#include "ua_server.h"
#include "ua_services.h"
#include "ua_statuscodes.h"

static void processHello(UA_Connection *connection, const UA_ByteString *msg,
                         UA_UInt32 *pos) {
    UA_UInt32 tmpPos = 0;
    UA_OPCUATcpHelloMessage helloMessage;

    if(connection->state != UA_CONNECTION_OPENING) {
        // multiple HEL are not allowed
        connection->close(connection->callbackHandle);
        return;
    }

    UA_OPCUATcpHelloMessage_decodeBinary(msg, pos, &helloMessage);
    connection->remoteConf.maxChunkCount   = helloMessage.maxChunkCount;
    connection->remoteConf.maxMessageSize  = helloMessage.maxMessageSize;
    connection->remoteConf.protocolVersion = helloMessage.protocolVersion;
    connection->remoteConf.recvBufferSize  = helloMessage.receiveBufferSize;
    connection->remoteConf.sendBufferSize  = helloMessage.sendBufferSize;

    connection->state = UA_CONNECTION_ESTABLISHED;

    // build acknowledge response
    UA_OPCUATcpMessageHeader ackHeader;
    ackHeader.messageType = UA_MESSAGETYPE_ACK;
    ackHeader.isFinal     = 'F';

    UA_OPCUATcpAcknowledgeMessage ackMessage;
    ackMessage.protocolVersion   = connection->localConf.protocolVersion;
    ackMessage.receiveBufferSize = connection->localConf.recvBufferSize;
    ackMessage.sendBufferSize    = connection->localConf.sendBufferSize;
    ackMessage.maxMessageSize    = connection->localConf.maxMessageSize;
    ackMessage.maxChunkCount     = connection->localConf.maxChunkCount;

    ackHeader.messageSize = UA_OPCUATcpAcknowledgeMessage_calcSizeBinary(&ackMessage) +
                            UA_OPCUATcpMessageHeader_calcSizeBinary(&ackHeader);
    UA_ByteString *ack_msg;
    UA_alloc((void **)&ack_msg, sizeof(UA_ByteString));
    UA_ByteString_newMembers(ack_msg, ackHeader.messageSize);
    tmpPos = 0;
    UA_OPCUATcpMessageHeader_encodeBinary(&ackHeader, ack_msg, &tmpPos);
    UA_OPCUATcpAcknowledgeMessage_encodeBinary(&ackMessage, ack_msg, &tmpPos);
    UA_ByteStringArray answer_buf = { .stringsSize = 1, .strings = ack_msg };
    connection->write(connection->callbackHandle, &answer_buf);
    UA_ByteString_delete(ack_msg);
}

static void processOpen(UA_Connection *connection, UA_Server *server,
                        const UA_ByteString *msg, UA_UInt32 *pos) {
    UA_UInt32 secureChannelId;
    if(connection->state != UA_CONNECTION_ESTABLISHED) {
        if(connection->state == UA_CONNECTION_OPENING)
            connection->close(connection->callbackHandle);
        return;
    }

    UA_UInt32_decodeBinary(msg, pos, &secureChannelId);
    // needs asym encoding for returning
    // call the service!!!!
    /* if(connection->channel != UA_NULL) { */
    /*  //create new channel */
    /*  SL_Channel *newChannel; */
    /*  retval |= SL_ChannelManager_generateChannel(cm, ) */
    /*  retval |= SL_ProcessOpenChannel(newChannel, server, msg, pos); */
    /*  retval |= SL_Channel_bind(newChannel, connection); */
    /*  return retval; */
    /* } */
    /* // channel already exists, renew token? */
    /* retval |= SL_ProcessOpenChannel(channel, server, msg, pos); */
    /* return retval; */
}

static void init_response_header(UA_RequestHeader const *p, UA_ResponseHeader *r) {
    r->requestHandle   = p->requestHandle;
    r->serviceResult   = UA_STATUSCODE_GOOD;
    r->stringTableSize = 0;
    r->timestamp       = UA_DateTime_now();
}

#define CHECK_PROCESS(CODE, CLEANUP) \
    do {                             \
        if(CODE != UA_SUCCESS) {     \
            CLEANUP;                 \
            goto clean_up;           \
        } } while(0)

#define INVOKE_SERVICE(TYPE) do {                                                                         \
        UA_##TYPE##Request p;                                                                             \
        UA_##TYPE##Response r;                                                                            \
        UA_Session *session = UA_NULL;                                                                    \
        CHECK_PROCESS(UA_##TYPE##Request_decodeBinary(msg, pos, &p),; );                                  \
        UA_##TYPE##Response_init(&r);                                                                     \
        init_response_header(&p.requestHeader, &r.responseHeader);                                        \
        UA_SessionManager_getSessionByToken(server->sessionManager, &p.requestHeader.authenticationToken, \
                                            &session);                                                    \
        DBG_VERBOSE(printf("Invoke Service: %s\n", # TYPE));                                              \
        Service_##TYPE(server, session, &p, &r);                                                          \
        DBG_VERBOSE(printf("Finished Service: %s\n", # TYPE));                                            \
        UA_ByteString_newMembers(&responseBuf.strings[1], UA_##TYPE##Response_calcSizeBinary(&r));        \
        UA_##TYPE##Response_encodeBinary(&r, &responseBuf.strings[1], &sendOffset);                       \
        UA_##TYPE##Request_deleteMembers(&p);                                                             \
        UA_##TYPE##Response_deleteMembers(&r);                                                            \
        responseType = requestType.nodeId.identifier.numeric + 3;                                         \
} while(0)

static void processMessage(UA_Connection *connection, UA_Server *server,
                           const UA_ByteString *msg, UA_UInt32 *pos) {
    // 1) Read in the securechannel
    UA_UInt32 secureChannelId;
    UA_UInt32_decodeBinary(msg, pos, &secureChannelId);
    UA_SecureChannel *channel;
    UA_SecureChannelManager_get(server->secureChannelManager, secureChannelId, &channel);

    // 2) Read the security header
    UA_UInt32 tokenId;
    UA_UInt32_decodeBinary(msg, pos, &tokenId);
    UA_SequenceHeader sequenceHeader;
    CHECK_PROCESS(UA_SequenceHeader_decodeBinary(msg, pos, &sequenceHeader),; );
    //UA_SecureChannel_checkSequenceNumber(channel,sequenceHeader.sequenceNumber);
    //UA_SecureChannel_checkRequestId(channel,sequenceHeader.requestId);

    // 3) Read the nodeid of the request
    UA_ExpandedNodeId requestType;
    CHECK_PROCESS(UA_ExpandedNodeId_decodeBinary(msg, pos, &requestType),; );
    if(requestType.nodeId.identifierType != UA_NODEIDTYPE_NUMERIC)
        goto close_connection;

    // 4) process the request
    UA_ByteStringArray responseBuf;
    UA_ByteStringArray_init(&responseBuf, 2);

    UA_UInt32 responseType;

    //subtract 2 for binary encoding
    UA_UInt32 sendOffset = 0;
    switch(requestType.nodeId.identifier.numeric - 2) {
    case UA_GETENDPOINTSREQUEST_NS0:
    {
        UA_GetEndpointsRequest  p;
        UA_GetEndpointsResponse r;
        CHECK_PROCESS(UA_GetEndpointsRequest_decodeBinary(msg, pos, &p),; );
        UA_GetEndpointsResponse_init(&r);
        init_response_header(&p.requestHeader, &r.responseHeader);
        Service_GetEndpoints(server, &p, &r);
        UA_ByteString_newMembers(&responseBuf.strings[1],
                                 UA_GetEndpointsResponse_calcSizeBinary(&r));
        UA_GetEndpointsResponse_encodeBinary(&r, &responseBuf.strings[1], &sendOffset);
        UA_GetEndpointsRequest_deleteMembers(&p);
        UA_GetEndpointsResponse_deleteMembers(&r);
        responseType = requestType.nodeId.identifier.numeric + 3;
        break;
    }

    case UA_CREATESESSIONREQUEST_NS0:
    {
        UA_CreateSessionRequest  p;
        UA_CreateSessionResponse r;
        CHECK_PROCESS(UA_CreateSessionRequest_decodeBinary(msg, pos, &p),; );
        UA_CreateSessionResponse_init(&r);
        init_response_header(&p.requestHeader, &r.responseHeader);
        Service_CreateSession(server, channel,  &p, &r);
        UA_ByteString_newMembers(&responseBuf.strings[1],
                                 UA_CreateSessionResponse_calcSizeBinary(&r));
        UA_CreateSessionResponse_encodeBinary(&r, &responseBuf.strings[1], &sendOffset);
        UA_CreateSessionRequest_deleteMembers(&p);
        UA_CreateSessionResponse_deleteMembers(&r);
        responseType = requestType.nodeId.identifier.numeric + 3;
        break;
    }

    case UA_ACTIVATESESSIONREQUEST_NS0:
        INVOKE_SERVICE(ActivateSession);
        break;

    case UA_READREQUEST_NS0:
        INVOKE_SERVICE(Read);
        break;

    case UA_WRITEREQUEST_NS0:
        INVOKE_SERVICE(Write);
        break;

    case UA_BROWSEREQUEST_NS0:
        INVOKE_SERVICE(Browse);
        break;

    case UA_CREATESUBSCRIPTIONREQUEST_NS0:
        INVOKE_SERVICE(CreateSubscription);
        break;

    case UA_TRANSLATEBROWSEPATHSTONODEIDSREQUEST_NS0:
        INVOKE_SERVICE(TranslateBrowsePathsToNodeIds);
        break;

    case UA_PUBLISHREQUEST_NS0:
        INVOKE_SERVICE(Publish);
        break;

    case UA_CREATEMONITOREDITEMSREQUEST_NS0:
        INVOKE_SERVICE(CreateMonitoredItems);
        break;

    case UA_SETPUBLISHINGMODEREQUEST_NS0:
        INVOKE_SERVICE(SetPublishingMode);
        break;

    default:
    {
        printf("SL_processMessage - unknown request, namespace=%d, request=%d\n",
               requestType.nodeId.namespaceIndex, requestType.nodeId.identifier.numeric);
        UA_RequestHeader  p;
        UA_ResponseHeader r;
        CHECK_PROCESS(UA_RequestHeader_decodeBinary(msg, pos, &p),; );
        UA_ResponseHeader_init(&r);
        r.requestHandle = p.requestHandle;
        r.serviceResult = UA_STATUSCODE_BADSERVICEUNSUPPORTED;
        UA_ByteString_newMembers(&responseBuf.strings[1], UA_ResponseHeader_calcSizeBinary(&r));
        UA_ResponseHeader_encodeBinary(&r, &responseBuf.strings[1], &sendOffset);
        UA_RequestHeader_deleteMembers(&p);
        UA_ResponseHeader_deleteMembers(&r);
        responseType = UA_RESPONSEHEADER_NS0 + 2;
    }
    }

    // 5) Build the header
#define SIZE_SECURECHANNEL_HEADER 12
#define SIZE_SEQHEADER_HEADER 8
    UA_NodeId response_nodeid = { .namespaceIndex     = 0, .identifierType = UA_NODEIDTYPE_NUMERIC,
                                  .identifier.numeric = responseType }; // add 2 for binary encoding

    UA_ByteString_newMembers(&responseBuf.strings[0],
                             8 + 16 + // normal header + 4*32bit secure channel information
                             UA_NodeId_calcSizeBinary(&response_nodeid));

    // sizePadding = 0;
    // sizeSignature = 0;
    UA_ByteString *header = &responseBuf.strings[0];

    // secure conversation message header
    header->data[0] = 'M';
    header->data[1] = 'S';
    header->data[2] = 'G';
    header->data[3] = 'F';
    UA_UInt32 rpos       = 4;

    UA_Int32  packetSize = header->length + responseBuf.strings[0].length;
    UA_Int32_encodeBinary(&packetSize, header, &rpos);
    UA_UInt32_encodeBinary(&channel->securityToken.channelId, header, &rpos);

    // algorithm security header
    UA_UInt32_encodeBinary(&channel->securityToken.tokenId, header, &rpos);

    // encode sequence header
    UA_UInt32_encodeBinary(&channel->sequenceNumber, header, &rpos);
    UA_UInt32_encodeBinary(&channel->requestId, header, &rpos);

    // add payload type
    UA_NodeId_encodeBinary(&response_nodeid, header, &rpos);

    // sign data

    // encrypt data

    // 6) Send it over the wire.
    connection->write(connection->callbackHandle, &responseBuf);

clean_up:
    UA_ExpandedNodeId_deleteMembers(&requestType);
    UA_ByteStringArray_deleteMembers(&responseBuf);
    return;

close_connection:
    // make sure allocated data has been freed
    connection->state = UA_CONNECTION_CLOSING;
    connection->close(connection->callbackHandle);
    return;
}

static void processClose(UA_Connection *connection, UA_Server *server,
                         const UA_ByteString *msg, UA_UInt32 *pos) {
    // just read in the sequenceheader

}

UA_Int32 UA_Server_processBinaryMessage(UA_Server *server, UA_Connection *connection,
                                        const UA_ByteString *msg) {
    UA_Int32  retval = UA_SUCCESS;
    UA_UInt32 pos    = 0;
    UA_OPCUATcpMessageHeader tcpMessageHeader;
    do {
        retval = UA_OPCUATcpMessageHeader_decodeBinary(msg, &pos, &tcpMessageHeader);
        if(retval == UA_SUCCESS) {
            // none of the process-functions returns an error its all contained inside.
            switch(tcpMessageHeader.messageType) {
            case UA_MESSAGETYPE_HEL:
                processHello(connection, msg, &pos);
                break;

            case UA_MESSAGETYPE_OPN:
                processOpen(connection, server, msg, &pos);
                break;

            case UA_MESSAGETYPE_MSG:
                // if this fails, the connection is closed (no break on the case)
                if(connection->state == UA_CONNECTION_ESTABLISHED &&
                   connection->channel != UA_NULL) {
                    processMessage(connection, server, msg, &pos);
                    break;
                }

            case UA_MESSAGETYPE_CLO:
                connection->state = UA_CONNECTION_CLOSING;
                processClose(connection, server, msg, &pos);
                connection->close(connection->callbackHandle);
                break;
            }
        } else {
            printf("TL_Process - ERROR: decoding of header failed \n");
            connection->state = UA_CONNECTION_CLOSING;
            processClose(connection, server, msg, &pos);
            connection->close(connection->callbackHandle);
        }
        UA_OPCUATcpMessageHeader_deleteMembers(&tcpMessageHeader);
    } while(msg->length > (UA_Int32)pos);
    return retval;
}