/*
 * eq.c
 *
 *  Created on: 09/06/2018
 *      Author: pedro
 */

#ifndef __OPENCL_VERSION__

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

#include "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 eq type and return the constraint ID
 * x = k
 * x_id - ID of variable x
 * k - value that must be assigned to variable x
 */
unsigned int c_eq(unsigned int x_id, unsigned int k) {

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

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

	// pointers to this type of constraint functions
	CS[c_id].kind = EQ;
	CS[c_id].check_sol_f = &eq_check;
	CS[c_id].constant_val = (int)k;

	return c_id;
}

/*
 * Creates a new reified constraint of the eq type and return the constraint ID
 * x = k
 * x_id - ID of variable x
 * k - value that must be assigned to variable x
 * reif_v_id - ID of the reification variable
 */
unsigned int c_eq_reif(unsigned int x_id, unsigned 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 EQ_REIF makes model inconsistent at creation:\n");
			exit(-1);
		}
	}

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

	// creates a new generic constraint
	unsigned int c_id = c_new(&x_id, 1, NULL, 0, reif_v_id);

	// pointers to this type of constraint functions
	CS[c_id].kind = EQ;
	CS[c_id].check_sol_f = &eq_check;
	CS[c_id].constant_val = (int)k;

	return c_id;
}

/*
 * Return true if the eq constraint is respected or false if not
 * x = 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 eq_check(constr* c, bool explored) {
	// check if any variable inside the eq constraint has domain 0, more than one value
	// or if a is different than b. 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) ||
#endif
			c->c_vs[0]->min != c->constant_val) {

		if (explored) {
			fprintf(stderr, "\nError: Constraint 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, "k=%d\n\n", c->constant_val);
		}
		return false;
	}

	return true;
}

#endif

#if CS_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 eq constraint
 * x = 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 eq_prop(CL_INTS_MEM int* vs_per_c_idx, CL_MEMORY VARS_PROP* vs_prop_, 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 k = current_cs->constant_val;
	bool changed = 0;

	cl_v_del_all_except_val_m(&changed, &vs_prop_[x_id], k 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
}

#if CS_R_EQ == 1
/*
 * Validate eq constraint to be normally propagated, when reified
 * x = 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 eq_reif( CL_INTS_MEM int* vs_per_c_idx, CL_MEMORY VARS_PROP* vs_prop_, CL_CS_MEM cl_constr* current_cs, CL_MEMORY unsigned short* vs_id_to_prop_
		CS_IGNORE_FUNC TTL_CTR) {

	int x_id = vs_per_c_idx[0];
	int k = current_cs->constant_val;
	bool contains = 0;

	// already fixed to k
	if (V_N_VALS(vs_prop_[x_id]) == 1) {

		if (V_MIN(vs_prop_[x_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));

		} else {
			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));
		}

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

		return;
	}

	// does not contain k
	cl_v_contains_val_m(&contains, &vs_prop_[x_id], k TTL_CTR_V);
	if (!contains) {
		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));

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

/*
 * Propagate the domain of the variable with the ID prop_v_id through all the other variables on the same c_numb ID eq opposite constraint
 * x != 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 eq_prop_opposite(CL_INTS_MEM int* vs_per_c_idx, CL_MEMORY VARS_PROP* vs_prop_, 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 k = current_cs->constant_val;
	bool changed = 0;

	cl_v_del_val_m(&changed, &vs_prop_[x_id], k 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 eq_propagate(CL_INTS_MEM int* vs_per_c_idx, CL_MEMORY VARS_PROP* vs_prop_, 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_EQ == 0
	eq_prop(vs_per_c_idx, vs_prop_, current_cs, vs_id_to_prop_, prop_ok CS_IGNORE_CALL TTL_CTR_V);

#if CL_STATS == 1
	*propagated = true;
#endif

#elif CS_R_EQ == 1
	if (current_cs->reified == 1) {
		if (V_N_VALS(vs_prop_[current_cs->reif_var_id]) > 1) {
			eq_reif(vs_per_c_idx, vs_prop_, current_cs, vs_id_to_prop_ CS_IGNORE_CALL TTL_CTR_V);

		} else {
			if (V_MIN(vs_prop_[current_cs->reif_var_id]) == 1) {
				eq_prop(vs_per_c_idx, vs_prop_, current_cs, vs_id_to_prop_, prop_ok CS_IGNORE_CALL TTL_CTR_V);
			} else {
				eq_prop_opposite(vs_per_c_idx, vs_prop_, current_cs, vs_id_to_prop_, prop_ok CS_IGNORE_CALL TTL_CTR_V);
			}
#if CL_STATS == 1
			*propagated = true;
#endif
		}
	} else {
		eq_prop(vs_per_c_idx, vs_prop_, current_cs, vs_id_to_prop_, prop_ok CS_IGNORE_CALL TTL_CTR_V);
#if CL_STATS == 1
		*propagated = true;
#endif
	}
#endif
}

#endif