Login Activity

package carel.twee.happyhourapp

import android.content.Intent
import android.os.Bundle
import android.util.Log
import android.view.View
import android.widget.CheckBox
import android.widget.Toast
import androidx.appcompat.app.AppCompatActivity
import com.google.android.gms.auth.api.signin.GoogleSignIn
import com.google.android.gms.auth.api.signin.GoogleSignInOptions
import com.google.android.gms.common.api.ApiException
import com.google.firebase.auth.FirebaseAuth
import com.google.firebase.auth.FirebaseUser
import com.google.firebase.auth.GoogleAuthProvider
import com.google.firebase.auth.ktx.auth
import com.google.firebase.ktx.Firebase

class LoginActivity : AppCompatActivity() {

    private companion object {
        private const val TAG = "LoginActivity"
        private const val RC_GOOGLE_SIGN_IN= 4915
    }

    private lateinit var auth: FirebaseAuth
    private lateinit var checkBox: CheckBox


    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)
        setContentView(R.layout.activity_login)

        auth = Firebase.auth

            // Configure Google Sign In
            val gso = GoogleSignInOptions.Builder(GoogleSignInOptions.DEFAULT_SIGN_IN)
                .requestIdToken(getString(R.string.default_web_client_id))
                .requestEmail()
                .build()
            val client = GoogleSignIn.getClient(this, gso)
            findViewById<View>(R.id.btnSignIn)?.setOnClickListener {
                val signInIntent = client.signInIntent
                startActivityForResult(signInIntent, RC_GOOGLE_SIGN_IN)
            }
    }

    override fun onStart() {
        super.onStart()
        // Check if user is signed in (non-null) and update UI accordingly.
        val currentUser = auth.currentUser
        updateUI(currentUser)
    }

    private fun updateUI(user: FirebaseUser?) {
        //Navigate to MainActivity
        if (user == null){
            Log.w(TAG, "User is null, not going to navigate")
            return
        } else {
            val mCheckBox = findViewById<CheckBox>(R.id.check_box_18)
            if (mCheckBox.isChecked) {
                startActivity(Intent(this, MainActivity::class.java))
                finish()
            } else {
                Toast.makeText(
                    applicationContext,
                    "Please confirm you are 18+ years old",
                    Toast.LENGTH_SHORT
                ).show()
            }
        }

    }

    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)

        // Result returned from launching the Intent from GoogleSignInApi.getSignInIntent(...);
        if (requestCode == RC_GOOGLE_SIGN_IN) {
            val task = GoogleSignIn.getSignedInAccountFromIntent(data)
            try {
                // Google Sign In was successful, authenticate with Firebase
                val account = task.getResult(ApiException::class.java)!!
                Log.d(TAG, "firebaseAuthWithGoogle:" + account.id)
                firebaseAuthWithGoogle(account.idToken!!)
            } catch (e: ApiException) {
                // Google Sign In failed, update UI appropriately
                Log.w(TAG, "Google sign in failed", e)
            }
        }
    }

    private fun firebaseAuthWithGoogle(idToken: String) {
        val credential = GoogleAuthProvider.getCredential(idToken, null)
        auth.signInWithCredential(credential)
            .addOnCompleteListener(this) { task ->
                if (task.isSuccessful) {
                    // Sign in success, update UI with the signed-in user's information
                    Log.d(TAG, "signInWithCredential:success")
                    val user = auth.currentUser
                    updateUI(user)
                } else {
                    // If sign in fails, display a message to the user.
                    Log.w(TAG, "signInWithCredential:failure", task.exception)
                    Toast.makeText(this, "Authentication Failed", Toast.LENGTH_SHORT).show()
                    updateUI(null)
                }
            }
    }
}