/* GStreamer

 * Copyright (C) <1999> Erik Walthinsen <omega@cse.ogi.edu>

 *

 * This library is free software; you can redistribute it and/or

 * modify it under the terms of the GNU Library General Public

 * License as published by the Free Software Foundation; either

 * version 2 of the License, or (at your option) any later version.

 *

 * This library 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

 * Library General Public License for more details.

 *

 * You should have received a copy of the GNU Library General Public

 * License along with this library; if not, write to the

 * Free Software Foundation, Inc., 59 Temple Place - Suite 330,

 * Boston, MA 02111-1307, USA.

 */

#include <gst/gst.h>

#define GST_TYPE_MEM_INDEX              \

  (gst_index_get_type ())

#define GST_MEM_INDEX(obj)              \

  (G_TYPE_CHECK_INSTANCE_CAST ((obj), GST_TYPE_MEM_INDEX, GstMemIndex))

#define GST_MEM_INDEX_CLASS(klass)      \

  (G_TYPE_CHECK_CLASS_CAST ((klass), GST_TYPE_MEM_INDEX, GstMemIndexClass))

#define GST_IS_MEM_INDEX(obj)           \

  (G_TYPE_CHECK_INSTANCE_TYPE ((obj), GST_TYPE_MEM_INDEX))

#define GST_IS_MEM_INDEX_CLASS(klass)     \

  (GST_TYPE_CHECK_CLASS_TYPE ((klass), GST_TYPE_MEM_INDEX))

/*

 * Object model:

 *

 * All entries are simply added to a GList first. Then we build

 * an index to each entry for each id/format

 *

 *

 *  memindex

 *    -----------------------------...

 *    !                  !

 *   id1                 id2

 *    ------------

 *    !          !

 *   format1  format2

 *    !          !

 *   GTree      GTree

 *

 *

 * The memindex creates a MemIndexId object for each writer id, a

 * Hashtable is kept to map the id to the MemIndexId

 *

 * The MemIndexId keeps a MemIndexFormatIndex for each format the

 * specific writer wants indexed.

 *

 * The MemIndexFormatIndex keeps all the values of the particular

 * format in a GTree, The values of the GTree point back to the entry.

 *

 * Finding a value for an id/format requires locating the correct GTree,

 * then do a lookup in the Tree to get the required value.

 */

typedef struct

{

  GstFormat format;

  gint offset;

  GTree *tree;

}

GstMemIndexFormatIndex;

typedef struct

{

  gint id;

  GHashTable *format_index;

}

GstMemIndexId;

typedef struct _GstMemIndex GstMemIndex;

typedef struct _GstMemIndexClass GstMemIndexClass;

struct _GstMemIndex

{

  GstIndex parent;

  GList *associations;

  GHashTable *id_index;

};

struct _GstMemIndexClass

{

  GstIndexClass parent_class;

};

/* Index signals and args */

enum

{

  LAST_SIGNAL

};

enum

{

  ARG_0,

  /* FILL ME */

};

static void gst_mem_index_class_init (GstMemIndexClass * klass);

static void gst_mem_index_init (GstMemIndex * index);

static void gst_mem_index_finalize (GObject * object);

static void gst_mem_index_add_entry (GstIndex * index, GstIndexEntry * entry);

static GstIndexEntry *gst_mem_index_get_assoc_entry (GstIndex * index, gint id,

    GstIndexLookupMethod method, GstAssocFlags flags,

    GstFormat format, gint64 value, GCompareDataFunc func, gpointer user_data);

#define CLASS(mem_index)  GST_MEM_INDEX_CLASS (G_OBJECT_GET_CLASS (mem_index))

static GstIndex *parent_class = NULL;

/*static guint gst_mem_index_signals[LAST_SIGNAL] = { 0 }; */

static GType

gst_mem_index_get_type (void)

{

  static GType mem_index_type = 0;

  if (!mem_index_type) {

    static const GTypeInfo mem_index_info = {

      sizeof (GstMemIndexClass),

      NULL,

      NULL,

      (GClassInitFunc) gst_mem_index_class_init,

      NULL,

      NULL,

      sizeof (GstMemIndex),

      1,

      (GInstanceInitFunc) gst_mem_index_init,

      NULL

    };

    mem_index_type =

        g_type_register_static (GST_TYPE_INDEX, "GstMemIndex", &mem_index_info,

        0);

  }

  return mem_index_type;

}

static void

gst_mem_index_class_init (GstMemIndexClass * klass)

{

  GObjectClass *gobject_class;

  GstIndexClass *gstindex_class;

  gobject_class = (GObjectClass *) klass;

  gstindex_class = (GstIndexClass *) klass;

  parent_class = g_type_class_peek_parent (klass);

  gobject_class->finalize = GST_DEBUG_FUNCPTR (gst_mem_index_finalize);

  gstindex_class->add_entry = GST_DEBUG_FUNCPTR (gst_mem_index_add_entry);

  gstindex_class->get_assoc_entry =

      GST_DEBUG_FUNCPTR (gst_mem_index_get_assoc_entry);

}

static void

gst_mem_index_init (GstMemIndex * index)

{

  GST_DEBUG ("created new mem index");

  index->associations = NULL;

  index->id_index = g_hash_table_new (g_int_hash, g_int_equal);

}

static void

gst_mem_index_free_format (gpointer key, gpointer value, gpointer user_data)

{

  GstMemIndexFormatIndex *index = (GstMemIndexFormatIndex *) value;

  if (index->tree) {

    g_tree_destroy (index->tree);

  }

}

static void

gst_mem_index_free_id (gpointer key, gpointer value, gpointer user_data)

{

  GstMemIndexId *id_index = (GstMemIndexId *) value;

  if (id_index->format_index) {

    g_hash_table_foreach (id_index->format_index, gst_mem_index_free_format,

        NULL);

    g_hash_table_destroy (id_index->format_index);

    id_index->format_index = NULL;

  }

}

static void

gst_mem_index_finalize (GObject * object)

{

  GstMemIndex *memindex = GST_MEM_INDEX (object);

  /* Delete the trees referencing the associations first */

  if (memindex->id_index) {

    g_hash_table_foreach (memindex->id_index, gst_mem_index_free_id, NULL);

    g_hash_table_destroy (memindex->id_index);

    memindex->id_index = NULL;

  }

  /* Then delete the associations themselves */

  if (memindex->associations) {

    g_list_foreach (memindex->associations, (GFunc) gst_index_entry_free, NULL);

    g_list_free (memindex->associations);

    memindex->associations = NULL;

  }

  G_OBJECT_CLASS (parent_class)->finalize (object);

}

static void

gst_mem_index_add_id (GstIndex * index, GstIndexEntry * entry)

{

  GstMemIndex *memindex = GST_MEM_INDEX (index);

  GstMemIndexId *id_index;

  id_index = g_hash_table_lookup (memindex->id_index, &entry->id);

  if (!id_index) {

    id_index->id = entry->id;

    id_index->format_index = g_hash_table_new (g_int_hash, g_int_equal);

    g_hash_table_insert (memindex->id_index, &id_index->id, id_index);

  }

}

static gint

mem_index_compare (gconstpointer a, gconstpointer b, gpointer user_data)

{

  GstMemIndexFormatIndex *index = user_data;

  gint64 val1, val2;

  gint64 diff;

  val1 = GST_INDEX_ASSOC_VALUE (((GstIndexEntry *) a), index->offset);

  val2 = GST_INDEX_ASSOC_VALUE (((GstIndexEntry *) b), index->offset);

  diff = (val2 - val1);

  return (diff == 0 ? 0 : (diff > 0 ? 1 : -1));

}

static void

gst_mem_index_index_format (GstMemIndexId * id_index, GstIndexEntry * entry,

    gint assoc)

{

  GstMemIndexFormatIndex *index;

  GstFormat *format;

  format = &GST_INDEX_ASSOC_FORMAT (entry, assoc);

  index = g_hash_table_lookup (id_index->format_index, format);

  if (!index) {

    index->format = *format;

    index->offset = assoc;

    index->tree = g_tree_new_with_data (mem_index_compare, index);

    g_hash_table_insert (id_index->format_index, &index->format, index);

  }

  g_tree_insert (index->tree, entry, entry);

}

static void

gst_mem_index_add_association (GstIndex * index, GstIndexEntry * entry)

{

  GstMemIndex *memindex = GST_MEM_INDEX (index);

  GstMemIndexId *id_index;

  memindex->associations = g_list_prepend (memindex->associations, entry);

  id_index = g_hash_table_lookup (memindex->id_index, &entry->id);

  if (id_index) {

    gint i;

    for (i = 0; i < GST_INDEX_NASSOCS (entry); i++) {

      gst_mem_index_index_format (id_index, entry, i);

    }

  }

}

static void

gst_mem_index_add_object (GstIndex * index, GstIndexEntry * entry)

{

}

static void

gst_mem_index_add_format (GstIndex * index, GstIndexEntry * entry)

{

}

static void

gst_mem_index_add_entry (GstIndex * index, GstIndexEntry * entry)

{

  GST_LOG_OBJECT (index, "added this entry");

  switch (entry->type) {

    case GST_INDEX_ENTRY_ID:

      gst_mem_index_add_id (index, entry);

      break;

    case GST_INDEX_ENTRY_ASSOCIATION:

      gst_mem_index_add_association (index, entry);

      break;

    case GST_INDEX_ENTRY_OBJECT:

      gst_mem_index_add_object (index, entry);

      break;

    case GST_INDEX_ENTRY_FORMAT:

      gst_mem_index_add_format (index, entry);

      break;

    default:

      break;

  }

}

typedef struct

{

  gint64 value;

  GstMemIndexFormatIndex *index;

  gboolean exact;

  GstIndexEntry *lower;

  gint64 low_diff;

  GstIndexEntry *higher;

  gint64 high_diff;

}

GstMemIndexSearchData;

static gint

mem_index_search (gconstpointer a, gconstpointer b)

{

  GstMemIndexSearchData *data = (GstMemIndexSearchData *) b;

  GstMemIndexFormatIndex *index = data->index;

  gint64 val1, val2;

  gint64 diff;

  val1 = GST_INDEX_ASSOC_VALUE (((GstIndexEntry *) a), index->offset);

  val2 = data->value;

  diff = (val1 - val2);

  if (diff == 0)

    return 0;

  /* exact matching, don't update low/high */

  if (data->exact)

    return (diff > 0 ? 1 : -1);

  if (diff < 0) {

    if (diff > data->low_diff) {

      data->low_diff = diff;

      data->lower = (GstIndexEntry *) a;

    }

    diff = -1;

  } else {

    if (diff < data->high_diff) {

      data->high_diff = diff;

      data->higher = (GstIndexEntry *) a;

    }

    diff = 1;

  }

  return diff;

}

static GstIndexEntry *

gst_mem_index_get_assoc_entry (GstIndex * index, gint id,

    GstIndexLookupMethod method,

    GstAssocFlags flags,

    GstFormat format, gint64 value, GCompareDataFunc func, gpointer user_data)

{

  GstMemIndex *memindex = GST_MEM_INDEX (index);

  GstMemIndexId *id_index;

  GstMemIndexFormatIndex *format_index;

  GstIndexEntry *entry;

  GstMemIndexSearchData data;

  id_index = g_hash_table_lookup (memindex->id_index, &id);

  if (!id_index)

    return NULL;

  format_index = g_hash_table_lookup (id_index->format_index, &format);

  if (!format_index)

    return NULL;

  data.value = value;

  data.index = format_index;

  data.exact = (method == GST_INDEX_LOOKUP_EXACT);

  /* setup data for low/high checks if we are not looking

   * for an exact match */

  if (!data.exact) {

    data.low_diff = G_MININT64;

    data.lower = NULL;

    data.high_diff = G_MAXINT64;

    data.higher = NULL;

  }

  entry = g_tree_search (format_index->tree, mem_index_search, &data);

  /* get the low/high values if we're not exact */

  if (entry == NULL && !data.exact) {

    if (method == GST_INDEX_LOOKUP_BEFORE)

      entry = data.lower;

    else if (method == GST_INDEX_LOOKUP_AFTER) {

      entry = data.higher;

    }

  }

  if (entry) {

    if ((GST_INDEX_ASSOC_FLAGS (entry) & flags) != flags) {

      GList *l_entry = g_list_find (memindex->associations, entry);

      entry = NULL;

      while (l_entry) {

        entry = (GstIndexEntry *) l_entry->data;

        if (entry->id == id && (GST_INDEX_ASSOC_FLAGS (entry) & flags) == flags)

          break;

        if (method == GST_INDEX_LOOKUP_BEFORE)

          l_entry = g_list_next (l_entry);

        else if (method == GST_INDEX_LOOKUP_AFTER) {

          l_entry = g_list_previous (l_entry);

        }

      }

    }

  }

  return entry;

}

#ifdef __SYMBIAN32__

EXPORT_C

#endif

gboolean

gst_mem_index_plugin_init (GstPlugin * plugin)

{

  GstIndexFactory *factory;

  factory = gst_index_factory_new ("memindex",

      "A index that stores entries in memory", gst_mem_index_get_type ());

  if (factory == NULL) {

    g_warning ("failed to create memindex factory");

    return FALSE;

  }

  GST_PLUGIN_FEATURE (factory)->plugin_name = g_strdup (plugin->desc.name);

  GST_PLUGIN_FEATURE (factory)->loaded = TRUE;

  gst_registry_add_feature (gst_registry_get_default (),

      GST_PLUGIN_FEATURE (factory));

  return TRUE;

}