#include "fracture.h"

bool update_factor(cholmod_factor *factor, unsigned int v1, unsigned int v2,
									 cholmod_common *c) {
	int n = factor->n;
	assert(v1 < n);
	assert(v2 < n);

	cholmod_sparse *update_mat =
			CHOL_F(allocate_sparse)(n, n, 2, true, true, 0, CHOLMOD_REAL, c);

	unsigned int v3, v4;
	v3 = v1 < v2 ? v1 : v2;
	v4 = v1 > v2 ? v1 : v2;

	for (int i = 0; i < n; i++) {
		if (i <= v3)
			((int_t *)update_mat->p)[i] = 0;
		else
			((int_t *)update_mat->p)[i] = 2;
	}
	((int_t *)update_mat->p)[n] = 2;
	((int_t *)update_mat->i)[0] = v3;
	((int_t *)update_mat->i)[1] = v4;
	((double *)update_mat->x)[0] = 1;
	((double *)update_mat->x)[1] = -1;

	// assert(CHOL_F(check_sparse)(update_mat, c));

	cholmod_sparse *perm_update_mat = CHOL_F(submatrix)(
			update_mat, factor->Perm, factor->n, NULL, -1, true, true, c);

	// assert(CHOL_F(check_sparse)(perm_update_mat, c));

	CHOL_F(updown)(false, perm_update_mat, factor, c);

	// assert(CHOL_F(check_factor)(factor, c));

	CHOL_F(free_sparse)(&perm_update_mat, c);
	CHOL_F(free_sparse)(&update_mat, c);

	return true;
}