package org.mercury_im.messenger.usecase;

import org.jivesoftware.smack.AbstractXMPPConnection;
import org.jivesoftware.smack.SmackException;
import org.jivesoftware.smack.XMPPException;
import org.jivesoftware.smack.sasl.SASLErrorException;
import org.mercury_im.messenger.Messenger;
import org.mercury_im.messenger.data.repository.AccountRepository;
import org.mercury_im.messenger.entity.Account;
import org.mercury_im.messenger.entity.IAccount;
import org.mercury_im.messenger.xmpp.MercuryConnection;

import java.io.IOException;
import java.util.logging.Level;
import java.util.logging.Logger;

import io.reactivex.Completable;
import io.reactivex.Single;
import io.reactivex.disposables.CompositeDisposable;
import io.reactivex.schedulers.Schedulers;

public class AddAccount {

    private static final Logger LOGGER = Logger.getLogger(AddAccount.class.getName());

    public enum ConnectionResult {
        success,
        credential_error,
        server_error,
        other_error
    }

    private Account account;
    private MercuryConnection connection;

    private final AccountRepository accountRepository;
    private final Messenger messenger;

    private final CompositeDisposable disposable = new CompositeDisposable();

    public AddAccount(AccountRepository accountRepository, Messenger messenger) {
        this.accountRepository = accountRepository;
        this.messenger = messenger;
        this.account = new IAccount();
    }

    public AddAccount setAddress(String address) {
        this.account.setAddress(address);
        return this;
    }

    public AddAccount setPassword(String password) {
        this.account.setPassword(password);
        return this;
    }

    public Completable execute() {
        return loginAndStoreAccountIfSuccessful();
    }

    public Completable loginAndStoreAccountIfSuccessful() {
        return logIntoAccount()
                .andThen(insertEnabledAccountIntoDatabase()).ignoreElement()
                .andThen(addConnectionToMessenger());
    }

    private Single<Account> insertEnabledAccountIntoDatabase() {
        account.setEnabled(true);
        return accountRepository.upsertAccount(account)
                .map(this::updateAccount);
    }

    private Completable addConnectionToMessenger() {
        return Completable.fromAction(() -> messenger.addConnection(connection));
    }

    private Account updateAccount(Account account) {
        this.account = account;
        updateAccountIdInConnection(account);
        return account;
    }

    private void updateAccountIdInConnection(Account account) {
        if (connection != null) {
            connection.getAccount().setId(account.getId());
        }
    }

    private Completable logIntoAccount() {
        return Completable.fromAction(
                () -> {
                    getOrCreateConnection();
                    doAuthenticateIfNecessary();
                })
                .subscribeOn(Schedulers.io());
    }

    private void getOrCreateConnection() {
        connection = messenger.getConnection(account);
        if (connection == null) {
            connection = new MercuryConnection(account);
        }
    }

    private ConnectionResult authenticateIfNecessary() {
        try {
            doAuthenticateIfNecessary();
            return ConnectionResult.success;
        } catch (SASLErrorException e) {
            LOGGER.log(Level.WARNING, "SASL Error while connecting to account " + account.getAddress(), e);
            return ConnectionResult.credential_error;
        } catch (SmackException.ConnectionException e) {
            LOGGER.log(Level.WARNING, "Connectivity error while connecting to account " + account.getAddress(), e);
            return ConnectionResult.server_error;
        }
        catch (IOException | XMPPException | SmackException | InterruptedException e) {
            LOGGER.log(Level.WARNING, "Error connecting to account " + account.getAddress(), e);
            return ConnectionResult.other_error;
        }
    }

    private void doAuthenticateIfNecessary()
            throws InterruptedException, XMPPException, SmackException, IOException {
        if (!connection.getConnection().isAuthenticated()) {
            ((AbstractXMPPConnection) connection.getConnection()).connect().login();
        }
    }
}