/**
 * vim: set ts=4 :
 * =============================================================================
 * SourceMod (C)2004-2011 AlliedModders LLC.  All rights reserved.
 * =============================================================================
 *
 * This file is part of the SourceMod/SourcePawn SDK.
 *
 * This program is free software; you can redistribute it and/or modify it under
 * the terms of the GNU General Public License, version 3.0, as published by the
 * Free Software Foundation.
 *
 * 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, see <http://www.gnu.org/licenses/>.
 *
 * As a special exception, AlliedModders LLC gives you permission to link the
 * code of this program (as well as its derivative works) to "Half-Life 2," the
 * "Source Engine," the "SourcePawn JIT," and any Game MODs that run on software
 * by the Valve Corporation.  You must obey the GNU General Public License in
 * all respects for all other code used.  Additionally, AlliedModders LLC grants
 * this exception to all derivative works.  AlliedModders LLC defines further
 * exceptions, found in LICENSE.txt (as of this writing, version JULY-31-2007),
 * or <http://www.sourcemod.net/license.php>.
 *
 * Version: $Id$
 */

#if defined _entity_included
 #endinput
#endif
#define _entity_included

/**
 * Property types for entities.
 */
enum PropType
{
	Prop_Send = 0,	/**< This property is networked. */
	Prop_Data = 1,	/**< This property is for save game data fields. */
};

/**
 * @section For more information on these, see the HL2SDK (public/edict.h)
 */
#define FL_EDICT_CHANGED		(1<<0)	/**< Game DLL sets this when the entity state changes
										 Mutually exclusive with FL_EDICT_PARTIAL_CHANGE. */
#define FL_EDICT_FREE			(1<<1)	/**< this edict if free for reuse */
#define FL_EDICT_FULL			(1<<2)	/**< this is a full server entity */
#define FL_EDICT_FULLCHECK		(0<<0)  /**< call ShouldTransmit() each time, this is a fake flag */
#define FL_EDICT_ALWAYS			(1<<3)	/**< always transmit this entity */
#define FL_EDICT_DONTSEND		(1<<4)	/**< don't transmit this entity */
#define FL_EDICT_PVSCHECK		(1<<5)	/**< always transmit entity, but cull against PVS */
#define FL_EDICT_PENDING_DORMANT_CHECK	(1<<6)
#define FL_EDICT_DIRTY_PVS_INFORMATION	(1<<7)
#define FL_FULL_EDICT_CHANGED		(1<<8)

enum PropFieldType
{
	PropField_Unsupported,		/**< The type is unsupported. */
	PropField_Integer,			/**< Valid for SendProp and Data fields */
	PropField_Float,			/**< Valid for SendProp and Data fields */
	PropField_Entity,			/**< Valid for Data fields only (SendProp shows as int) */
	PropField_Vector,			/**< Valid for SendProp and Data fields */
	PropField_String,			/**< Valid for SendProp and Data fields */
	PropField_String_T,			/**< Valid for Data fields.  Read only.
									 Note that the size of a string_t is dynamic, and
									 thus FindDataMapOffs() will return the constant size
									 of the string_t container (which is 32 bits right now).
								 */
};

/**
 * @endsection
 */

/**
 * Returns the maximum number of networked entities.
 *
 * Note: For legacy reasons, this only returns the maximum
 * networked entities (maximum edicts), rather than total
 * maximum entities.
 *
 * @return				Maximum number of networked entities.
 */
native int GetMaxEntities();

/**
 * Returns the number of networked entities in the server.
 *
 * Note: For legacy reasons, this only returns the current count
 * of networked entities (current edicts), rather than total
 * count of current entities.
 *
 * @return				Number of entities in the server.
 */
native int GetEntityCount();

/**
 * Returns whether or not an entity is valid.  Returns false
 * if there is no matching CBaseEntity for this entity index.
 *
 * @param entity		Index of the entity.
 * @return				True if valid, false otherwise.
 */
native bool IsValidEntity(int entity);

/**
 * Returns whether or not an edict index is valid.
 *
 * @param edict			Index of the edict.
 * @return				True if valid, false otherwise.
 */
native bool IsValidEdict(int edict);

/**
 * Returns whether or not an entity has a valid networkable edict.
 *
 * @param edict			Index of the entity.
 * @return				True if networkable, false if invalid or not networkable.
 */
native bool IsEntNetworkable(int entiy);

/**
 * Creates a new edict (the basis of a networkable entity)
 *
 * @return				Index of the edict, 0 on failure.
 */
native int CreateEdict();

/**
 * Removes an edict from the world.
 *
 * @param edict			Index of the edict.
 * @error				Invalid edict index.
 */
native void RemoveEdict(int edict);

/**
 * Returns the flags on an edict.  These are not the same as entity flags.
 *
 * @param edict			Index of the entity.
 * @return				Edict flags.
 * @error				Invalid edict index.
 */
native int GetEdictFlags(int edict);

/**
 * Sets the flags on an edict.  These are not the same as entity flags.
 *
 * @param edict			Index of the entity.
 * @param flags			Flags to set.
 * @error				Invalid edict index.
 */
native void SetEdictFlags(int edict, int flags);

/**
 * Retrieves an edict classname.
 *
 * @param edict			Index of the entity.
 * @param clsname		Buffer to store the classname.
 * @param maxlength		Maximum length of the buffer.
 * @return				True on success, false if there is no classname set.
 */
native bool GetEdictClassname(int edict, char[] clsname, int maxlength);

/**
 * Retrieves an entity's networkable serverclass name.
 * This is not the same as the classname and is used for networkable state changes.
 *
 * @param edict			Index of the entity.
 * @param clsname		Buffer to store the serverclass name.
 * @param maxlength		Maximum length of the buffer.
 * @return				True on success, false if the edict is not networkable.
 * @error				Invalid edict index.
 */
native bool GetEntityNetClass(int edict, char[] clsname, int maxlength);

/**
 * @section Entity offset functions
 *
 * Offsets should be specified in byte distance from the CBaseEntity
 * structure, not short (double byte) or integer (four byte) multiples.
 * It is somewhat common practice to use offsets aligned to their final
 * type, and thus make sure you are not falling to this error in SourceMod.
 * For example, if your "integer-aligned" offset was 119, your byte-aligned
 * offset is 119*4, or 476.

 * Specifying incorrect offsets or the incorrect data type for an offset
 * can have fatal consequences.  If you are hardcoding offsets, and the
 * layout of CBaseEntity does not match, you can easily crash the server.
 *
 * The reasonable bounds for offsets is greater than or equal to 0 and
 * below 32768.  Offsets out of these bounds will throw an error.  However,
 * this does not represent any real range, it is simply a sanity check for
 * illegal values.  Any range outside of the CBaseEntity structure's private
 * size will cause undefined behavior or even crash.
 */

/**
 * Marks an entity as state changed.  This can be useful if you set an offset
 * and wish for it to be immediately changed over the network.  By default this
 * is not done for offset setting functions.
 *
 * @param edict			Index to the edict.
 * @param offset		Offset to mark as changed.  If 0,
 *						the entire edict is marked as changed.
 * @error				Invalid entity or offset out of bounds.
 */
native void ChangeEdictState(int edict, int offset = 0);

/**
 * Peeks into an entity's object data and retrieves the integer value at
 * the given offset.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @param size			Number of bytes to read (valid values are 1, 2, or 4).
 * @return				Value at the given memory location.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native int GetEntData(int entity, int offset, int size=4);

/**
 * Peeks into an entity's object data and sets the integer value at
 * the given offset.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @param value			Value to set.
 * @param size			Number of bytes to write (valid values are 1, 2, or 4).
 * @param changeState	If true, change will be sent over the network.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native void SetEntData(int entity, int offset, any value, int size=4, bool changeState=false);

/**
 * Peeks into an entity's object data and retrieves the float value at
 * the given offset.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @return				Value at the given memory location.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native float GetEntDataFloat(int entity, int offset);

/**
 * Peeks into an entity's object data and sets the float value at
 * the given offset.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @param value			Value to set.
 * @param changeState	If true, change will be sent over the network.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native void SetEntDataFloat(int entity, int offset, float value, bool changeState=false);

/**
 * This function is deprecated.  Use GetEntDataEnt2 instead, for
 * reasons explained in the notes.
 *
 * Note: This function returns 0 on failure, which may be misleading,
 * as the number 0 is also used for the world entity index.
 *
 * Note: This function makes no attempt to validate the returned
 * entity, and in fact, it could be garbage or completely unexpected.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @return				Entity index at the given location, or 0 if none.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
#pragma deprecated Use GetEntDataEnt2() instead.
native int GetEntDataEnt(int entity, int offset);

/**
 * This function is deprecated.   Use SetEntDataEnt2 instead, for
 * reasons explained in the notes.
 *
 * Note: This function uses 0 as an indicator to unset data, but
 * 0 is also the world entity index.  Thus, a property cannot
 * be set to the world entity using this native.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @param other			Entity index to set, or 0 to clear.
 * @param changeState	If true, change will be sent over the network.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
#pragma deprecated Use SetEntDataEnt2() instead.
native void SetEntDataEnt(int entity, int offset, int other, bool changeState=false);

/**
 * Peeks into an entity's object data and retrieves the entity index
 * at the given offset.
 *
 * Note: This will only work on offsets that are stored as "entity
 * handles" (which usually looks like m_h* in properties).  These
 * are not SourceMod Handles, but internal Source structures.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @return				Entity index at the given location.  If there is no entity,
 *						or the stored entity is invalid, then -1 is returned.
 * @error				Invalid input entity, or offset out of reasonable bounds.
 */
native int GetEntDataEnt2(int entity, int offset);

/**
 * Peeks into an entity's object data and sets the entity index at the
 * given offset.
 *
 * Note: This will only work on offsets that are stored as "entity
 * handles" (which usually looks like m_h* in properties).  These
 * are not SourceMod Handles, but internal Source structures.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @param other			Entity index to set, or -1 to clear.
 * @param changeState	If true, change will be sent over the network.
 * @error				Invalid input entity, or offset out of reasonable bounds.
 */
native void SetEntDataEnt2(int entity, int offset, int other, bool changeState=false);

/**
 * Peeks into an entity's object data and retrieves the vector at the
 * given offset.
 * @note Both a Vector and a QAngle are three floats.  This is a
 * convenience function and will work with both types.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @param vec			Vector buffer to store data in.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native void GetEntDataVector(int entity, int offset, float vec[3]);

/**
 * Peeks into an entity's object data and sets the vector at the given
 * offset.
 * @note Both a Vector and a QAngle are three floats.  This is a
 * convenience function and will work with both types.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @param vec			Vector to set.
 * @param changeState	If true, change will be sent over the network.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native void SetEntDataVector(int entity, int offset, const float vec[3], bool changeState=false);

/**
 * Peeks into an entity's object data and retrieves the string at
 * the given offset.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @param buffer		Destination string buffer.
 * @param maxlen		Maximum length of output string buffer.
 * @return			Number of non-null bytes written.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native int GetEntDataString(int entity, int offset, char[] buffer, int maxlen);

/**
 * Peeks into an entity's object data and sets the string at
 * the given offset.
 *
 * @param entity		Edict index.
 * @param offset		Offset to use.
 * @param buffer		String to set.
 * @param maxlen		Maximum length of bytes to write.
 * @param changeState	If true, change will be sent over the network.
 * @return			Number of non-null bytes written.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native int SetEntDataString(int entity, int offset, const char[] buffer, int maxlen, bool changeState=false);

/**
 * @endsection
 */

/**
 * Given a ServerClass name, finds a networkable send property offset.
 * This information is cached for future calls.
 *
 * Note, this function may return offsets that do not work!
 * If a property is nested beneath a parent object, the resulting offset
 * will be invalid for direct use with data functions.  Therefore, you
 * should use FindSendPropInfo() instead.  An example of such a property is
 * CTFPlayer::DT_LocalPlayer.m_nDisguiseClass on Team Fortress.
 *
 * @param cls			Classname.
 * @param prop			Property name.
 * @return				An offset, or -1 on failure.
 */
#pragma deprecated Use FindSendPropInfo instead, or HasEntProp if you just want to check for existence.
native int FindSendPropOffs(const char[] cls, const char[] prop);

/**
 * Given a ServerClass name, finds a networkable send property offset.
 * This information is cached for future calls.
 *
 * @param cls			Classname.
 * @param prop			Property name.
 * @param type			Optional parameter to store the type.
 * @param num_bits		Optional parameter to store the number of bits the field
 *						uses, if applicable (otherwise 0 is stored).  The number
 *						of bits varies for integers and floats, and is always 0
 * 						for strings.
 * @param local_offset	Optional parameter to store the local offset, as
 *						FindSendPropOffs() would return.
 * @return				On success, returns an absolutely computed offset.
 *						If no offset is available, 0 is returned.
 *						If the property is not found, -1 is returned.
 */
native int FindSendPropInfo(const char[] cls,
						const char[] prop,
						PropFieldType &type=view_as<PropFieldType>(0),
						int &num_bits=0,
						int &local_offset=0);

/**
 * Given an entity, finds a datamap property offset.
 * This information is cached for future calls.
 *
 * @param entity		Entity index.
 * @param prop			Property name.
 * @param type			Optional parameter to store the type.
 * @param num_bits		Optional parameter to store the number of bits the field
 *						uses.  The bit count will either be 1 (for boolean) or
 *						divisible by 8 (including 0 if unknown).
 * @return				An offset, or -1 on failure.
 */
#pragma deprecated Use FindDataMapInfo instead, or HasEntProp if you just want to check for existence.
native int FindDataMapOffs(int entity,
					   const char[] prop,
					   PropFieldType &type=view_as<PropFieldType>(0),
					   int &num_bits=0);

/**
 * Given an entity, finds a nested datamap property offset.
 * This information is cached for future calls.
 *
 * @param entity		Entity index.
 * @param prop			Property name.
 * @param type			Optional parameter to store the type.
 * @param num_bits		Optional parameter to store the number of bits the field
 *						uses.  The bit count will either be 1 (for boolean) or
 *						divisible by 8 (including 0 if unknown).
 * @param local_offset	Optional parameter to store the local offset, as
 *						FindDataMapOffs() would return.
 * @return				An offset, or -1 on failure.
 */
native int FindDataMapInfo(int entity,
					   const char[] prop,
					   PropFieldType &type=view_as<PropFieldType>(0),
					   int &num_bits=0,
					   int &local_offset=0);

/**
 * Wrapper function for finding a send property for a particular entity.
 *
 * @param ent			Entity index.
 * @param prop			Property name.
 * @param actual		Defaults to false for backwards compatibility.
 *						If true, the newer FindSendPropInfo() function
 *						is used instead.
 * @return				An offset, or -1 on failure.
 */
stock int GetEntSendPropOffs(int ent, const char[] prop, bool actual=false)
{
	char cls[64];

	if (!GetEntityNetClass(ent, cls, sizeof(cls)))
	{
		return -1;
	}

	int local = -1;
	int offset = FindSendPropInfo(cls, prop, _, _, local);

	if (actual)
	{
		return offset;
	} else {
		return local;
	}
}

/**
 * Checks if an entity property exists on an entity.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @return				Whether the property exists on the entity.
 * @error				Invalid entity.
 */
stock bool HasEntProp(int entity, PropType type, const char[] prop)
{
	if (type == Prop_Data) {
		return (FindDataMapInfo(entity, prop) != -1);
	}

	if (type != Prop_Send) {
		return false;
	}

	char cls[64];
	if (!GetEntityNetClass(entity, cls, sizeof(cls))) {
		return false;
	}

	return (FindSendPropInfo(cls, prop) != -1);
}

/**
 * Retrieves an integer value from an entity's property.
 *
 * This function is considered safer and more robust over GetEntData,
 * because it performs strict offset checking and typing rules.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @param size			Number of bytes to write (valid values are 1, 2, or 4).
 *						This value is auto-detected, and the size parameter is
 *						only used as a fallback in case detection fails.
 * @param element		Element # (starting from 0) if property is an array.
 * @return				Value at the given property offset.
 * @error				Invalid entity or property not found.
 */
native int GetEntProp(int entity, PropType type, const char[] prop, int size=4, int element=0);

/**
 * Sets an integer value in an entity's property.
 *
 * This function is considered safer and more robust over SetEntData,
 * because it performs strict offset checking and typing rules.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @param value			Value to set.
 * @param size			Number of bytes to write (valid values are 1, 2, or 4).
 *						This value is auto-detected, and the size parameter is
 *						only used as a fallback in case detection fails.
 * @param element		Element # (starting from 0) if property is an array.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native void SetEntProp(int entity, PropType type, const char[] prop, any value, int size=4, int element=0);

/**
 * Retrieves a float value from an entity's property.
 *
 * This function is considered safer and more robust over GetEntDataFloat,
 * because it performs strict offset checking and typing rules.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @param element		Element # (starting from 0) if property is an array.
 * @return				Value at the given property offset.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native float GetEntPropFloat(int entity, PropType type, const char[] prop, int element=0);

/**
 * Sets a float value in an entity's property.
 *
 * This function is considered safer and more robust over SetEntDataFloat,
 * because it performs strict offset checking and typing rules.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @param value			Value to set.
 * @param element		Element # (starting from 0) if property is an array.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native void SetEntPropFloat(int entity, PropType type, const char[] prop, float value, int element=0);

/**
 * Retrieves an entity index from an entity's property.
 *
 * This function is considered safer and more robust over GetEntDataEnt*,
 * because it performs strict offset checking and typing rules.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @param element		Element # (starting from 0) if property is an array.
 * @return				Entity index at the given property.
 *						If there is no entity, or the entity is not valid,
 *						then -1 is returned.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native int GetEntPropEnt(int entity, PropType type, const char[] prop, int element=0);

/**
 * Sets an entity index in an entity's property.
 *
 * This function is considered safer and more robust over SetEntDataEnt*,
 * because it performs strict offset checking and typing rules.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @param other			Entity index to set, or -1 to unset.
 * @param element		Element # (starting from 0) if property is an array.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
native void SetEntPropEnt(int entity, PropType type, const char[] prop, int other, int element=0);

/**
 * Retrieves a vector of floats from an entity, given a named network property.
 *
 * This function is considered safer and more robust over GetEntDataVector,
 * because it performs strict offset checking and typing rules.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @param vec			Vector buffer to store data in.
 * @param element		Element # (starting from 0) if property is an array.
 * @error				Invalid entity, property not found, or property not
 *						actually a vector data type.
 */
native void GetEntPropVector(int entity, PropType type, const char[] prop, float vec[3], int element=0);

/**
 * Sets a vector of floats in an entity, given a named network property.
 *
 * This function is considered safer and more robust over SetEntDataVector,
 * because it performs strict offset checking and typing rules.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @param vec			Vector to set.
 * @param element		Element # (starting from 0) if property is an array.
 * @error				Invalid entity, property not found, or property not
 *						actually a vector data type.
 */
native void SetEntPropVector(int entity, PropType type, const char[] prop, const float vec[3], int element=0);

/**
 * Gets a network property as a string.
 *
 * @param entity		Edict index.
 * @param type			Property type.
 * @param prop			Property to use.
 * @param buffer		Destination string buffer.
 * @param maxlen		Maximum length of output string buffer.
 * @param element		Element # (starting from 0) if property is an array.
 * @return				Number of non-null bytes written.
 * @error				Invalid entity, offset out of reasonable bounds, or property is not a valid string.
 */
native int GetEntPropString(int entity, PropType type, const char[] prop, char[] buffer, int maxlen, int element=0);

/**
 * Sets a network property as a string.
 *
 * @param entity		Edict index.
 * @param type			Property type.
 * @param prop			Property to use.
 * @param buffer		String to set.
 * @param element		Element # (starting from 0) if property is an array.
 * @return				Number of non-null bytes written.
 * @error				Invalid entity, offset out of reasonable bounds, or property is not a valid string.
 */
native int SetEntPropString(int entity, PropType type, const char[] prop, const char[] buffer, int element=0);

/**
 * Retrieves the count of values that an entity property's array can store.
 *
 * @param entity		Entity/edict index.
 * @param type			Property type.
 * @param prop			Property name.
 * @return				Size of array (in elements) or 1 if property is not an array.
 * @error				Invalid entity or property not found.
 */
native int GetEntPropArraySize(int entity, PropType type, const char[] prop);

/**
 * Copies an array of cells from an entity at a given offset.
 *
 * @param entity		Entity index.
 * @param offset		Offset to use.
 * @param array			Array to read into.
 * @param arraySize		Number of values to read.
 * @param dataSize		Size of each value in bytes (1, 2, or 4).
 * @error				Invalid entity or offset out of reasonable bounds.
 */
stock void GetEntDataArray(int entity, int offset, int[] array, int arraySize, int dataSize=4)
{
	for (int i=0; i<arraySize; i++)
		array[i] = GetEntData(entity, offset + i*dataSize, dataSize);
}

/**
 * Copies an array of cells to an entity at a given offset.
 *
 * @param entity		Entity index.
 * @param offset		Offset to use.
 * @param array			Array of values to copy.
 * @param arraySize		Number of values to copy.
 * @param dataSize		Size of each value in bytes (1, 2, or 4).
 * @param changeState	True to set the network state as changed; false otherwise.
 * @error				Invalid entity or offset out of reasonable bounds.
 */
stock void SetEntDataArray(int entity, int offset, const int[] array, int arraySize, int dataSize=4, bool changeState=false)
{
	for (int i=0; i<arraySize; i++)
	{
		SetEntData(entity, offset + i*dataSize, array[i], dataSize, changeState);
	}
}

/**
 * Gets the memory address of an entity.
 *
 * @param entity		Entity index.
 * @return				Address of the entity.
 * @error				Invalid entity.
 */
native Address GetEntityAddress(int entity);

/**
 * Retrieves the classname of an entity.
 * This is like GetEdictClassname(), except it works for ALL
 * entities, not just edicts.
 *
 * @param entity			Index of the entity.
 * @param clsname		Buffer to store the classname.
 * @param maxlength		Maximum length of the buffer.
 * @return				True on success, false if there is no classname set.
 */
stock bool GetEntityClassname(int entity, char[] clsname, int maxlength)
{
	return !!GetEntPropString(entity, Prop_Data, "m_iClassname", clsname, maxlength);
}