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

#define FILE_EXTENSION ".csv"

int main(int argc, char const *argv[])
{

	if (argc <= 1)
	{
		fprintf(stderr, "Failed to provide a csv file\n");
		exit(1);
	}

	size_t file_len = strlen(argv[1]);

	/*char pointer of*/
	char *FILE_NAME = malloc(file_len + 1);
	if (FILE_NAME == NULL)
	{
		fprintf(stderr, "Failed to allocate memory for file name!");
		exit(1);
	}

	/* Copy file name from executable's first arguments.*/
	strcpy(FILE_NAME, argv[1]);

	/*Returns a pointer to the location the substring if found*/
	if (strstr(FILE_NAME, FILE_EXTENSION) == NULL)
	{
		fprintf(stderr, "What the fuck are you doing? That %s isn't a csv file!\n", FILE_NAME);
		free(FILE_NAME);
		FILE_NAME = 0;
		exit(1);
	}

	char name[128], phone_number[13];
	// puts(FILE_NAME);
	FILE *_target_file = fopen(FILE_NAME, "a");
	if (_target_file == NULL)
	{
		exit(1);
	}

	puts("Name: ");
	scanf("%s", name);
	puts("Number: ");
	scanf("%s", phone_number);

	printf("Appending %s and %s to %s", name, phone_number, FILE_NAME);
	fprintf(_target_file, "%s,%s\n", name, phone_number);
	fclose(_target_file);
	/*clean up*/
	free(FILE_NAME);
	FILE_NAME = 0;

	return 0;
}