/* Dia -- an diagram creation/manipulation program
 * Copyright (C) 1998 Alexander Larsson
 *
 * object_defaults.c : manage default properties of dia objects
 *	The serialization is done with standard object methods in 
 *	a diagram compatible format.
 *
 * Copyright (C) 2002 Hans Breuer
 *
 * 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.
 */
#include <config.h>

#include <stdlib.h> /* atoi() */
#include <string.h>

#include <glib.h>

#include "intl.h"

#include <libxml/tree.h>
#include "dia_xml_libxml.h"
#include "dia_xml.h"
#include "object.h"
#include "message.h"
#include "dia_dirs.h"

static GHashTable *defaults_hash = NULL;
static gboolean object_default_create_lazy = FALSE;

static void
_obj_create (gpointer key,
             gpointer value,
             gpointer user_data)
{
  gchar *name = (gchar *)key;
  DiaObjectType *type = (DiaObjectType *)value;
  GHashTable *ht = (GHashTable *) user_data;
  DiaObject *obj;
  Point startpoint = {0.0,0.0};
  Handle *handle1,*handle2;
  
  g_assert (g_hash_table_lookup (ht, name) == NULL);

  /* at least 'Group' has no ops */
  if (!type->ops)
    return;

  /* the custom objects needs extra_data */
  obj = type->ops->create(&startpoint, type->default_user_data, &handle1,&handle2);
  if (!obj)
    g_warning ("Failed to create default object for '%s'", name);
  else if (0 != strcmp (obj->type->name, name))
    object_destroy (obj); /* Skip over 'compatibility' names/objects */
  else
    g_hash_table_insert(ht, obj->type->name, obj);
}

static void
_obj_destroy (gpointer val)
{
  DiaObject *obj = (DiaObject *)val;

  obj->ops->destroy (obj);
}

/**
 * @param filename the file to load from or NULL for default
 * @param create_lazy if FALSE creates default objects for
 *             every known type. Otherwise default objects
 *             are created on demand
 * 
 * Create all the default objects.
 */
gboolean
dia_object_defaults_load (const gchar *filename, gboolean create_lazy)
{
  xmlDocPtr doc;
  xmlNsPtr name_space;
  ObjectNode obj_node, layer_node;

  object_default_create_lazy = create_lazy;

  if (!defaults_hash)
    {
      defaults_hash = g_hash_table_new_full(g_str_hash, g_str_equal,
                                            NULL, _obj_destroy);

      if (!create_lazy)
        object_registry_foreach (_obj_create, defaults_hash);
    }

    
  /* overload properties from file */
  if (!filename) 
    {
      gchar *default_filename = dia_config_filename("defaults.dia");

      if (g_file_test(default_filename, G_FILE_TEST_EXISTS))
        doc = xmlDiaParseFile(default_filename);
      else
        doc = NULL;
      g_free (default_filename);
    } 
  else
      doc = xmlDiaParseFile(filename);

  if (!doc)
      return FALSE;

  name_space = xmlSearchNs(doc, doc->xmlRootNode, "dia");
  if (   strcmp (doc->xmlRootNode->name, "diagram") 
      || (name_space == NULL))
    {
      message_error(_("Error loading defaults '%s'.\n"
                      "Not a Dia diagram file."), filename);
      xmlFreeDoc (doc);
      return FALSE;
    }

  layer_node = doc->xmlRootNode->xmlChildrenNode;
  while (layer_node)
    {
      if (   !xmlIsBlankNode(layer_node)
          && 0 == strcmp(layer_node->name, "layer")) 
        {
	  obj_node = layer_node->xmlChildrenNode;
	  while (obj_node)
	    {
	      if (   !xmlIsBlankNode(obj_node)
		  && 0 == strcmp(obj_node->name, "object")) 
		{
		  char *typestr = xmlGetProp(obj_node, "type");
		  char *version = xmlGetProp(obj_node, "version");
		  if (typestr)
		    {
		      DiaObject *obj = g_hash_table_lookup (defaults_hash, typestr);
		      if (!obj)
		        {
			  if (!create_lazy)
			    g_warning ("Unknown object '%s' while reading '%s'",
				       typestr, filename);
			  else
			    {
			      DiaObjectType *type = object_get_type (typestr);
			      if (type)
			        obj = type->ops->load (
					obj_node,
					version ? atoi(version) : 0,
					filename);
			      if (obj)
			        g_hash_table_insert (defaults_hash,
			                             obj->type->name, obj);
			    }
			}
		      else
		        {
#if 0 /* lots of complaining about missing attributes */
			  object_load_props(obj, obj_node); /* leaks ?? */
#else
			  DiaObject *def_obj;
			  def_obj = obj->type->ops->load (
					obj_node,
			                version ? atoi(version) : 0,
					filename);
			  if (def_obj->ops->set_props)
			    { 
			      object_copy_props (obj, def_obj, FALSE);
			      def_obj->ops->destroy (def_obj);
			    }
			  else
			    {
			      /* can't copy props */
			      g_hash_table_replace (defaults_hash,
			                            def_obj->type->name, def_obj);
			    }
#endif
			}
		      if (version)
		          xmlFree (version);
		      xmlFree (typestr);
		    }
		}
	      obj_node = obj_node->next;
	    }
	}
      layer_node = layer_node->next;
    }

  xmlFreeDoc(doc);
  return TRUE;
}

/*
 * Remember as defaults from a diagram object
 */
void
dia_object_default_make (const DiaObject *obj_from)
{
  DiaObject *obj_to;

  g_return_if_fail (obj_from);

  obj_to = dia_object_default_get (obj_from->type);
  g_return_if_fail (obj_to);

  object_copy_props (obj_to, obj_from, TRUE);
}

/**
 * dia_object_default_get :
 * @param type The type of the object for which you want the defaults object.
 *
 * Allows to edit one defaults object properties
 */
DiaObject *
dia_object_default_get (const DiaObjectType *type)
{
  DiaObject *obj;

  obj = g_hash_table_lookup (defaults_hash, type->name);
  if (!obj && object_default_create_lazy)
    {
      Point startpoint = {0.0,0.0};
      Handle *handle1,*handle2;
  
      /* at least 'Group' has no ops */
      if (!type->ops)
	return NULL;

      /* the custom objects needs extra_data */
      obj = type->ops->create(&startpoint, 
                              type->default_user_data, 
			      &handle1,&handle2);
      if (obj)
        g_hash_table_insert (defaults_hash, obj->type->name, obj);
    }

  return obj;
}

/**
 * dia_object_default_create:
 * @param type The objects type
 * @param startpoint The left upper corner
 * @param user_data
 * @param handle1
 * @param handle2
 * @return A newly created object.
 *
 * Create an object respecting defaults if available
 */
DiaObject *
dia_object_default_create (const DiaObjectType *type,
                           Point *startpoint,
                           void *user_data,
                           Handle **handle1,
                           Handle **handle2)
{
  const DiaObject *def_obj;
  DiaObject *obj;

  g_return_val_if_fail (type != NULL, NULL);

  def_obj = dia_object_default_get (type);
  if (def_obj && def_obj->ops->describe_props)
    {
      /* copy properties to new object, but keep position */
      obj = type->ops->create (startpoint, user_data, handle1, handle2);
      if (obj)
        {
          object_copy_props (obj, def_obj, TRUE);
	  obj->ops->move (obj, startpoint);
	}
    }
  else
    {
      obj = type->ops->create (startpoint, user_data, handle1, handle2);
    }

  return obj;
}

typedef struct _MyLayerInfo MyLayerInfo;
struct _MyLayerInfo
{
  Point      pos;
  xmlNodePtr node;
};

typedef struct _MyRootInfo MyRootInfo;
struct _MyRootInfo
{
  xmlNodePtr  node;
  gchar      *filename;
  GHashTable *layer_hash;
  xmlNs      *name_space;
  gint        obj_nr;
};

static void
_obj_store (gpointer key,
            gpointer value,
            gpointer user_data)
{
  gchar *name = (gchar *)key;
  DiaObject *obj = (DiaObject *)value;
  MyRootInfo *ri = (MyRootInfo *)user_data;
  ObjectNode obj_node;
  gchar *layer_name;
  gchar buffer[31];
  gchar *p;
  MyLayerInfo *li;

  /* fires if you have messed up the hash keys, 
   * e.g. by using non permanent memory */
  g_assert (0 == strcmp (obj->type->name, name));

  p = strstr (name, " - ");
  if (p) {
    if (p > name)
      layer_name = g_strndup (name, p - name);
    else
      layer_name = g_strdup("NULL");
  }
  else
    layer_name = g_strdup ("default");

  li = g_hash_table_lookup (ri->layer_hash, layer_name);
  if (!li)
    {
      li = g_new (MyLayerInfo, 1);
      li->node = xmlNewChild(ri->node, ri->name_space, "layer", NULL);
      xmlSetProp(li->node, "name", layer_name);
      xmlSetProp(li->node, "visible", "false");
      li->pos.x = li->pos.y = 0.0;
      g_hash_table_insert (ri->layer_hash, layer_name, li);
    }
  else
    g_free (layer_name);

  obj_node = xmlNewChild(li->node, NULL, "object", NULL);
  xmlSetProp(obj_node, "type", obj->type->name);

  g_snprintf(buffer, 30, "%d", obj->type->version);
  xmlSetProp(obj_node, "version", buffer);

  g_snprintf(buffer, 30, "O%d", ri->obj_nr++);
  xmlSetProp(obj_node, "id", buffer);

  obj->ops->move (obj,&(li->pos));
  obj->type->ops->save (obj, obj_node, ri->filename);
  /* arrange following objects below */
  li->pos.y += (obj->bounding_box.bottom - obj->bounding_box.top + 1.0); 
}

/**
 * dia_object_defaults_save:
 *
 * Saves all the currently created default objects into a
 * valid diagram file. All the objects are placed into
 * separate invisible layers.
 */
gboolean
dia_object_defaults_save (const gchar *filename)
{
  MyRootInfo ni;
  xmlDocPtr doc;
  gboolean ret;
  gchar *real_filename;
  int old_blanks_default = pretty_formated_xml;

  /* FIXME HACK: we always want nice readable default files,
   *  but toggling it by a global var is ugly   --hb 
   */
  pretty_formated_xml = TRUE;
  
  if (!filename)
    real_filename = dia_config_filename("defaults.dia");
  else
    real_filename = g_strdup (filename);

  doc = xmlNewDoc("1.0");
  doc->encoding = xmlStrdup("UTF-8");
  doc->xmlRootNode = xmlNewDocNode(doc, NULL, "diagram", NULL);

  ni.name_space = xmlNewNs(doc->xmlRootNode, 
                           DIA_XML_NAME_SPACE_BASE,
			   "dia");
  xmlSetNs(doc->xmlRootNode, ni.name_space);

  ni.obj_nr = 0;
  ni.node = doc->xmlRootNode;
  ni.filename = real_filename;  
  ni.layer_hash = g_hash_table_new_full (g_str_hash, g_str_equal,
                                         g_free, g_free);

  g_hash_table_foreach (defaults_hash, _obj_store, &ni);

  ret = xmlDiaSaveFile (real_filename, doc);
  g_free (real_filename);
  xmlFreeDoc(doc);
  pretty_formated_xml = old_blanks_default;

  g_hash_table_destroy (ni.layer_hash);

  return ret;
}