#include "include/lsort.h"
#include "include/types.h"
#include "include/quicksort.h"
#include <stdio.h>

typedef int (*int_function_pointer)(int, int);

static int default_compare_function(int a, int b) {
    return a - b;
}

static int partition(lsort_array_i* array, int L, int R, int_function_pointer compare_function) {
    int pivot = array->items[R];
    int i = L - 1;

    for (int j = L; j < R; j++) {
        if (compare_function(array->items[j], pivot) < 0) {
            i = i + 1;
            lsort_array_i_swap(array, i, j);
        }
    }

    lsort_array_i_swap(array, i + 1, R);
    return i + 1;
}

static void _quicksort(lsort_array_i* array, int L, int R, int_function_pointer compare_function) {
    if (L < R) {
        int pivotIndex = partition(array, L, R, compare_function);
        _quicksort(array, L, pivotIndex - 1, compare_function);
        _quicksort(array, pivotIndex + 1, R, compare_function);
    }
}

int lsort_quicksort(lsort_array_i* array, int_function_pointer compare_function) {
    if (array->count < 1) {
        return 0;
    }
    
    if (compare_function == NULL) compare_function = default_compare_function;
    
    _quicksort(array, 0, (int)array->count - 1, compare_function);
    
    return check_sorted(array) ? 1 : 0;
}