#include "inputHandling.h"
#include <string.h>
#include <stdio.h>
#include <stdlib.h>


char formulaBuffer[1000];

void processInput(char* formulaString, int length) {
    deleteWhitespace(formulaString, length);
    calc_op temp;
    memcpy(formulaBuffer, formulaString, length);
    temp.formel = formulaString;
    temp.funktionstyp = detectFunctionOperator(formulaBuffer, 10);
    if (getNumbers(formulaBuffer, length, &temp) == NULL){
        showStruct(&temp);
    } else {
        printf("Formular %s not supported", temp.formel);
    }
}

//Leerzeichen löschen
void deleteWhitespace(char* formulaString, int length){
    for(int stringPos=0; stringPos < length; stringPos++){
        if((formulaString[stringPos] == ' ') || (formulaString[stringPos] == '\n') || (formulaString[stringPos] == '\r')){
            for (int j=stringPos; j < length; j++){
                formulaString[j]=formulaString[j + 1];
            }
            stringPos--;
        }
    }
}

//Einfachste Rechenoperationen lesen
op detectFunctionOperator(char* formulaString, int length){
    for(int stringCount=0; stringCount < length; stringCount++){
        switch (formulaString[stringCount]){
            case '+': return opAdd;
            case '-': return opSub;
            case '/':case ':': return opDiv;
            case '*': return opMult;
            case '^': return opExp;
            case '\0': return opEmpty;
        }
    }
    return opNotSupported;
}

//Zahlen auslesen (+)
char* getNumbers(char* formulaString, int length, calc_op* formulaRef){ //processInput sind: string, länge vom String, berechnungsstruct
    // char tmp[length];
    char* splitPnt;
    int numPos = 0;
    char delimiter;
    switch (formulaRef->funktionstyp) {
        case opAdd:
            delimiter = '+';
            break;
        case opSub:
            delimiter = '-';
            break;
        case opDiv:
            delimiter = '/';
            break;
        case opMult:
            delimiter = '*';
            break;
        default: return NULL;
    }
    // memcpy(tmp, formulaString, length);     //string kopiert
    char *token = strtok(formulaString, &delimiter); //An der Stelle von dem ersten Plus wird ein NULL (Stringende) gesetzt
    while (token != NULL) {
        formulaRef->array[numPos] = atof(token);  // String zu double konvertiert
        numPos++;
        splitPnt = token;
        token = strtok(NULL, "+"); //Sucht von der letzten Plus-Stelle an weiter
    }
    formulaRef->arraylength=numPos; //Länge des Arrays (also zu berechnende Zahlen) gespeichert
    op type = detectFunctionOperator(splitPnt, strlen(splitPnt) + 1);
    if (type != opNotSupported && type != opEmpty){
        return splitPnt;
    } else {
        return NULL;
    }
}

void showStruct(calc_op* formulaRef){
    printf("Berechnung: %s\n", formulaRef->formel);
    switch (formulaRef->funktionstyp) {
        case opAdd:
            printf("Rechenoperation: Addition\n"); break;
        case opSub:
            printf("Rechenoperation: Subtraktion\n"); break;
        case opMult:
            printf("Rechenoperation: Multiplikation\n"); break;
        case opDiv:
            printf("Rechenoperation: Division\n"); break;
        default:
            printf("Fehler bei Auswahl der Rechenoperationen \n");
    }
    printf("Calculation Variables:\n");
    for (int arrayCount = 0; arrayCount < formulaRef->arraylength; ++arrayCount) {
        printf("Array[%i] = %f\n", arrayCount, formulaRef->array[arrayCount]);
    }
    printf("Result: %f", formulaRef->result);
}