/*
 * main.c
 *
 *  Created on: Oct 8, 2016
 *      Author: Aden
 */

#include<stdio.h>
#include<stdlib.h>
#include<conio.h>
#include<unistd.h>

double calcMach(float alt, float vel);

int main(){

    FILE *fp1, *fp2;
    char buffer[4], swap[4];
    float value, alt, vel, mach, timeS;
    int timeMS=0;
    int i=1;

//  printf("Hello World\n");
//  system("PAUSE");

    fp1 = fopen("tmp/Alt_AS.dat", "rb");
    fp2 = fopen("tmp/flightdata.csv", "w");
    fprintf(fp2,"time (s),altitude (ft),velocity (knots),mach\n");
    fclose (fp2);                                   // Create blank file with headder

    fp2 = fopen("tmp/flightdata.csv", "a");

    while (fread(buffer, 1, 4, fp1) == 4) {         // Read the data file
        swap[3]=buffer[0];
        swap[2]=buffer[1];                          // Byte swap 4 bytes
        swap[1]=buffer[2];
        swap[0]=buffer[3];
        value=*((float*)&swap);                     // Convert to Float
        if (i==1) {                                 // Alternate* every other swap between Altitude and Velocity
            timeS = (timeMS*0.1);
            printf("Time: %*.1f\n", 6, timeS);      // Display while running
            alt=value;
//          printf("Alt: %*.0f\n", 7, alt);
            fprintf(fp2,"%.1f,%g,", timeS, alt);    // Record altitude to CSV
        } else {
            vel=value;
//          printf("Vel: %*.2f\n", 7, vel);
            mach=calcMach(alt, vel);                // Calculate the Mach Speed
//          printf("Mach: %*.2f\n\n", 6, mach);
            timeMS+=1;
            fprintf(fp2,"%g,%.2f\n", vel, mach);    // Record the Velocity & Mach Speed
        }

        i*=-1;                                      // Alternate*

    }


    fclose (fp1);
    fclose (fp2);                                   // Close Files
//  system("PAUSE");
    return 0;
}

double calcMach(float alt, float vel) {
    float mach=0;

    if (alt > 4000){
        mach=573;
    } else if (alt>30000){
        mach=alt-30000;
        mach*=-0.0016;
        mach+=589;
    } else if (alt>20000){
        mach=alt-20000;
        mach*=-0.0025;
        mach+=614;
    } else if (alt>10000){
        mach=alt-10000;
        mach*=-0.0024;
        mach+=638;
    } else if (alt>0){
        mach*=-0.0023;
        mach+=661;
    } else {
        mach=661;
    }
    mach=vel/mach;

    return mach;

}