/*
 * minus_eq.c
 *
 *  Created on: 26/01/2017
 *      Author: pedro
 */

#ifndef __OPENCL_VERSION__

#include <stddef.h>
#include <stdio.h>

#include "minus_eq.h"

#include "../bitmaps.h"
#include "../config.h"
#include "../variables.h"

#endif

#include "../kernels/cl_aux_functions.h"
#if CL_D_TYPE == CL_BITMAP
#include "../kernels/cl_bitmaps.h"
#elif CL_D_TYPE == CL_INTERVAL
#include  "../kernels/cl_intervals.h"
#endif
#include "../kernels/cl_constraints.h"
#include "../kernels/cl_variables.h"
#include "../kernels/cl_ttl.h"

#ifndef __OPENCL_VERSION__

/*
 * Creates a new constraint of the minus_eq type and return the constraint ID
 * x − y = k
 * x_id - ID of variable x
 * y_id - ID of variable y
 * k - constant value for this constraint
 */
unsigned int c_minus_eq(unsigned int x_id, unsigned int y_id, int k) {

	// set to include in kernel compilation
	USE_CS[MINUS_EQ] = 1;
	USE_NON_CS_REIFI[MINUS_EQ] = 1;
	REV = 1;

	unsigned int c_vs[2];
	c_vs[0] = x_id;
	c_vs[1] = y_id;

	// creates a new generic constraint
	unsigned int c_id = c_new(c_vs, 2, NULL, 0, -1);

	// pointers to this type of constraint functions
	CS[c_id].kind = MINUS_EQ;
	CS[c_id].check_sol_f = &minus_eq_check;
	CS[c_id].constant_val = k;

	return c_id;
}

/*
 * Creates a new reified constraint of the minus_eq type and return the constraint ID
 * x − y = k
 * x_id - ID of variable x
 * y_id - ID of variable y
 * k - constant value for this constraint
 * reif_v_id - ID of the reification variable
 */
unsigned int c_minus_eq_reif(unsigned int x_id, unsigned int y_id, int k, int reif_v_id) {

	if (VS[reif_v_id].max > 1) {
		v_del_gt(&VS[reif_v_id], 1);

		if (VS[reif_v_id].n_vals == 0) {
			fprintf(stderr, "\nError: Constraint MINUS_EQ_REIF makes model inconsistent at creation:\n");
			exit(-1);
		}
	}

	// set to include in kernel compilation
	USE_CS[MINUS_EQ] = 1;
	USE_CS_REIFI[MINUS_EQ] = 1;
	REV = 1;

	unsigned int c_vs[2];
	c_vs[0] = x_id;
	c_vs[1] = y_id;

	// creates a new generic constraint
	unsigned int c_id = c_new(c_vs, 2, NULL, 0, reif_v_id);

	// pointers to this type of constraint functions
	CS[c_id].kind = MINUS_EQ;
	CS[c_id].check_sol_f = &minus_eq_check;
	CS[c_id].constant_val = k;

	return c_id;
}

/*
 * Return true if the minus_eq constraint is respected or false if not
 * x − y = k
 * c - constraint to check if is respected
 * explored - if the CSP was already explored, which mean that all the variables must already be singletons
 * */
bool minus_eq_check(constr* c, bool explored) {
	// check if any variable inside same a_minus_b_ne_c constraint has domain 0, more than one value
	// or if the difference is equal to constant_val. If so, return false. Else return true.
	if (
#if CHECK_SOL_N_VALS
			(c->c_vs[0]->to_label && c->c_vs[0]->n_vals != 1) || (c->c_vs[1]->to_label && c->c_vs[1]->n_vals != 1) ||
#endif
			c->c_vs[0]->min - c->c_vs[1]->min != c->constant_val) {
		if (explored) {
			fprintf(stderr, "\nError: Constraint MINUS_EQ (%d) not respected:\n", c->c_id);

			fprintf(stderr, "Variable ID=%u -> minimum=%u, maximum=%u, number of values=%u\n\n", c->c_vs[0]->v_id, b_get_min_val(&c->c_vs[0]->domain_b),
					b_get_max_val(&c->c_vs[0]->domain_b), b_cnt_vals(&c->c_vs[0]->domain_b));
			fprintf(stderr, "Variable ID=%u -> minimum=%u, maximum=%u, number of values=%u\n\n", c->c_vs[1]->v_id, b_get_min_val(&c->c_vs[1]->domain_b),
					b_get_max_val(&c->c_vs[1]->domain_b), b_cnt_vals(&c->c_vs[1]->domain_b));
		}
		return false;
	}

	return true;
}

#endif

#if CS_MINUS_EQ == 1
/*
 * Propagate the domain of the variable with the ID prop_v_id through all the other variables on the same c_numb ID minus_eq constraint
 * x − y = k
 * prop_ok will be set to 1 if success or to 0 if any domain became empty
 * vs_per_c_idx - vector with all constrained variables ID per constraint, per constraint ID order
 * vs_prop_ - all CSP variables with current step values
 * prop_v_id - variable ID to propagate
 * current_cs - constraint that should be propagated for the variable with prop_v_id ID
 * vs_id_to_prop_ - circular vector with the ids of the variables to propagate
 */
CUDA_FUNC void minus_eq_prop(CL_INTS_MEM int* vs_per_c_idx, CL_MEMORY VARS_PROP* vs_prop_, unsigned int prop_v_id, CL_CS_MEM cl_constr* current_cs, CL_MEMORY unsigned short* vs_id_to_prop_,
		bool* prop_ok TTL_CTR) {

	int x_id = vs_per_c_idx[0];
	int y_id = vs_per_c_idx[1];
	int k = current_cs->constant_val;
	bool changed1 = 0;
	bool changed2 = 0;

	if (prop_v_id == (unsigned int)x_id) {
		cl_v_del_lt_m(&changed1, &vs_prop_[y_id], V_MIN(vs_prop_[x_id]) - k TTL_CTR_V);
		if (changed1) {
			if (V_IS_EMPTY(vs_prop_[y_id])) {
				*prop_ok = 0;
				return;
			}
		}
		cl_v_del_gt_m(&changed2, &vs_prop_[y_id], V_MAX(vs_prop_[x_id]) - k TTL_CTR_V);
		if (changed2) {
			if (V_IS_EMPTY(vs_prop_[y_id])) {
				*prop_ok = 0;
				return;
			}
		}
		if (changed1 || changed2) {
			v_add_to_prop(vs_id_to_prop_, vs_prop_, y_id);
		}
		return;
	}
	// if prop_v_id == y_id
	cl_v_del_lt_m(&changed1, &vs_prop_[x_id], V_MIN(vs_prop_[y_id]) + k TTL_CTR_V);
	if (changed1) {
		if (V_IS_EMPTY(vs_prop_[x_id])) {
			*prop_ok = 0;
			return;
		}
	}
	cl_v_del_gt_m(&changed2, &vs_prop_[x_id], V_MAX(vs_prop_[y_id]) + k TTL_CTR_V);
	if (changed2) {
		if (V_IS_EMPTY(vs_prop_[x_id])) {
			*prop_ok = 0;
			return;
		}
	}
	if (changed1 || changed2) {
		v_add_to_prop(vs_id_to_prop_, vs_prop_, x_id);
	}
}

#if CS_R_MINUS_EQ == 1
/*
 * Validate minus_eq constraint to be normally propagated, when reified
 * x − y = k
 * vs_per_c_idx - vector with all constrained variables ID per constraint, per constraint ID order
 * vs_prop_ - all CSP variables with current step values
 * current_cs - constraint that should be propagated for the variable with prop_v_id ID
 * vs_id_to_prop_ - circular vector with the ids of the variables to propagate
 */
CUDA_FUNC void minus_eq_reif( CL_INTS_MEM int* vs_per_c_idx, CL_MEMORY VARS_PROP* vs_prop_, unsigned int prop_v_id, CL_CS_MEM cl_constr* current_cs, CL_MEMORY unsigned short* vs_id_to_prop_ TTL_CTR) {

	int x_id = vs_per_c_idx[0];
	VARS_PROP x;
	int y_id = vs_per_c_idx[1];
	VARS_PROP y;
	int k = current_cs->constant_val;
	bool changed = 0;

	// constraint already fixed
	if (V_N_VALS(vs_prop_[x_id]) == 1 && V_N_VALS(vs_prop_[y_id]) == 1 && V_MIN(vs_prop_[x_id]) - V_MIN(vs_prop_[y_id]) == k) {
		cl_v_bool_del_val_m(&vs_prop_[current_cs->reif_var_id], 0 TTL_CTR_V);
		v_add_to_prop(vs_id_to_prop_, vs_prop_, convert_int(current_cs->reif_var_id));
		return;
	}

	// if the variable have only one value on its domain
	if (prop_v_id == (unsigned int)x_id) {
		cl_v_copy_pm(&y, &vs_prop_[y_id] TTL_CTR_V);

		cl_v_del_lt_n(&changed, &y, V_MIN(vs_prop_[x_id]) - k TTL_CTR_V);
		if (V_IS_EMPTY(y)) {
			cl_v_bool_del_val_m(&vs_prop_[current_cs->reif_var_id], 1 TTL_CTR_V);
			v_add_to_prop(vs_id_to_prop_, vs_prop_, convert_int(current_cs->reif_var_id));
			return;
		}

		cl_v_del_gt_n(&changed, &y, V_MAX(vs_prop_[x_id]) - k TTL_CTR_V);
		if (V_IS_EMPTY(y)) {
			cl_v_bool_del_val_m(&vs_prop_[current_cs->reif_var_id], 1 TTL_CTR_V);
			v_add_to_prop(vs_id_to_prop_, vs_prop_, convert_int(current_cs->reif_var_id));
		}
		return;

	}

	// if prop_v_id == y_id
	cl_v_copy_pm(&x, &vs_prop_[x_id] TTL_CTR_V);

	cl_v_del_lt_n(&changed, &x, V_MIN(vs_prop_[y_id]) + k TTL_CTR_V);
	if (V_IS_EMPTY(x)) {
		cl_v_bool_del_val_m(&vs_prop_[current_cs->reif_var_id], 1 TTL_CTR_V);
		v_add_to_prop(vs_id_to_prop_, vs_prop_, convert_int(current_cs->reif_var_id));
		return;
	}

	cl_v_del_gt_n(&changed, &x, V_MAX(vs_prop_[y_id]) + k TTL_CTR_V);
	if (V_IS_EMPTY(x)) {
		cl_v_bool_del_val_m(&vs_prop_[current_cs->reif_var_id], 1 TTL_CTR_V);
		v_add_to_prop(vs_id_to_prop_, vs_prop_, convert_int(current_cs->reif_var_id));
	}
}

/*
 * Propagate the domain of the variable with the ID prop_v_id through all the other variables on the same c_numb ID minus_eq opposite constraint
 * x − y != k
 * vs_per_c_idx - vector with all constrained variables ID per constraint, per constraint ID order
 * vs_prop_ - all CSP variables with current step values
 * prop_v_id - variable ID to propagate
 * current_cs - constraint that should be propagated for the variable with prop_v_id ID
 * vs_id_to_prop_ - circular vector with the ids of the variables to propagate
 */
CUDA_FUNC void minus_eq_prop_opposite(CL_INTS_MEM int* vs_per_c_idx, CL_MEMORY VARS_PROP* vs_prop_, unsigned int prop_v_id, CL_CS_MEM cl_constr* current_cs, CL_MEMORY unsigned short* vs_id_to_prop_,
		bool* prop_ok CS_IGNORE_FUNC TTL_CTR) {

	int x_id = vs_per_c_idx[0];
	int y_id = vs_per_c_idx[1];
	bool changed = 0;

	// if the variable have only one value on its domain
	if (V_N_VALS(vs_prop_[prop_v_id]) == 1) {

		if (prop_v_id == (unsigned int)x_id) {

			// prune domain
			cl_v_del_val_m(&changed, &vs_prop_[y_id], V_MIN(vs_prop_[x_id]) - current_cs->constant_val TTL_CTR_V);
			if (changed) {

				// if the removal of the value resulted in an empty domain return 0
				if (V_IS_EMPTY(vs_prop_[y_id])) {
					*prop_ok = 0;
					return;
				}
				// Add variable to the vector that contains the variables that must be propagated
				v_add_to_prop(vs_id_to_prop_, vs_prop_, y_id);
			}
			return;
		}

		cl_v_del_val_m(&changed, &vs_prop_[x_id], V_MIN(vs_prop_[y_id]) + current_cs->constant_val TTL_CTR_V);
		if (changed) {

			// if the removal of the value resulted in an empty domain return 0
			if (V_IS_EMPTY(vs_prop_[x_id])) {
				*prop_ok = 0;
				return;
			}
			// Add variable to the vector that contains the variables that must be propagated
			v_add_to_prop(vs_id_to_prop_, vs_prop_, x_id);
		}

#if CL_CS_IGNORE
	cs_ignore[current_cs->c_id] = 1;
#endif
	}
}
#endif


CUDA_FUNC void minus_eq_propagate(CL_INTS_MEM int* vs_per_c_idx, CL_MEMORY VARS_PROP* vs_prop_, unsigned int prop_v_id, CL_CS_MEM cl_constr* current_cs, CL_MEMORY unsigned short* vs_id_to_prop_,
		bool* prop_ok PROPAGATED_FUNC CS_IGNORE_FUNC TTL_CTR) {

#if CS_R_MINUS_EQ == 0
	minus_eq_prop(vs_per_c_idx, vs_prop_, prop_v_id, current_cs, vs_id_to_prop_, prop_ok TTL_CTR_V);
#if CL_STATS == 1
	*propagated = true;
#endif
#elif CS_R_MINUS_EQ == 1
	if (current_cs->reified == 1) {
		if (prop_v_id != current_cs->reif_var_id) {
			if (V_N_VALS(vs_prop_[current_cs->reif_var_id]) > 1) {
				minus_eq_reif(vs_per_c_idx, vs_prop_, prop_v_id, current_cs, vs_id_to_prop_ TTL_CTR_V);
			}
			if (V_N_VALS(vs_prop_[current_cs->reif_var_id]) == 1) {
				if (V_MIN(vs_prop_[current_cs->reif_var_id]) == 1) {
					minus_eq_prop(vs_per_c_idx, vs_prop_, prop_v_id, current_cs, vs_id_to_prop_, prop_ok TTL_CTR_V);
				} else {
					minus_eq_prop_opposite(vs_per_c_idx, vs_prop_, prop_v_id, current_cs, vs_id_to_prop_, prop_ok CS_IGNORE_CALL TTL_CTR_V);
				}
#if CL_STATS == 1
				*propagated = true;
#endif
			}
		}
	} else {
		minus_eq_prop(vs_per_c_idx, vs_prop_, prop_v_id, current_cs, vs_id_to_prop_, prop_ok TTL_CTR_V);
#if CL_STATS == 1
		*propagated = true;
#endif
	}
#endif
}

#endif