DrawYourPath/DrawYourPath

package com.epfl.drawyourpath.login

import android.app.Activity
import android.content.Intent
import android.os.Bundle
import android.util.Log
import android.widget.Toast
import androidx.activity.viewModels
import androidx.annotation.LayoutRes
import androidx.appcompat.app.AppCompatActivity
import androidx.fragment.app.Fragment
import androidx.fragment.app.activityViewModels
import androidx.fragment.app.commit
import androidx.fragment.app.replace
import com.epfl.drawyourpath.R
import com.epfl.drawyourpath.authentication.*
import com.epfl.drawyourpath.mainpage.MainActivity
import com.epfl.drawyourpath.userProfileCreation.UserProfileCreationActivity

const val LOG_LOGIN_KEY = "DYP_Login"

/**
 * Base class for any fragment displayed in the login activity.
 */
abstract class LoginActivityFragment(@LayoutRes layout: Int) : Fragment(layout) {
    protected val viewModel: LoginViewModel by activityViewModels()
    protected inline fun <reified T> getLoginActivity(): T {
        return activity as T
    }
}

fun launchLoginActivity(activity: Activity) {
    val intent = Intent(activity, LoginActivity::class.java)
    activity.startActivity(intent)
}

/**
 * Class used to display an authentication UI to the user and perform the auth
 * operations through the Auth object.
 */
class LoginActivity :
    AppCompatActivity(R.layout.activity_login),
    RegisterActivityListener,
    LoginActivityListener {
    private val viewModel: LoginViewModel by viewModels()

    // The auth object used to authenticate the user.
    private lateinit var auth: Auth

    // If we should use onetap sign-in when the login activity is launched
    // Can be controlled with ENABLE_ONETAP_SIGNIN in the intent.
    private var useOneTapSignIn: Boolean = true

    // If we should restore user information from the keychain to automatically
    // log the user in.
    // Can be controlled with RESTORE_USER_IN_KEYCHAIN in the intent.
    private var restoreUserFromKeychain: Boolean = true

    override fun onCreate(savedInstanceState: Bundle?) {
        super.onCreate(savedInstanceState)

        // Overwrites the one tap sign-in behavior if set in the intent.
        useOneTapSignIn = intent.getBooleanExtra(ENABLE_ONETAP_SIGNIN, useOneTapSignIn)

        // Overwrites the user keychain restoration behavior if set in the intent.
        restoreUserFromKeychain =
            intent.getBooleanExtra(RESTORE_USER_IN_KEYCHAIN, restoreUserFromKeychain)

        // Creates the auth object depending on the mock data in the intent.
        auth = createAuth(intent.extras, false, restoreUserFromKeychain)

        auth.onActivityCreate(this, savedInstanceState)

        viewModel.setViewListener { view ->
            when (view) {
                ELoginView.Register -> showRegisterUI()
                ELoginView.Login -> showLoginUI()
            }
        }

        // When the user changed. i.e. signed out or signed in.
        auth.onAuthStateChanged { _, _ ->
        }

        showRegisterUI()
    }

    override fun onStart() {
        super.onStart()

        // If a user is available now, it was restored from keychain.
        if (restoreUserFromKeychain && auth.getUser() != null) {
            Log.i(LOG_LOGIN_KEY, "User restored from keychain.")
            openMainMenu()
        }

        // Otherwise, we try a one-tap sign-in.
        else if (useOneTapSignIn) {
            Log.i(LOG_LOGIN_KEY, "Attempting One-Tap Sign-In.")
            auth.launchOneTapGoogleSignIn(this) { _, error ->
                when (error) {
                    null -> openMainMenu()
                }
            }
        }
    }

    override fun onDestroy() {
        auth.clearListener()

        super.onDestroy()
    }

    /**
     * @note The non-deprecated way doesn't catch results of Google Sign-In.
     */
    @Deprecated("Deprecated in Java")
    override fun onActivityResult(requestCode: Int, resultCode: Int, data: Intent?) {
        super.onActivityResult(requestCode, resultCode, data)
        auth.onActivityResult(this, requestCode, resultCode, data)
    }

    private fun showLoginUI() {
        switchFragment<LoginActions>()
    }

    private fun showRegisterUI() {
        switchFragment<RegisterActions>()
    }

    private inline fun <reified T : LoginActivityFragment> switchFragment() {
        supportFragmentManager.commit {
            // setCustomAnimations(R.anim.slide_in, R.anim.slide_out)
            replace<T>(R.id.fragment_container_view)
        }
    }

    private fun openAccountRegistration() {
        val registrationScreen = Intent(this, UserProfileCreationActivity::class.java)
        this.startActivity(registrationScreen)
    }

    private fun openMainMenu() {
        val mainMenuIntent = Intent(this, MainActivity::class.java)
        mainMenuIntent.putExtra(MainActivity.EXTRA_USER_ID, auth.getUser()?.getUid())
        this.startActivity(mainMenuIntent)
    }

    private fun showError(error: java.lang.Exception) {
        Log.w("Login", "Error: ${error.localizedMessage}")
        Toast.makeText(applicationContext, error.localizedMessage, Toast.LENGTH_LONG).show()
    }

    private fun onRegistrationResult(user: User?, error: Exception?) {
        when (error) {
            null -> {
                Log.i("Login", "Registered, redirecting to main activity.")
                openAccountRegistration()
            }
            else -> showError(error)
        }
    }

    private fun onLoginResult(user: User?, error: Exception?) {
        when (error) {
            null -> {
                Log.i("Login", "Logged in, redirecting to main activity.")
                openMainMenu()
            }
            else -> showError(error)
        }
    }

    override fun registerWithGoogle() {
        Log.i("Login", "Trying to register with Google.")
        auth.registerWithGoogle(this) { user, error -> onRegistrationResult(user, error) }
    }

    override fun registerAnonymously() {
        Log.i("Login", "Trying to login anonymously.")
        auth.loginAnonymously { user, error -> onRegistrationResult(user, error) }
    }

    override fun loginWithGoogle() {
        Log.i("Login", "Trying to login with Google.")
        auth.loginWithGoogle(this) { user, error -> onLoginResult(user, error) }
    }

    override fun loginWithEmailAndPassword(email: String, password: String) {
        Log.i("Login", "Trying to login with email.")
        auth.loginWithEmail(email, password) { user, error -> onLoginResult(user, error) }
    }

    override fun registerWithEmailAndPassword(email: String, password: String) {
        Log.i("Login", "Trying to register with email.")
        auth.registerWithEmail(email, password) { user, error -> onRegistrationResult(user, error) }
    }
}