add function to delete a playlist item

src/db-generic.c

@@ -49,6 +49,7 @@ typedef struct tag_db_functions {
     int(*dbs_add_playlist)(char *, int, char *,char *, int *);
     int(*dbs_add_playlist_item)(int, int);
     int(*dbs_delete_playlist)(int);
+    int(*dbs_delete_playlist_item)(int, int);
     int(*dbs_enum_start)(DBQUERYINFO *);
     int(*dbs_enum_size)(DBQUERYINFO *, int *);
     int(*dbs_enum_fetch)(DBQUERYINFO *, unsigned char **);
@@ -76,6 +77,7 @@ DB_FUNCTIONS db_functions[] = {
 	db_sqlite_add_playlist,
 	db_sqlite_add_playlist_item,
 	db_sqlite_delete_playlist,
+	db_sqlite_delete_playlist_item,
 	db_sqlite_enum_start,
 	db_sqlite_enum_size,
 	db_sqlite_enum_fetch,
@@ -523,6 +525,25 @@ int db_delete_playlist(int playlistid) {
     return retval;
 }
 
+/**
+ * delete an item from a playlist
+ *
+ * \param playlistid id of the playlist to delete
+ * \param songid id of the song to delete
+ * \returns 0 on success, error code otherwise 
+ */
+int db_delete_playlist_item(int playlistid, int songid) {
+    int retval;
+
+    db_writelock();
+    retval=db_current->dbs_delete_playlist_item(playlistid,songid);
+    if(retval == DB_E_SUCCESS)
+	db_revision_no++;
+    db_unlock();
+
+    return retval;
+}
+
 /**
  * start a db enumeration, based info in the DBQUERYINFO struct
  *

src/dbs-sqlite.c

@@ -331,6 +331,46 @@ int db_sqlite_delete_playlist(int playlistid) {
     return DB_E_SUCCESS;
 }
 
+/**
+ * delete a song from a playlist
+ *
+ * \param playlistid playlist to delete item from
+ * \param songid song to delete from playlist
+ */
+extern int db_sqlite_delete_playlist_item(int playlistid, int songid) {
+    int result;
+    int playlist_type;
+    int count;
+
+    /* first, check the playlist */
+    result=db_sqlite_get_int(E_DBG,&playlist_type,
+			     "select type from playlists where id=%d",playlistid);
+
+    if(result != DB_E_SUCCESS) {
+	if(result == DB_E_NOROWS)
+	    return DB_E_INVALID_PLAYLIST;
+	return result;
+    }
+
+    if(playlist_type == 1)       /* can't delete from a smart playlist */
+	return DB_E_INVALIDTYPE;
+
+    /* make sure the songid is valid */
+    result=db_sqlite_get_int(E_DBG,&count,"select count(*) from playlistitems where id=%d "
+			     "and songid=%d",playlistid,songid);
+    if(result != DB_E_SUCCESS) {
+	if(result == DB_E_NOROWS)
+	    return DB_E_INVALID_SONGID;
+	return result;
+    }
+
+    /* looks valid, so lets add the item */
+    result=db_sqlite_exec(E_DBG,"delete from playlistitems where id=%d and songid=%d",
+			  playlistid,songid);
+    return result;
+}
+
+
 /**
  * add a playlist
  *
@@ -396,7 +436,7 @@ int db_sqlite_add_playlist_item(int playlistid, int songid) {
 	return result;
     }
 
-    if(playlist_type != 0)       /* can't add to smart playlists, or static */
+    if(playlist_type == 1)       /* can't add to smart playlists, or static */
 	return DB_E_INVALIDTYPE;
 
     /* make sure the songid is valid */

src/dbs-sqlite.h

@@ -42,6 +42,7 @@ extern void db_sqlite_dispose_playlist(M3UFILE *pm3u);
 extern int db_sqlite_add_playlist(char *name, int type, char *clause, char *path, int *playlistid);
 extern int db_sqlite_add_playlist_item(int playlistid, int songid);
 extern int db_sqlite_delete_playlist(int playlistid);
+extern int db_sqlite_delete_playlist_item(int playlistid, int songid);
 
 typedef enum {
     songID,