/*
 * To change this license header, choose License Headers in Project Properties.
 * To change this template file, choose Tools | Templates
 * and open the template in the editor.
 */

#include <stdlib.h>
#include <ctype.h>
#include <string.h>

#include <unistd.h>
#include <dirent.h>
#include <stdio.h>
#include <limits.h>

#include "network.h"

static int procnetdev_version(char *buf) {
    if (strstr(buf, "compressed"))
        return 3;
    if (strstr(buf, "bytes"))
        return 2;
    return 1;
}

static int get_dev_fields(char *bp, int version, NetDeviceStats *stats) {
    switch (version) {
        case 3:
            sscanf(bp,
                    "%llu %llu %lu %lu %lu %lu %lu %lu %llu %llu %lu %lu %lu %lu %lu %lu",
                    &stats->rx_bytes,
                    &stats->rx_packets,
                    &stats->rx_errors,
                    &stats->rx_dropped,
                    &stats->rx_fifo_errors,
                    &stats->rx_frame_errors,
                    &stats->rx_compressed,
                    &stats->rx_multicast,

                    &stats->tx_bytes,
                    &stats->tx_packets,
                    &stats->tx_errors,
                    &stats->tx_dropped,
                    &stats->tx_fifo_errors,
                    &stats->collisions,
                    &stats->tx_carrier_errors,
                    &stats->tx_compressed);
            break;
        case 2:
            sscanf(bp, "%llu %llu %lu %lu %lu %lu %llu %llu %lu %lu %lu %lu %lu",
                    &stats->rx_bytes,
                    &stats->rx_packets,
                    &stats->rx_errors,
                    &stats->rx_dropped,
                    &stats->rx_fifo_errors,
                    &stats->rx_frame_errors,

                    &stats->tx_bytes,
                    &stats->tx_packets,
                    &stats->tx_errors,
                    &stats->tx_dropped,
                    &stats->tx_fifo_errors,
                    &stats->collisions,
                    &stats->tx_carrier_errors);
            stats->rx_multicast = 0;
            break;
        case 1:
            sscanf(bp, "%llu %lu %lu %lu %lu %llu %lu %lu %lu %lu %lu",
                    &stats->rx_packets,
                    &stats->rx_errors,
                    &stats->rx_dropped,
                    &stats->rx_fifo_errors,
                    &stats->rx_frame_errors,

                    &stats->tx_packets,
                    &stats->tx_errors,
                    &stats->tx_dropped,
                    &stats->tx_fifo_errors,
                    &stats->collisions,
                    &stats->tx_carrier_errors);
            stats->rx_bytes = 0;
            stats->tx_bytes = 0;
            stats->rx_multicast = 0;
            break;
    }
    return 0;
}

void readNetworkUsageFromProc(NetworkUsage *buf) {
    //Clear Buffer
    memset(buf,0,sizeof(NetworkUsage));
    //Open /proc/net/dev
    FILE *fh;
    fh = fopen("/proc/net/dev", "r");
    
    char buffer[512];
    // eat headers
    fgets(buffer, sizeof buffer, fh);
    fgets(buffer, sizeof buffer, fh);
    // end eat headers :D
    
    int version=procnetdev_version(buffer);
    NetDeviceStats stat;
    while(fgets(buffer, sizeof buffer, fh)){
        get_dev_fields(buffer,version,&stat);
        buf->download+=stat.rx_bytes;
        buf->upload+=stat.tx_bytes;
    }
    fclose(fh);
}

void readNetworkUsageFromSys(NetworkUsage *buf){
    memset(buf,0,sizeof(NetworkUsage));

    DIR* sysDir=opendir("/sys/class/net");
    struct dirent* sysDirEntry=0;
    
    if (!sysDir){
        return;
    }

    while((sysDirEntry = readdir(sysDir))){
        if (strcmp(sysDirEntry->d_name,".")==0 || strcmp(sysDirEntry->d_name,"..") == 0)
            continue;
        char path[PATH_MAX];
        memset(path,0,sizeof(path));
        char buffer[512];
        FILE* fh;
        sprintf(path,"/sys/class/net/%s/statistics/rx_bytes",sysDirEntry->d_name);
        fh=fopen(path,"r");
        if (fh){
            fgets(buffer,512,fh);
            unsigned long long x;
            sscanf(buffer,"%llu",&x);
            buf->download+=x;
            fclose(fh);
        }
        
        sprintf(path,"/sys/class/net/%s/statistics/tx_bytes",sysDirEntry->d_name);
        fh=fopen(path,"r");
        if (fh){
            fgets(buffer,512,fh);
            unsigned long long x;
            sscanf(buffer,"%llu",&x);
            buf->upload+=x;
            fclose(fh);
        }
    }

    closedir(sysDir);
}

char *formatNetworkUsage(long upOrDownValue) {

}