#include "e.h"

#include "window_tree.h"

void
tiling_window_tree_walk(Window_Tree *root, void (*func)(void *))
{
   Eina_Inlist *itr_safe;
   Window_Tree *itr;
   EINA_INLIST_FOREACH_SAFE(root->children, itr_safe, itr)
     {
        tiling_window_tree_free(itr);
     }
   func(root);
}

void
tiling_window_tree_free(Window_Tree *root)
{
   tiling_window_tree_walk(root, free);
}

Window_Tree *
tiling_window_tree_add(Window_Tree *parent, E_Client *client, Tiling_Split_Type split_type)
{
   Window_Tree *new_node = calloc(1, sizeof(*new_node));
   new_node->client = client;

   if (!parent)
     {
        new_node->weight = 1.0;
        return new_node;
     }
   else if (parent->parent && parent->parent->children && (parent->parent->split_type == split_type))
     {
        /* Adjust existing children's weights */
        Window_Tree *grand_parent = parent->parent;
        Window_Tree *itr;
        int children_count = eina_inlist_count(grand_parent->children);
        float weight = 1.0 / (children_count + 1);

        new_node->parent = grand_parent;
        new_node->weight = weight;

        weight *= children_count;
        EINA_INLIST_FOREACH(grand_parent->children, itr)
          {
             itr->weight *= weight;
          }

        grand_parent->children = eina_inlist_append(grand_parent->children,
              EINA_INLIST_GET(new_node));
     }
   else
     {
        /* Make a new node for the parent client and split the weights in half. */
        Window_Tree *new_parent_client = calloc(1, sizeof(*new_node));
        new_node->parent = parent;
        new_parent_client->parent = parent;
        new_parent_client->client = parent->client;
        parent->client = NULL;
        new_parent_client->weight = 0.5;
        new_node->weight = 0.5;
        parent->split_type = split_type;

        parent->children = eina_inlist_append(parent->children,
              EINA_INLIST_GET(new_parent_client));
        parent->children = eina_inlist_append(parent->children,
              EINA_INLIST_GET(new_node));
     }

   return new_node;
}

Window_Tree *
tiling_window_tree_remove(Window_Tree *root, Window_Tree *item)
{
   if (root == item)
     {
        free(item);
        return NULL;
     }

   int children_count = eina_inlist_count(item->parent->children);

   if (children_count <= 2)
     {
        Window_Tree *item_keep = NULL;
        /* Adjust existing children's weights */
        EINA_INLIST_FOREACH(item->parent->children, item_keep)
          {
             if (item_keep != item)
                break;
          }

        item->parent->client = item_keep->client;
        item->parent->children = NULL;

        free(item_keep);
     }
   else
     {
        Window_Tree *itr;
        float weight = (((float) children_count) - 1.0) / children_count;

        item->parent->children = eina_inlist_remove(item->parent->children,
              EINA_INLIST_GET(item));

        /* Adjust existing children's weights */
        EINA_INLIST_FOREACH(item->parent->children, itr)
          {
             itr->weight /= weight;
          }
     }

  free(item);
  return root;
}

Window_Tree *
tiling_window_tree_client_find(Window_Tree *root, E_Client *client)
{
   Window_Tree *itr;

   if (!root || (root->client == client))
      return root;

   EINA_INLIST_FOREACH(root->children, itr)
     {
        Window_Tree *ret;
        ret = tiling_window_tree_client_find(itr, client);
        if (ret)
           return ret;
     }

   return NULL;
}

/* FIXME: Deduplicate this func. */
static void
_e_client_move_resize(E_Client *ec,
                      int       x,
                      int       y,
                      int       w,
                      int       h)
{
    DBG("%p -> %dx%d+%d+%d", ec, w, h, x, y);
    evas_object_geometry_set(ec->frame, x, y, w, h);
}

void
tiling_window_tree_apply(Window_Tree *root, Evas_Coord x, Evas_Coord y,
      Evas_Coord w, Evas_Coord h)
{
   Window_Tree *itr;

   if (root->client)
      _e_client_move_resize(root->client, x, y, w, h);

   if (root->split_type == TILING_SPLIT_HORIZONTAL)
     {
        EINA_INLIST_FOREACH(root->children, itr)
          {
             Evas_Coord itw = w * itr->weight;
             tiling_window_tree_apply(itr, x, y, itw, h);
             x += itw;
          }
     }
   else if (root->split_type == TILING_SPLIT_VERTICAL)
     {
        EINA_INLIST_FOREACH(root->children, itr)
          {
             Evas_Coord ith = h * itr->weight;
             tiling_window_tree_apply(itr, x, y, w, ith);
             y += ith;
          }
     }
}