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

#define USAGE(err) printf("USAGE: fibo [number]\nError: %s", err)

// Typedef heap and stack strings
typedef char* string;

// Define functions
int fibo_index(int index);
int fibo(int** output, int limit);
int intLength(int input);

// Main function
int main(int argc, const char** args)
{
    // Application expects 2 arguments
    if(argc != 2)
    {
        // Build an error message
        const char errorMsg[] = "Got %d arguments";
        char error[strlen(errorMsg) - 2 + intLength(argc - 1) + 1];
        sprintf(error, errorMsg, argc - 1);

        // Output usage
        USAGE(error);
    }
    else
    {
        int input;

        if(sscanf(args[1], "%d", &input))
        {
            int* range;

            if(fibo(&range, input))
            {
                printf("The fibonacci range:\n");

                int index;

                for(index = 0; index < input; index++)
                {
                    printf("%d, ", range[index]);
                }

                free(range);
            }
            else
            {
                printf("Couldn't use the input to make a fibonacci range");
            }
        }
        else
        {
            // Build an error message
            const char errorMsg[] = "Input was not a valid number: %s";
            char error[strlen(errorMsg) - 2 + strlen(args[1]) + 1];
            sprintf(error, errorMsg, args[1]);

            // Print error message
            USAGE(error);
        }
    }

    printf("\n");
}

// Returns the specified index from the fibonacci range
int fibo_index(int index)
{

}

// Returns the fibonacci range until the specified limit
int fibo(int** output, int limit)
{
    // Must be 1 or more
    if(limit < 1) return 0;

    int* range = (int*)malloc(sizeof(int) * limit);
    assert(range);

    int i;

    // Calculate the range
    for(i = 0; i < limit; i++)
    {
        int value;

        if(i == 0)  value = 0;
        if(i == 1)  value = 1;
        else        value = range[i - 2] + range[i - 1];

        range[i] = value;
    }

    *output = range;

    return 1;
}

// Count the digits by counting the number of times dividing by 10 is necessary
int intLength(int input)
{
    // 1 digit
    if(input < 10) return 1;

    else return 1 + intLength(input / 10);
}