-2 border-blue-500"></div>
        <span className="ml-2 text-gray-400 text-base">Loading...</span>
      </div>
    );
  }

  // Not logged in state
  if (!userInfo?.connected) {
    return (
      <div className="text-center">
        <p className="text-gray-400 text-base mb-4">
          Please log in to use the counter
        </p>
      </div>
    );
  }

  return (
    <div className="space-y-4">
      {error && (
        <div className="p-3 bg-red-900/20 border border-red-700 rounded-lg">
          <p className="text-red-400 text-base">{error}</p>
        </div>
      )}

      <button
        onClick={handleIncrement}
        disabled={incrementing}
        className="w-full bg-gradient-to-r from-blue-600 to-blue-700 hover:from-blue-700 hover:to-blue-800 disabled:from-gray-600 disabled:to-gray-700 text-white font-semibold py-4 px-8 rounded-xl border border-transparent hover:border-blue-400 transition-all duration-300 focus:outline-none focus:ring-4 focus:ring-blue-500/50 shadow-lg hover:shadow-xl transform hover:-translate-y-1 disabled:transform-none disabled:hover:shadow-lg relative"
      >
        <div
          className={`flex items-center justify-center space-x-2 transition-opacity duration-200 ${incrementing ? "opacity-0" : "opacity-100"}`}
        >
          Count is {count}
        </div>

        <div
          className={`absolute inset-0 flex items-center justify-center space-x-2 transition-opacity duration-200 ${incrementing ? "opacity-100" : "opacity-0"}`}
        >
          <div className="animate-spin rounded-full h-4 w-4 border-b-2 border-white"></div>
          <span>Incrementing...</span>
        </div>
      </button>

      <p className="text-gray-400 text-sm">
        Logged in as: {userInfo.username || "User"}
      </p>
    </div>
  );
};

export default Counter;