/**

  * $Id$

  *

  * VMU management - maintains a list of all known VMUs

  *

  * Copyright (c) 2009 Nathan Keynes.

  *

  * 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.

  */

 #include <string.h>

 #include <stdlib.h>

 #include <glib/glist.h>

 #include <glib/gstrfuncs.h>

 #include "vmulist.h"

 #include "config.h"

 DEFINE_HOOK(vmulist_change_hook, vmulist_change_hook_t);

 typedef struct vmulist_entry {

     const gchar *filename;

     vmu_volume_t vol;

     int attach_count;

 } *vmulist_entry_t;

 /** 

  * Doubly-linked list of vmulist_entry_t maintained in sorted order by display name.

  * Could be augmented with a hashtable if it gets too long

  */

 static GList *vmu_list;

 #define ENTRY(it) ((vmulist_entry_t)(it)->data)

 #define VOLUME(it) (ENTRY(it)->vol)

 #define DISPLAY_NAME(it) vmulist_display_name(ENTRY(it))

 static const char *vmulist_display_name(vmulist_entry_t ent)

 {

     if( ent->filename == NULL ) {

         return NULL;

     }

     const char *s = strrchr(ent->filename, '/' );

     if( s == NULL || *(s+1) == '\0' ) {

         return ent->filename;

     } else {

         return s+1;

     }

 }

 static void vmulist_update_config( void ) 

 {

     GList *temp = NULL, *it;

     for( it = vmu_list; it != NULL; it = g_list_next(it) ) {

         vmulist_entry_t entry = ENTRY(it);

         temp = g_list_append( temp, (char *)entry->filename );

     }

     lxdream_set_global_config_list_value( CONFIG_VMU, temp );

     g_list_free( temp );

 }

 static vmulist_entry_t vmulist_get_entry_by_name( const gchar *name )

 {

     GList *it;

     for( it = vmu_list; it != NULL; it = g_list_next(it) ) {

         const gchar *vmu_name = DISPLAY_NAME(it);

         if( name == NULL ? vmu_name == NULL : vmu_name != NULL && strcmp( vmu_name, name ) == 0 ) {

             return ENTRY(it);

         }

     }

     return NULL; // not found

 }

 static vmulist_entry_t vmulist_get_entry_by_filename( const gchar *name )

 {

     GList *it;

     for( it = vmu_list; it != NULL; it = g_list_next(it) ) {

         const gchar *vmu_name = ENTRY(it)->filename;

         if( name == NULL ? vmu_name == NULL : vmu_name != NULL && strcmp( vmu_name, name ) == 0 ) {

             return ENTRY(it);

         }

     }

     return NULL; // not found

 }

 static vmulist_entry_t vmulist_get_entry_by_volume( vmu_volume_t vol )

 {

     GList *it;

     for( it = vmu_list; it != NULL; it = g_list_next(it) ) {

         if( VOLUME(it) == vol ) {

             return ENTRY(it);

         }

     }

     return NULL; // not found

 }

 static vmulist_entry_t vmulist_get_entry_by_index( unsigned int index )

 {

     return (vmulist_entry_t)g_list_nth_data(vmu_list,index);

 }

 static gint vmulist_display_name_compare( gconstpointer a, gconstpointer b )

 {

     const char *aname = vmulist_display_name((vmulist_entry_t)a);    

     const char *bname = vmulist_display_name((vmulist_entry_t)b);

     if( aname == bname )

         return 0;

     if( aname == NULL ) 

         return -1;

     if( bname == NULL )

         return 1;

     return strcmp(aname,bname);

 }

 /** 

  * Add a new entry into the list, maintaining the sorted order.

  * If the filename is already in the list, it is updated instead.

  */ 

 static vmulist_entry_t vmulist_add_entry( const gchar *filename, vmu_volume_t vol )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_filename(filename);

     if( entry == NULL ) {

         entry = g_malloc( sizeof(struct vmulist_entry) );

         entry->filename = g_strdup(filename);

         entry->vol = vol;

         vmu_list = g_list_insert_sorted(vmu_list, entry, vmulist_display_name_compare );

     } else {

         if( entry->vol != vol && entry->vol != NULL )

             vmu_volume_destroy( entry->vol );

         entry->vol = vol;

         /* NOTE: at the moment this can't require a resort, but if we allow

          * user-editable display names it will

          */ 

     }

     entry->attach_count = 0;

     vmulist_update_config();

     CALL_HOOKS( vmulist_change_hook, VMU_ADDED, g_list_index(vmu_list,entry) );

     return entry;

 }

 static void vmulist_remove_entry( vmulist_entry_t entry )

 {

     int idx = g_list_index(vmu_list, entry);

     vmu_list = g_list_remove( vmu_list, entry );

     g_free( (char *)entry->filename );

     g_free( entry );

     vmulist_update_config();

     CALL_HOOKS( vmulist_change_hook, VMU_REMOVED, idx );

 }

 static unsigned int vmulist_get_index( vmulist_entry_t entry )

 {

     return g_list_index( vmu_list, entry );

 }

 int vmulist_add_vmu( const gchar *filename, vmu_volume_t vol )

 {

     vmulist_entry_t entry = vmulist_add_entry( filename, vol );

     return vmulist_get_index(entry);

 }

 void vmulist_remove_vmu( vmu_volume_t vol )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_volume(vol);

     if( entry != NULL ) {

         vmulist_remove_entry(entry);

     }

 }

 const char *vmulist_get_name( unsigned int idx )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_index(idx);

     if( entry != NULL ) {

         return vmulist_display_name(entry);

     }

     return NULL;

 }

 const char *vmulist_get_filename( unsigned int idx )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_index(idx);

     if( entry != NULL ) {

         return entry->filename;

     }

     return NULL;

 }

 const char *vmulist_get_volume_name( vmu_volume_t vol )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_volume(vol);

     if( entry != NULL ) {

         return entry->filename;

     } 

     return NULL;

 }

 vmu_volume_t vmulist_get_vmu( unsigned int idx )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_index(idx);

     if( entry != NULL ) {

         if( entry->vol == NULL ) {

             entry->vol = vmu_volume_load(entry->filename);

         }

         return entry->vol;

     }

     return NULL;

 }

 vmu_volume_t vmulist_get_vmu_by_name( const gchar *name )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_name(name);

     if( entry != NULL ) {

         if( entry->vol == NULL ) {

             entry->vol = vmu_volume_load(entry->filename);

         }

         return entry->vol;

     }

     return NULL;

 }

 vmu_volume_t vmulist_get_vmu_by_filename( const gchar *name )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_filename(name);

     if( entry != NULL ) {

         if( entry->vol == NULL ) {

             entry->vol = vmu_volume_load(entry->filename);

         }

         return entry->vol;

     } else {

         vmu_volume_t vol = vmu_volume_load( name );

         vmulist_add_entry( name, vol );

         return vol;

     }

 }

 int vmulist_get_index_by_filename( const gchar *name )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_filename(name);

     if( entry != NULL ) {

         return g_list_index( vmu_list, entry );

     }

     return -1;

 }

 int vmulist_create_vmu( const gchar *filename, gboolean create_only )

 {

     vmu_volume_t vol = vmu_volume_new_default(filename);

     if( vmu_volume_save( filename, vol, create_only ) ) {

         return vmulist_add_vmu( filename, vol );

     } else {

         vmu_volume_destroy(vol);

     }

     return -1;

 }

 gboolean vmulist_attach_vmu( vmu_volume_t vol, const gchar *where )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_volume(vol);

     if( entry == NULL ) {

         return FALSE;

     }

     entry->attach_count++;

     return TRUE;

 }

 void vmulist_detach_vmu( vmu_volume_t vol )

 {

     vmulist_entry_t entry = vmulist_get_entry_by_volume(vol);

     if( entry != NULL && entry->attach_count > 0 ) {

         entry->attach_count--;

     }

 }

 unsigned int vmulist_get_size(void)

 {

     return g_list_length(vmu_list);

 }

 void vmulist_init( void )

 {

     GList *filenames = lxdream_get_global_config_list_value( CONFIG_VMU );

     GList *ptr;

     for( ptr = filenames; ptr != NULL; ptr = g_list_next(ptr) ) {

         vmulist_add_entry( (gchar *)ptr->data, NULL );

         g_free( ptr->data );

     }

     g_list_free( filenames );

 }

 void vmulist_save_all( void )

 {

     GList *it;

     for( it = vmu_list; it != NULL; it = g_list_next(it) ) {

         vmulist_entry_t entry = ENTRY(it);

         if( entry->vol != NULL && vmu_volume_is_dirty(entry->vol) ) {

             vmu_volume_save(entry->filename, entry->vol, FALSE);

         }

     }

 }

 void vmulist_shutdown( void )

 {

     vmulist_save_all();

 }