package electrosphere.server.datacell;

import java.util.Map;
import java.util.Set;
import java.util.concurrent.ConcurrentHashMap;
import java.util.concurrent.CopyOnWriteArraySet;

import org.joml.Vector3d;

import electrosphere.collision.CollisionEngine;
import electrosphere.collision.CollisionWorldData;
import electrosphere.collision.hitbox.HitboxManager;
import electrosphere.engine.Globals;
import electrosphere.entity.Entity;
import electrosphere.game.server.world.ServerWorldData;
import electrosphere.net.server.player.Player;
import electrosphere.server.chemistry.ServerChemistryCollisionCallback;
import electrosphere.server.collision.ServerHitboxResolutionCallback;
import electrosphere.server.content.ServerContentManager;

/**
 * Manages all realms for the engine. Should be a singleton
 */
public class RealmManager {

    //All realms in this manager
    Set<Realm> realms = new CopyOnWriteArraySet<Realm>();
    //Map of entities to the realm the entity is in
    Map<Entity,Realm> entityToRealmMap = new ConcurrentHashMap<Entity,Realm>();
    //Map of player to the realm the player is in
    Map<Player,Realm> playerToRealmMap = new ConcurrentHashMap<Player,Realm>();

    /**
     * Constructor
     */
    public RealmManager(){

    }


    /**
     * Creates a realm
     * @return The realm
     */
    public Realm createRealm(){
        //create chemistry engine
        CollisionEngine chemistryEngine = new CollisionEngine();
        chemistryEngine.setCollisionResolutionCallback(new ServerChemistryCollisionCallback());
        return new Realm(
            new ServerWorldData(),
            new CollisionEngine(),
            chemistryEngine,
            new HitboxManager(new ServerHitboxResolutionCallback()),
            ServerContentManager.createServerContentManager(false)
        );
    }

    /**
     * Creates a realm that uses a gridded layout (ie an array of cells in 3d space)
     * @return The realm
     */
    public Realm createGriddedRealm(ServerWorldData serverWorldData, ServerContentManager serverContentManager){
        //create collision engine
        CollisionEngine collisionEngine = new CollisionEngine();
        collisionEngine.setCollisionWorldData(new CollisionWorldData(serverWorldData));
        //create chemistry engine
        CollisionEngine chemistryEngine = new CollisionEngine();
        chemistryEngine.setCollisionWorldData(new CollisionWorldData(serverWorldData));
        chemistryEngine.setCollisionResolutionCallback(new ServerChemistryCollisionCallback());
        //create realm
        Realm realm = new Realm(
            serverWorldData,
            collisionEngine,
            chemistryEngine,
            new HitboxManager(new ServerHitboxResolutionCallback()),
            serverContentManager
        );
        //create function classes
        GriddedDataCellManager griddedDataCellManager = new GriddedDataCellManager(realm);
        //add function classes to realm
        realm.setDataCellManager(griddedDataCellManager);
        //register within the manager
        realms.add(realm);
        return realm;
    }

    /**
     * Creates a viewport realm
     * @return The viewport realm
     */
    public Realm createViewportRealm(Vector3d minPoint, Vector3d maxPoint){
        //create the server world data
        ServerWorldData serverWorldData = ServerWorldData.createFixedWorldData(minPoint, maxPoint);

        //create collision engine
        CollisionEngine collisionEngine = new CollisionEngine();
        collisionEngine.setCollisionWorldData(new CollisionWorldData(serverWorldData));

        //create chemistry engine
        CollisionEngine chemistryEngine = new CollisionEngine();
        chemistryEngine.setCollisionWorldData(new CollisionWorldData(serverWorldData));
        chemistryEngine.setCollisionResolutionCallback(new ServerChemistryCollisionCallback());

        //create realm
        Realm realm = new Realm(
            serverWorldData,
            collisionEngine,
            chemistryEngine,
            new HitboxManager(new ServerHitboxResolutionCallback()),
            ServerContentManager.createServerContentManager(false)
        );

        //add function classes to realm
        realm.setDataCellManager(ViewportDataCellManager.create(realm));

        //register
        realms.add(realm);

        return realm;
    }

    /**
     * Maps an entity to a realm
     * @param entity The entity
     * @param realm The realm
     */
    public void mapEntityToRealm(Entity entity, Realm realm){
        entityToRealmMap.put(entity, realm);
    }

    /**
     * Removes the entity from tracking in this realm manager
     * @param entity The entity to remove
     */
    public void removeEntity(Entity entity){
        entityToRealmMap.remove(entity);
    }

    /**
     * Gets the realm an entity is inside of
     * @param entity The entity
     * @return The realm, or null if the entity is not inside a realm
     */
    public Realm getEntityRealm(Entity entity){
        return entityToRealmMap.get(entity);
    }

    /**
     * Gets the set containing all realms in the manager
     * @return The set containing all realms in the manager
     */
    public Set<Realm> getRealms(){
        return realms;
    }


    /**
     * Simulates all realms in this manager
     */
    public void simulate(){
        Globals.profiler.beginCpuSample("RealmManager.simulate");
        for(Realm realm : realms){
            realm.simulate();
        }
        Globals.profiler.endCpuSample();
    }

    //TODO: !!URGENT!! come up with some mechanism to enforce this actually being called every time a player is added to a server data cell
    /**
     * Adds a player to a realm
     * @param player The player
     * @param realm The realm
     */
    public void setPlayerRealm(Player player, Realm realm){
        playerToRealmMap.put(player, realm);
    }

    /**
     * Gets the realm of a given player
     * @param player The player
     * @return The realm
     */
    public Realm getPlayerRealm(Player player){
        return playerToRealmMap.get(player);
    }

    /**
     * Saves all cells in all realms in the realm manager
     * @param saveName The name of the save
     */
    public void save(String saveName){
        for(Realm realm : realms){
            realm.save(saveName);
        }
    }

    /**
     * Returns the first realm in the manager
     * @return The first realm in the manager
     */
    public Realm first(){
        if(realms.size() == 0){
            return null;
        }
        return realms.iterator().next();
    }

    /**
     * Resets the realm manager
     */
    public void reset(){
        this.realms.clear();
        this.entityToRealmMap.clear();
        this.playerToRealmMap.clear();
    }

    /**
     * Closes the realm manager, destroying all resources
     */
    public void close(){
        for(Realm realm : this.realms){
            if(realm.getServerWorldData() != null && realm.getServerWorldData().getServerTerrainManager() != null){
                realm.getServerWorldData().getServerTerrainManager().closeThreads();
            }
        }
        this.reset();
    }

    
}