import { Request, Response, NextFunction } from "express";
import { createClient } from "@supabase/supabase-js";
import { logger } from "../lib/logger";

let supabaseInstance: any = null;

function getSupabase() {
  if (supabaseInstance) return supabaseInstance;

  const supabaseUrl = process.env.SUPABASE_URL || process.env.VITE_SUPABASE_URL;
  const supabaseAnonKey = process.env.SUPABASE_ANON_KEY || process.env.VITE_SUPABASE_ANON_KEY;

  if (!supabaseUrl || !supabaseAnonKey) {
    logger.warn("Supabase credentials not found. Authentication will fail.");
  }

  supabaseInstance = createClient(supabaseUrl || "", supabaseAnonKey || "");
  return supabaseInstance;
}

declare global {
  namespace Express {
    interface Request {
      user?: {
        id: string;
        email?: string;
      };
    }
  }
}

export const requireAuth = async (req: Request, res: Response, next: NextFunction) => {
  const authHeader = req.headers.authorization;

  if (!authHeader || !authHeader.startsWith("Bearer ")) {
    return res.status(401).json({ error: "Unauthorized: Missing or invalid token" });
  }

  const token = authHeader.split(" ")[1];

  try {
    const supabase = getSupabase();
    const { data: { user }, error } = await supabase.auth.getUser(token);

    if (error || !user) {
      logger.error({ error }, "Error verifying Supabase token");
      return res.status(401).json({ error: "Unauthorized: Invalid token" });
    }

    req.user = {
      id: user.id,
      email: user.email,
    };

    next();
  } catch (error) {
    logger.error({ error }, "Unexpected error verifying token");
    return res.status(500).json({ error: "Internal Server Error" });

  }
};