//
//  Octree.h
//  libraries/octree/src
//
//  Created by Stephen Birarda on 3/13/13.
//  Copyright 2013 High Fidelity, Inc.
//
//  Distributed under the Apache License, Version 2.0.
//  See the accompanying file LICENSE or http://www.apache.org/licenses/LICENSE-2.0.html
//

#ifndef hifi_Octree_h
#define hifi_Octree_h

#include <memory>
#include <set>
#include <stdint.h>

#include <QHash>
#include <QObject>
#include <QtCore/QJsonObject>

#include <shared/ReadWriteLockable.h>
#include <SimpleMovingAverage.h>
#include <ViewFrustum.h>

#include "JurisdictionMap.h"
#include "OctreeElement.h"
#include "OctreeElementBag.h"
#include "OctreePacketData.h"
#include "OctreeSceneStats.h"

class ReadBitstreamToTreeParams;
class Octree;
class OctreeElement;
class OctreePacketData;
class Shape;
using OctreePointer = std::shared_ptr<Octree>;

extern QVector<QString> PERSIST_EXTENSIONS;

/// derive from this class to use the Octree::recurseTreeWithOperator() method
class RecurseOctreeOperator {
public:
    virtual bool preRecursion(const OctreeElementPointer& element) = 0;
    virtual bool postRecursion(const OctreeElementPointer& element) = 0;
    virtual OctreeElementPointer possiblyCreateChildAt(const OctreeElementPointer& element, int childIndex) { return NULL; }
};

// Callback function, for recuseTreeWithOperation
using RecurseOctreeOperation = std::function<bool(const OctreeElementPointer&, void*)>;
typedef enum {GRADIENT, RANDOM, NATURAL} creationMode;
typedef QHash<uint, AACube> CubeList;

const bool NO_EXISTS_BITS         = false;
const bool WANT_EXISTS_BITS       = true;
const bool COLLAPSE_EMPTY_TREE    = true;
const bool DONT_COLLAPSE          = false;

const int DONT_CHOP              = 0;
const int NO_BOUNDARY_ADJUST     = 0;
const int LOW_RES_MOVING_ADJUST  = 1;

#define IGNORE_COVERAGE_MAP      NULL
#define IGNORE_JURISDICTION_MAP  NULL

class EncodeBitstreamParams {
public:
    ViewFrustum viewFrustum;
    ViewFrustum lastViewFrustum;
    int maxEncodeLevel;
    int maxLevelReached;
    bool includeExistsBits;
    int chopLevels;
    bool deltaView;
    bool recurseEverything { false };
    int boundaryLevelAdjust;
    float octreeElementSizeScale;
    bool forceSendScene;
    JurisdictionMap* jurisdictionMap;
    NodeData* nodeData;

    // output hints from the encode process
    typedef enum {
        UNKNOWN,
        DIDNT_FIT,
        NULL_NODE,
        NULL_NODE_DATA,
        TOO_DEEP,
        OUT_OF_JURISDICTION,
        LOD_SKIP,
        OUT_OF_VIEW,
        WAS_IN_VIEW,
        NO_CHANGE,
        OCCLUDED,
        FINISHED
    } reason;
    reason stopReason;

    EncodeBitstreamParams(
        int maxEncodeLevel = INT_MAX,
        bool includeExistsBits = WANT_EXISTS_BITS,
        int  chopLevels = 0,
        bool useDeltaView = false,
        int boundaryLevelAdjust = NO_BOUNDARY_ADJUST,
        float octreeElementSizeScale = DEFAULT_OCTREE_SIZE_SCALE,
        bool forceSendScene = true,
        JurisdictionMap* jurisdictionMap = IGNORE_JURISDICTION_MAP,
        NodeData* nodeData = nullptr) :
            maxEncodeLevel(maxEncodeLevel),
            maxLevelReached(0),
            includeExistsBits(includeExistsBits),
            chopLevels(chopLevels),
            deltaView(useDeltaView),
            boundaryLevelAdjust(boundaryLevelAdjust),
            octreeElementSizeScale(octreeElementSizeScale),
            forceSendScene(forceSendScene),
            jurisdictionMap(jurisdictionMap),
            nodeData(nodeData),
            stopReason(UNKNOWN)
    {
        lastViewFrustum.invalidate();
    }

    void displayStopReason() {
        printf("StopReason: ");
        switch (stopReason) {
            default:
            case UNKNOWN: qDebug("UNKNOWN"); break;

            case DIDNT_FIT: qDebug("DIDNT_FIT"); break;
            case NULL_NODE: qDebug("NULL_NODE"); break;
            case TOO_DEEP: qDebug("TOO_DEEP"); break;
            case OUT_OF_JURISDICTION: qDebug("OUT_OF_JURISDICTION"); break;
            case LOD_SKIP: qDebug("LOD_SKIP"); break;
            case OUT_OF_VIEW: qDebug("OUT_OF_VIEW"); break;
            case WAS_IN_VIEW: qDebug("WAS_IN_VIEW"); break;
            case NO_CHANGE: qDebug("NO_CHANGE"); break;
            case OCCLUDED: qDebug("OCCLUDED"); break;
        }
    }

    QString getStopReason() {
        switch (stopReason) {
            default:
            case UNKNOWN: return QString("UNKNOWN"); break;

            case DIDNT_FIT: return QString("DIDNT_FIT"); break;
            case NULL_NODE: return QString("NULL_NODE"); break;
            case TOO_DEEP: return QString("TOO_DEEP"); break;
            case OUT_OF_JURISDICTION: return QString("OUT_OF_JURISDICTION"); break;
            case LOD_SKIP: return QString("LOD_SKIP"); break;
            case OUT_OF_VIEW: return QString("OUT_OF_VIEW"); break;
            case WAS_IN_VIEW: return QString("WAS_IN_VIEW"); break;
            case NO_CHANGE: return QString("NO_CHANGE"); break;
            case OCCLUDED: return QString("OCCLUDED"); break;
        }
    }

    std::function<void(const QUuid& dataID, quint64 itemLastEdited)> trackSend { [](const QUuid&, quint64){} };
};

class ReadElementBufferToTreeArgs {
public:
    const unsigned char* buffer;
    int length;
    bool destructive;
    bool pathChanged;
};

class ReadBitstreamToTreeParams {
public:
    bool includeExistsBits;
    OctreeElementPointer destinationElement;
    QUuid sourceUUID;
    SharedNodePointer sourceNode;
    bool wantImportProgress;
    PacketVersion bitstreamVersion;
    int elementsPerPacket = 0;
    int entitiesPerPacket = 0;

    ReadBitstreamToTreeParams(
        bool includeExistsBits = WANT_EXISTS_BITS,
        OctreeElementPointer destinationElement = NULL,
        QUuid sourceUUID = QUuid(),
        SharedNodePointer sourceNode = SharedNodePointer(),
        bool wantImportProgress = false,
        PacketVersion bitstreamVersion = 0) :
            includeExistsBits(includeExistsBits),
            destinationElement(destinationElement),
            sourceUUID(sourceUUID),
            sourceNode(sourceNode),
            wantImportProgress(wantImportProgress),
            bitstreamVersion(bitstreamVersion)
    {}
};

class Octree : public QObject, public std::enable_shared_from_this<Octree>, public ReadWriteLockable {
    Q_OBJECT
public:
    Octree(bool shouldReaverage = false);
    virtual ~Octree();

    /// Your tree class must implement this to create the correct element type
    virtual OctreeElementPointer createNewElement(unsigned char * octalCode = NULL) = 0;

    // These methods will allow the OctreeServer to send your tree inbound edit packets of your
    // own definition. Implement these to allow your octree based server to support editing
    virtual bool getWantSVOfileVersions() const { return false; }
    virtual PacketType expectedDataPacketType() const { return PacketType::Unknown; }
    virtual bool canProcessVersion(PacketVersion thisVersion) const {
                    return thisVersion == versionForPacketType(expectedDataPacketType()); }
    virtual PacketVersion expectedVersion() const { return versionForPacketType(expectedDataPacketType()); }
    virtual bool handlesEditPacketType(PacketType packetType) const { return false; }
    virtual int processEditPacketData(ReceivedMessage& message, const unsigned char* editData, int maxLength,
                                      const SharedNodePointer& sourceNode) { return 0; }

    virtual bool recurseChildrenWithData() const { return true; }
    virtual bool rootElementHasData() const { return false; }
    virtual int minimumRequiredRootDataBytes() const { return 0; }
    virtual bool suppressEmptySubtrees() const { return true; }
    virtual void releaseSceneEncodeData(OctreeElementExtraEncodeData* extraEncodeData) const { }
    virtual bool mustIncludeAllChildData() const { return true; }

    /// some versions of the SVO file will include breaks with buffer lengths between each buffer chunk in the SVO
    /// file. If the Octree subclass expects this for this particular version of the file, it should override this
    /// method and return true.
    virtual bool versionHasSVOfileBreaks(PacketVersion thisVersion) const { return false; }

    virtual void update() { } // nothing to do by default

    OctreeElementPointer getRoot() { return _rootElement; }

    virtual void eraseAllOctreeElements(bool createNewRoot = true);

    virtual void readBitstreamToTree(const unsigned char* bitstream,  uint64_t bufferSizeBytes, ReadBitstreamToTreeParams& args);
    void deleteOctalCodeFromTree(const unsigned char* codeBuffer, bool collapseEmptyTrees = DONT_COLLAPSE);
    void reaverageOctreeElements(OctreeElementPointer startElement = OctreeElementPointer());

    void deleteOctreeElementAt(float x, float y, float z, float s);

    /// Find the voxel at position x,y,z,s
    /// \return pointer to the OctreeElement or NULL if none at x,y,z,s.
    OctreeElementPointer getOctreeElementAt(float x, float y, float z, float s) const;

    /// Find the voxel at position x,y,z,s
    /// \return pointer to the OctreeElement or to the smallest enclosing parent if none at x,y,z,s.
    OctreeElementPointer getOctreeEnclosingElementAt(float x, float y, float z, float s) const;

    OctreeElementPointer getOrCreateChildElementAt(float x, float y, float z, float s);
    OctreeElementPointer getOrCreateChildElementContaining(const AACube& box);

    void recurseTreeWithOperation(const RecurseOctreeOperation& operation, void* extraData = NULL);
    void recurseTreeWithPostOperation(const RecurseOctreeOperation& operation, void* extraData = NULL);

    /// \param operation type of operation
    /// \param point point in world-frame (meters)
    /// \param extraData hook for user data to be interpreted by special context
    void recurseTreeWithOperationDistanceSorted(const RecurseOctreeOperation& operation,
                                                const glm::vec3& point, void* extraData = NULL);

    void recurseTreeWithOperator(RecurseOctreeOperator* operatorObject);

    int encodeTreeBitstream(const OctreeElementPointer& element, OctreePacketData* packetData, OctreeElementBag& bag,
                            EncodeBitstreamParams& params) ;

    bool isDirty() const { return _isDirty; }
    void clearDirtyBit() { _isDirty = false; }
    void setDirtyBit() { _isDirty = true; }

    // output hints from the encode process
    typedef enum {
        Lock,
        TryLock
    } lockType;


    bool findSpherePenetration(const glm::vec3& center, float radius, glm::vec3& penetration, void** penetratedObject = NULL,
                                    Octree::lockType lockType = Octree::TryLock, bool* accurateResult = NULL);

    bool findCapsulePenetration(const glm::vec3& start, const glm::vec3& end, float radius, glm::vec3& penetration,
                                    Octree::lockType lockType = Octree::TryLock, bool* accurateResult = NULL);

    /// \param cube query cube in world-frame (meters)
    /// \param[out] cubes list of cubes (world-frame) of child elements that have content
    bool findContentInCube(const AACube& cube, CubeList& cubes);

    /// \param point query point in world-frame (meters)
    /// \param lockType how to lock the tree (Lock, TryLock, NoLock)
    /// \param[out] accurateResult pointer to output result, will be set "true" or "false" if non-null
    OctreeElementPointer getElementEnclosingPoint(const glm::vec3& point,
                                    Octree::lockType lockType = Octree::TryLock, bool* accurateResult = NULL);

    // Note: this assumes the fileFormat is the HIO individual voxels code files
    void loadOctreeFile(const char* fileName);

    // Octree exporters
    bool writeToFile(const char* filename, const OctreeElementPointer& element = NULL, QString persistAsFileType = "json.gz");
    bool writeToJSONFile(const char* filename, const OctreeElementPointer& element = NULL, bool doGzip = false);
    virtual bool writeToMap(QVariantMap& entityDescription, OctreeElementPointer element, bool skipDefaultValues,
                            bool skipThoseWithBadParents) = 0;

    // Octree importers
    bool readFromFile(const char* filename);
    bool readFromURL(const QString& url); // will support file urls as well...
    bool readFromStream(uint64_t streamLength, QDataStream& inputStream, const QString& marketplaceID="");
    bool readSVOFromStream(uint64_t streamLength, QDataStream& inputStream);
    bool readJSONFromStream(uint64_t streamLength, QDataStream& inputStream, const QString& marketplaceID="");
    bool readJSONFromGzippedFile(QString qFileName);
    virtual bool readFromMap(QVariantMap& entityDescription) = 0;

    uint64_t getOctreeElementsCount();

    bool getShouldReaverage() const { return _shouldReaverage; }

    void recurseElementWithOperation(const OctreeElementPointer& element, const RecurseOctreeOperation& operation,
                void* extraData, int recursionCount = 0);

    /// Traverse child nodes of node applying operation in post-fix order
    ///
    void recurseElementWithPostOperation(const OctreeElementPointer& element, const RecurseOctreeOperation& operation,
                void* extraData, int recursionCount = 0);

    void recurseElementWithOperationDistanceSorted(const OctreeElementPointer& element, const RecurseOctreeOperation& operation,
                const glm::vec3& point, void* extraData, int recursionCount = 0);

    bool recurseElementWithOperator(const OctreeElementPointer& element, RecurseOctreeOperator* operatorObject, int recursionCount = 0);

    bool getIsViewing() const { return _isViewing; } /// This tree is receiving inbound viewer datagrams.
    void setIsViewing(bool isViewing) { _isViewing = isViewing; }

    bool getIsServer() const { return _isServer; } /// Is this a server based tree. Allows guards for certain operations
    void setIsServer(bool isServer) { _isServer = isServer; }

    bool getIsClient() const { return !_isServer; } /// Is this a client based tree. Allows guards for certain operations
    void setIsClient(bool isClient) { _isServer = !isClient; }

    virtual void dumpTree() { }
    virtual void pruneTree() { }

    virtual void resetEditStats() { }
    virtual quint64 getAverageDecodeTime() const { return 0; }
    virtual quint64 getAverageLookupTime() const { return 0;  }
    virtual quint64 getAverageUpdateTime() const { return 0;  }
    virtual quint64 getAverageCreateTime() const { return 0;  }
    virtual quint64 getAverageLoggingTime() const { return 0;  }
    virtual quint64 getAverageFilterTime() const { return 0; }

signals:
    void importSize(float x, float y, float z);
    void importProgress(int progress);

public slots:
    void cancelImport();


protected:
    void deleteOctalCodeFromTreeRecursion(const OctreeElementPointer& element, void* extraData);

    int encodeTreeBitstreamRecursion(const OctreeElementPointer& element,
                                     OctreePacketData* packetData, OctreeElementBag& bag,
                                     EncodeBitstreamParams& params, int& currentEncodeLevel,
                                     const ViewFrustum::intersection& parentLocationThisView) const;

    static bool countOctreeElementsOperation(const OctreeElementPointer& element, void* extraData);

    OctreeElementPointer nodeForOctalCode(const OctreeElementPointer& ancestorElement, const unsigned char* needleCode, OctreeElementPointer* parentOfFoundElement) const;
    OctreeElementPointer createMissingElement(const OctreeElementPointer& lastParentElement, const unsigned char* codeToReach, int recursionCount = 0);
    int readElementData(const OctreeElementPointer& destinationElement, const unsigned char* nodeData,
                int bufferSizeBytes, ReadBitstreamToTreeParams& args);

    OctreeElementPointer _rootElement = nullptr;

    bool _isDirty;
    bool _shouldReaverage;
    bool _stopImport;

    bool _isViewing;
    bool _isServer;
};

#endif // hifi_Octree_h