tmp.js

const [loginState,setLoginState]=useState();
const checkUser = async()=>{
    const {data}= await supabase.from("users").select("*")
    console.log(`data`,data)
}
const login = async() => {
    setLoginState("Connecting to your wallet...");
    if(!window.ethereum){
        setLoginState("No MetaMask wallet ... Please install it");
        return;
    }
    const provider = new ethers.provider.Web3Provider(window.ethereum);
    await provider.send("eth_requestAccounts",[]);
    const signer = provider.getSigner();
    const walletAddr=await signer.getAddress();
    setLoginState("Generating nonce...");
    console.log(`walletAddr`, walletAddr)

    let response =await fetch("/api/auth/nonce",{
        method:"POST",
        body: JSON.stringify({
            walletAddr,
        }),
        headers:{
            "Content-Type":"application/json"
        }
    })

    const {nonce}=await response.json();
    setLoginState("Please sign the nonce...");
    const signature=await signer.signMessage(nonce);
    console.log(`signature`,signature)
    
    response = await fetch("/api/auth/wallet",{
        method:"POST",
        body:JSON.stringify({
            walletAddr,
            nonce,
            signature,
        }),
        headers:{
            "Content-Type":"application/json"
        }
    })
    setLoginState("Login completed");
    const data=await response.json();
    console.log(`data`,data)
}

const walletApi = async(req,res)=>{
    try{
        const { walletAddr,signature,nonce} = req.body;
        const signerAddr=ethers.utils.verifyMessage(nonce, signature);

        if ( signerAddr!==walletAddr){
            throw new Error ("wrong_signature");
        }
        let {data:user,error}= await supabase
            .from('user')
            .select('*')
            .eq('walletAddr',walletAddr)
            .eq('nonce',nonce)
            .single()


        const token = jwt.sign({
            "aud": "authenticated",
            "exp":Math.floor((Date.now() /1000) + (60*60)),
            "sub" : user.id,
            "user_metadata":{
                id:user.id,
            },
            "role":"authenticated"
        }, process.env.SUPABASE_JWT_SECRET);
        res.status(200).json({user,token});
    } catch(err){
        res.status(400).json({error: err.message});
    }
}


const nonceApi=async(req,res)=>{
    const {walletAddr} = req.body;
    const nonce = uuidv4();
    let {data,error}=await supabase
        .from('users')
        .select('nonce')
        .eq('walletAddr',walletAddr)

    if(data.length>0){
        let {data,error}=await supabase.from('users').update({nonce}).match({walletAddr})
    } else{
        let{data,error}=await supabase.from('users').insert({nonce,walletAddr})
    }
    console.log(`error`,error);
    console.log(`data`,data);
    if(error){
        res.status(400).json({error:error.message})
    }else{
        res.status(200).json({nonce})
    }
}