/* Virginia Tech Cognitive Radio Open Source Systems
 * Virginia Tech, 2009
 *
 * TODO LICENSE INFORMATION GOES HERE
 */

/* TODO DESCRIPTION OF FILE.
 */


#include <arpa/inet.h>
#include <iostream>
#include <netinet/in.h>
#include <netdb.h>
#include <fcntl.h>
#include <sys/ioctl.h>
#include <sys/mman.h>
#include <sys/socket.h>
#include <sys/types.h>
#include <sys/wait.h>

#include "tinyxml/tinyxml.h"
#include "tinyxml/tinystr.h"

#include "vtcross/common.h"
#include "vtcross/components.h"
#include "vtcross/containers.h"
#include "vtcross/debug.h"
#include "vtcross/error.h"
#include "vtcross/socketcomm.h"


using namespace std;


#define CE_SERVER_PORT 30001
#define PE_SERVER_PORT 30003


void 
print_current_config(Utility* uList[], Parameter* pList[], \
        Observable* oList[], CE_Info* ce_info)
{
	for(size_t i = 0; i < ce_info->numUtilities ; i++) {
        LOG("Shell:: Utility: %s\n\tUnits: %s\n\tGoal: %s\n\tTarget: %s\n", \
                uList[i]->name, uList[i]->units, uList[i]->goal, \
                uList[i]->target);
	}

	for(size_t i = 0; i < ce_info->numParameters; i++) {
	    LOG("Shell:: Radio Operation Profile has been sucessfully sent.\n");
        LOG("Shell:: Parameter: %s\n\tUnits: %s\n\tMin: %s\n\t", \
                pList[i]->name, pList[i]->units, pList[i]->min);
        LOG("\tMax: %s\n\tStep: %s\n", pList[i]->max, pList[i]->step);

		for(size_t j = 0; j < pList[i]->numAffects; j++) {
			LOG("\t\tAffect %s -> %s\n", pList[i]->affection_list[j].u->name, \
                    pList[i]->affection_list[j].relation);
		}
	}
	
    for(size_t i = 0; i < ce_info->numObservables; i++) {
		LOG("Observable: %s\n", oList[i]->name);

		for(size_t j = 0; j < oList[i]->numAffects; j++) {
			LOG("\t\tAffect %s -> %s ", oList[i]->affection_list[j].u->name, \
                    oList[i]->affection_list[j].relation);
		}
	}
}


int32_t
parse_ce_config(TiXmlDocument* doc, Utility* u[], Parameter* p[], \
        Observable* o[], CE_Info* ce_info)
{

	TiXmlElement *pElem;
	TiXmlElement *pChild;
	TiXmlElement *pChild1;
	TiXmlElement *pSecondChild;
	TiXmlHandle hDoc(doc);
	TiXmlHandle hRoot(0);

	int32_t count = 0;
	size_t item_count = 0;
    size_t affect_count = 0;
	int32_t attribute_count = 0;
    bool match_found = false;

	pElem = hDoc.FirstChildElement().Element();

	if(!pElem) 
        ERROR(1, "No valid root!");

	hRoot = TiXmlHandle(pElem);

	pElem = hRoot.FirstChild("utilities").Element();
	pChild1 = hRoot.Child("utilities", count).Element();

	for(pChild = pChild1->FirstChildElement("utility"); pChild; \
            pChild = pChild->NextSiblingElement()) {

		u[item_count] = new Utility;

   		const char *uName = pChild->Attribute("name");
   		if(uName)
            u[item_count]->name = uName;	

		const char *uUnits = pChild->Attribute("units");
   		if(uUnits) 
            u[item_count]->units = uUnits;

   		const char *uGoal = pChild->Attribute("goal");
   		if(uGoal) 
            u[item_count]->goal = uGoal;

   		if(pChild->QueryFloatAttribute("target", &u[i]->target) != TIXML_SUCCESS) 
            u[i]->target = -1;

		item_count++;
	}

	ce_info->numUtilities = item_count;	
	LOG("Initialize:: Parsed %d utilities.\n", ce_info->numUtilities);

	item_count = 0;
	pElem = hRoot.FirstChild("observables").Element();
	pChild1 = hRoot.Child("observables", count).Element();

	for(pChild = pChild1->FirstChildElement("observable"); pChild; \
            pChild = pChild->NextSiblingElement()) {

   		const char *oName = pChild->Attribute("name");
		o[item_count] = new Observable;
   		if(oName) 
            o[item_count]->name = oName;
		
		affect_count = 0;
		for(pSecondChild = pChild->FirstChildElement("affect"); pSecondChild; \
                pSecondChild = pSecondChild->NextSiblingElement()) {

   			const char *oUtilName = pSecondChild->Attribute("utility");
			if(oUtilName) {
				for(attribute_count = 0; u[attribute_count]! = NULL; attribute_count++ ) {
					if(u[attribute_count]->name == oUtilName) {
						o[i]->affection_list[affect_count].u = u[attribute_count];

						const char *oRelate = pSecondChild->Attribute("relationship");
   						if(oRelate) 
                            o[item_count]->affection_list[affect_count].relation = oRelate;

						affect_count++;
						match_found = true;
				 		break;
					}
				}
			}

			if(!match_found) 
                ERROR(1, "Error: %s: %s is not a valid utility.\n", \
                        o[i]->name, oUtilName);
            else
                match_found = false;	
		}

		o[item_count]->numAffects = affect_count; 
		item_count++;
	}

	ce_info->numObservables = item_count;	
	LOG("Initialize:: Parsed %d observables.\n", ce_info->numObservables);

	pElem = hRoot.FirstChild("parameters").Element();
	pChild1 = hRoot.Child("parameters", count).Element();
	
	item_count = 0;
	for(pChild = pChild1->FirstChildElement("parameter"); pChild; \
            pChild = pChild->NextSiblingElement()) {

		p[item_count] = new Parameter;

		const char *pName = pChild->Attribute("name");
   		if(pName) 
            p[item_count]->name = pName;	

		const char *pUnits = pChild->Attribute("units");
   		if(pUnits) 
            p[item_count]->units = pUnits;

   		if(pChild->QueryFloatAttribute("min", &p[i]->min) != TIXML_SUCCESS) 
            p[item_count]->min = -1;

   		if(pChild->QueryFloatAttribute("max", &p[i]->max) != TIXML_SUCCESS) 
            p[item_count]->max = -1;

   		if(pChild->QueryFloatAttribute("step", &p[i]->step) != TIXML_SUCCESS) 
            p[item_count]->step = -1;
		
		affect_count = 0;
		for(pSecondChild = pChild->FirstChildElement("affect"); pSecondChild; \
                pSecondChild = pSecondChild->NextSiblingElement()) {

   			const char *pUtilName = pSecondChild->Attribute("utility");
			if(pUtilName) {
				for(attribute_count = 0; u[attribute_count] != NULL; attribute_count++) {
					if(u[attribute_count]->name == pUtilName) {
						p[item_count]->affection_list[affect_count].u = u[attribute_count];	

						const char *pRelate = pSecondChild->Attribute("relationship");
   						if(pRelate)
							p[item_count]->affection_list[affect_count].relation = pRelate;
						else
							LOG("Error: No relation found.\n");

						match_found = true;
						affect_count++;
						break;
					}
				}
			}

			if(!match_found) {
                ERROR(1, "Error: %s: %s is not a valid utility.\n", \
                        p[item_count]->name, pUtilName);
            }

			match_found = false;	
		}

		p[item_count]->numAffects = affect_count;
		item_count++;
	}

	ce_info->numParameters = item_count;
	LOG("Initialize:: Parsed %d parameters.\n", ce_info->numParameters);

	return 1;
}


int32_t 
ReceiveMessage(int32_t socket, char* buffer) 
{
    int32_t i,n;
   
    n = recv(socket,buffer,256,MSG_PEEK);
    
    for(i=0;i<256;i++){
        if(strcmp(&buffer[i],"\0") == 0) break;
    }
    n = recv(socket,buffer,i+1,0);
    if (n < 0)
        ERROR(1, "Error reading from socket!\n");
    //    printf("ReadMessage:%s %d\n",buffer,n);

    return n;
}


int32_t
SendMessage(int32_t socketfd, string message) 
{
	int32_t n;

	message.append("\0");	
	// Write message back to client
    n = send(socketfd,message.c_str(),(message.size()+1),0);
    if (n<0)
        ERROR(1, "Error sending to client\n");
    if(n == 0)
        printf("Client closed the socket.\n");

	//printf("SendMessage:%s %d\n",message.c_str(),n);	
    return n;
}


void 
LoadCEConfiguration(int32_t socketfd,Utility * uList[], Parameter * pList[], Observable * oList[], CE_Info * ce_info){
	int32_t n,i,j;
	char counter[55];
	char var[50];
	//int32_t total_bytes;   

	printf("Cognitive Radio:: Sending Radio Operating Profile to Cognitive Engine.\n\n");
 
 	// utilities
	// Send number of utilities
	sprintf(counter,"%d",ce_info->numUtilities);
	SendMessage(socketfd,counter);
	// send utility	
    for(i = 0; i < ce_info->numUtilities; i++) {
		SendMessage(socketfd,uList[i]->name);
		SendMessage(socketfd,uList[i]->units);
		SendMessage(socketfd,uList[i]->goal);
		sprintf(var,"%f",uList[i]->target);
		SendMessage(socketfd,var);
	}

	// parameters
    sprintf(counter,"%i",ce_info->numParameters);
	SendMessage(socketfd,counter);
	for(i = 0; i < ce_info->numParameters; i++) {
		SendMessage(socketfd,pList[i]->name);
		SendMessage(socketfd,pList[i]->units);
		sprintf(var,"%f",pList[i]->min);
		SendMessage(socketfd,var);
		sprintf(var,"%f",pList[i]->max);
		SendMessage(socketfd,var);
		sprintf(var,"%f",pList[i]->step);
		SendMessage(socketfd,var);
		
		sprintf(counter,"%i",pList[i]->numAffects); 
		SendMessage(socketfd,counter);
		for(j = 0; j < pList[i]->numAffects; j++) {
			SendMessage(socketfd,pList[i]->affection_list[j].u->name);
			SendMessage(socketfd,pList[i]->affection_list[j].relation);
		}
	}

    // observables
	sprintf(counter,"%i",ce_info->numObservables);
	SendMessage(socketfd,counter);
	for(i = 0; i < ce_info->numObservables; i++) {
		SendMessage(socketfd,oList[i]->name);
		
		sprintf(counter,"%i",oList[i]->numAffects); 
		SendMessage(socketfd,counter);
		for(j = 0; j < oList[i]->numAffects; j++) {
			SendMessage(socketfd,oList[i]->affection_list[j].u->name);
			SendMessage(socketfd,oList[i]->affection_list[j].relation);
		}
	}
	
	// Receive ACK for utils
    char buffer[256];
        string message;
	n = ReceiveMessage(socketfd, buffer);
    //printf("%s\n", buffer);
        //cout << message << endl;
	//printf("ACK received.\n");

}

void UpdateCEConfiguration() {

}

void ResetCEConfiguration(){

}

void UpdateCEExperience(int32_t socketfd, int32_t num_rows, int32_t num_cols, 
        float * past_exp[]) 
{
    int32_t i, j;
	char counter[55];
	char var[50];

    for (i = 0; i < num_rows; i++){
        for (j = 0; j< num_cols; j++){
		sprintf(var,"%f",past_exp[i][j]);
        //printf("%f, \n", past_exp[i][j]);
        //printf("%s, \n", var);
        }
    }
    
    // send the number of rows to the ce first
	sprintf(counter,"%d",num_rows);
	SendMessage(socketfd,counter);
    // send the number of columns to the ce
	sprintf(counter,"%d",num_cols);
	SendMessage(socketfd,counter);
    // update ce with experience
    for (i = 0; i < num_rows; i++){
        for (j = 0; j< num_cols; j++){
		sprintf(var,"%f",past_exp[i][j]);
		SendMessage(socketfd,var);
        }
    }

}

void ResetCEExperience() {

}

// Update operating settings
// This function will int32_teract with the hardware "drivers"
void UpdateRadioSettings() 
{
}


int32_t RequestPolicyValidation(Parameter * pList[], CE_Info *ce_info)
{
	char counter[55];
	char var[50];
    int32_t i;
    string control_msg;
    
    int32_t socketfd = ce_info->policy_socket;

    // Control message that validation request is coming
    control_msg = "val";
	SendMessage(socketfd,control_msg);

    printf("Cognitive Radio:: Here. %i\n\n", socketfd);

	// Send parameter information 
    sprintf(counter,"%i",ce_info->numParameters);
	SendMessage(socketfd,counter);
	for(i = 0; i < ce_info->numParameters; i++) {
		SendMessage(socketfd,pList[i]->name);
		SendMessage(socketfd,pList[i]->units);
		sprintf(var,"%f",pList[i]->min);
		SendMessage(socketfd,var);
		sprintf(var,"%f",pList[i]->max);
		SendMessage(socketfd,var);
		sprintf(var,"%f",pList[i]->step);
		SendMessage(socketfd,var);
		sprintf(var,"%f",pList[i]->value);
		SendMessage(socketfd,var);
		
	}
    return 1;

}


int32_t RequestCEOptimization(int32_t sockfd, Utility *uList[], 
        Parameter *pList[], Observable *oList[],
        CE_Info *ce_info)
{
    char buffer[256];
    int32_t i;
    float var;

    // Send request optimization message followed by the current environment parameters.
    /*
    SendMessage(sockfd,"request"); 
    for (i = 0; i < ce_info->numObservables; i++){
        SendMessage(sockfd,..);
    }
    */

    // Receive optimized values from the Cognitive Engine 
    for (i = 0; i < ce_info->numParameters; i++){
        bzero(buffer,256);
        ReceiveMessage(sockfd,buffer);
        var = atof(buffer);
        pList[i]->value = var;
    }


    // If policy engine is connect, validate new values
    if(ce_info->policy_engine == 1) {

        printf("Cognitive Radio:: Found Policy Engine!\n");
        printf("Cognitive Radio:: Validating parameters with Policy Engine\n\n");
        RequestPolicyValidation(pList,ce_info); 
        printf("Cognitive Radio:: Done\n\n");

    }


    return 1;
}

void RunSimulator(int32_t socketfd, Utility * uList[], 
        Parameter * pList[], Observable * oList[], 
        CE_Info * ce_info) {
	
	float **past_exp;
    int32_t num_rows, num_cols;

	// Set fake current environment params = current environment
	RequestCEOptimization(socketfd, uList, pList, oList, ce_info);

	// Act like we are updating the hardware tranmission settings
	UpdateRadioSettings();

	// Send back fake utility values
    // need to initialize
	//UpdateCEExperience(socketfd, num_rows, num_cols, past_exp);	
}

void InitializePE(int32_t socket, CE_Info * ce_info) 
{
    // Policy Engine is connected
    // Set global policy engine value to 1
    ce_info->policy_engine = 1;
    ce_info->policy_socket = socket;

    return;
}

void InitializeCE(int32_t socketfd, Utility * uList[], Parameter * pList[], Observable * oList[], CE_Info * ce_info) 
{
	LoadCEConfiguration(socketfd, uList, pList, oList, ce_info);
	
    // cr experience
    float **past_exp;
	int32_t num_cols;
    // get number of columns
    num_cols = ce_info->numUtilities + ce_info->numParameters;
    num_cols = num_cols + ce_info->numObservables;
    num_cols = num_cols + 1;    // overall utility
    int32_t num_rows = 2;
    past_exp = (float **)malloc(sizeof(float)*num_rows);
    int32_t i;
    for (i=0; i<num_rows; i++){
        past_exp[i] = (float*)malloc(sizeof(float)*num_cols);
    }
    // sample experience #1
    past_exp[0][0] = 1e3f;  // throughput
    past_exp[0][1] = 1;     // spectral_efficiency
    past_exp[0][2] = -3.5;  // log10_ber
    past_exp[0][3] = 1;     // mod_scheme
    past_exp[0][4] = -10;   // tx_power
    past_exp[0][5] = 10.0;  // SNR
    past_exp[0][6] = 0.762; // overall utility*/
    // sample experience #2
    past_exp[1][0] = 1e2f;  // throughput
    past_exp[1][1] = 1;     // spectral_efficiency
    past_exp[1][2] = -3.5;  // log10_ber
    past_exp[1][3] = 1;     // mod_scheme
    past_exp[1][4] = -14;   // tx_power
    past_exp[1][5] = 3.0;   // SNR
    past_exp[1][6] = 0.462; // overall utility

	// update ce with experience
    printf("Cognitive Radio:: Sending Previous Experience to New Cognitive Engine.\n\n");
    UpdateCEExperience(socketfd, num_rows, num_cols, past_exp);	

	RunSimulator(socketfd, uList, pList, oList, ce_info);
}

int32_t AcceptTCPConnection(int32_t servSock)
{
    int32_t clntSock;                    /* Socket descriptor for client */
    struct sockaddr_in echoClntAddr;
    uint32_t clntLen;

    /* Set the size of the in-out parameter */
    clntLen = sizeof(echoClntAddr);

    /* Wait for a client to connect */
    //if ((clntSock = accept(servSock, (struct sockaddr *) &echoClntAddr, &clntLen)) < 0) {
    if ((clntSock = accept(servSock, NULL, NULL)) < 0) {
        return -1;
    } 
   
    /* clntSock is connected to a client! */
    
    printf("Handling client %s\n", inet_ntoa(echoClntAddr.sin_addr));

    return clntSock;
}

int32_t CreateTCPServerSocket(unsigned short port)
{
    int32_t sock;                        /* socket to create */
    struct sockaddr_in echoServAddr; /* Local address */

    /* Create socket for incoming connections */
    if ((sock = socket(PF_INET, SOCK_STREAM, IPPROTO_TCP)) < 0)
        ERROR(1, "socket() failed\n");
      
    /* Construct local address structure */
    memset(&echoServAddr, 0, sizeof(echoServAddr));   /* Zero out structure */
    echoServAddr.sin_family = AF_INET;                /* int32_ternet address family */
    echoServAddr.sin_addr.s_addr = htonl(INADDR_ANY); /* Any incoming int32_terface */
    echoServAddr.sin_port = htons(port);              /* Local port */

    /* Bind to the local address */
    if (bind(sock, (struct sockaddr *) &echoServAddr, sizeof(echoServAddr)) < 0)
        ERROR(1, "bind() failed\n");

    /* Mark the socket so it will listen for incoming connections */
    if (listen(sock, 5) < 0) {
        printf("listen() failed\n");
        return 0;
    }

    return sock;
}

void HandleTCPClient(int32_t socketfd, Utility * uList[], Parameter * pList[], Observable * oList[], CE_Info * ce_info) 
{
    char buffer[256];        /* Buffer for echo string */

    /* Receive message from client */
    bzero(buffer,256);
    ReceiveMessage(socketfd,buffer);

    printf("Cognitive Radio:: Message Received - %s.\n\n", buffer);

    if(strcmp(buffer,"c_register") == 0) 
	    InitializeCE(socketfd, uList, pList, oList, ce_info);

    if(strcmp(buffer,"p_register") == 0)
	    InitializePE(socketfd, ce_info);

    if(strcmp(buffer,"optimize") == 0)
	    RunSimulator(socketfd, uList, pList, oList, ce_info);
        
    //close(socketfd);    /* Close client socket */
}

int32_t StartServers(Utility * uList[], Parameter * pList[], Observable * oList[], CE_Info * ce_info) {
    int32_t * servSock; 
    int32_t running = 1;
    struct timeval selTimeout;
    int32_t timeout = 10;
    int32_t cognitive_engine = 0; 
    int32_t policy_engine = 1; 
    int32_t port, rc, on = 1;
    int32_t new_sd;
    int32_t desc_ready = 0;
    fd_set sockSet;
    
    servSock = (int32_t *) malloc(2 * sizeof(int32_t));

    servSock[cognitive_engine] = CreateTCPServerSocket(CE_SERVER_PORT);
    servSock[policy_engine] = CreateTCPServerSocket(PE_SERVER_PORT);


    int32_t maxDescriptor = servSock[cognitive_engine];

    if(servSock[cognitive_engine] < servSock[policy_engine])
        maxDescriptor = servSock[policy_engine];

    rc = setsockopt(servSock[cognitive_engine], SOL_SOCKET, SO_REUSEADDR, (char*)&on, sizeof(on));
    if(rc < 0)
    {
        perror("setsockopt() failed");
        close(servSock[cognitive_engine]);
        exit(-1);
    }
    
    rc = setsockopt(servSock[policy_engine], SOL_SOCKET, SO_REUSEADDR, (char*)&on, sizeof(on));
    if(rc < 0)
    {
        perror("setsockopt() failed");
        close(servSock[policy_engine]);
        exit(-1);
    }
    
    rc = ioctl(servSock[cognitive_engine], FIONBIO, (char*)&on);
    if(rc < 0)
    {
        perror("ioctl() failed");
        close(servSock[cognitive_engine]);
        exit(-1);
    }
    
    rc = ioctl(servSock[policy_engine], FIONBIO, (char*)&on);
    if(rc < 0)
    {
        perror("ioctl() failed");
        close(servSock[policy_engine]);
        exit(-1);
    }
    
    printf("Starting server:  Hit return to shutdown\n");
    while (running)
    {
        /* Zero socket descriptor vector and set for server sockets */
        /* This must be reset every time select() is called */
        FD_ZERO(&sockSet);
        /* Add keyboard to descriptor vector */
        FD_SET(STDIN_FILENO, &sockSet);
        FD_SET(servSock[cognitive_engine], &sockSet);
        FD_SET(servSock[policy_engine], &sockSet);

        /* Timeout specification */
        /* This must be reset every time select() is called */
        selTimeout.tv_sec = timeout;       /* timeout (secs.) */
        selTimeout.tv_usec = 0;            /* 0 microseconds */

        /* Suspend program until descriptor is ready or timeout */
        rc = select(maxDescriptor + 1, &sockSet, NULL, NULL, &selTimeout); 
        if (rc == 0)
            printf("No echo requests for %i secs...Server still alive\n", timeout);
        else 
        {
            if (FD_ISSET(0, &sockSet)) /* Check keyboard */
            {
                printf("Shutting down server\n");
                getchar();
                running = 0;
            }

            desc_ready = rc;

            for (port = 0; port <= maxDescriptor && desc_ready > 0; port++) {
                if (FD_ISSET(port, &sockSet))
                {
                    printf("Request on port %d:  ", port);
	                desc_ready -= 1;


                    if( (port == servSock[cognitive_engine]) || (port == servSock[policy_engine])) { 
                       
                        do
                        { 
                            new_sd = AcceptTCPConnection(port);
                            if(new_sd < 0) 
                            {
                                break;
                            }
                            
                            HandleTCPClient(new_sd, uList, pList, oList, ce_info);
                            FD_SET(new_sd,&sockSet);
                            if(new_sd > maxDescriptor) 
                                maxDescriptor = new_sd;
                            printf("New incoming connection - %i\n\n",new_sd);
                        } while(new_sd != -1);
                    } else {
                        
                        printf("Request on already open descriptor.\n\n");
                        HandleTCPClient(port, uList, pList, oList, ce_info);

                    }

                }
            }
        }
    }

    /* Close sockets */
    for (port = 0; port < 2; port++)
        close(servSock[port]);

    /* Free list of sockets */
    free(servSock);        
        
	return 0;
}

int32_t 
main(int32_t argc, char* argv[])
{
	// CognitiveEngine CE;
	// CognitiveEngineShell Shell;
	string pFilename; 
    int32_t fd;

	Utility * uList[10];
	Parameter * pList[10];
	Observable * oList[10];
	struct CE_Info *ce_info;

    if((fd = open("/dev/zero", O_RDWR)) == -1)
            return 1;

    ce_info = (struct CE_Info *)mmap(0,sizeof(CE_Info),PROT_READ|PROT_WRITE,MAP_SHARED,fd,0);

    close(fd);

	if(argc < 2) { 
		cout << "Warning no XML file specific using default: example.xml" << endl;
		pFilename = "example.xml";
	} else {  
		pFilename = argv[1];
	}

	TiXmlDocument doc( pFilename.c_str() );
	bool loadOkay = doc.LoadFile();
	if (!loadOkay)
	{
		cout << "Loading " << pFilename << " failed." << endl;
		return 0;
	}

	cout << "\n\nInitialize:: Attemping to parse " << pFilename << "." << endl;
	parse_ce_config( &doc , uList, pList, oList, ce_info);
	cout << "Initialize:: Configuration file parsing completed.\n" << endl;

    //print_current_config(uList, pList, oList, &ce_info);
	
   StartServers(uList, pList, oList, ce_info);
   return 1;
}