/**
 * @file llworld.h
 * @brief Collection of viewer regions in the vacinity of the user.
 *
 * Represents the whole world, so far as 3D functionality is conserned.
 * Always contains the region that the user's avatar is in along with
 * neighboring regions. As the user crosses region boundaries, new
 * regions are added to the world and distant ones are rolled up.
 *
 * $LicenseInfo:firstyear=2001&license=viewerlgpl$
 * Second Life Viewer Source Code
 * Copyright (C) 2010, Linden Research, Inc.
 *
 * This library is free software; you can redistribute it and/or
 * modify it under the terms of the GNU Lesser General Public
 * License as published by the Free Software Foundation;
 * version 2.1 of the License only.
 *
 * This library 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
 * Lesser General Public License for more details.
 *
 * You should have received a copy of the GNU Lesser General Public
 * License along with this library; if not, write to the Free Software
 * Foundation, Inc., 51 Franklin Street, Fifth Floor, Boston, MA  02110-1301  USA
 *
 * Linden Research, Inc., 945 Battery Street, San Francisco, CA  94111  USA
 * $/LicenseInfo$
 */

#ifndef LL_LLWORLD_H
#define LL_LLWORLD_H

#include "llpatchvertexarray.h"

#include "llmath.h"
#include "v3math.h"
#include "llsingleton.h"
#include "llstring.h"
#include "llviewerpartsim.h"
#include "llviewertexture.h"
#include "llvowater.h"

class LLViewerRegion;
class LLVector3d;
class LLMessageSystem;
class LLNetMap;
class LLHost;

class LLViewerObject;
class LLSurfacePatch;

class LLCharacter;
class LLCloudPuff;
class LLCloudGroup;
class LLVOAvatar;

// LLWorld maintains a stack of unused viewer_regions and an array of pointers to viewer regions
// as simulators are connected to, viewer_regions are popped off the stack and connected as required
// as simulators are removed, they are pushed back onto the stack

class LLWorld : public LLSimpleton<LLWorld>
{
public:
    LLWorld();

    // Clear any objects, regions
    // Prepares class to be reused or destroyed
    void resetClass();

    LLViewerRegion* addRegion(const U64 &region_handle, const LLHost &host);
        // safe to call if already present, does the "right thing" if
        // hosts are same, or if hosts are different, etc...
    void            removeRegion(const LLHost &host);

    void    disconnectRegions(); // Send quit messages to all child regions

    LLViewerRegion*         getRegion(const LLHost &host);
    LLViewerRegion*         getRegionFromPosGlobal(const LLVector3d &pos);
    LLViewerRegion*         getRegionFromPosAgent(const LLVector3 &pos);
    LLViewerRegion*         getRegionFromHandle(const U64 &handle);
    LLViewerRegion*         getRegionFromID(const LLUUID& region_id);
    bool                    positionRegionValidGlobal(const LLVector3d& pos);           // true if position is in valid region
    LLVector3d              clipToVisibleRegions(const LLVector3d &start_pos, const LLVector3d &end_pos);

    void                    updateAgentOffset(const LLVector3d &offset);

    // All of these should be in the agent coordinate frame
    LLViewerRegion*         resolveRegionGlobal(LLVector3 &localpos, const LLVector3d &position);
    LLViewerRegion*         resolveRegionAgent(LLVector3 &localpos, const LLVector3 &position);
    F32                     resolveLandHeightGlobal(const LLVector3d &position);
    F32                     resolveLandHeightAgent(const LLVector3 &position);

    // Return the lowest allowed Z point to prevent objects from being moved
    // underground.
    F32 getMinAllowedZ(LLViewerObject* object, const LLVector3d &global_pos);

    // takes a line segment defined by point_a and point_b, then
    // determines the closest (to point_a) point of intersection that is
    // on the land surface or on an object of the world.
    // Stores results in "intersection" and "intersection_normal" and
    // returns a scalar value that is the normalized (by length of line segment)
    // distance along the line from "point_a" to "intersection".
    //
    // Currently assumes point_a and point_b only differ in z-direction,
    // but it may eventually become more general.
    F32 resolveStepHeightGlobal(const LLVOAvatar* avatarp, const LLVector3d &point_a, const LLVector3d &point_b,
                            LLVector3d &intersection, LLVector3 &intersection_normal,
                            LLViewerObject** viewerObjectPtr=NULL);

    LLSurfacePatch *        resolveLandPatchGlobal(const LLVector3d &position);
    LLVector3               resolveLandNormalGlobal(const LLVector3d &position);        // absolute frame

    U32                     getRegionWidthInPoints() const  { return mWidth; }
    F32                     getRegionScale() const          { return mScale; }

    // region X and Y size in meters
    F32                     getRegionWidthInMeters() const  { return mWidthInMeters; }
    F32                     getRegionMinHeight() const      { return -mWidthInMeters; }
    F32                     getRegionMaxHeight() const      { return MAX_OBJECT_Z; }

    void                    updateRegions(F32 max_update_time);
    void                    updateVisibilities();
    void                    updateParticles();

    void                    renderPropertyLines();

    void updateNetStats(); // Update network statistics for all the regions...

    void printPacketsLost();
    void requestCacheMisses();

    // deal with map object updates in the world.
    static void processCoarseUpdate(LLMessageSystem* msg, void** user_data);

    F32 getLandFarClip() const;
    void setLandFarClip(const F32 far_clip);

    LLViewerTexture *getDefaultWaterTexture();
    void updateWaterObjects();

    void waterHeightRegionInfo(std::string const& sim_name, F32 water_height);
    void shiftRegions(const LLVector3& offset);

    void setSpaceTimeUSec(const U64MicrosecondsImplicit space_time_usec);
    U64MicrosecondsImplicit getSpaceTimeUSec() const;

    void getInfo(LLSD& info);
    U32  getNumOfActiveCachedObjects() const {return mNumOfActiveCachedObjects;}

    void clearAllVisibleObjects();
public:
    typedef std::list<LLViewerRegion*> region_list_t;
    const region_list_t& getRegionList() const { return mActiveRegionList; }

    typedef boost::signals2::signal<void(LLViewerRegion*)> region_remove_signal_t;
    boost::signals2::connection setRegionRemovedCallback(const region_remove_signal_t::slot_type& cb);

    // Returns lists of avatar IDs and their world-space positions within a given distance of a point.
    // All arguments are optional. Given containers will be emptied and then filled.
    // Not supplying origin or radius input returns data on all avatars in the known regions.
    void getAvatars(
        uuid_vec_t* avatar_ids = NULL,
        std::vector<LLVector3d>* positions = NULL,
        const LLVector3d& relative_to = LLVector3d(), F32 radius = FLT_MAX) const;

    // Returns 'true' if the region is in mRegionList,
    // 'false' if the region has been removed due to region change
    // or if the circuit to this simulator had been lost.
    bool isRegionListed(const LLViewerRegion* region) const;

    // profile nearby avatars using gPipeline.profileAvatar and update their render times
    // return max GPU time
    F32 getNearbyAvatarsAndMaxGPUTime(std::vector<LLVOAvatar*> &valid_nearby_avs);

private:
    void clearHoleWaterObjects();
    void clearEdgeWaterObjects();

    region_list_t   mActiveRegionList;
    region_list_t   mRegionList;
    region_list_t   mVisibleRegionList;
    region_list_t   mCulledRegionList;

    region_remove_signal_t mRegionRemovedSignal;

    // Number of points on edge
    static const U32 mWidth;

    // meters/point, therefore mWidth * mScale = meters per edge
    static const F32 mScale;

    static const F32 mWidthInMeters;

    F32 mLandFarClip;                   // Far clip distance for land.
    LLPatchVertexArray      mLandPatch;
    S32 mLastPacketsIn;
    S32 mLastPacketsOut;
    S32 mLastPacketsLost;
    U32 mNumOfActiveCachedObjects;
    U64MicrosecondsImplicit mSpaceTimeUSec;

    ////////////////////////////
    //
    // Data for "Fake" objects
    //

    std::list<LLPointer<LLVOWater> > mHoleWaterObjects;
    static const S32 EDGE_WATER_OBJECTS_COUNT = 8;
    LLPointer<LLVOWater> mEdgeWaterObjects[EDGE_WATER_OBJECTS_COUNT];

    LLPointer<LLViewerTexture> mDefaultWaterTexturep;
};


void process_enable_simulator(LLMessageSystem *mesgsys, void **user_data);
void process_disable_simulator(LLMessageSystem *mesgsys, void **user_data);

void process_region_handshake(LLMessageSystem* msg, void** user_data);

void send_agent_pause();
void send_agent_resume();

#endif