using System;
using System.Collections;
using System.Collections.Generic;
using Firebase;
using Firebase.Auth;
using UnityEngine;
using UnityEngine.SceneManagement;
using UnityEngine.UIElements;

public class LoginManager : MonoBehaviour
{

    public UIDocument uiDocument;

    [Header("Login")]
    Button loginButton;
    Button registerButton;
    TextField username;
    TextField password;
    TextField registerEmailTextField;
    TextField registerPasswordTextField;
    TextField registerPasswordConfirmTextField;
    Label warningText;
    Label registerWarningText;
    private FirebaseAuth auth;
    private FirebaseUser user;
    VisualElement loginPanel;
    VisualElement registerPanel;
    private TextField registerUsernameTextField;
    VisualElement root;

    private void Awake()
    {
        FirebaseApp.CheckAndFixDependenciesAsync().ContinueWith(task =>
        {
            DependencyStatus dependencyStatus = task.Result;
            if (dependencyStatus.Equals(DependencyStatus.Available))
            {
                InitializeFirebase();
            }
            else
            {
                Debug.Log("Could not resolve all Firebase dependencis: " + dependencyStatus);
            }
        });

        root = uiDocument.rootVisualElement;
        loginButton = root.Q<Button>("LoginButton");
        registerButton = root.Q<Button>("RegisterButton");

        username = root.Q<TextField>("UsernameTextField");
        password = root.Q<TextField>("PasswordTextField");
        warningText = root.Q<Label>("WarningText");
        registerWarningText = root.Q<Label>("RegisterWarningText");
        loginPanel = root.Q<VisualElement>("LoginPanel");
        registerPanel = root.Q<VisualElement>("RegisterPanel");

        registerUsernameTextField = root.Q<TextField>("RegisterUsernameTextField");
        registerEmailTextField = root.Q<TextField>("RegisterEmailTextField");
        registerPasswordTextField = root.Q<TextField>("RegisterPasswordTextField");
        registerPasswordConfirmTextField = root.Q<TextField>("RegisterPasswordConfirmTextField");

        loginButton.clicked += () => LoginAction();
        registerButton.clicked += () => ShowRegisterPanel();
        Button registerOKButton = registerPanel.Q<Button>("RegisterOKButton");
        Button RegisterBackButton = registerPanel.Q<Button>("RegisterBackButton");
        RegisterBackButton.clicked += () => ShowLoginPanel();
        registerOKButton.clicked += () => RegisterUserAction();
    }

    private void RegisterUserAction()
    {
        StartCoroutine(Register(registerEmailTextField.text, registerPasswordTextField.text, registerPasswordConfirmTextField.text));
    }

    private void ShowRegisterPanel()
    {
        loginPanel.style.display = DisplayStyle.None;
        registerPanel.style.display = DisplayStyle.Flex;
    }

    private void ShowLoginPanel()
    {
        loginPanel.style.display = DisplayStyle.Flex;
        registerPanel.style.display = DisplayStyle.None;
        registerEmailTextField.value = "Email";
        registerPasswordTextField.value = "Password";
        registerPasswordConfirmTextField.value = "PasswordConfirm";
    }

    private void InitializeFirebase()
    {
        auth = FirebaseAuth.DefaultInstance;
    }

    private void LoginAction()
    {
        StartCoroutine(Login(username.text, password.text));
    }

    private IEnumerator Register(string email, string password, string passwordConfirm)
    {
        if (registerUsernameTextField.text == "" || registerUsernameTextField.text.Equals("Username"))
        {
            registerWarningText.text = "Missing username";
        }
        if (email == "" || email.Equals("Email"))
        {
            registerWarningText.text = "Missing email";
        }
        else if (password != passwordConfirm)
        {
            registerWarningText.text = "Passwords does not match!";
        }
        else if (DatabaseController.Instance.CheckUsername(registerUsernameTextField.text))
        {
            registerWarningText.text = "Username is taken, choose another one";
        }
        else
        {

            var RegisterTask = auth.CreateUserWithEmailAndPasswordAsync(email, password);

            yield return new WaitUntil(predicate: () => RegisterTask.IsCompleted);

            if (RegisterTask.Exception != null)
            {
                FirebaseException firebaseEx = RegisterTask.Exception.GetBaseException() as FirebaseException;
                AuthError errorCode = (AuthError)firebaseEx.ErrorCode;

                string message = "Register Failed!";
                switch (errorCode)
                {
                    case AuthError.MissingEmail:
                        message = "Missing Email";
                        break;
                    case AuthError.MissingPassword:
                        message = "Missing Password";
                        break;
                    case AuthError.WeakPassword:
                        message = "Weak Password";
                        break;
                    case AuthError.EmailAlreadyInUse:
                        message = "Email already in use";
                        break;
                }
                registerWarningText.text = message;
            }
            else
            {
                user = RegisterTask.Result;

                if (user != null)
                {
                    UserProfile profile = new UserProfile { DisplayName = email };

                    var ProfileTask = user.UpdateUserProfileAsync(profile);
                    yield return new WaitUntil(predicate: () => ProfileTask.IsCompleted);

                    if (ProfileTask.Exception != null)
                    {
                        FirebaseException firebaseEx = ProfileTask.Exception.GetBaseException() as FirebaseException;
                        AuthError errorCode = (AuthError)firebaseEx.ErrorCode;
                        registerWarningText.text = "Email set Failed!";
                    }
                    else
                    {
                        DatabaseController.Instance.InsertUser(registerUsernameTextField.text, user.UserId);
                        registerWarningText.text = "";
                        SceneManager.LoadScene("MenuScene");
                    }
                }
            }
        }
        if (registerWarningText.text.Length > 0)
        {
            registerWarningText.style.visibility = Visibility.Visible;
        }
        else
        {
            registerWarningText.style.visibility = Visibility.Hidden;
        }
    }

    private IEnumerator Login(string username, string password)
    {
        var LoginTask = auth.SignInWithEmailAndPasswordAsync(username, password);

        yield return new WaitUntil(predicate: () => LoginTask.IsCompleted);

        if (LoginTask.Exception != null)
        {
            warningText.style.visibility = Visibility.Visible;
            // There is an error, handle it
            Debug.LogWarning(message: $"Failed to register task with {LoginTask.Exception}");
            FirebaseException firebaseEx = LoginTask.Exception.GetBaseException() as FirebaseException;
            AuthError errorCode = (AuthError)firebaseEx.ErrorCode;

            string message = "Login failed!";
            switch (errorCode)
            {
                case AuthError.MissingEmail:
                    message = "Missing email";
                    break;
                case AuthError.MissingPassword:
                    message = "Missing password";
                    break;
                case AuthError.WrongPassword:
                    message = "Wrong password";
                    break;
                case AuthError.InvalidEmail:
                    message = "Invalid email";
                    break;
                case AuthError.UserNotFound:
                    message = "Account does not exist";
                    break;
            }

            warningText.text = message;
        }
        else
        {
            warningText.text = "";
            warningText.style.visibility = Visibility.Hidden;
            user = LoginTask.Result;

            SceneManager.LoadScene("MenuScene");
        }
    }
}