#include <pthread.h>
#include <sys/sysinfo.h>
#include <sys/types.h>
#include <sys/stat.h>
#include <fcntl.h>
#include <stdio.h>
#include <stdlib.h>
#include <unistd.h>
#include <errno.h>

#include <iostream>
#include <list>
#include <cstring>


struct SystemInfo{
    unsigned long memTotal;
    unsigned long memFree;
    long upTime;
    unsigned long swapTotal;
    unsigned long swapFree;
};

struct MesData{
    unsigned int size, delay;
};

struct MesData mezureData;
std::list<SystemInfo> listSI;
int running = 1;
int icev1, icev2, icev3;
pthread_t tid[4];

void* glavna(void* arg){
    int i, l;
    while (running == 1){
        icev3 = open("izklop",O_RDONLY);
        if(icev3 < 0) std::cout << "tezava pri odpiranju cevi 2\n";

        l = read(icev3, &i, sizeof(i));
        if(l<0) std::cout << "tezava pri branju cevi 2\n";

        if(i > 2){
            pthread_cancel(tid[2]);
            pthread_cancel(tid[3]);
            running = 0;
        }

        if(close(icev3) != 0) std::cout << "tezava pri zapiranju cevi 0\n";
    }
    return 0;
}

void* mezuringNode(void* arg){
    struct sysinfo si;
    struct SystemInfo info;
    unsigned int microsecond = 1000000;
    while (running == 1)
    {
        sysinfo (&si);
        info.memTotal = si.totalram;
        info.memFree = si.freeram;
        info.upTime = si.uptime;
        info.swapFree = si.freeswap;
        info.swapTotal = si.totalswap;
        listSI.push_front(info);
        while(listSI.size() > mezureData.size){
            listSI.pop_back();
        }
        usleep(mezureData.delay * microsecond);
    }
    return 0;
}

void* input(void* arg){
    int tmp[2];
    int l;
    while(running == 1){

        icev1 = open("vhod",O_RDONLY);
        if(icev1 < 0) std::cout << "tezava pri odpiranju cevi 0\n";

        l = read(icev1, &tmp, sizeof(tmp));
        if(l<0) std::cout << "tezava pri branju cevi 0\n";

        std::cout << tmp[0] << " " << tmp[1] << "\n";
        mezureData.delay = tmp[0];
        mezureData.size = tmp[1];

        if(close(icev1) != 0) std::cout << "tezava pri zapiranju cevi 0\n";
    }
    return 0;
}

void* output(void* arg){
    unsigned long array[100];
    int l, i = 0;

    while(running == 1){
        icev2 = open("izhod",O_WRONLY);
        if(icev2 < 0) 
            std::cout << "Napaka pri odprtju cevi 1\n";
        else
            std::cout << "Odprta cevi 1\n";

        i = 0;
        for (auto& elm : listSI){
            array[i] = elm.memTotal;
            i++;
            array[i] = elm.memFree;
            i++;
            array[i] = elm.upTime;
            i++;
            array[i] = elm.swapFree;
            i++;
            array[i] = elm.swapTotal;
            i++;
        }
        

        l = write(icev2, &array, sizeof(array));
        if(l < 0) 
            std::cout << "tezave pri pisanju v cev\n";
        else
            std::cout << "Vpisano v cevi 1\n";
        
        if(close(icev2) != 0) 
            std::cout << "tezava pri zapiranju cevi 1\n";
        else
            std::cout << "Zaprta cevi 1\n";

        usleep(10000);
    }
    return 0;
}


int main(){
    std::cout << "Hello World\n";
    
    mezureData.delay = 1;
    mezureData.size = 4;
    
    mkfifo("vhod", S_IRUSR|S_IWUSR);
    mkfifo("izhod", S_IRUSR|S_IWUSR);
    mkfifo("izklop", S_IRUSR|S_IWUSR);

    pthread_create(&tid[0], NULL, glavna, NULL);
    pthread_create(&tid[1], NULL, mezuringNode, NULL);
    pthread_create(&tid[2], NULL, input, NULL);
    pthread_create(&tid[3], NULL, output, NULL);

    pthread_join(tid[0], NULL);
    pthread_join(tid[1], NULL);
    pthread_join(tid[2], NULL);
    pthread_join(tid[3], NULL);

    std::string str;
    char* strc;
    for (auto& elm : listSI){
        str += "TotalMemory: " + std::to_string(elm.memTotal) + " ";
        str += "FreeMemory: " +  std::to_string(elm.memFree) + " ";
        str += "UpTime: " + std::to_string(elm.upTime) + " ";
        str += "FreeSwap: " + std::to_string(elm.swapFree) + " ";
        str += "TotalSwap: " + std::to_string(elm.swapTotal) + "\n";
    }
    strc = &str[0];

    printf("%s",strc);

    close(icev1);
    close(icev2);
    close(icev3);

    unlink("vhod");
    unlink("izhod");
    unlink("izklop");

    return 0;
}