/*
 *  sketcherMinimizerAtom.h
 *
 *  Created by Nicola Zonta on 13/04/2010.
 *   Copyright Schrodinger, LLC. All rights reserved.
 *
 */

#ifndef sketcherMINIMIZERATOM_H
#define sketcherMINIMIZERATOM_H

// #include <sketcherMinimizerPointF>
#include "CoordgenConfig.hpp"
#include "sketcherMinimizerMaths.h"
#include <iostream>
#include <map>
#include <vector>

static const int COORDINATES_LIMIT = 10000000;
static const int INVALID_COORDINATES = COORDINATES_LIMIT + 1;

class sketcherMinimizerBond;

class sketcherMinimizerFragment;
class sketcherMinimizerRing;
class sketcherMinimizerMolecule;

class sketcherMinimizerAtom;
typedef struct {
    sketcherMinimizerAtom* a;
    unsigned int priority;
} sketcherMinimizerAtomPriority;

struct sketcherMinimizerAtomChiralityInfo {
    enum sketcherMinimizerChirality {
        clockwise,
        counterClockwise,
        unspecified
    };

    sketcherMinimizerAtom* lookingFrom = nullptr;
    sketcherMinimizerAtom* atom1 = nullptr;
    sketcherMinimizerAtom* atom2 = nullptr;
    sketcherMinimizerChirality direction = unspecified;
};

/* structure to represent an atom in Cahn–Ingold–Prelog priorities assignment */
struct CIPAtom {
    CIPAtom(std::vector<std::pair<int, sketcherMinimizerAtom*>> us,
            sketcherMinimizerAtom* dad,
            std::vector<sketcherMinimizerAtom*> allPars,
            std::map<sketcherMinimizerAtom*, int>* scors,
            std::map<sketcherMinimizerAtom*, std::vector<int>>* meds,
            std::map<sketcherMinimizerAtom*, int>* visits

            )
        : theseAtoms(std::move(us)), parent(dad),
          allParents(std::move(allPars)), scores(scors), visited(visits),
          medals(meds)
    {
    }
    bool operator<(const CIPAtom& rhs) const;
    bool operator==(const CIPAtom& rhs) const;
    bool isBetter(CIPAtom& rhs,
                  std::map<sketcherMinimizerAtom*, unsigned int>* m) const;

    std::vector<std::pair<int, sketcherMinimizerAtom*>>
        theseAtoms; // NULL if dummy
    sketcherMinimizerAtom* parent;
    std::vector<sketcherMinimizerAtom*> allParents;
    std::map<sketcherMinimizerAtom*, int>* scores;
    std::map<sketcherMinimizerAtom*, int>* visited;
    std::map<sketcherMinimizerAtom*, std::vector<int>>* medals;

  private:
    friend std::ostream& operator<<(std::ostream& os, const CIPAtom& a);
};

/* class to represent an atom */
class EXPORT_COORDGEN sketcherMinimizerAtom
{
  public:
    sketcherMinimizerAtom();
    virtual ~sketcherMinimizerAtom();

    bool crossLayout; // atoms with 4 substituents displayed in a cross style
                      // (such as S in sulphate)
    bool fixed, constrained, rigid;
    bool isSharedAndInner; // shared by two rings and needs to be drawn inside a
                           // ring
    bool hidden;
    int atomicNumber, charge, _valence, _generalUseN, _generalUseN2;
    int m_chmN; // idx of the corresponding ChmAtom if molecule comes from 3d

    bool _generalUseVisited, _generalUseVisited2;
    bool m_clockwiseInvert;
    bool m_ignoreRingChirality;
    std::vector<int> m_RSPriorities;
    int _implicitHs = -1;
    sketcherMinimizerMolecule* molecule;
    sketcherMinimizerFragment* fragment;
    void setFragment(sketcherMinimizerFragment* fragmentToSet)
    {
        fragment = fragmentToSet;
    }
    sketcherMinimizerFragment* getFragment() const { return fragment; }
    const std::vector<sketcherMinimizerBond*>& getBonds() const
    {
        return bonds;
    }
    const std::vector<sketcherMinimizerRing*>& getRings() const
    {
        return rings;
    }

    sketcherMinimizerMolecule* getMolecule() const { return molecule; }

    /*
     Find all connected atoms, pruning the search at the excludedAtom."
     This function assumes that the bond between this atom and excludedAtom
     is not part of a ring.
     */
    std::vector<sketcherMinimizerAtom*>
    getSubmolecule(sketcherMinimizerAtom* excludedAtom);
    std::vector<sketcherMinimizerAtom*> neighbors;
    std::vector<sketcherMinimizerBond*> bonds;
    std::vector<sketcherMinimizerAtom*> residueInteractionPartners;
    std::vector<sketcherMinimizerBond*> residueInteractions;
    std::vector<sketcherMinimizerRing*> rings;
    float m_pseudoZ;

    float m_x3D;
    float m_y3D;
    float m_z3D;

    bool m_isClashing, m_isWaterMap;
    float m_pocketDistance;

    bool needsCheckForClashes;
    bool m_isLigand;
    bool visited, coordinatesSet;
    bool isR; // stereochemistry
    bool hasStereochemistrySet, m_isStereogenic;
    bool _hasRingChirality; // used to keep track of cyclohexane cis/trans
                            // chirality

    /* write coordinates to atom */
    void setCoordinates(sketcherMinimizerPointF coords);

    /* check that the atom has no double bonds possibly involved in E/Z
     * stereochemistry */
    bool hasNoStereoActiveBonds() const;

    const sketcherMinimizerPointF& getCoordinates() const
    {
        return coordinates;
    }
    int getAtomicNumber() const { return atomicNumber; }

    void setAtomicNumber(int number) { atomicNumber = number; }

    void setStereoChemistry(sketcherMinimizerAtomChiralityInfo info)
    {
        m_chiralityInfo = info;
    }

    /* write template coordinates to atom */
    void setCoordinatesToTemplate() { setCoordinates(templateCoordinates); }
    sketcherMinimizerPointF coordinates;
    sketcherMinimizerPointF templateCoordinates;
    sketcherMinimizerPointF force;

    /* return the expected valence for the atom */
    unsigned int expectedValence(unsigned int atomicNumber) const;

    bool canBeChiral() const; // checks if the atom can have 4 substituents (one
                              // can be implicit H). Doesn't actually check if
                              // two of them are the same, so can return true
                              // for achiral centers

    /* return true if this and at2 share a bond */
    bool isNeighborOf(sketcherMinimizerAtom* at2) const
    {
        for (auto& neighbor : at2->neighbors) {
            if (neighbor == this) {
                return true;
            }
        }
        return false;
    }

    sketcherMinimizerAtomChiralityInfo::sketcherMinimizerChirality
    getRelativeStereo(sketcherMinimizerAtom* lookingFrom,
                      sketcherMinimizerAtom* atom1,
                      sketcherMinimizerAtom* atom2);
    bool setAbsoluteStereoFromChiralityInfo();

    /* if this atom and the given one share a bond, return it */
    sketcherMinimizerBond* bondTo(sketcherMinimizerAtom* at) const;

    /* return all bonded atoms, ordered as they appear clockwise around this */
    std::vector<sketcherMinimizerAtom*> clockwiseOrderedNeighbors() const;
    int findHsNumber() const;

    void writeStereoChemistry(); // assigns up-down bond flags based on isR and
                                 // hasStereochemistrySet

    /* return true if the two sequences represent the same isomer */
    static bool matchCIPSequence(std::vector<int>& v1, std::vector<int>& v2);

    /* calculate CIP priorities and assign them */
    static bool
    setCIPPriorities(std::vector<sketcherMinimizerAtomPriority>& atomPriorities,
                     sketcherMinimizerAtom* center);

    static void orderAtomPriorities(
        std::vector<sketcherMinimizerAtomPriority>& atomPriorities,
        sketcherMinimizerAtom* center); // orders trying to keep long chains in
                                        // position 2 and 3 and side
                                        // substituents in 1 and 4

    /* return which between at1 and at2 has higher CIP priority. Returns NULL if
     * they have the same */
    static sketcherMinimizerAtom* CIPPriority(sketcherMinimizerAtom* at1,
                                              sketcherMinimizerAtom* at2,
                                              sketcherMinimizerAtom* center);

    /* consider one additional level of bound atoms in the CIP algorithm to
     * break a tie */
    static std::vector<CIPAtom> expandOneLevel(std::vector<CIPAtom>& oldV);

    /* if any ties between parent atoms was solved, assign two different scores
     to them. Also clear the medals for the next iteration */
    static void finalizeScores(std::vector<CIPAtom>& v);

    /* medals are used to mark parent atoms according to the priorities of their
     children and also their numbers. */
    static void assignMedals(std::vector<CIPAtom>& v);

    /* first atom will be the highest priority, subsequent will be based on
     * atoms that have already been picked, giving priorities to branches that
     * have been already been visited. friendsMask keeps track of parents that
     * have a child that has been already selected */
    static void chooseFirstAndSortAccordingly(std::vector<CIPAtom>& V);

    /* if the two atoms share a ring, return it */
    static sketcherMinimizerRing*
    shareARing(const sketcherMinimizerAtom* atom1,
               const sketcherMinimizerAtom* atom2);

    /* mirror the coordinates of at wrt bond */
    static void mirrorCoordinates(sketcherMinimizerAtom* at,
                                  const sketcherMinimizerBond* bond);

    /* return the stereochemistry set in the wedges around the atom.  0 if not
     * assigned, 1 if R, -1 if S */
    int readStereochemistry(bool readOnly = false);

    /* return a direction perpendicular to the atom's bonds average */
    sketcherMinimizerPointF getSingleAdditionVector() const;

    static sketcherMinimizerPointF
    getSingleAdditionVector(const std::vector<sketcherMinimizerAtom*>& ats);

    /* return true if the atom  has valid 3d coordinates */
    bool hasValid3DCoordinates() const;

    /* return true if the atom is a residue */
    virtual bool isResidue() const;

    /* return true if atomicNumber represents a metal */
    static bool isMetal(const unsigned int atomicNumber);

    sketcherMinimizerAtomChiralityInfo m_chiralityInfo;
};

#endif // sketcherMINIMIZERATOM_H