/*
 * Copyright (C) 2002,2003,2004 Daniel Heck
 *
 * This program is free software; you can redistribute it and/or
 * modify it under the terms of the GNU General Public License
 * as published by the Free Software Foundation; either version 2
 * of the License, or (at your option) any later version.
 *
 * This program 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 General Public License for more details.
 *
 * You should have received a copy of the GNU General Public License along
 * with this program; if not, write to the Free Software Foundation, Inc.,
 * 59 Temple Place, Suite 330, Boston, MA 02111-1307, USA.
 *
 * $Id: world_internal.hh,v 1.8 2004/04/24 11:46:51 dheck Exp $
 */

#include <memory>

namespace world
{
    class Field;
    struct Signal;

    typedef px::Array2<Field> FieldArray;

    typedef vector<ForceField*>  ForceList;
    typedef vector<StoneContact> StoneContactList;
    typedef vector<Actor*>       ActorList;
    typedef vector<Signal>       SignalList;


/* -------------------- Signals -------------------- */

    struct Signal {
        // Variables
        Object *source;
        GridLoc destloc;
        string message;

        // Constructor
        Signal (Object *src, GridLoc dstloc, const string &msg)
        : source (src), destloc(dstloc), message(msg)
        {}
    };

/* -------------------- RubberBand -------------------- */
    
    /*! Stores the physical information about a rubber band (to which
      object it is attached, its length and force, etc.) */
    class RubberBand {
    public:
        RubberBand (Actor *a1, Actor *a2, const RubberBandData &d);
        RubberBand (Actor *a1, Stone *st, const RubberBandData &d);
        ~RubberBand();

        void apply_forces ();
        void tick (double dtime);

        Actor *get_actor() const { return actor; }
        Actor *get_actor2() const { return actor2; }
        Stone *get_stone() const { return stone; }

        const RubberBandData get_data () const { return data; }
    private:
        V2 get_p1() const;
        V2 get_p2() const;

        // Variables.
        Actor *actor, *actor2;
        Stone *stone;
        display::RubberHandle model;
        RubberBandData data;
    };

/* -------------------- MouseForce -------------------- */

    /*! This class implements the "force field" that accelerates
      objects when the mouse is moved.  Only objects that have the
      "mouseforce" and the "controllers" attributes set are affected
      by this force field. */
    class MouseForce {
    public:
        void set_force(V2 f) { force=f; }
        void add_force(V2 f) { force+=f; }

        V2 get_force(Actor *a) {
            if (a->is_flying() || a->is_dead())
                return V2();
            else 
                return force * a->get_mouseforce();
        }

        void tick (double /*dtime*/) {
            force=V2();
        }
    private:
        V2 force;
    };


/* -------------------- Scramble -------------------- */

    /*! Stores all positions plus direction where puzzle scrambling
      should be performed */
    struct Scramble {
        // Variables
        GridPos   pos;
        Direction dir;
        int       intensity;

        Scramble(GridPos p, Direction d, int i) : pos(p), dir(d), intensity(i) {}

        bool expired() const { return intensity<1; }
    };

/* -------------------- DelayedImpulse -------------------- */

    class DelayedImpulse {
        Impulse      impulse;
        double       delay;
        const Stone *receiver;  // to test if stone has changed

        DelayedImpulse& operator = (const DelayedImpulse& other); // forbidden
    public:
        DelayedImpulse(const Impulse& impulse_, double delay_, const Stone *receiver_)
        : impulse(impulse_), delay(delay_), receiver(receiver_) {}

        DelayedImpulse(const DelayedImpulse& other)
        : impulse(other.impulse), delay(other.delay), receiver(other.receiver) {}

        bool tick(double dtime) { // returns true if Impulse has to be sent NOW
            delay -= dtime;
            return delay <= 0;
        }

        const GridPos& destination() const { return impulse.dest; }

        void send_impulse(Stone *target) const {

            // @@@ FIXME: the test for equality of Stones sometimes fails
            // (e.g. with turnstiles rotated by rotators)
            //
            // I guess this happens, because when the turnstile-pivot
            // removes and add arms during turn, it may happen, that
            // the Stone receives the same memory address
            //
            // Possible fix : add unique ID to all objects

            if (target == receiver) { 
                // if object did not change since impulse was initiated
                target->on_impulse(impulse);
            }
        }
    };

    typedef list<DelayedImpulse> ImpulseList;

/* -------------------- Layer -------------------- */

    template <class T>
    class Layer {
        T *defaultval;
    public:
        Layer(T* deflt = 0) : defaultval(deflt) {}
        virtual ~Layer() {}

        T *get(GridPos p);
        T *yield(GridPos p);
        void set(GridPos p, T *x);
        void kill(GridPos p) { dispose(yield(p)); }

        virtual T* raw_get (Field &) = 0;
        virtual void raw_set (Field &, T *) = 0;

    private:
        virtual void dispose(T *x) { if (x) DisposeObject(x); }
    };

    /*
    ** Floor layer
    */
    class FloorLayer : public Layer<Floor> {
    private:
        Floor *raw_get (Field &f) { return f.floor; }
        void raw_set (Field &f, Floor *x) { f.floor = x;}
    };


    /*
    ** Item layer
    */
    class ItemLayer : public Layer<Item> {
    private:
        Item *raw_get (Field &f) { return f.item; }
        void raw_set (Field &f, Item *x) { f.item = x;}
    };

    /*
    ** Stone layer
    */
    class StoneLayer : public Layer<Stone>
    {
    public:
        StoneLayer() : Layer<Stone>(&borderstone) {}
    private:
        Stone *raw_get (Field &f) { return f.stone; }
        void raw_set (Field &f, Stone *st) { f.stone = st;}
        void dispose (Stone *st) {
            if (st) {
                KillRubberBands(st);
                DisposeObject(st);
            }
        }

        /* This stone is used as the virtual border of the playing area.
           It is immovable and indestructible and makes sure the player's
           marble cannot leave the level. */
        class BorderStone : public Stone {
        public:
            BorderStone() : Stone("borderstone") {}
            Stone *clone() { return this; }
            void dispose() {}
        };

        BorderStone borderstone;
    };


/* -------------------- World -------------------- */

    /*! Contains the level information (in theory everything that is
      local to the current level; in practice a lot of things are
      still stored in global variables). */
    class World {
    public:
        World (int ww, int hh);
        ~World();

        bool contains (GridPos p) {
            return (p.x>=0 && p.y>=0 && p.x<w && p.y<h);
        }

        bool is_border (GridPos p);

        Field *get_field (GridPos p) {
            if (this->contains(p))
                return &fields(p.x,p.y);
            else
                return 0;
        }

        void    name_object (Object *obj, const string &name);
        void    unname (Object *);
        Object *get_named (const string &);

        void tick (double dtime);
        void remove (ForceField *ff);

        void add_scramble(GridPos p, Direction dir);
        void scramble_puzzles();

        void add_actor (Actor *a);
        void add_actor (Actor *a, const V2 &pos);

        void tick_actor(Actor *a, double dtime);

    private:

        /* ---------- Private methods ---------- */

        void add_mouseforce (Actor *a, Floor *floor, V2 &mforce);
        V2 get_local_force (Actor *a);
        V2 get_global_force (Actor *a);

        void advance_actor (Actor *a, double h);
        void move_actors (double dtime);
        void find_contact_with_stone (Actor *a, GridPos p, StoneContact &c);
        void find_stone_contacts (Actor *a, StoneContactList &cl);
        void handle_stone_contact (StoneContact &sc);
        void handle_actor_contacts ();
        void handle_actor_contact (unsigned a1, unsigned a2);
        void handle_contacts (unsigned actoridx);
        void handle_delayed_impulses (double dtime);

        void stone_change (GridPos p);

    public:

        /* ---------- Variables ---------- */

        FieldArray           fields; // Contains floors, items, etc.
        int                  w, h; // Width and height of the level
        ForceList            forces;
        ActorList            actorlist; // List of movable, dynamic objects
        vector<RubberBand *> m_rubberbands;
        SignalList           m_signals;
        MouseForce           m_mouseforce;
        ConstantForce        m_flatforce;
        int                  scrambleIntensity;

        //! True if game is not running yet
        bool                 preparing_level;

        ImpulseList          delayed_impulses;
        vector<GridPos>      changed_stones;

        FloorLayer      fl_layer;
        ItemLayer       it_layer;
        StoneLayer      st_layer;

    private:
        px::Dict<Object *> m_objnames; // Name -> object mapping

        list<Scramble> scrambles;
    };
}