//* Reading complex data from a file - parsing with char[] and with atoi or atof *
#include <iostream>
#include <fstream>
#include <cstdlib>
#include <cstring>
#include <cfloat>
using namespace std;


int main() {
    char inName[80];
    cout << "Read text from: ";
    cin  >> inName;
    ifstream inFile;
    inFile.open(inName);
    if (!inFile.is_open()) {
        cout << "ERROR: Cannot open " << inName << " file for reading." << endl;
        return(1);
    }

    char SSIDname[16];
    cout << "SSID to watch: ";
    cin  >> SSIDname;
    int SSIDlen=strlen(SSIDname);


    double sum=0.0;
    int    cnt=0;
    double max=-DBL_MAX;

    unsigned line=0;
    for (;;) {
        char buffer[1024];
        inFile.getline(buffer, 1024);

        if (inFile.fail()) {
            if (inFile.eof()) break; // the failure was caused by the end of file - expected behavior
                              // breaks quits one level of loops - exit the line reading loop - reminder
            cerr << "ERROR: file reading error - data corrupted, exiting at line number " << line << endl;
            break;
        }

        line++;
        cout << line << "\r";

        if (buffer[0]=='#')
            continue; // next line - comment, empty line would still have buffer[0] defined as =='\0'

        int p1 = 1;
        while (buffer[p1]!='\0' && buffer[p1]!='(') p1++;
        if (buffer[p1]=='\0') continue; // next line - this one does not contain SSID data
        if (strncmp(&buffer[p1+2], SSIDname, SSIDlen) !=0 ) continue; // next line - interested only in a particular SSID
        // note that we need to start comparing the part of buffer that starts at p1+2 instead of at 0
        // note that we need to enforce comparing only up to SSIDlen and buffer has more data after the name

        int b1 = p1;
        while (buffer[b1]!='\0' && buffer[b1]!='[') b1++;
        if (buffer[b1]=='\0') continue; // next line - this one does not contain SNR data

        double x, y, z;
        int s1=b1+1; // skip the '['
        x = atof(&buffer[s1]); // note initial space and any more data after the number is ignored
        // note: use atoi if parsing an integer number

        s1++; // skip the initial one space
        while (buffer[s1]!='\0' && buffer[s1]!=' ') s1++;
        if (buffer[s1]=='\0') continue; // next line - this one does not contain SNR data
        y = atof(&buffer[s1]);

        s1++; // skip the initial one space
        while (buffer[s1]!='\0' && buffer[s1]!=' ') s1++;
        if (buffer[s1]=='\0') continue; // next line - this one does not contain SNR data
        z = atof(&buffer[s1]);

        sum=sum+x;
        cnt++;
        if (max<x)
            max=x;

    }
    inFile.clear();
    inFile.close();

    if (cnt==0)
        cout << "No data!" << endl;
    else {
        cout << "total: " << line << endl;
        cout << "data = " << cnt  << endl;
        cout << "avg  = " << sum/cnt << endl;
        cout << "max  = " << max  << endl;
    }

    return(0);
}
/*
Read text from: wifi.txt
SSID to watch: MMTEK
total: 40481
data = 1888
avg  = 27.0524
max  = 34
Press any key to continue . . .
*/