#include "server.h"
#include "network/tcp-chat-protocol/v1.h"

void ClientConnection_close(ClientConnection* conn){
    if(conn == NULL)
        return;
    EncryptedSocketTCP_destroy(&conn->sock);
    free(conn->session_key.data);
    free(conn);
}

Result(ClientConnection*) ClientConnection_accept(ServerCredentials* server_credentials, 
    Socket sock_tcp, EndpointIPv4 client_end, u64 session_id)
{
    Deferral(32);

    ClientConnection* conn = (ClientConnection*)malloc(sizeof(ClientConnection));
    memset(conn, 0, sizeof(*conn));
    bool success = false;
    Defer(
        if(!success)
            ClientConnection_close(conn);
    );

    conn->client_end = client_end;
    conn->session_id = session_id;
    conn->session_key = Array_alloc_size(AES_SESSION_KEY_SIZE);
    // correct session key will be received from client later
    Array_memset(conn->session_key, 0);
    EncryptedSocketTCP_construct(&conn->sock, sock_tcp, NETWORK_BUFFER_SIZE, conn->session_key);
    try_void(socket_TCP_enableAliveChecks_default(sock_tcp));
    
    // decrypt the rsa messages using server private key
    RSADecryptor rsa_dec;
    RSADecryptor_construct(&rsa_dec, &server_credentials->rsa_sk);

    // receive PacketHeader
    PacketHeader packet_header = {0};
    try_void(EncryptedSocketTCP_recvStructRSA(&conn->sock, &rsa_dec, &packet_header));
    try_void(PacketHeader_validateMagic(&packet_header));
    try_void(PacketHeader_validateType(&packet_header, PacketType_ClientHandshake));
    try_void(PacketHeader_validateContentSize(&packet_header, sizeof(ClientHandshake)));

    // receive ClientHandshake
    ClientHandshake client_handshake = {0};
    try_void(EncryptedSocketTCP_recvStructRSA(&conn->sock, &rsa_dec, &client_handshake));

    // use received session key
    memcpy(conn->session_key.data, client_handshake.session_key, conn->session_key.size);
    EncryptedSocketTCP_changeKey(&conn->sock, conn->session_key);
    
    // send PacketHeader and ServerHandshake over encrypted TCP socket
    ServerHandshake server_handshake = {0};
    ServerHandshake_construct(&server_handshake, &packet_header,
        session_id);
    try_void(EncryptedSocketTCP_sendStruct(&conn->sock, &packet_header));
    try_void(EncryptedSocketTCP_sendStruct(&conn->sock, &server_handshake));

    success = true;
    Return RESULT_VALUE(p, conn);
}