/*
  Copyright (c) Tőkés Attila (bluetiger9)

  Released under LGPL 2.0
*/

#include "smtpclient.h"

#include <QFileInfo>
#include <QByteArray>


/* [1] Constructors and destructors */

SmtpClient::SmtpClient(QString host, int port, ConnectionType ct) :
    authMethod(AuthPlain),
    connectionTimeout(5000),
    responseTimeout(5000)
{
    if (ct == TcpConnection)
        this->useSsl = false;
    else if (ct == SslConnection)
        this->useSsl = true;

    if (useSsl == false)
        socket = new QTcpSocket(this);
    else
        socket = new QSslSocket(this);

    this->host = host;
    this->port = port;

    connect(socket, SIGNAL(stateChanged(QAbstractSocket::SocketState)),
            this, SLOT(socketStateChanged(QAbstractSocket::SocketState)));
    connect(socket, SIGNAL(error(QAbstractSocket::SocketError)),
            this, SLOT(socketError(QAbstractSocket::SocketError)));
    connect(socket, SIGNAL(readyRead()),
            this, SLOT(socketReadyRead()));
}

SmtpClient::~SmtpClient() {}

/* [1] --- */


/* [2] Getters and Setters */

void SmtpClient::setUser(const QString &user)
{
    this->user = user;
}

void SmtpClient::setPassword(const QString &password)
{
    this->password = password;
}

void SmtpClient::setAuthMethod(AuthMethod method)
{
    this->authMethod = method;
}

void SmtpClient::setHost(QString &host)
{
    this->host = host;
}

void SmtpClient::setPort(int port)
{
    this->port = port;
}

void SmtpClient::setConnectionType(ConnectionType ct)
{
    if (ct == TcpConnection)
        this->useSsl = false;
    else if (ct == SslConnection)
        this->useSsl = true;

    if (useSsl == false)
        socket = new QTcpSocket(this);
    else
        socket = new QSslSocket(this);
}

const QString& SmtpClient::getHost() const
{
    return this->host;
}

const QString& SmtpClient::getUser() const
{
    return this->user;
}

const QString& SmtpClient::getPassword() const
{
    return this->password;
}

SmtpClient::AuthMethod SmtpClient::getAuthMethod() const
{
    return this->authMethod;
}

int SmtpClient::getPort() const
{
    return this->port;
}

SmtpClient::ConnectionType SmtpClient::getConnectionType() const
{
    if (useSsl)
        return SslConnection;
    else
        return TcpConnection;
}

/* [2] --- */


/* [3] Public methods */

bool SmtpClient::connectToHost()
{
    if (useSsl)
        ((QSslSocket*) socket)->connectToHostEncrypted(host, port);
    else
        socket->connectToHost(host, port);

    // Tries to connect to server
    if (!socket->waitForConnected(connectionTimeout))
    {
        emit smtpError(ConnectionTimeoutError);
        return false;
    }

    try
    {
        // Wait for the server's response
        waitForResponse();

        // If the response code is not 220 (Service ready)
        // means that is something wrong with the server
        if (responseCode != 220)
        {
            emit smtpError(ServerError);
            return false;
        }

        // Send a EHLO/HELO message to the server
        // The client's first command must be EHLO/HELO
        sendMessage("EHLO SmtpClient for Qt/C++");

        // Wait for the server's response
        waitForResponse();

        // The response code needs to be 250.
        if (responseCode != 250)
        {
            emit smtpError(ServerError);
            return false;
        }
    }
    catch (ResponseTimeoutException)
    {
        return false;
    }

    // If no errors occured the function returns true.
    return true;
}

bool SmtpClient::login()
{
    return login(user, password, authMethod);
}

bool SmtpClient::login(const QString &user, const QString &password, AuthMethod method)
{
    try {
        if (method == AuthPlain)
        {
            // Sending command: AUTH PLAIN base64('\0' + username + '\0' + password)
            sendMessage("AUTH PLAIN " + QByteArray().append((char) 0).append(user).append((char) 0).append(password).toBase64());

            // Wait for the server's response
            waitForResponse();

            // If the response is not 235 then the authification was faild
            if (responseCode != 235)
            {
                emit smtpError(AuthentificationFailedError);
                return false;
            }
        }
        else if (method == AuthLogin)
        {
            // Sending command: AUTH LOGIN
            sendMessage("AUTH LOGIN");

            // Wait for 334 response code
            waitForResponse();
            if (responseCode != 334) { emit smtpError(AuthentificationFailedError); return false; }

            // Send the username in base64
            sendMessage(QByteArray().append(user).toBase64());

            // Wait for 334
            waitForResponse();
            if (responseCode != 334) { emit smtpError(AuthentificationFailedError); return false; }

            // Send the password in base64
            sendMessage(QByteArray().append(password).toBase64());

            // Wait for the server's responce
            waitForResponse();

            // If the response is not 235 then the authification was faild
            if (responseCode != 235)
            {
                emit smtpError(AuthentificationFailedError);
                return false;
            }
        }
    }
    catch (ResponseTimeoutException e)
    {
        // Responce Timeout exceeded
        emit smtpError(AuthentificationFailedError);
        return false;
    }

    return true;
}

bool SmtpClient::sendMail(MimeMessage& email)
{
    try
    {
        // Send the MAIL command with the sender
        sendMessage("MAIL FROM: <" + email.getSender().getAddress() + ">");

        waitForResponse();

        if (responseCode != 250) return false;

        // Send RCPT command for each recipient
        for (int i = 0; i < email.getRecipients().size(); ++i)
        {
            sendMessage("RCPT TO: <" + email.getRecipients().at(i)->getAddress() + ">");
            waitForResponse();

            if (responseCode != 250) return false;
        }

        // Send DATA command
        sendMessage("DATA");
        waitForResponse();

        if (responseCode != 354) return false;

        sendMessage(email.toString());

        // Send \n.\n to end the mail data
        sendMessage(".");

        waitForResponse();

        if (responseCode != 250) return false;
    }
    catch (ResponseTimeoutException)
    {
        return false;
    }

    return true;
}

void SmtpClient::quit()
{
    sendMessage("QUIT");
}

/* [3] --- */


/* [4] Protected methods */

void SmtpClient::waitForResponse() throw (ResponseTimeoutException)
{
    if (!socket->waitForReadyRead(responseTimeout))
    {
        emit smtpError(ResponseTimeoutError);
        throw ResponseTimeoutException();
    }

    // Save the server's response
    responseText = socket->readAll();

    // Extract the respose code from the server's responce (first 3 digits)
    responseCode = responseText.left(3).toInt();

    if (responseCode / 100 == 4)
        emit smtpError(ServerError);

    if (responseCode / 100 == 5)
        emit smtpError(ClientError);
}

void SmtpClient::sendMessage(const QString &text)
{
    socket->write(text.toUtf8() + "\r\n");
}

/* [4] --- */


/* [5] Slots for the socket's signals */

void SmtpClient::socketStateChanged(QAbstractSocket::SocketState state)
{
}

void SmtpClient::socketError(QAbstractSocket::SocketError socketError)
{
}

void SmtpClient::socketReadyRead()
{
}

/* [5] --- */