/*
 * $Revision: 2564 $
 *
 * last checkin:
 *   $Author: gutwenger $
 *   $Date: 2012-07-07 00:03:48 +0200 (Sat, 07 Jul 2012) $
 ***************************************************************/

/** \file
 * \brief Declaration of class NMM (New Multipole Method).
 *
 * \author Stefan Hachul
 *
 * \par License:
 * This file is part of the Open Graph Drawing Framework (OGDF).
 *
 * \par
 * Copyright (C)<br>
 * See README.txt in the root directory of the OGDF installation for details.
 *
 * \par
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * Version 2 or 3 as published by the Free Software Foundation;
 * see the file LICENSE.txt included in the packaging of this file
 * for details.
 *
 * \par
 * This program is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU General Public License for more details.
 *
 * \par
 * You should have received a copy of the GNU General Public
 * License along with this program; if not, write to the Free
 * Software Foundation, Inc., 51 Franklin Street, Fifth Floor,
 * Boston, MA 02110-1301, USA.
 *
 * \see  http://www.gnu.org/copyleft/gpl.html
 ***************************************************************/


#ifdef _MSC_VER
#pragma once
#endif

#ifndef OGDF_NMM_H
#define OGDF_NMM_H

#include <ogdf/basic/Graph.h>
#include <ogdf/basic/List.h>
#include <ogdf/basic/Array2D.h>
#include <ogdf/basic/geometry.h>
#include <ogdf/internal/energybased/NodeAttributes.h>
#include <ogdf/internal/energybased/EdgeAttributes.h>
#include <ogdf/internal/energybased/QuadTreeNM.h>
#include <ogdf/internal/energybased/ParticleInfo.h>
#include <ogdf/internal/energybased/FruchtermanReingold.h>
#include <complex>


namespace ogdf {

class OGDF_EXPORT NMM
{
public:
	NMM();          //constructor
	~NMM() { }      //destructor

	//Calculate rep. forces for each node.
	void calculate_repulsive_forces(const Graph &G,
		NodeArray<NodeAttributes>& A,
		NodeArray<DPoint>& F_rep);

	//Make all initialisations that are needed for New Multipole Method (NMM)
	void make_initialisations (const Graph &G,
		double boxlength,
		DPoint down_left_corner,
		int particles_in_leaves,
		int precision,
		int tree_construction_way,
		int find_small_cell);

	//Dynamically allocated memory is freed here.
	void deallocate_memory();

	//Import updated information of the drawing area.
	void update_boxlength_and_cornercoordinate(double b_l,DPoint d_l_c);

private:
	int MIN_NODE_NUMBER; //The minimum number of nodes for which the forces are
						 //calculated using NMM (for lower values the exact
						 //calculation is used).
	bool using_NMM; //Indicates whether the exact method or NMM is used for force
					//calculation (value depends on MIN_NODE_NUMBER)
	FruchtermanReingold ExactMethod; //needed in case that using_NMM == false

	int _tree_construction_way;//1 = pathwise;2 = subtreewise
	int _find_small_cell;//0 = iterative; 1= Aluru
	int _particles_in_leaves;//max. number of particles for leaves of the quadtree
	int _precision;  //precision for p-term multipole expansion

	double boxlength;//length of drawing box
	DPoint down_left_corner;//down left corner of drawing box

	int* power_of_2; //holds the powers of 2 (for speed reasons to calculate the
					 //maximal boxindex (index is from 0 to max_power_of_2_index)
	int max_power_of_2_index;//holds max. index for power_of_2 (= 30)
	double ** BK; //holds the binomial coefficients
	List<DPoint> rep_forces;	//stores the rep. forces of the last iteration
								//(needed for error calculation)

	//private helping functions

	//The array power_of_2 is calculated for values from 0 to max_power_of_2_index
	//which is set here to 30.
	void init_power_of_2_array();

	//The space of power_of_2 is freed.
	void free_power_of_2_array();

	//Returns power_of_2[i] for values <= max_power_of_2_index else it returns
	//pow(2,i).
	int power_of_two(int i);

	//Returns the maximal index of a box in level i.
	int maxboxindex (int level);

	//Use NMM for force calculation (used for large Graphs (|V| > MIN_NODE_NUMBER)).
	void  calculate_repulsive_forces_by_NMM(const Graph &G, NodeArray
		<NodeAttributes>& A, NodeArray<DPoint>& F_rep);

	//Use the exact method for force calculation (used for small Graphs (|V| <=
	//MIN_NODE_NUMBER) for speed reasons).
	void  calculate_repulsive_forces_by_exact_method(const Graph &G,
		NodeArray<NodeAttributes>& A,
		NodeArray<DPoint>& F_rep);

	// *********Functions needed for path by path tree construction***********

	//The reduced quadtree is build up path by path (the Lists LE,ME, the
	//centers, D1, D2, M, and quad_tree_leaves are not calculated here.
	void  build_up_red_quad_tree_path_by_path(const Graph& G,
		NodeArray<NodeAttributes>& A,
		QuadTreeNM& T);

	//Makes L_x(y)_copy a copy of L_x(y)_orig and sets p.copy_item for each element in
	//L_x(y)_orig to the ListIterator of the corresponding element in L_x(y)_copy;
	//Furthermore, the p.cross_ref_items in L_x(y)_copy are set and p.subList_ptr and
	//p.tmp_cross_ref_item is reset to NULL in both lists.
	void make_copy_and_init_Lists(List<ParticleInfo>& L_x_orig,
		List<ParticleInfo>& L_x_copy,
		List<ParticleInfo>& L_y_orig,
		List<ParticleInfo>& L_y_copy);

	//The root node of T is constructed.
	void build_up_root_node(const Graph& G,NodeArray<NodeAttributes>& A, QuadTreeNM& T);

	//The sorted and linked Lists L_x and L_y for the root node are created.
	void create_sorted_coordinate_Lists(const Graph& G,NodeArray<NodeAttributes>& A,
		List<ParticleInfo>& L_x, List<ParticleInfo>& L_y);

	//T is extended by a subtree T1 rooted at the T.get_act_node().
	//The boxlength and down_left_corner of the actual node is reduced if it is
	//not the minimal subquad that contains all the particles in the represented area.
	void  decompose_subtreenode(QuadTreeNM& T,
		List<ParticleInfo>& act_x_List_copy,
		List<ParticleInfo>& act_y_List_copy,
		List<QuadTreeNodeNM*>& new_leaf_List);

	//The extreme coordinates of the particles contained in *act_ptr are calculated.
	void calculate_boundaries_of_act_node(QuadTreeNodeNM* act_ptr,
		double& x_min,
		double& x_max,
		double& y_min,
		double& y_max);

	//Returns true if the rectangle defined by x_min,...,y_max lies within the
	//left(right)_top(bottom) quad of the small cell of *act_ptr.
	bool in_lt_quad(QuadTreeNodeNM* act_ptr, double x_min,double x_max, double y_min, double y_max);
	bool in_rt_quad(QuadTreeNodeNM* act_ptr, double x_min,double x_max, double y_min, double y_max);
	bool in_lb_quad(QuadTreeNodeNM* act_ptr, double x_min,double x_max, double y_min, double y_max);
	bool in_rb_quad(QuadTreeNodeNM* act_ptr, double x_min,double x_max, double y_min, double y_max);

	//The Lists *act_ptr->get_x(y)_List_ptr() are split into two sublists containing
	//the particles in the left and right half of the actual quad. The list that is
	//larger is constructed from *act_ptr->get_x(y)_List_ptr() by deleting the other
	//elements; The smaller List stays empty at this point, but the corresponding
	//elements in L_x(y)_copy contain a pointer to the x(y) List, where they belong to.
	void split_in_x_direction(
		QuadTreeNodeNM* act_ptr,
		List<ParticleInfo>*& L_x_left_ptr,
		List<ParticleInfo>*& L_y_left_ptr,
		List<ParticleInfo>*& L_x_right_ptr,
		List <ParticleInfo>*& L_y_right_ptr);

	//The Lists *act_ptr->get_x(y)_List_ptr() are split into two subLists containing
	//the particles in the top /bottom half ...
	void split_in_y_direction(
		QuadTreeNodeNM* act_ptr,
		List<ParticleInfo>*& L_x_bottom_ptr,
		List<ParticleInfo>*& L_y_bottom_ptr,
		List<ParticleInfo>*& L_x_top_ptr,
		List<ParticleInfo>*& L_y_top_ptr);


	//The Lists *L_x(y)_left_ptr are constructed from *act_ptr->get_x(y)_List_ptr()
	//by deleting all elements right from last_left_item in *act_ptr->get_x_List_ptr()
	//the corresponding values in  *act_ptr->get_y_List_ptr() are deleted as well.
	//The corresponding List-elements of the deleted elements in the Lists L_x(y)_copy
	//hold the information, that they belong to the Lists *L_x(y)_left_ptr.
	void x_delete_right_subLists(
		QuadTreeNodeNM* act_ptr,
		List<ParticleInfo>*& L_x_left_ptr,
		List <ParticleInfo>*& L_y_left_ptr,
		List<ParticleInfo>*& L_x_right_ptr,
		List <ParticleInfo>*& L_y_right_ptr,
		ListIterator<ParticleInfo> last_left_item);

	//Analogue as above.
	void x_delete_left_subLists(
		QuadTreeNodeNM* act_ptr,
		List<ParticleInfo>*& L_x_left_ptr,
		List <ParticleInfo>*& L_y_left_ptr,
		List<ParticleInfo>*& L_x_right_ptr,
		List <ParticleInfo>*& L_y_right_ptr,
		ListIterator<ParticleInfo> last_left_item);

	//The Lists *L_x(y)_left_ptr are constructed from *act_ptr->get_x(y)_List_ptr()
	//by deleting all elements right from last_left_item in *act_ptr->get_y_List_ptr()
	//the ...
	void y_delete_right_subLists(
		QuadTreeNodeNM* act_ptr,
		List<ParticleInfo>*& L_x_left_ptr,
		List<ParticleInfo>*& L_y_left_ptr,
		List<ParticleInfo>*& L_x_right_ptr,
		List <ParticleInfo>*& L_y_right_ptr,
		ListIterator<ParticleInfo> last_left_item);

	//Analogue as above.
	void y_delete_left_subLists(
		QuadTreeNodeNM* act_ptr,
		List<ParticleInfo>*& L_x_left_ptr,
		List<ParticleInfo>*& L_y_left_ptr,
		List<ParticleInfo>*& L_x_right_ptr,
		List <ParticleInfo>*& L_y_right_ptr,
		ListIterator<ParticleInfo> last_left_item);


	//The Lists *L_x(y)_b_ptr and *L_x(y)_t_ptr are constructed from the Lists
	// *L_x(y)_ptr.
	void split_in_y_direction(
		QuadTreeNodeNM* act_ptr,
		List<ParticleInfo>*& L_x_ptr,
		List<ParticleInfo>*& L_x_b_ptr,
		List<ParticleInfo>*& L_x_t_ptr,
		List<ParticleInfo>*& L_y_ptr,
		List<ParticleInfo>*& L_y_b_ptr,
		List<ParticleInfo>*& L_y_t_ptr);

	//The Lists *L_x(y)_b(t)_ptr are constructed from the Lists *L_x(y)_ptr by
	//moving all List elements from *L_x(y)_ptr that belong to *L_x(y)_l_ptr
	//to this List. the L_x(y)_right_ptr point  to the reduced Lists L_x(y)_ptr
	//afterwards.
	void y_move_left_subLists(List<ParticleInfo>*& L_x_ptr,
		List<ParticleInfo>*& L_x_b_ptr,
		List<ParticleInfo>*& L_x_t_ptr,
		List<ParticleInfo>*& L_y_ptr,
		List <ParticleInfo>*& L_y_b_ptr,
		List<ParticleInfo>*& L_y_t_ptr,
		ListIterator<ParticleInfo> last_left_item);

	//Same as above but the elements that belong to *&L_x(y)_right_ptr are moved.
	void y_move_right_subLists(List<ParticleInfo>*& L_x_ptr,
		List<ParticleInfo>*& L_x_b_ptr,
		List<ParticleInfo>*& L_x_t_ptr,
		List<ParticleInfo>*&L_y_ptr,
		List <ParticleInfo>*& L_y_b_ptr,
		List<ParticleInfo>*& L_y_t_ptr,
		ListIterator<ParticleInfo> last_left_item);

	//The sorted subLists, that can be accesssed by the entries in L_x(y)_copy->
	//get_subList_ptr() are constructed.
	void build_up_sorted_subLists(List<ParticleInfo>& L_x_copy,
		List<ParticleInfo>& act_y_List_copy);

	// ************functions needed for subtree by subtree tree construction **********

	//The reduced quadtree is build up subtree by subtree (the lists LE, ME the
	//centers, D1, D2, M, quad_tree_leaves are not calculated here.
	void  build_up_red_quad_tree_subtree_by_subtree(const Graph& G,
		NodeArray<NodeAttributes>& A,
		QuadTreeNM& T);

	//The root node of T is constructed and contained_nodes is set to the list of
	//all nodes of G.
	void build_up_root_vertex(const Graph&G, QuadTreeNM& T);

	//The reduced subtree of T rooted at *subtree_root_ptr containing all the particles
	//of subtree_root_ptr->get_contained_nodes() is constructed; Pointers to leaves
	//of the subtree that contain more than particles_in_leaves() particles in their
	//contained_nodes() lists are added to new_subtree_root_List_ptr; The lists
	//contained_nodes() are nonempty only for the (actual) leaves of T.
	void construct_subtree(NodeArray<NodeAttributes>& A,
		QuadTreeNM& T,
		QuadTreeNodeNM*	subtree_root_ptr,
		List<QuadTreeNodeNM*>& new_subtree_root_List);

	//A complete subtree of T and of depth subtree_depth, rooted at *T.get_act_ptr() is
	//constructed. Furthermore leaf_ptr[i][j] points to a leaf node of the subtree
	//that represents the quadratic subregion of *T.get_act_ptr() at subtree_depth
	//and position [i][j] i,j in 0,...,maxindex;act_depth(x_index,y_index) are
	//helping variables for recursive calls.
	void construct_complete_subtree(QuadTreeNM& T,
		int subtree_depth,
		Array2D<QuadTreeNodeNM*>& leaf_ptr,
		int act_depth,
		int act_x_index,
		int act_y_index);

	//The particles in subtree_root_ptr->get_contained_nodes() are assigned to
	//the the contained_nodes lists of the leaves of the subtree by using the
	//information of A,leaf_ptr and maxindex. Afterwards contained_nodes of
	// *subtree_root_ptr is empty.
	void set_contained_nodes_for_leaves(NodeArray<NodeAttributes>& A,
		QuadTreeNodeNM* subtree_root_ptr,
		Array2D<QuadTreeNodeNM*>& leaf_ptr,
		int maxindex);

	//The subtree of T rooted at *T.get_act_ptr() is traversed bottom up, such that
	//the subtreeparticlenumber of every node in this subtree is set correctly.
	void set_particlenumber_in_subtree_entries(QuadTreeNM& T);

	//The reduced subtree rooted at *T.get_act_ptr() is calculated ; A pointer to
	//every leaf of this subtree that contains more then particles_in_leaves()
	//particles is added to new_subtree_root_List; The lists contained_nodes are
	//empty for all but the leaves.
	void construct_reduced_subtree(NodeArray<NodeAttributes>& A,
		QuadTreeNM& T,
		List<QuadTreeNodeNM*>& new_subtree_root_List);

	//All subtrees of *T.get_act_ptr() that have a child c of *T.get_act_ptr() as root
	//and c.get_particlenumber_in_subtree() == 0 are deleted.
	void delete_empty_subtrees(QuadTreeNM& T);

	//If *T.get_act_ptr() is a degenerated node (has only one child c) *T.get_act_ptr()
	//is deleted from T and the child c is linked with the father of *T.get_act_ptr()
	//if *T.get_act_ptr() is the root of T than c is set to the new root of T
	//T.get_act_ptr() points to c afterwards; Furthermore true is returned if
	// *T.get_act_ptr() has been degenerated, else false is returned.
	bool check_and_delete_degenerated_node(QuadTreeNM& T);

	//The subtree rooted at new_leaf_ptr is deleted, *new_leaf_ptr is a leaf
	//of T and new_leaf_ptr->get_contained_nodes() contains all the particles
	//contained in the leaves of the deleted subtree; Precondition: T.get_act_ptr() is
	//new_leaf_ptr.
	void delete_sparse_subtree(QuadTreeNM& T, QuadTreeNodeNM* new_leaf_ptr);

	//new_leaf_ptr->get_contained_nodes() contains all the particles contained in
	//the leaves of its subtree afterwards; Precondition: T.get_act_ptr() is
	//new_leaf_ptr
	void collect_contained_nodes(QuadTreeNM& T, QuadTreeNodeNM* new_leaf_ptr);

	//If all nodes in T.get_act_ptr()->get_contained_nodes() have the same position
	//false is returned. Else true is returned and
	//the boxlength, down_left_corner and level of *T.get_act_ptr() is updated
	//such that this values are minimal (i.e. the smallest quad that contains all
	//the particles of T.get_act_ptr()->get_contained_nodes(); If all this particles
	//are placed at a point nothing is done.
	bool find_smallest_quad(NodeArray<NodeAttributes>& A, QuadTreeNM& T);

	// *********functions needed for subtree by subtree tree construction(end) ********

	//Finds the small cell of the actual Node of T iteratively,and updates
	//Sm_downleftcorner, Sm_boxlength, and level of *act_ptr.
	void find_small_cell_iteratively(QuadTreeNodeNM* act_ptr,
		double x_min,
		double x_max,
		double y_min,
		double y_max);

	//Finds the small cell of the actual Node of T by Aluru's Formula, and updates
	//Sm_downleftcorner, Sm_boxlength, and level of *act_ptr.
	void find_small_cell_by_formula(QuadTreeNodeNM* act_ptr,
		double x_min,
		double x_max,
		double y_min,
		double y_max);

	//The reduced quad tree is deleted; Furthermore the treenode_number is calculated.
	void delete_red_quad_tree_and_count_treenodes(QuadTreeNM& T);

	//The multipole expansion terms ME are calculated for all nodes of T ( centers are
	//initialized for each cell and quad_tree_leaves stores pointers to leaves of T).
	void form_multipole_expansions(NodeArray<NodeAttributes>& A,
		QuadTreeNM& T,
		List<QuadTreeNodeNM*>& quad_tree_leaves);

	//The multipole expansion List ME for the tree rooted at T.get_act_ptr() is
	//recursively calculated.
	void form_multipole_expansion_of_subtree(NodeArray<NodeAttributes>& A,
		QuadTreeNM& T,
		List<QuadTreeNodeNM*>& quad_tree_leaves);

	//The Lists ME and LE are both initialized to zero entries for *act_ptr.
	void init_expansion_Lists(QuadTreeNodeNM* act_ptr);

	//The center of the box of *act_ptr is initialized.
	void set_center(QuadTreeNodeNM* act_ptr);

	//Calculate List ME for *act_ptr Precondition: *act_ptr is a leaf.
	void form_multipole_expansion_of_leaf_node(NodeArray<NodeAttributes>& A,
		QuadTreeNodeNM* act_ptr);

	//Add the shifted ME Lists of *act_ptr to act_ptr->get_father_ptr() ; precondition
	// *act_ptr has a father_node.
	void add_shifted_expansion_to_father_expansion(QuadTreeNodeNM* act_ptr);

	//According to NMM T is traversed recursively top-down starting from act_node_ptr
	//== T.get_root_ptr() and thereby the lists D1, D2, M and LE are calculated for all
	//treenodes.
	void calculate_local_expansions_and_WSPRLS(NodeArray<NodeAttributes>&A,
		QuadTreeNodeNM* act_node_ptr);

	//If the small cell of ptr_1 and ptr_2 are well separated true is returned (else
	//false).
	bool well_separated(QuadTreeNodeNM* ptr_1, QuadTreeNodeNM* ptr_2);

	//If ptr_1 and ptr_2 are nonequal and bordering true is returned; else false.
	bool bordering(QuadTreeNodeNM* ptr_1, QuadTreeNodeNM* ptr_2);

	//The shifted local expansion of the father of node_ptr is added to the local
	//expansion of node_ptr;precondition: node_ptr is not the root of T.
	void add_shifted_local_exp_of_parent(QuadTreeNodeNM* node_ptr);

	//The multipole expansion of *ptr_1 is transformed into a local expansion around
	//the center of *ptr_2 and added to *ptr_2 s local expansion list.
	void add_local_expansion(QuadTreeNodeNM* ptr_1, QuadTreeNodeNM* ptr_2);

	//The multipole expansion for every particle of leaf_ptr->contained_nodes
	//(1,0,...) is transformed into a local expansion around the center of *ptr_2 and
	//added to *ptr_2 s local expansion List;precondition: *leaf_ptr is a leaf.
	void add_local_expansion_of_leaf(NodeArray<NodeAttributes>&A,
		QuadTreeNodeNM*	leaf_ptr,
		QuadTreeNodeNM* act_ptr);

	//For each leaf v in quad_tree_leaves the force contribution defined by
	//v.get_local_exp() is calculated and stored in F_local_exp.
	void transform_local_exp_to_forces(NodeArray <NodeAttributes>&A,
		List<QuadTreeNodeNM*>& quad_tree_leaves,
		NodeArray<DPoint>& F_local_exp);

	//For each leaf v in quad_tree_leaves the force contribution defined by all nodes
	//in v.get_M() is calculated and stored in F_multipole_exp.
	void transform_multipole_exp_to_forces(NodeArray<NodeAttributes>& A,
		List<QuadTreeNodeNM*>& quad_tree_leaves,
		NodeArray<DPoint>& F_multipole_exp);

	//For each leaf v in quad_tree_leaves the force contributions from all leaves in
	//v.get_D1() and v.get_D2() are calculated.
	void calculate_neighbourcell_forces(NodeArray<NodeAttributes>& A,
		List<QuadTreeNodeNM*>& quad_tree_leaves,
		NodeArray<DPoint>& F_direct);

	//Add repulsive force contributions for each node.
	void add_rep_forces(const Graph& G,
		NodeArray<DPoint>& F_direct,
		NodeArray<DPoint>& F_multipole_exp,
		NodeArray<DPoint>& F_local_exp,
		NodeArray<DPoint>& F_rep);

	//Returns the repulsing force_function_value of scalar d.
	double f_rep_scalar (double d);

	//Init BK -matrix for values n, k in 0 to t.
	void init_binko(int t);

	//Free space for BK.
	void free_binko();

	//Returns n over k.
	double binko(int n, int k);

	//The way to construct the reduced tree (0) = level by level (1) path by path
	//(2) subtree by subtree
	int tree_construction_way() const { return _tree_construction_way; }

	void tree_construction_way(int a) {
		_tree_construction_way = (((0<=a)&&(a<=2)) ? a : 0);
	}

	//(0) means that the smallest quadratic cell that surrounds a node of the
	//quadtree is calculated iteratively in constant time (1) means that it is
	//calculated by the formula of Aluru et al. in constant time
	int find_sm_cell() const { return _find_small_cell; }

	void find_sm_cell(int a) {
		_find_small_cell = (((0<=a)&&(a<=1)) ? a : 0);
	}

	//Max. number of particles that are contained in a leaf of the red. quadtree.
	void particles_in_leaves (int b) { _particles_in_leaves = ((b>= 1)? b : 1); }
	int particles_in_leaves () const { return _particles_in_leaves; }

	//The precision p for the p-term multipole expansions.
	void precision (int p) { _precision  = ((p >= 1 ) ? p : 1); }
	int  precision () const { return _precision; }
};

}//namespace ogdf
#endif

