/* -*- mode: C++ -*-  */
/*
   igraph library.
   Copyright (C) 2011-2012  Gabor Csardi <csardi.gabor@gmail.com>
   334 Harvard street, Cambridge, MA 02139 USA

   This program is free software; you can redistribute it and/or modify
   it under the terms of the GNU General Public License as published by
   the Free Software Foundation; either version 2 of the License, or
   (at your option) any later version.

   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.

   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

*/

// ****************************************************************************************************
// *** COPYRIGHT NOTICE *******************************************************************************
// splittree_eq.h - a binary search tree data structure for storing dendrogram split frequencies
// Copyright (C) 2006-2008 Aaron Clauset
//
// This program is free software; you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation; either version 2 of the License, or
// (at your option) any later version.
//
// 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.
//
// 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., 59 Temple Place, Suite 330, Boston, MA  02111-1307  USA
//
// See http://www.gnu.org/licenses/gpl.txt for more details.
//
// ****************************************************************************************************
// Author       : Aaron Clauset  ( aaronc@santafe.edu | http://www.santafe.edu/~aaronc/ )
// Collaborators: Cristopher Moore and Mark E.J. Newman
// Project      : Hierarchical Random Graphs
// Location     : University of New Mexico, Dept. of Computer Science AND Santa Fe Institute
// Created      : 19 April 2006
// Modified     : 19 May 2007
//           : 20 May 2008 (cleaned up for public consumption)
//
// ***********************************************************************
//
// Data structure for storing the split frequences in the sampled
// dendrograms. Data is stored efficiently as a red-black binary
// search tree (this is a modified version of the rbtree.h file).
//
// ***********************************************************************

#ifndef IGRAPH_HRG_SPLITTREE
#define IGRAPH_HRG_SPLITTREE

#include <string>

namespace fitHRG {

// ******** Basic Structures *********************************************

struct slist {
    std::string x;          // stored elementd in linked-list
    slist* next = nullptr;  // pointer to next elementd
};

struct keyValuePairSplit {
    std::string x;          // elementsp split (string)
    double y = 0.0;         // stored weight   (double)
    int c = 0;              // stored count    (int)
    keyValuePairSplit* next = nullptr;  // linked-list pointer
};

// ******** Tree elementsp Class *****************************************

struct elementsp {
    std::string split;             // split represented as a string
    double weight = 0.0;            // total weight of this split
    int count = 0;                // number of observations of this split

    bool color = false;           // F: BLACK, T: RED
    short int mark = 0;       // marker

    elementsp *parent = nullptr;        // pointer to parent node
    elementsp *left = nullptr;      // pointer for left subtree
    elementsp *right = nullptr;     // pointer for right subtree
};

// ******** Red-Black Tree Class *****************************************
// This vector implementation is a red-black balanced binary tree data
// structure. It provides find a stored elementsp in time O(log n),
// find the maximum elementsp in time O(1), delete an elementsp in
// time O(log n), and insert an elementsp in time O(log n).
//
// Note that the split="" is assumed to be a special value, and thus
// you cannot insert such an item. Beware of this limitation.
//

class splittree {
    elementsp* root;      // binary tree root
    elementsp* leaf;      // all leaf nodes
    int support = 0;          // number of nodes in the tree
    double total_weight = 0.0;      // total weight stored
    int total_count = 0;      // total number of observations stored

    // left-rotation operator
    void rotateLeft(elementsp*);
    // right-rotation operator
    void rotateRight(elementsp*);
    // house-keeping after insertion
    void insertCleanup(elementsp*);
    // house-keeping after deletion
    void deleteCleanup(elementsp*);
    keyValuePairSplit* returnSubtreeAsList(elementsp*, keyValuePairSplit*);
    // delete subtree rooted at z
    void deleteSubTree(elementsp*);
    // returns minimum of subtree rooted at z
    elementsp* returnMinKey(elementsp*);
    // returns successor of z's key
    elementsp* returnSuccessor(elementsp*);

public:
    // default constructor/destructor
    splittree(); ~splittree();
    // returns value associated with searchKey
    double returnValue(const std::string &);
    // returns T if searchKey found, and points foundNode at the
    // corresponding node
    elementsp* findItem(const std::string &);
    // update total_count and total_weight
    void finishedThisRound();
    // insert a new key with stored value
    bool insertItem(const std::string &, double);
    void clearTree();
    // delete a node with given key
    void deleteItem(const std::string &);
    // delete the entire tree
    void deleteTree();
    // return array of keys in tree
    std::string* returnArrayOfKeys();
    // return list of keys in tree
    slist* returnListOfKeys();
    // return the tree as a list of keyValuePairSplits
    keyValuePairSplit* returnTreeAsList();
    // returns the maximum key in the tree
    keyValuePairSplit returnMaxKey();
    // returns the minimum key in the tree
    keyValuePairSplit returnMinKey();
    // returns number of items in tree
    int returnNodecount();
    // returns list of splits with given number of Ms
    keyValuePairSplit* returnTheseSplits(int);
    // returns sum of stored values
    double returnTotal() const;
};

} // namespace fitHRG

#endif
