#include "efl_gesture_private.h"

#define MY_CLASS EFL_GESTURE_TOUCH_CLASS

typedef struct _Pointer_Data
{
   struct
   {
      Eina_Vector2 pos;
      double timestamp;
   } start, prev, cur;
   Efl_Pointer_Action action;
} Pointer_Data;

typedef struct _Efl_Gesture_Touch_Data
{
   Efl_Gesture_Touch_State state;
   Eina_Hash              *touch_points;
   int                     touch_down;
   Eina_Bool               multi_touch;
   Eo                     *target;
} Efl_Gesture_Touch_Data;


// This event object accumulates all the touch points
// that are directed to a particular object from the
// first finger down to the last finger up

static void _hash_free_cb(Pointer_Data *point)
{
   free(point);
}

static inline void
_touch_points_reset(Efl_Gesture_Touch_Data *pd)
{
   eina_hash_free(pd->touch_points);
   pd->touch_points = eina_hash_int32_new(EINA_FREE_CB(_hash_free_cb));
   pd->touch_down = 0;
   pd->state = EFL_GESTURE_TOUCH_UNKNOWN;
}

EOLIAN static Efl_Object *
_efl_gesture_touch_efl_object_constructor(Eo *obj, Efl_Gesture_Touch_Data *pd)
{
   obj = efl_constructor(efl_super(obj, MY_CLASS));
   _touch_points_reset(pd);
   return obj;
}

EOLIAN static void
_efl_gesture_touch_efl_object_destructor(Eo *obj, Efl_Gesture_Touch_Data *pd)
{
   eina_hash_free(pd->touch_points);
   efl_destructor(efl_super(obj, MY_CLASS));
}

EOLIAN static Efl_Gesture_Touch_State
_efl_gesture_touch_state_get(Eo *obj EINA_UNUSED, Efl_Gesture_Touch_Data *pd)
{
   return pd->state;
}

EOLIAN static void
_efl_gesture_touch_point_record(Eo *obj EINA_UNUSED, Efl_Gesture_Touch_Data *pd,
                                int id, Eina_Vector2 pos, double timestamp, Efl_Pointer_Action action)
{
   Pointer_Data *point = eina_hash_find(pd->touch_points, &id);

   if (action == EFL_POINTER_ACTION_DOWN)
     pd->touch_down++;
   else if ((action == EFL_POINTER_ACTION_UP) ||
            (action == EFL_POINTER_ACTION_CANCEL))
     pd->touch_down--;
   EINA_SAFETY_ON_FALSE_GOTO(pd->touch_down >= 0, bad_fingers);

   if (point)
     {
        // the point already exists. update the cur and prev point
        point->prev = point->cur;
        point->cur.pos = pos;
        point->cur.timestamp = timestamp;
     }
   else
     {
        // new finger
        if (!id && (action != EFL_POINTER_ACTION_DOWN))
          {
             // discard any other event
             return;
          }
        point = calloc(1, sizeof(Pointer_Data));
        if (!point) return;
        point->start.pos = point->prev.pos = point->cur.pos = pos;
        point->start.timestamp = point->prev.timestamp = point->cur.timestamp = timestamp;

        // add to the hash
        eina_hash_add(pd->touch_points, &id, point);
        // FIXME: finger_list was broken
        if (id)
          pd->multi_touch = EINA_TRUE;
     }
   point->action = action;

   if (!id && (action ==  EFL_POINTER_ACTION_DOWN))
     {
        pd->state = EFL_GESTURE_TOUCH_BEGIN;
     }
   else if ((action ==  EFL_POINTER_ACTION_UP) && (pd->touch_down == 0))
     {
        pd->state = EFL_GESTURE_TOUCH_END;
     }
   else
     {
        pd->state = EFL_GESTURE_TOUCH_UPDATE;
     }
   return;

bad_fingers:
   ERR("Inconsistent touch events received!");
   _touch_points_reset(pd);
}

EOLIAN static Eina_Bool
_efl_gesture_touch_multi_touch_get(Eo *obj EINA_UNUSED, Efl_Gesture_Touch_Data *pd)
{
   return pd->multi_touch;
}

EOLIAN static Eina_Vector2
_efl_gesture_touch_start_point_get(Eo *obj EINA_UNUSED, Efl_Gesture_Touch_Data *pd)
{
   int tool = 0;
   Pointer_Data *point = eina_hash_find(pd->touch_points, &tool);
   Eina_Vector2 vec = { 0, 0 };

   if (!point)
     return vec;

   return point->start.pos;
}

EOLIAN static Eina_Vector2
_efl_gesture_touch_delta(const Eo *obj EINA_UNUSED, Efl_Gesture_Touch_Data *pd, int tool)
{
   Pointer_Data *point = eina_hash_find(pd->touch_points, &tool);
   Eina_Vector2 vec = { 0, 0 };

   if (!point)
     return vec;

   eina_vector2_subtract(&vec, &point->cur.pos, &point->prev.pos);
   return vec;
}

EOLIAN static Eina_Vector2
_efl_gesture_touch_distance(const Eo *obj EINA_UNUSED, Efl_Gesture_Touch_Data *pd, int tool)
{
   Pointer_Data *point = eina_hash_find(pd->touch_points, &tool);
   Eina_Vector2 vec = { 0, 0 };

   if (!point)
     return vec;

   eina_vector2_subtract(&vec, &point->cur.pos, &point->start.pos);
   return vec;
}

#include "efl_gesture_touch.eo.c"