/*
 * linear_ne.c
 *
 *  Created on: 31/12/2017
 *      Author: pedro
 */

#ifndef __OPENCL_VERSION__

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

#include "linear_ne.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 linear_ne type and return the constraint ID
 * K · Y != c
 * K - constant unsigned integers for this constraint
 * Y_ids - IDs of the variables constrained by this constraint
 * n - number of constants (or variables)
 * c - result of the equation
 */
unsigned int c_linear_ne(int* K, unsigned int* Y_ids, unsigned int n, int c) {
	unsigned int i;

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

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

	for (i = 0; i < n; i++) {
		c_vs[i] = Y_ids[i];
	}

	// creates a new generic constraint
	unsigned int c_id = c_new(c_vs, n, K, n, -1);

	// pointers to this type of constraint functions
	CS[c_id].kind = LINEAR_NE;
	CS[c_id].check_sol_f = &linear_ne_check;
	CS[c_id].constant_val = c;

	free(c_vs);

	return c_id;
}

/*
 * Creates a new reified constraint of the linear_ne type and return the constraint ID
 * K · Y != c
 * K - constant unsigned integers for this constraint
 * Y_ids - IDs of the variables constrained by this constraint
 * n - number of constants (or variables)
 * c - result of the equation
 * reif_v_id - ID of the reification variable
 */
unsigned int c_linear_ne_reif(int* K, unsigned int* Y_ids, unsigned int n, int c, 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) {
			fprintf(stderr, "\nError: Constraint LINEAR_NE_REIF makes model inconsistent at creation:\n");
			exit(-1);
		}
	}

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

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

	for (i = 0; i < n; i++) {
		c_vs[i] = Y_ids[i];
	}

	// creates a new generic constraint
	unsigned int c_id = c_new(c_vs, n, K, n, reif_v_id);

	// pointers to this type of constraint functions
	CS[c_id].kind = LINEAR_NE;
	CS[c_id].check_sol_f = &linear_ne_check;
	CS[c_id].constant_val = c;

	free(c_vs);

	return c_id;
}

/*
 * Return true if the linear_ne constraint is respected or false if not
 * K · Y != c
 * 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 linear_ne_check(constr* c, bool explored) {
	unsigned int n = c->n_c_consts;		// number of constants and variables constrained by this constraint
	int* K = c->c_consts;	// constants constrained by this constraint
	var** Y = c->c_vs;	// variables constrained by this constraint
	int equat_result = 0;
	unsigned int i;

	// if any other variable has more than one value or is empty
#if CHECK_SOL_N_VALS
	for (i = 0; i < n; i++) {
		if (Y[i]->to_label && Y[i]->n_vals != 1) {

			if (explored) {
				fprintf(stderr, "\nError: Constraint LINEAR_NE (%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;
		}
	}
#endif

	for (i = 0; i < n; i++) {
		equat_result += K[i] * Y[i]->min;
	}

	if (equat_result == c->constant_val) {

		if (explored) {
			fprintf(stderr, "\nError: Constraint LINEAR_NE (%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_LINEAR_NE == 1
/*
 * Propagate the domain of the variable with the ID prop_v_id through all the other variables on the same c_numb ID linear_ne constraint
 * K · Y != c
 * 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
 * c_consts - vector with all constrained constants 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 linear_ne_prop(CL_INTS_MEM int* vs_per_c_idx, CL_INTS_MEM int* c_consts, 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_consts;	// number of constants and variables constrained by this constraint
	CL_INTS_MEM int* K = c_consts;	// constants constrained by this constraint
	int equat_result = current_cs->constant_val;
	int y_id;
	__global int* mins = terms_mem;
	int vl, vh;
	int min, max;
	bool changed = 0;
	int not_singl = 0;
	int not_singl_idx = 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];
		if (K[i] > 0) {
			vl = mins[i] = V_MIN(vs_prop_[y_id]);
			vh = V_MAX(vs_prop_[y_id]);
		} else {
			vl = V_MAX(vs_prop_[y_id]);
			vh = mins[i] = V_MIN(vs_prop_[y_id]);
		}

		if (K[i] != 0) {
			if (vl != vh) {
				not_singl_idx = i;
				not_singl_id = y_id;
				not_singl++;

			} else {
				sum += K[i] * mins[i];
			}
		}

		min += K[i] * vl;
		max += K[i] * vh;
	}
	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 variable that is not singleton that would lead to equality
	if (not_singl == 1) {
		val_to_rem = (-1) * (sum / K[not_singl_idx]);

		if (sum % K[not_singl_idx] == 0 && 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

	}
}

#if CS_R_LINEAR_NE == 1
/*
 * Validate linear_ne constraint to be normally propagated, when reified
 * K · Y != c
 * vs_per_c_idx - vector with all constrained variables ID per constraint, per constraint ID order
 * c_consts - vector with all constrained constants 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 linear_ne_reif( CL_INTS_MEM int* vs_per_c_idx, CL_INTS_MEM int* c_consts, CL_MEMORY VARS_PROP* vs_prop_, CL_CS_MEM cl_constr* current_cs,
		CL_MEMORY unsigned short* vs_id_to_prop_, __global int* terms_mem CS_IGNORE_FUNC TTL_CTR) {

	int terms = current_cs->n_c_consts;	// number of constants and variables constrained by this constraint
	CL_INTS_MEM int* K = c_consts;	// constants constrained by this constraint
	int equat_result = current_cs->constant_val;
	int y_id;
	VARS_PROP y;
	__global int* mins = terms_mem;
	int vl, vh;
	int min, max;
	bool changed = 0;
	int not_singl = 0;
	int not_singl_idx;
	int not_singl_id;
	int val_to_rem;
	int sum = 0;
	int i;

	min = 0;
	max = 0;
	for (i = 0; i < terms; ++i) {
		CHECK_TTL(ttl_ctr, 74)
		y_id = vs_per_c_idx[i];
		if (K[i] > 0) {
			vl = mins[i] = V_MIN(vs_prop_[y_id]);
			vh = V_MAX(vs_prop_[y_id]);
		} else {
			vl = V_MAX(vs_prop_[y_id]);
			vh = mins[i] = V_MIN(vs_prop_[y_id]);
		}

		if (vl != vh) {
			not_singl_idx = i;
			not_singl_id = y_id;
			not_singl++;
		} else {
			sum += K[i] * mins[i];
		}

		min += K[i] * vl;
		max += K[i] * vh;
	}
	sum -= equat_result;

	if (min > equat_result || max < 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;
	}

	if (min == max && min == 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;
	}

	// 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 / K[not_singl_idx]);

		if (sum % K[not_singl_idx] > 0 || val_to_rem < 0) {
			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;
		}

		cl_v_copy_pm(&y, &vs_prop_[not_singl_id] TTL_CTR_V);

		cl_v_del_val_n(&changed, &y, val_to_rem TTL_CTR_V);

		if (changed) {
			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));
			}
		}
	}
}


/*
 * Propagate the domain of the variable with the ID prop_v_id through all the other variables on the same c_numb ID linear_ne opposite constraint
 * K · Y = c
 * vs_per_c_idx - vector with all constrained variables ID per constraint, per constraint ID order
 * c_consts - vector with all constrained constants 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 linear_ne_prop_opposite(CL_INTS_MEM int* vs_per_c_idx, CL_INTS_MEM int* c_consts, 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_consts;	// number of constants and variables constrained by this constraint
	CL_INTS_MEM int* K = c_consts;	// constants 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_consts];
	int vl, vh;
	int min, max;
	int xmin, xmax, bound;
	bool changed = 0;
	int c;
	int i;

	min = 0;
	max = 0;
	for (i = 0; i < terms; i++) {
		CHECK_TTL(ttl_ctr, 69)
		y_id = vs_per_c_idx[i];
		if (K[i] > 0) {
			vl = mins[i] = V_MIN(vs_prop_[y_id]);
			vh = maxs[i] = V_MAX(vs_prop_[y_id]);
		} else if (K[i] < 0) {
			vl = maxs[i] = V_MAX(vs_prop_[y_id]);
			vh = mins[i] = V_MIN(vs_prop_[y_id]);
		} else {
			vl = 0;
			vh = 0;
		}

		min += K[i] * vl;
		max += K[i] * vh;
	}

	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) {
				c = K[i];

				if (c > 0) {
					cl_v_del_all_except_val_m(&changed, &vs_prop_[y_id], mins[i] TTL_CTR_V);
					if (changed) {
						v_add_to_prop(vs_id_to_prop_, vs_prop_, y_id);
					}
				} else if (c < 0) {
					cl_v_del_all_except_val_m(&changed, &vs_prop_[y_id], maxs[i] TTL_CTR_V);
					if (changed) {
						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) {
				c = K[i];

				if (c > 0) {
					cl_v_del_all_except_val_m(&changed, &vs_prop_[y_id], maxs[i] TTL_CTR_V);
					if (changed) {
						v_add_to_prop(vs_id_to_prop_, vs_prop_, y_id);
					}
				} else if (c < 0) {
					cl_v_del_all_except_val_m(&changed, &vs_prop_[y_id], mins[i] TTL_CTR_V);
					if (changed) {
						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_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) {

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

					if (c > 0) {
						if ((xmax - xmin) * c > equat_result - min) {
							bound = (equat_result - min) / c + 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);
							}
						}
					} else if (c < 0) {
						if ((xmin - xmax) * c > equat_result - min) {
							bound = convert_int(ceil((equat_result - min * 1.0) / c + 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 (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) {

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

					if (c > 0) {
						if ((xmax - xmin) * c > max - equat_result) {
							bound = convert_int(ceil((equat_result - max * 1.0) / c + 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);
							}
						}
					} else if (c < 0) {
						if ((xmax - xmin) * c < equat_result - max) {
							bound = (equat_result - max) / c + 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 CL_BOOLEAN_VS
	}
#endif
}

#endif

CUDA_FUNC void linear_ne_propagate(CL_INTS_MEM int* vs_per_c_idx, CL_INTS_MEM int* c_consts, 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_LINEAR_NE == 0
	linear_ne_prop(vs_per_c_idx, c_consts, 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_LINEAR_NE == 1
	if (current_cs->reified == 1) {
		if (V_N_VALS(vs_prop_[current_cs->reif_var_id]) > 1) {
			linear_ne_reif(vs_per_c_idx, c_consts, vs_prop_, current_cs, vs_id_to_prop_, terms_mem CS_IGNORE_CALL TTL_CTR_V);

		} else {
			if (V_MIN(vs_prop_[current_cs->reif_var_id]) == 1) {
				linear_ne_prop(vs_per_c_idx, c_consts, vs_prop_, current_cs, vs_id_to_prop_, prop_ok, terms_mem CS_IGNORE_CALL TTL_CTR_V);
			} else {
				linear_ne_prop_opposite(vs_per_c_idx, c_consts, 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
		}
	} else {
		linear_ne_prop(vs_per_c_idx, c_consts, 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