/*
 * sum.c
 *
 *  Created on: 14/03/2017
 *      Author: Pedro
 */

#ifndef __OPENCL_VERSION__

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

#include "sum.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 sum type and return the ID of the constraint
 * sum(X, k)
 * X_ids - vector with the ID of the variables that may contain the value of y
 * n_vs - maximum number of variables in X vector
 * k - value of the sum of all the variables in X
 */
unsigned int c_sum(unsigned int *X_ids, unsigned int n_vs, unsigned int k) {
	unsigned int i;

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

	unsigned int *c_vs = malloc((n_vs) * sizeof(unsigned int));

	for (i = 0; i < n_vs; i++) {
		c_vs[i] = X_ids[i];
	}

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

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

	free(c_vs);

	return c_id;
}

/*
 * Creates a new reified constraint of the sum type and return the ID of the constraint
 * sum(X, k)
 * X_ids - vector with the ID of the variables that may contain the value of y
 * n_vs - maximum number of variables in X vector
 * k - value of the sum of all the variables in X
 * reif_v_id - ID of the reification variable
 */
unsigned int c_sum_reif(unsigned int *X_ids, unsigned int n_vs, unsigned int k, int reif_v_id) {
	unsigned int i;

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

		if (VS[reif_v_id].n_vals == 0) {
			printf("\nConstraint SUM_REIF makes model inconsistent at creation. No solution found.\n");

#if defined(WIN32) || defined(_WIN32) || defined(__WIN32) && !defined(__CYGWIN__)
			printf("\nPress any key to exit\n");
			int a = getchar();
#endif

			exit(0);
		}
	}

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

	unsigned int *c_vs = malloc((n_vs) * sizeof(unsigned int));

	for (i = 0; i < n_vs; i++) {
		c_vs[i] = X_ids[i];
	}

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

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

	free(c_vs);

	return c_id;
}

/*
 * Return true if the sum constraint is respected or false if not
 * sum(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 sum_check(constr *c, bool explored) {
	var **X = c->c_vs;
	var *x;
	int k = c->constant_val;
	int sum = 0;
	unsigned int i;

	if (!explored) {
		for (i = 0; i < c->n_c_vs; i++) {
			if (c->c_vs[i]->n_vals > 1) {
				return false;
			}
		}
	}

	if (c->reified && VS[c->reif_v_id].n_vals > 1) {
		if (explored) {
			fprintf(stderr, "\nError: Reification variable of constraint SUM_REIF (%d) has 2 values.\n", c->c_id);
			return false;
		}
	}

	for (i = 0; i < c->n_c_vs; i++) {
		x = X[i];

		sum += x->min;
	}

	if (((!c->reified || (c->reified && VS[c->reif_v_id].min == 1)) && sum != k) || (c->reified && VS[c->reif_v_id].min == 0 && sum == k)) {

		if (explored) {

			if (c->reified) {
				fprintf(stderr, "\nError: Constraint SUM_REIF (%d) not respected:\n", c->c_id);
				fprintf(stderr, "Reif ID=%u -> minimum=%u, maximum=%u, number of values=%u\n\n", c->reif_v_id, b_get_min_val(&VS[c->reif_v_id].domain_b),
						b_get_max_val(&VS[c->reif_v_id].domain_b), b_cnt_vals(&VS[c->reif_v_id].domain_b));

			} else {
				fprintf(stderr, "\nError: Constraint SUM_LE (%d) not respected:\n", c->c_id);
			}

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

	return true;
}

#endif

#if CS_SUM == 1
/*
 * Propagate the domain of the variable with the ID prop_v_id through all the other variables on the same c_numb ID sum constraint
 * sum(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
 * prop_ok - will be set to 1 or 0 if the constraint is respected or not
 * terms_mem - auxiliary buffer
 */
CUDA_FUNC void sum_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, __global int *terms_mem CS_IGNORE_FUNC TTL_CTR) {

	int terms = current_cs->n_c_vs;	// number of constants and variables constrained by this constraint
	int equat_result = current_cs->constant_val;
	int y_id;
	__global int *mins = terms_mem;
	__global int *maxs = &terms_mem[current_cs->n_c_vs];
	int min, max;
	int xmin, xmax, bound;
	bool changed = 0;
	int i;

	min = 0;
	max = 0;
	for (i = 0; i < terms; i++) {
		CHECK_TTL(ttl_ctr, 69)
		y_id = vs_per_c_idx[i];

		min += mins[i] = V_MIN(vs_prop_[y_id]);
		max += maxs[i] = V_MAX(vs_prop_[y_id]);
	}

	if (min > equat_result || max < equat_result) {
		*prop_ok = 0;
		return;
	}

	if (min == max) {

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

	if (min == equat_result) {
		for (i = 0; i < terms; i++) {
			CHECK_TTL(ttl_ctr, 70)
			y_id = vs_per_c_idx[i];

			if (V_N_VALS(vs_prop_[y_id]) > 1) {
				cl_v_del_all_except_val_m(&changed, &vs_prop_[y_id], mins[i] TTL_CTR_V);
				v_add_to_prop(vs_id_to_prop_, vs_prop_, y_id);
			}
		}

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

		return;
	}

	if (max == equat_result) {
		for (i = 0; i < terms; i++) {
			CHECK_TTL(ttl_ctr, 71)
			y_id = vs_per_c_idx[i];

			if (V_N_VALS(vs_prop_[y_id]) > 1) {
				cl_v_del_all_except_val_m(&changed, &vs_prop_[y_id], maxs[i] TTL_CTR_V);
				v_add_to_prop(vs_id_to_prop_, vs_prop_, y_id);
			}
		}

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

#if CL_USE_BOOLEAN_VS
	if (current_cs->boolean == 0) {	// not all X are boolean
#endif
		if (max > equat_result) {
			for (i = 0; i < terms; i++) {
				CHECK_TTL(ttl_ctr, 72)
				y_id = vs_per_c_idx[i];

				if (V_N_VALS(vs_prop_[y_id]) > 1) {

					xmin = mins[i];
					xmax = maxs[i];

					if (xmax - xmin > equat_result - min) {
						bound = equat_result - min + xmin;

						cl_v_del_gt_m(&changed, &vs_prop_[y_id], bound TTL_CTR_V);
						if (changed) {
							if (V_IS_EMPTY(vs_prop_[y_id])) {
								*prop_ok = 0;
								return;
							}
							v_add_to_prop(vs_id_to_prop_, vs_prop_, y_id);
						}
					}
				}
			}
		}

		if (min < equat_result) {
			for (i = 0; i < terms; i++) {
				CHECK_TTL(ttl_ctr, 73)
				y_id = vs_per_c_idx[i];

				if (V_N_VALS(vs_prop_[y_id]) > 1) {

					xmin = mins[i];
					xmax = maxs[i];

					if (xmax - xmin > max - equat_result) {
						bound = equat_result - max + xmax;

						cl_v_del_lt_m(&changed, &vs_prop_[y_id], bound TTL_CTR_V);
						if (changed) {
							if (V_IS_EMPTY(vs_prop_[y_id])) {
								*prop_ok = 0;
								return;
							}
							v_add_to_prop(vs_id_to_prop_, vs_prop_, y_id);
						}
					}
				}
			}
		}
#if CL_USE_BOOLEAN_VS
	}
#endif
}

#if CS_R_SUM == 1
/*
 * Validate sum constraint to be normally propagated, when reified
 * sum(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 sum_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 terms = current_cs->n_c_vs;	// number of constants and variables constrained by this constraint
	int equat_result = current_cs->constant_val;
	int y_id;
	int min, max;
	int i;

	min = 0;
	max = 0;
	for (i = 0; i < terms; i++) {
		CHECK_TTL(ttl_ctr, 74)
		y_id = vs_per_c_idx[i];

		min += V_MIN(vs_prop_[y_id]);
		max += V_MAX(vs_prop_[y_id]);
	}

	if (min > equat_result || max < equat_result) {
		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;
	}

	// constraint already fixed
	if (min == max && min == equat_result) {
		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));

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

/*
 * Propagate the domain of the variable with the ID prop_v_id through all the other variables on the same c_numb ID sum opposite constraint
 * !sum(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
 * prop_ok - will be set to 1 or 0 if the constraint is respected or not
 */
CUDA_FUNC void sum_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 terms = current_cs->n_c_vs;	// number of constants and variables constrained by this constraint
	int equat_result = current_cs->constant_val;
	int y_id;
	int min, max;
	bool changed = 0;
	int not_singl = 0;
	int not_singl_id = -1;
	int val_to_rem;
	int sum = 0;
	int i;

	min = 0;
	max = 0;
	for (i = 0; i < terms; i++) {
		CHECK_TTL(ttl_ctr, 69)
		y_id = vs_per_c_idx[i];

		min += V_MIN(vs_prop_[y_id]);
		max += V_MAX(vs_prop_[y_id]);

		if (V_N_VALS(vs_prop_[y_id]) != 1) {
			not_singl_id = y_id;
			not_singl++;

		} else {
			sum += V_MIN(vs_prop_[y_id]);
		}
	}
	sum -= equat_result;

	if (min == max && min == equat_result) {
		*prop_ok = 0;
		return;
	}

	if (min > equat_result || max < equat_result) {

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

	// if all but one variable are already singleton, remove the only value from the one that is not singleton that would lead to equality
	if (not_singl == 1) {
		val_to_rem = (-1) * sum;

		if (val_to_rem >= 0) {

			cl_v_del_val_m(&changed, &vs_prop_[not_singl_id], val_to_rem TTL_CTR_V);

			if (changed) {
				v_add_to_prop(vs_id_to_prop_, vs_prop_, not_singl_id);
			}
		}

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

#endif

/*
 * Decides the propagator to call for this constraint
 * 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
 * prop_ok - will be set to 1 or 0 if the constraint is respected or not
 * terms_mem - auxiliary buffer
 */
CUDA_FUNC void sum_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, __global int *terms_mem PROPAGATED_FUNC CS_IGNORE_FUNC TTL_CTR) {

#if CS_R_SUM == 0
	sum_prop(vs_per_c_idx, vs_prop_, current_cs, vs_id_to_prop_, prop_ok, terms_mem CS_IGNORE_CALL TTL_CTR_V);
#if CL_STATS == 1
	*propagated = true;
#endif

#elif CS_R_SUM == 1
	if (current_cs->reified == 1) {
		if (V_N_VALS(vs_prop_[current_cs->reif_var_id]) > 1) {
			sum_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) {
				sum_prop(vs_per_c_idx, vs_prop_, current_cs, vs_id_to_prop_, prop_ok, terms_mem CS_IGNORE_CALL TTL_CTR_V);
			} else {
				sum_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 {
		sum_prop(vs_per_c_idx, vs_prop_, current_cs, vs_id_to_prop_, prop_ok, terms_mem CS_IGNORE_CALL TTL_CTR_V);
#if CL_STATS == 1
		*propagated = true;
#endif
	}
#endif
}

#endif