#include "fracture.h"

bool break_edge(net_t *instance, uint_t edge, cholmod_common *c) {
	instance->fuses[edge] = true;

	if (instance->factor != NULL) {
		uint_t w1 = instance->graph->ev_break[2 * edge];
		uint_t w2 = instance->graph->ev_break[2 * edge + 1];
		factor_update(instance->factor, w1, w2, c);
	}

	uint_t v1, v2, s1, s2, dv1, dv2, ds1, ds2;

	v1 = instance->graph->ev[2 * edge];
	v2 = instance->graph->ev[2 * edge + 1];
	dv1 = instance->graph->dev[2 * edge];
	dv2 = instance->graph->dev[2 * edge + 1];

	s1 = v1 > v2 ? v1 : v2;
	s2 = v1 > v2 ? v2 : v1;
	ds1 = dv1 > dv2 ? dv1 : dv2;
	ds2 = dv1 > dv2 ? dv2 : dv1;

	{
		int_t *lap_p = (int_t *)instance->adjacency->p;
		int_t *lap_i = (int_t *)instance->adjacency->i;
		double *lap_x = (double *)instance->adjacency->x;

		for (int i = 0; i < lap_p[s1 + 1] - lap_p[s1]; i++) {
			if (lap_i[lap_p[s1] + i] == s2)
				lap_x[lap_p[s1] + i] = 0;
		}
		for (int i = 0; i < lap_p[s2 + 1] - lap_p[s2]; i++) {
			if (lap_i[lap_p[s2] + i] == s1)
				lap_x[lap_p[s2] + i] = 0;
		}
	}

	int_t old_num_components = instance->num_components;

	instance->num_components = update_components(
			instance->adjacency, instance->marks, old_num_components, s1, s2, 0);


	if (instance->graph->boundary == TORUS_BOUND) {
		if (instance->dual_marks[dv1] == instance->dual_marks[dv2]) {
			int **cycles = (int **)malloc(4*instance->graph->ne * sizeof(int *));
			unsigned int num_cycles = find_cycles(instance->graph->ne, instance->fuses, instance->graph->dev, instance->graph->dvei, instance->graph->dve, cycles);

			for (unsigned int i = 0; i < num_cycles; i++) {
				int x_num_crossings = 0;
				int y_num_crossings = 0;
				int ee; unsigned int j = 0;
				while ((ee = cycles[2*i][j]) >= 0) {
					int side = cycles[2*i+1][j];
					j++;
					unsigned int v1, v2;
					double v1x, v1y, v2x, v2y;
					v1 = instance->graph->dev[2 * ee + !side];
					v2 = instance->graph->dev[2 * ee + side];
					v1x = instance->graph->dvx[2 * v1];
					v1y = instance->graph->dvx[2 * v1 + 1];
					v2x = instance->graph->dvx[2 * v2];
					v2y = instance->graph->dvx[2 * v2 + 1];
					double dx = v1x - v2x;
					double dy = v1y - v2y;
					if (((v1x > 0.5 && v2x < 0.5) || (v1x < 0.5 && v2x > 0.5)) && fabs(dx) < 0.5) {
						x_num_crossings += dx > 0 ? 1 : -1;
					}
					if (((v1y > 0.5 && v2y < 0.5) || (v1y < 0.5 && v2y > 0.5)) && fabs(dy) < 0.5) {
						y_num_crossings += dy > 0 ? 1 : -1;
					}
				}
				if ((abs(y_num_crossings) == 0 && abs(x_num_crossings) > 0) || (abs(y_num_crossings) > 0 && abs(x_num_crossings) > 0 && num_cycles > 1)) {
					instance->num_components = 2;
				}
				free(cycles[2*i]);
				free(cycles[2*i+1]);
			}
			free(cycles);
		}
	}

	{
		int_t *lap_p = (int_t *)instance->dual_adjacency->p;
		int_t *lap_i = (int_t *)instance->dual_adjacency->i;
		double *lap_x = (double *)instance->dual_adjacency->x;

		for (int i = 0; i < lap_p[ds1 + 1] - lap_p[ds1]; i++) {
			if (lap_i[lap_p[ds1] + i] == ds2)
				lap_x[lap_p[ds1] + i] = 1;
		}
		for (int i = 0; i < lap_p[ds2 + 1] - lap_p[ds2]; i++) {
			if (lap_i[lap_p[ds2] + i] == ds1)
				lap_x[lap_p[ds2] + i] = 1;
		}
	}

	set_connected(instance->dual_adjacency, instance->dual_marks, dv1, instance->dual_marks[dv2], -1, 0);

	return true;
}