package asteroids.model;

import be.kuleuven.cs.som.annotate.*;
import java.util.*;
import asteroids.model.Entity;

/**
 * @invar  Each world can have its width as width .
 *       | canHaveAsWidth(this.getWidth())
 * @invar  Each world can have its height as height .
 *       | canHaveAsHeight(this.getHeight())
 * @invar   Each world must have proper ships.
 *        | hasProperShips()
 * @invar Each world must have proper bullets.
 *          |hasProperBullets()
 */
public class World {
    /**
     * Initialize this new world with given width and height as a non-terminated world with no ships or bullets yet.
     *
     * @param  width
     *         The width for this new world.
     * @param  height
     *         The height for this new world
     * @post   If the given height is a valid height for any world,
     *         the height of this new world is equal to the given
     *         height. Otherwise, the height of this new world is equal
     *         to 0.
     *       | if (isValidValue(height))
     *       |   then new.getHeight == height
     *       |   else new.getHeight == 0
     * @post   If the given width is a valid width for any world,
     *         the width of this new world is equal to the given
     *         width. Otherwise, the width of this new world is equal
     *         to 0.
     *       | if (isValidValue(width))
     *       |   then new.getWidth == width
     *       |   else new.getWidth == 0
     * @post   This new world has no ships yet.
     *       | new.getNbShips() == 0
     * @post   This new world has no bullets yet.
     *       | new.getNbBullets() == 0
     */

    @Raw
    public World(double width, double height) {
        if (! canHaveAsValue(width))
            width = 0;
        if (! canHaveAsValue(height))
            height = 0;
        this.width = width;
        this.height = height;
    }
    /**
     * Terminate this world.
     *
     * @post   This world  is terminated.
     *       | new.isTerminated()
     * @post   ...
     *       | ...
     */
     public void terminate() {
         this.isTerminated = true;
     }

     /**
      * Return a boolean indicating whether or not this world
      * is terminated.
      */
     @Basic @Raw
     public boolean isTerminated() {
         return this.isTerminated;
     }

     /**
      * Variable registering whether this person is terminated.
      */
     private boolean isTerminated = false;


    /**
     * Return the width of this world.
     */
    @Basic @Raw @Immutable
    public double getWidth() {
        return this.width;
    }

    /**
     *
     * @return the height of this world.
     */
    @Basic @Raw @Immutable
    public double getHeight() {
        return this.height;
    }

    /**
     * Check whether this world can have the given value as its height/width.
     *
     * @param  value
     *         The value to check.
     * @return
     *       | result == (value>=0 && value <= Double.MAX_VALUE && value !=Double.NaN)
    */
    @Raw
    public boolean canHaveAsValue(double value) {
        return ((value >= 0) && (value <= Double.MAX_VALUE) && (value != Double.NaN));
    }

    /**
     * Variable registering the width of this world.
     */
    private final double width;

    /**
     * Variable registering the height of this world.
     */
    private final double height;



    /**
     * Check whether this world has the given ship as one of its
     * ships.
     *
     * @param  ship
     *         The ship to check.
     */
    @Basic
    @Raw
    public boolean hasAsShip(@Raw Ship ship) {
        return ships.contains(ship);
    }

    /**
     * Check whether this world can have the given ship
     * as one of its ships.
     *
     * @param  ship
     *         The ship to check.
     * @return True if and only if the given ship is effective
     *         and that ship is a valid ship for a world.
     *       | result ==
     *       |   (ship != null) &&
     *       |   Ship.isValidWorld(this)
     */
    @Raw
    public boolean canHaveAsShip(Ship ship) throws IllegalNumberException {
        if ((ship == null) || (!ship.canHaveAsWorld(this)) || (hasAsShip(ship)))
            return false;
        if ((!canHaveAsWidthCoordinate(ship)) ||(!canHaveAsHeightCoordinate(ship)))
            return false;
        for (Entity entity : entities) {
            if (significantOverlap(ship, entity))
                return false;
        }
        return true;
    }

    public boolean significantOverlap(Entity entity1, Entity entity2) throws IllegalNumberException{
        if (entity1.overlap(entity2))
            if (entity1.getDistanceBetween(entity2)+entity1.getRadius()+entity2.getRadius()<=0.99*(entity1.getRadius()+entity2.getRadius()))
                return true;
        return false;


    }

    public boolean apparentlyWithinBoundaries(Entity entity){
        return (Math.abs(this.getWidth()-entity.getPosition()[0])>=0.99*entity.getRadius() && Math.abs(entity.getPosition()[0])>=0.99*entity.getRadius()
                &&Math.abs(entity.getPosition()[1])>=0.99*entity.getRadius()&& Math.abs(this.getHeight()-entity.getPosition()[1])>=0.99*entity.getRadius());
    }

    public boolean canHaveAsWidthCoordinate(Entity entity){
        if (!((entity.getPosition()[0] + entity.getRadius()) <= this.getWidth()))
            return false;
        if ((!canHaveAsValue(entity.getPosition()[0] + entity.getRadius())) || (! canHaveAsValue(entity.getPosition()[0] - entity.getRadius())))
            return false;
        return true;
    }

    public boolean canHaveAsHeightCoordinate(Entity entity){
        if (!((entity.getPosition()[1] + entity.getRadius()) <= this.getHeight()))
            return false;
        if ((!canHaveAsValue(entity.getPosition()[1] + entity.getRadius())) || (! canHaveAsValue(entity.getPosition()[1] - entity.getRadius())))
            return false;
        return true;
    }

    /**
     * Check whether this world has proper ships attached to it.
     *
     * @return True if and only if this world can have each of the
     *         ships attached to it as one of its ships,
     *         and if each of these ships references this world as
     *         the world to which they are attached.
     *       | for each ship in Ship:
     *       |   if (hasAsShip(ship))
     *       |     then canHaveAsShip(ship) &&
     *       |          (ship.getWorld() == this)
     */
    public boolean hasProperShips() throws IllegalNumberException{
        for (Ship ship : ships) {
            if (!canHaveAsShip(ship))
                return false;
            if (ship.getWorld() != this)
                return false;
        }
        return true;
    }

    /**
     * Return the number of ships associated with this world.
     *
     * @return  The total number of ships collected in this world.
     *        | result ==
     *        |   card({ship:Ship | hasAsShip({ship)})
     */
    public int getNbShips() {
        return ships.size();
    }

    /**
     * Add the given ship to the set of ships of this world.
     *
     * @param  ship
     *         The ship to be added.
     * @pre    The given ship is effective and already references
     *         this world.
     *       | (ship != null) && (ship.getWorld() == this)
     * @post   This world has the given ship as one of its ships.
     *       | new.hasAsShip(ship)
     */
    public void addShip(@Raw Ship ship) throws IllegalArgumentException, IllegalNumberException{
        if (!canHaveAsShip(ship))
            throw new IllegalArgumentException();
        ships.add(ship);
        entities.add(ship);
    }

    /**
     * Remove the given ship from the set of ships of this world.
     *
     * @param  ship
     *         The ship to be removed.
     * @pre    This world has the given ship as one of
     *         its ships, and the given ship does not
     *         reference any world.
     *       | this.hasAsShip(ship) &&
     *       | (ship.getWorld() == null)
     * @post   This world no longer has the given ship as
     *         one of its ships.
     *       | ! new.hasAsShip(ship)
     */
    @Raw
    public void removeShip(Ship ship) throws IllegalArgumentException{
        if( !this.hasAsShip(ship) || !(ship.getWorld() == null))
            throw new IllegalArgumentException();
        ships.remove(ship);
        entities.remove(ship);
    }

    /**
     * Variable referencing a set collecting all the ships
     * of this world.
     *
     * @invar  The referenced set is effective.
     *       | ships != null
     * @invar  Each ship registered in the referenced list is
     *         effective and not yet terminated.
     *       | for each ship in ships:
     *       |   ( (ship != null) &&
     *       |     (! ship.isTerminated()) )
     */
    private final Set<Ship> ships = new HashSet<Ship>();
    private final Set<Entity> entities = new HashSet<Entity>();

    /**
     * Check whether this world has the given entity as one of its
     * entity.
     *
     * @param  entity
     *         The entity to check.
     */
    @Basic
    @Raw
    public boolean hasAsEntity(@Raw Entity entity) {
        return entities.contains(entity);
    }

    /**
     * Check whether this world can have the given bullet
     * as one of its bullets.
     *
     * @param  bullet
     *         The bullet to check.
     * @return True if and only if the given bullet is effective
     *         and that bullet is a valid bullet for a world.
     *       | result ==
     *       |   (bullet != null) &&
     *       |   bullet.isValidWorld(this)
     */
    @Raw
    public boolean canHaveAsEntity(Entity entity) throws IllegalNumberException{
        if ((entity == null) || (!entity.canHaveAsWorld(this)) || (hasAsEntity(entity)))
            return false;
        if ((!canHaveAsWidthCoordinate(entity)) ||(!canHaveAsHeightCoordinate(entity)))
            return false;
        for (Entity entity1 : entities) {
            if (significantOverlap(entity1, entity))
                return false;
        }
        return true;
    }

    /**
     * Check whether this world has proper bullets attached to it.
     *
     * @return True if and only if this world can have each of the
     *         bullets attached to it as one of its bullets,
     *         and if each of these bullets references this world as
     *         the world to which they are attached.
     *       | for each bullet in bullet:
     *       |   if (hasAsbullet(bullet))
     *       |     then canHaveAsbullet(bullet) &&
     *       |          (bullet.getWorld() == this)
     */
    public boolean hasProperEntities() throws IllegalNumberException{
        for (Entity entity : entities) {
            if (!canHaveAsEntity(entity))
                return false;
            if (entity.getWorld() != this)
                return false;
        }
        return true;
    }

    /**
     * Return the number of bullets associated with this world.
     *
     * @return  The total number of bullets collected in this world.
     *        | result ==
     *        |   card({bullet:bullet | hasAsbullet({bullet)})
     */
    public int getNbEntities() {
        return entities.size();
    }


    /**
     * Check whether this world has the given entity as one of its
     * entity.
     *
     * @param  entity
     *         The entity to check.
     */
    @Basic
    @Raw
    public boolean hasAsBullet(@Raw Bullet bullet) {
        return bullets.contains(bullet);
    }


    /**
     * Check whether this world can have the given bullet
     * as one of its bullets.
     *
     * @param  bullet
     *         The bullet to check.
     * @return True if and only if the given bullet is effective
     *         and that bullet is a valid bullet for a world.
     *       | result ==
     *       |   (bullet != null) &&
     *       |   bullet.isValidWorld(this)
     */
    @Raw
    public boolean canHaveAsBullet(Bullet bullet) throws IllegalNumberException{
        if ((bullet == null) || (!bullet.canHaveAsWorld(this)) || (hasAsBullet(bullet)))
            return false;
        if ((!canHaveAsWidthCoordinate(bullet)) ||(!canHaveAsHeightCoordinate(bullet)))
            return false;
        for (Entity entity : entities) {
            if (significantOverlap(bullet, entity))
                return false;
        }
        return true;
    }


    /**
     * Check whether this world has proper bullets attached to it.
     *
     * @return True if and only if this world can have each of the
     *         bullets attached to it as one of its bullets,
     *         and if each of these bullets references this world as
     *         the world to which they are attached.
     *       | for each bullet in bullet:
     *       |   if (hasAsbullet(bullet))
     *       |     then canHaveAsbullet(bullet) &&
     *       |          (bullet.getWorld() == this)
     */
    public boolean hasProperBullets() throws IllegalNumberException{
        for (Bullet bullet : bullets) {
            if (!canHaveAsBullet(bullet))
                return false;
            if (bullet.getWorld() != this)
                return false;
        }
        return true;
    }

    /**
     * Return the number of bullets associated with this world.
     *
     * @return  The total number of bullets collected in this world.
     *        | result ==
     *        |   card({bullet:bullet | hasAsbullet({bullet)})
     */
    public int getNbBullets() {
        return bullets.size();
    }

    /**
     * Add the given bullet to the set of bullets of this world.
     *
     * @param  bullet
     *         The bullet to be added.
     * @pre    The given bullet is effective and already references
     *         this world.
     *       | (bullet != null) && (bullet.getWorld() == this)
     * @post   This world has the given bullet as one of its bullets.
     *       | new.hasAsbullet(bullet)
     */
    public void addBullet(@Raw Bullet bullet) throws IllegalArgumentException,IllegalNumberException{
        if (!canHaveAsBullet(bullet))
            throw new IllegalArgumentException();
        bullets.add(bullet);
        entities.add(bullet);
    }

    /**
     * Remove the given bullet from the set of bullets of this world.
     *
     * @param  bullet
     *         The bullet to be removed.
     * @pre    This world has the given bullet as one of
     *         its bullets, and the given bullet does not
     *         reference any world.
     *       | this.hasAsbullet(bullet) &&
     *       | (bullet.getWorld() == null)
     * @post   This world no longer has the given bullet as
     *         one of its bullets.
     *       | ! new.hasAsbullet(bullet)
     */
    @Raw
    public void removeBullet(Bullet bullet) throws IllegalArgumentException{
        if( !this.hasAsBullet(bullet) || !(bullet.getWorld() == null))
            throw new IllegalArgumentException();
        bullets.remove(bullet);
        entities.remove(bullet);
    }

    /**
     * Variable referencing a set collecting all the bullets
     * of this world.
     *
     * @invar  The referenced set is effective.
     *       | bullets != null
     * @invar  Each bullet registered in the referenced list is
     *         effective and not yet terminated.
     *       | for each bullet in bullets:
     *       |   ( (bullet != null) &&
     *       |     (! bullet.isTerminated()) )
     */
    private final Set<Bullet> bullets = new HashSet<Bullet>();

    public Entity entityAtPosition(double[] position){
        for (Entity entity : entities) {
            if (entity.getPosition()[0]==position[0] && entity.getPosition()[1]==position[1])
                return entity;
        }
        return null;
    }
}