#include "../include/cfetch.h"

/* function: char *string_format(char* string)
 * input: pointer to a null-terminated string (must not be NULL)
 * return: pointer to a newly allocated string containing all space-separated words,
 * 	joined by single spaces; leading/trailing/multiple spaces are ignored.
 * on-error: returns NULL if memory allocation fails
 * misc: the returned pointer must be freed by the caller using free()
 * limits: processes at most 10 words, each up to 49 characters (last '\0')
 */
char *string_format(char* string) {
    // Wörterbuch array [Wort][Zeichenkette]
    char woerter[10][50] = { 0 };
    int wort_index = 0;
    int char_index = 0;

    while (*string != '\0') {
	// add '\0' stringterminator to end of word
	if (*string == ' ' && char_index > 0) {
	    // safty check for array length
	    if (wort_index > 9 || char_index > 49) {
		break;
	    }

	    // next slot is char
	    // add '\0' to end string
	    woerter[wort_index][char_index] = '\0';
	    wort_index++;
	    char_index = 0;
	    string++;
	    continue;
	} 
	// skip extra spaces
	else if (*string == ' ' && char_index == 0) {
	    string++;
	    continue;
	}

	// safty check for array length
	if (char_index >= 49) {
	    break;
	}

	woerter[wort_index][char_index] = *string;
	char_index++;
	string++;
    }

    // terminate last word with '\0'
    if (char_index > 0 && wort_index < 10 && char_index < 49) {
	woerter[wort_index][char_index] = '\0';
	wort_index++;
    }

    /* 
     * return
     */
    char *ptr = NULL;

    // get length of woerter array
    if (wort_index == 0) {
	ptr = NULL;
    } else {
    	int sum = 0;

	for (int i = 0; i < wort_index; i++) {
	    sum += strlen(woerter[i]);
	}
	sum += wort_index - 1; // for spaces
	sum += 1; // for Nulltermination
    

	ptr = (char *)malloc(sum);

	// check for NULL pointer
	if (ptr == NULL) {
	    return NULL;
	}

	//strcpy
	char *ende = ptr;

	for (int i = 0; i < wort_index; i++) {
	    ende = stpcpy(ende, woerter[i]);

	    if (i != wort_index - 1) {
		*(ende++) = ' ';
	    }
	}
    }

    return ptr;
}

// input two char pointer
// output: one char pointer
// misc: caller needs to free the memory
char *concat(const char *s1, const char *s2) {
    const size_t len1 = strlen(s1);
    const size_t len2 = strlen(s2);
    char *result = malloc(len1 + len2 + 1); // +1 for '\0'
    
    if (result == NULL) {
	perror("allocating memory for strings failed");
	return NULL;
    }

    memcpy(result, s1, len1);
    memcpy(result + len1, s2, len2 + 1); // +1 for null-terminator
    return result; //caller needs to free memory
}