/*
 * DSFML - The Simple and Fast Multimedia Library for D
 *
 * Copyright (c) 2013 - 2017 Jeremy DeHaan (dehaan.jeremiah@gmail.com)
 *
 * This software is provided 'as-is', without any express or implied warranty.
 * In no event will the authors be held liable for any damages arising from the
 * use of this software.
 *
 * Permission is granted to anyone to use this software for any purpose,
 * including commercial applications, and to alter it and redistribute it
 * freely, subject to the following restrictions:
 *
 * 1. The origin of this software must not be misrepresented; you must not claim
 * that you wrote the original software. If you use this software in a product,
 * an acknowledgment in the product documentation would be appreciated but is
 * not required.
 *
 * 2. Altered source versions must be plainly marked as such, and must not be
 * misrepresented as being the original software.
 *
 * 3. This notice may not be removed or altered from any source distribution
 */

/**
 * TCP is a connected protocol, which means that a TCP socket can only
 * communicate with the host it is connected to.
 *
 * It can't send or receive anything if it is not connected.
 *
 * The TCP protocol is reliable but adds a slight overhead. It ensures that your
 * data will always be received in order and without errors (no data corrupted,
 * lost or duplicated).
 *
 * When a socket is connected to a remote host, you can retrieve informations
 * about this host with the `getRemoteAddress` and `getRemotePort` functions.
 *
 * You can also get the local port to which the socket is bound (which is
 * automatically chosen when the socket is connected), with the `getLocalPort`
 * function.
 *
 * Sending and receiving data can use either the low-level or the high-level
 * functions. The low-level functions process a raw sequence of bytes, and
 * cannot ensure that one call to Send will exactly match one call to Receive at
 * the other end of the socket.
 *
 * The high-level interface uses packets (see $(PACKET_LINK)), which are easier
 * to use and provide more safety regarding the data that is exchanged. You can
 * look at the $(PACKET_LINK) class to get more details about how they work.
 *
 * The socket is automatically disconnected when it is destroyed, but if you
 * want to explicitely close the connection while the socket instance is still
 * alive, you can call disconnect.
 *
 * Example:
 * ---
 * // ----- The client -----
 *
 * // Create a socket and connect it to 192.168.1.50 on port 55001
 * auto socket = new TcpSocket();
 * socket.connect("192.168.1.50", 55001);
 *
 * // Send a message to the connected host
 * string message = "Hi, I am a client";
 * socket.send(message);
 *
 * // Receive an answer from the server
 * char[1024] buffer;
 * size_t received = 0;
 * socket.receive(buffer, received);
 * writeln("The server said: ", buffer[0 .. received]);
 *
 * // ----- The server -----
 *
 * // Create a listener to wait for incoming connections on port 55001
 * auto listener = TcpListener();
 * listener.listen(55001);
 *
 * // Wait for a connection
 * auto socket = new TcpSocket();
 * listener.accept(socket);
 * writeln("New client connected: ", socket.getRemoteAddress());
 *
 * // Receive a message from the client
 * char[1024] buffer;
 * size_t received = 0;
 * socket.receive(buffer, received);
 * writeln("The client said: ", buffer[0 .. received]);
 *
 * // Send an answer
 * string message = "Welcome, client";
 * socket.send(message);
 * ---
 *
 * See_Also:
 * $(SOCKET_LINK), $(UDPSOCKET_LINK), $(PACKET_LINK)
 */
module dsfml.network.tcpsocket;

import core.time;

import dsfml.network.ipaddress;
import dsfml.network.packet;
import dsfml.network.socket;

import dsfml.system.err;

/**
 * Specialized socket using the TCP protocol.
 */
class TcpSocket:Socket
{
    package sfTcpSocket* sfPtr;

    /// Default constructor.
    this()
    {
        sfPtr = sfTcpSocket_create();
    }

    /// Destructor.
    ~this()
    {
        import dsfml.system.config;
        mixin(destructorOutput);
        sfTcpSocket_destroy(sfPtr);
    }

    /**
     * Get the port to which the socket is bound locally.
     *
     * If the socket is not connected, this function returns 0.
     *
     * Returns: Port to which the socket is bound.
     */
    ushort getLocalPort()
    {
        return sfTcpSocket_getLocalPort(sfPtr);
    }

    /**
     * Get the address of the connected peer.
     *
     * It the socket is not connected, this function returns `IpAddress.None`.
     *
     * Returns: Address of the remote peer.
     */
    IpAddress getRemoteAddress()
    {
        IpAddress temp;

        sfTcpSocket_getRemoteAddress(sfPtr,&temp);

        return temp;
    }

    /**
     * Get the port of the connected peer to which the socket is connected.
     *
     * If the socket is not connected, this function returns 0.
     *
     * Returns: Remote port to which the socket is connected.
     */
    ushort getRemotePort()
    {
        return sfTcpSocket_getRemotePort(sfPtr);
    }

    /**
     * Set the blocking state of the socket.
     *
     * In blocking mode, calls will not return until they have completed their
     * task. For example, a call to `receive` in blocking mode won't return
     * until some data was actually received.
     *
     * In non-blocking mode, calls will always return immediately, using the
     * return code to signal whether there was data available or not. By
     * default, all sockets are blocking.
     *
     * Params:
     *  blocking = true to set the socket as blocking, false for non-blocking
     */
    void setBlocking(bool blocking)
    {
        sfTcpSocket_setBlocking(sfPtr, blocking);
    }

    /**
     * Connect the socket to a remote peer.
     *
     * In blocking mode, this function may take a while, especially if the
     * remote peer is not reachable. The last parameter allows you to stop
     * trying to connect after a given timeout.
     *
     * If the socket was previously connected, it is first disconnected.
     *
     * Params:
     *  host    = Address of the remote peer
     * 	port    = Port of the remote peer
     * 	timeout = Optional maximum time to wait
     *
     * Returns: Status code.
     */
    Status connect(IpAddress host, ushort port, Duration timeout = Duration.zero())
    {
        return sfTcpSocket_connect(sfPtr, &host, port, timeout.total!"usecs");
    }

    /**
     * Disconnect the socket from its remote peer.
     *
     * This function gracefully closes the connection. If the socket is not
     * connected, this function has no effect.
     */
    void disconnect()
    {
        sfTcpSocket_disconnect(sfPtr);
    }

    /**
     * Tell whether the socket is in blocking or non-blocking mode.
     *
     * Returns: true if the socket is blocking, false otherwise.
     */
    bool isBlocking() const
    {
        return (sfTcpSocket_isBlocking(sfPtr));
    }

    /**
     * Send raw data to the remote peer.
     *
     * This function will fail if the socket is not connected.
     *
     * Params:
     * 	data = Sequence of bytes to send
     *
     * Returns: Status code.
     */
    Status send(const(void)[] data)
    {
        import dsfml.system..string;

        Status toReturn = sfTcpSocket_send(sfPtr, data.ptr, data.length);
        err.write(dsfml.system..string.toString(sfErr_getOutput()));
        return toReturn;
    }

    /**
     * Send a formatted packet of data to the remote peer.
     *
     * This function will fail if the socket is not connected.
     *
     * Params:
     * 	packet = Packet to send
     *
     * Returns: Status code.
     */
    Status send(Packet packet)
    {
        import std.stdio;
        //temporary packet to be removed on function exit
        scope SfPacket temp = new SfPacket();

        //getting packet's "to send" data
        temp.append(packet.onSend());

        //send the data
        return sfTcpSocket_sendPacket(sfPtr, temp.sfPtr);
    }

    /**
     * Receive raw data from the remote peer.
     *
     * In blocking mode, this function will wait until some bytes are actually
     * received. This function will fail if the socket is not connected.
     *
     * Params:
     * 	data = Array to fill with the received bytes
     * 	sizeReceived = This variable is filled with the actual number of bytes
                       received
     *
     * Returns: Status code.
     */
    Status receive(void[] data , out size_t sizeReceived)
    {
        return sfTcpSocket_receive(sfPtr, data.ptr, data.length, &sizeReceived);
    }

    /**
     * Receive a formatted packet of data from the remote peer.
     *
     * In blocking mode, this function will wait until the whole packet has been
     * received. This function will fail if the socket is not connected.
     *
     * Params:
     * 	packet = Packet to fill with the received data
     *
     * Returns: Status code.
     */
    Status receive(Packet packet)
    {
        //temporary packet to be removed on function exit
        scope SfPacket temp = new SfPacket();

        //get the sent data
        Status status = sfTcpSocket_receivePacket(sfPtr, temp.sfPtr);

        //put data into the packet so that it can process it first if it wants.
        packet.onRecieve(temp.getData());

        return status;
    }
}

unittest
{
    //TODO: Expand to use more methods in TcpSocket
    version(DSFML_Unittest_Network)
    {
        import std.stdio;
        import dsfml.network.tcplistener;

        writeln("Unittest for Tcp Socket");

        //socket connecting to server
        auto clientSocket = new TcpSocket();

        //listener looking for new sockets
        auto listener = new TcpListener();
        listener.listen(55003);

        //get our client socket to connect to the server
        clientSocket.connect(IpAddress.LocalHost, 55003);

        //packet to send data
        auto sendPacket = new Packet();

        //Packet to receive data
        auto receivePacket = new Packet();

        //socket on the server side connected to the client's socket
        auto serverSocket = new TcpSocket();

        //accepts a new connection and binds it to the socket in the parameter
        listener.accept(serverSocket);

        string temp = "I'm sending you stuff!";

        //Let's greet the server!
        //sendPacket.writeString("Hello, I'm a client!");
        //clientSocket.send(sendPacket);

        clientSocket.send(temp);

        //And get the data on the server side
        //serverSocket.receive(receivePacket);

        char[1024] temp2;
        size_t received;

        serverSocket.receive(temp2, received);

        //What did we get from the client?
        writeln("Gotten from client: ", cast(string)temp2[0..received]);

        //clear the packets to send/get new information
        sendPacket.clear();
        receivePacket.clear();

        //Respond back to the client
        sendPacket.write("Hello, I'm your server.");

        serverSocket.send(sendPacket);

        clientSocket.receive(receivePacket);

        string message;
        receivePacket.read!string(message);
        writeln("Gotten from server: ", message);

        clientSocket.disconnect();
        writeln();
    }
}

package extern(C):

struct sfTcpSocket;

//Create a new TCP socket
sfTcpSocket* sfTcpSocket_create();


//Destroy a TCP socket
void sfTcpSocket_destroy(sfTcpSocket* socket);


//Set the blocking state of a TCP listener
void sfTcpSocket_setBlocking(sfTcpSocket* socket, bool blocking);


//Tell whether a TCP socket is in blocking or non-blocking mode
bool sfTcpSocket_isBlocking(const(sfTcpSocket)* socket);


//Get the port to which a TCP socket is bound locally
ushort sfTcpSocket_getLocalPort(const(sfTcpSocket)* socket);


//Get the address of the connected peer of a TCP socket
void sfTcpSocket_getRemoteAddress(const(sfTcpSocket)* socket, IpAddress* ipAddress);


//Get the port of the connected peer to which a TCP socket is connected
ushort sfTcpSocket_getRemotePort(const(sfTcpSocket)* socket);


//Connect a TCP socket to a remote peer
Socket.Status sfTcpSocket_connect(sfTcpSocket* socket, IpAddress* host, ushort port, long timeout);


//Disconnect a TCP socket from its remote peer
void sfTcpSocket_disconnect(sfTcpSocket* socket);


//Send raw data to the remote peer of a TCP socket
Socket.Status sfTcpSocket_send(sfTcpSocket* socket, const void* data, size_t size);


//Receive raw data from the remote peer of a TCP socket
Socket.Status sfTcpSocket_receive(sfTcpSocket* socket, void* data, size_t maxSize, size_t* sizeReceived);


//Send a formatted packet of data to the remote peer of a TCP socket
Socket.Status sfTcpSocket_sendPacket(sfTcpSocket* socket, sfPacket* packet);


//Receive a formatted packet of data from the remote peer
Socket.Status sfTcpSocket_receivePacket(sfTcpSocket* socket, sfPacket* packet);

const(char)* sfErr_getOutput();