/**
 * vim: set ts=4 :
 * =============================================================================
 * SourceMod (C)2004-2016 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 _halflife_included
 #endinput
#endif
#define _halflife_included

#define SOURCE_SDK_UNKNOWN           0      /**< Could not determine the engine version */
#define SOURCE_SDK_ORIGINAL         10      /**< Original Source engine (still used by "The Ship") */
#define SOURCE_SDK_DARKMESSIAH      15      /**< Modified version of original engine used by Dark Messiah (no SDK) */
#define SOURCE_SDK_EPISODE1         20      /**< SDK+Engine released after Episode 1 */
#define SOURCE_SDK_EPISODE2         30      /**< SDK+Engine released after Episode 2/Orange Box */
#define SOURCE_SDK_BLOODYGOODTIME   32      /**< Modified version of ep2 engine used by Bloody Good Time (no SDK) */
#define SOURCE_SDK_EYE              33      /**< Modified version of ep2 engine used by E.Y.E Divine Cybermancy (no SDK) */
#define SOURCE_SDK_CSS              34      /**< Sometime-older version of Source 2009 SDK+Engine, used for Counter-Strike: Source */
#define SOURCE_SDK_EPISODE2VALVE    35      /**< SDK+Engine released after Episode 2/Orange Box, "Source 2009" or "Source MP" */
#define SOURCE_SDK_LEFT4DEAD        40      /**< Engine released after Left 4 Dead (no SDK yet) */
#define SOURCE_SDK_LEFT4DEAD2       50      /**< Engine released after Left 4 Dead 2 (no SDK yet) */
#define SOURCE_SDK_ALIENSWARM       60      /**< SDK+Engine released after Alien Swarm */
#define SOURCE_SDK_CSGO             80      /**< Engine released after CS:GO (no SDK yet) */
#define SOURCE_SDK_DOTA             90      /**< Engine released after Dota 2 (no SDK) */

#define MOTDPANEL_TYPE_TEXT          0      /**< Treat msg as plain text */
#define MOTDPANEL_TYPE_INDEX         1      /**< Msg is auto determined by the engine */
#define MOTDPANEL_TYPE_URL           2      /**< Treat msg as an URL link */
#define MOTDPANEL_TYPE_FILE          3      /**< Treat msg as a filename to be opened */

enum DialogType
{
	DialogType_Msg = 0,     /**< just an on screen message */
	DialogType_Menu,        /**< an options menu */
	DialogType_Text,        /**< a richtext dialog */
	DialogType_Entry,       /**< an entry box */
	DialogType_AskConnect   /**< ask the client to connect to a specified IP */
};

enum EngineVersion
{
	Engine_Unknown,             /**< Could not determine the engine version */
	Engine_Original,            /**< Original Source Engine (used by The Ship) */
	Engine_SourceSDK2006,       /**< Episode 1 Source Engine (second major SDK) */
	Engine_SourceSDK2007,       /**< Orange Box Source Engine (third major SDK) */
	Engine_Left4Dead,           /**< Left 4 Dead */
	Engine_DarkMessiah,         /**< Dark Messiah Multiplayer (based on original engine) */
	Engine_Left4Dead2 = 7,      /**< Left 4 Dead 2 */
	Engine_AlienSwarm,          /**< Alien Swarm (and Alien Swarm SDK) */
	Engine_BloodyGoodTime,      /**< Bloody Good Time */
	Engine_EYE,                 /**< E.Y.E Divine Cybermancy */
	Engine_Portal2,             /**< Portal 2 */
	Engine_CSGO,                /**< Counter-Strike: Global Offensive */
	Engine_CSS,                 /**< Counter-Strike: Source */
	Engine_DOTA,                /**< Dota 2 */
	Engine_HL2DM,               /**< Half-Life 2 Deathmatch */
	Engine_DODS,                /**< Day of Defeat: Source */
	Engine_TF2,                 /**< Team Fortress 2 */
	Engine_NuclearDawn,         /**< Nuclear Dawn */
	Engine_SDK2013,             /**< Source SDK 2013 */
	Engine_Blade,               /**< Blade Symphony */
	Engine_Insurgency,          /**< Insurgency (2013 Retail version)*/
	Engine_Contagion,           /**< Contagion */
	Engine_BlackMesa,           /**< Black Mesa Multiplayer */
	Engine_DOI                  /**< Day of Infamy */
};

enum FindMapResult
{
	// A direct match for this name was found
	FindMap_Found,
	// No match for this map name could be found.
	FindMap_NotFound,
	// A fuzzy match for this map name was found.
	// Ex: cp_dust -> cp_dustbowl, c1m1 -> c1m1_hotel
	// Only supported for maps that the engine knows about. (This excludes workshop maps on Orangebox).
	FindMap_FuzzyMatch,
	// A non-canonical match for this map name was found.
	// Ex: workshop/1234 -> workshop/cp_qualified_name.ugc1234
	// Only supported on "Orangebox" games with workshop support.
	FindMap_NonCanonical,
	// No currently available match for this map name could be found, but it may be possible to load
	// Only supported on "Orangebox" games with workshop support.
	FindMap_PossiblyAvailable
};

#define INVALID_ENT_REFERENCE 0xFFFFFFFF

/**
 * Logs a generic message to the HL2 logs.
 *
 * @param format        String format.
 * @param ...           Format arguments.
 */
native void LogToGame(const char[] format, any ...);

/**
 * Sets the seed value for the global Half-Life 2 Random Stream.
 *
 * @param seed         Seed value.
 */
native void SetRandomSeed(int seed);

/**
 * Returns a random floating point number from the Half-Life 2 Random Stream.
 *
 * @param fMin          Minimum random bound.
 * @param fMax          Maximum random bound.
 * @return              A random number between (inclusive) fMin and fMax.
 */
native float GetRandomFloat(float fMin=0.0, float fMax=1.0);

/**
 * Returns a random number from the Half-Life 2 Random Stream.
 *
 * @param nmin          Minimum random bound.
 * @param nmax          Maximum random bound.
 * @return              A random number between (inclusive) nmin and nmax.
 */
native int GetRandomInt(int nmin, int nmax);

/**
 * Returns whether a map is valid or not.
 *
 * @param map           Map name, excluding .bsp extension.
 * @return              True if valid, false otherwise.
 */
native bool IsMapValid(const char[] map);

/**
 * Returns whether a full or partial map name is found or can be resolved
 *
 * @param map           Map name (usually same as map path relative to maps/ dir,
 *                      excluding .bsp extension).
 * @param foundmap      Resolved map name. If the return is FindMap_FuzzyMatch
 *                      or FindMap_NonCanonical the buffer will be the full path.
 * @param maxlen        Maximum length to write to map var.
 * @return              Result of the find operation. Not all result types are supported on all games.
 */
native FindMapResult FindMap(const char[] map, char[] foundmap, int maxlen);

/**
 * Get the display name of a workshop map.
 *
 * Note: You do not need to call FindMap first.  This native will call FindMap internally.
 *
 * @param map           Map name (usually same as map path relative to maps/ dir,
 *                      excluding .bsp extension).
 * @param displayName   Map's display name, i.e. cp_mymapname or de_mymapname.
 *                      If FindMap returns FindMap_PossiblyAvailable or FindMap_NotFound,
 *                      the map cannot be resolved and this native will return false,
 *                      but displayName will be a copy of map.
 * @param maxlen        Maximum length to write to displayName var.
 * @return              true if FindMap returns FindMap_Found, FindMap_FuzzyMatch, or
 *                      FindMap_NonCanonical.
 *                      false if FindMap returns FindMap_PossiblyAvailable or FindMap_NotFound.
 */
native bool GetMapDisplayName(const char[] map, char[] displayName, int maxlen);

/**
 * Returns whether the server is dedicated.
 *
 * @return              True if dedicated, false otherwise.
 */
native bool IsDedicatedServer();

/**
 * Returns a high-precision time value for profiling the engine.
 *
 * @return              A floating point time value.
 */
native float GetEngineTime();

/**
 * Returns the game time based on the game tick.
 *
 * @return              Game tick time.
 */
native float GetGameTime();

/**
 * Returns the game's internal tick count.
 *
 * @return              Game tick count.
 */
native int GetGameTickCount();

/**
 * Returns the time the Game took processing the last frame.
 *
 * @return              Game frame time.
 */
native float GetGameFrameTime();

/**
 * Returns the game description from the mod.
 *
 * @param buffer        Buffer to store the description.
 * @param maxlength     Maximum size of the buffer.
 * @param original      If true, retrieves the original game description,
 *                      ignoring any potential hooks from plugins.
 * @return              Number of bytes written to the buffer (UTF-8 safe).
 */
native int GetGameDescription(char[] buffer, int maxlength, bool original=false);

/**
 * Returns the name of the game's directory.
 *
 * @param buffer        Buffer to store the directory name.
 * @param maxlength     Maximum size of the buffer.
 * @return              Number of bytes written to the buffer (UTF-8 safe).
 */
native int GetGameFolderName(char[] buffer, int maxlength);

/**
 * Returns the current map name.
 *
 * @param buffer        Buffer to store map name.
 * @param maxlength     Maximum length of buffer.
 * @return              Number of bytes written (UTF-8 safe).
 */
native int GetCurrentMap(char[] buffer, int maxlength);

/**
 * Precaches a given model.
 *
 * @param model         Name of the model to precache.
 * @param preload       If preload is true the file will be precached before level startup.
 * @return              Returns the model index, 0 for error.
 */
native int PrecacheModel(const char[] model, bool preload=false);

/**
 * Precaches a given sentence file.
 *
 * @param file          Name of the sentence file to precache.
 * @param preload       If preload is true the file will be precached before level startup.
 * @return              Returns a sentence file index.
 */
native int PrecacheSentenceFile(const char[] file, bool preload=false);

/**
 * Precaches a given decal.
 *
 * @param decal         Name of the decal to precache.
 * @param preload       If preload is true the file will be precached before level startup.
 * @return              Returns a decal index.
 */
native int PrecacheDecal(const char[] decal, bool preload=false);

/**
 * Precaches a given generic file.
 *
 * @param generic       Name of the generic file to precache.
 * @param preload       If preload is true the file will be precached before level startup.
 * @return              Returns a generic file index.
 */
native int PrecacheGeneric(const char[] generic, bool preload=false);

/**
 * Returns if a given model is precached.
 *
 * @param model         Name of the model to check.
 * @return              True if precached, false otherwise.
 */
native bool IsModelPrecached(const char[] model);

/**
 * Returns if a given decal is precached.
 *
 * @param decal         Name of the decal to check.
 * @return              True if precached, false otherwise.
 */
native bool IsDecalPrecached(const char[] decal);

/**
 * Returns if a given generic file is precached.
 *
 * @param generic       Name of the generic file to check.
 * @return              True if precached, false otherwise.
 */
native bool IsGenericPrecached(const char[] generic);

/**
 * Precaches a given sound.
 *
 * @param sound         Name of the sound to precache.
 * @param preload       If preload is true the file will be precached before level startup.
 * @return              True if successfully precached, false otherwise.
 */
native bool PrecacheSound(const char[] sound, bool preload=false);

/**
 * Returns if a given sound is precached.
 *
 * @param sound         Name of the sound to check.
 * @return              True if precached, false otherwise.
 */
native bool IsSoundPrecached(const char[] sound);

/**
 * Creates different types of ingame messages.
 *
 * @param client        Index of the client.
 * @param kv            KeyValues handle to set the menu keys and options. (Check iserverplugin.h for more information).
 * @param type          Message type to display ingame.
 * @error               Invalid client index, or client not connected.
 */
native void CreateDialog(int client, Handle kv, DialogType type);

/**
 * Guesses the SDK version a mod was compiled against.  If nothing
 * specific is known about the game, the engine version is used instead.
 *
 * The return values are guaranteed to increase chronologically (that is,
 * a later release will have a higher value).
 *
 * @return              SOURCE_SDK version code.
 * @deprecated          See GetEngineVersion()
 */
#pragma deprecated See GetEngineVersion()
native int GuessSDKVersion();

/**
 * Gets the engine version that the currently-loaded SM core was compiled against.
 *
 * The engine version values are not guaranteed to be in any particular order,
 * and should only be compared by (in)equality.
 *
 * @return              An EngineVersion value.
 */
native EngineVersion GetEngineVersion();

/**
 * Prints a message to a specific client in the chat area.
 *
 * @param client        Client index.
 * @param format        Formatting rules.
 * @param ...           Variable number of format parameters.
 * @error               If the client is not connected an error will be thrown.
 */
native void PrintToChat(int client, const char[] format, any ...);

/**
 * Prints a message to all clients in the chat area.
 *
 * @param format        Formatting rules.
 * @param ...           Variable number of format parameters.
 */
stock void PrintToChatAll(const char[] format, any ...)
{
	char buffer[254];

	for (int i = 1; i <= MaxClients; i++)
	{
		if (IsClientInGame(i))
		{
			SetGlobalTransTarget(i);
			VFormat(buffer, sizeof(buffer), format, 2);
			PrintToChat(i, "%s", buffer);
		}
	}
}

/**
 * Prints a message to a specific client in the center of the screen.
 *
 * @param client        Client index.
 * @param format        Formatting rules.
 * @param ...           Variable number of format parameters.
 * @error               If the client is not connected an error will be thrown.
 */
native void PrintCenterText(int client, const char[] format, any ...);

/**
 * Prints a message to all clients in the center of the screen.
 *
 * @param format        Formatting rules.
 * @param ...           Variable number of format parameters.
 */
stock void PrintCenterTextAll(const char[] format, any ...)
{
	char buffer[254];

	for (int i = 1; i <= MaxClients; i++)
	{
		if (IsClientInGame(i))
		{
			SetGlobalTransTarget(i);
			VFormat(buffer, sizeof(buffer), format, 2);
			PrintCenterText(i, "%s", buffer);
		}
	}
}

/**
 * Prints a message to a specific client with a hint box.
 *
 * @param client        Client index.
 * @param format        Formatting rules.
 * @param ...           Variable number of format parameters.
 * @error               If the client is not connected an error will be thrown.
 */
native void PrintHintText(int client, const char[] format, any ...);

/**
 * Prints a message to all clients with a hint box.
 *
 * @param format        Formatting rules.
 * @param ...           Variable number of format parameters.
 */
stock void PrintHintTextToAll(const char[] format, any ...)
{
	char buffer[254];

	for (int i = 1; i <= MaxClients; i++)
	{
		if (IsClientInGame(i))
		{
			SetGlobalTransTarget(i);
			VFormat(buffer, sizeof(buffer), format, 2);
			PrintHintText(i, "%s", buffer);
		}
	}
}

/**
 * Shows a VGUI panel to a specific client.
 *
 * @param client        Client index.
 * @param name          Panel type name (Check viewport_panel_names.h to see a list of
 *                      some panel names).
 * @param Kv            KeyValues handle with all the data for the panel setup (Depends
 *                      on the panel type and may be unused).
 * @param show          True to show the panel, or false to remove it from the client screen.
 * @error               If the client is not connected an error will be thrown.
 */
native void ShowVGUIPanel(int client, const char[] name, Handle Kv=INVALID_HANDLE, bool show=true);

/**
 * Creates a HUD synchronization object.  This object is used to automatically assign and
 * re-use channels for a set of messages.
 *
 * The HUD has a hardcoded number of channels (usually 6) for displaying
 * text.  You can use any channel for any area of the screen.  Text on
 * different channels can overlap, but text on the same channel will
 * erase the old text first.  This overlapping and overwriting gets problematic.
 *
 * A HUD synchronization object automatically selects channels for you based on
 * the following heuristics:
 *  - If channel X was last used by the object, and hasn't been modified again,
 *    channel X gets re-used.
 *  - Otherwise, a new channel is chosen based on the least-recently-used channel.
 *
 * This ensures that if you display text on a sync object, that the previous text
 * displayed on it will always be cleared first.  This is because your new text
 * will either overwrite the old text on the same channel, or because another
 * channel has already erased your text.
 *
 * Note that messages can still overlap if they are on different synchronization
 * objects, or they are displayed to manual channels.
 *
 * These are particularly useful for displaying repeating or refreshing HUD text, in
 * addition to displaying multiple message sets in one area of the screen (for example,
 * center-say messages that may pop up randomly that you don't want to overlap each
 * other).
 *
 * @return              New HUD synchronization object.
 *                      The Handle can be closed with CloseHandle().
 *                      If HUD text is not supported on this mod, then
 *                      INVALID_HANDLE is returned.
 */
native Handle CreateHudSynchronizer();

/**
 * Sets the HUD parameters for drawing text.  These parameters are stored
 * globally, although nothing other than this function and SetHudTextParamsEx
 * modify them.
 *
 * You must call this function before drawing text.  If you are drawing
 * text to multiple clients, you can set the parameters once, since
 * they won't be modified.  However, as soon as you pass control back
 * to other plugins, you must reset the parameters next time you draw.
 *
 * @param x             x coordinate, from 0 to 1.  -1.0 is the center.
 * @param y             y coordinate, from 0 to 1.  -1.0 is the center.
 * @param holdTime      Number of seconds to hold the text.
 * @param r             Red color value.
 * @param g             Green color value.
 * @param b             Blue color value.
 * @param a             Alpha transparency value.
 * @param effect        0/1 causes the text to fade in and fade out.
 *                      2 causes the text to flash[?].
 * @param fxTime        Duration of chosen effect (may not apply to all effects).
 * @param fadeIn        Number of seconds to spend fading in.
 * @param fadeOut       Number of seconds to spend fading out.
 */
native void SetHudTextParams(float x, float y, float holdTime, int r, int g, int b, int a, int effect = 0,
						float fxTime=6.0, float fadeIn=0.1, float fadeOut=0.2);

/**
 * Sets the HUD parameters for drawing text.  These parameters are stored
 * globally, although nothing other than this function and SetHudTextParams
 * modify them.
 *
 * This is the same as SetHudTextParams(), except it lets you set the alternate
 * color for when effects require it.
 *
 * @param x             x coordinate, from 0 to 1.  -1.0 is the center.
 * @param y             y coordinate, from 0 to 1.  -1.0 is the center.
 * @param holdTime      Number of seconds to hold the text.
 * @param color1        First color set, array values being [red, green, blue, alpha]
 * @param color2        Second color set, array values being [red, green, blue, alpha]
 * @param effect        0/1 causes the text to fade in and fade out.
 *                      2 causes the text to flash[?].
 * @param fxTime        Duration of chosen effect (may not apply to all effects).
 * @param fadeIn        Number of seconds to spend fading in.
 * @param fadeOut       Number of seconds to spend fading out.
 */
native void SetHudTextParamsEx(float x, float y, float holdTime, int color1[4],
						  int color2[4]={255,255,255,0}, int effect = 0, float fxTime=6.0,
						  float fadeIn=0.1, float fadeOut=0.2);

/**
 * Shows a synchronized HUD message to a client.
 *
 * As of this writing, only TF, HL2MP, and SourceForts support HUD Text.
 *
 * @param client        Client index to send the message to.
 * @param sync          Synchronization object.
 * @param message       Message text or formatting rules.
 * @param ...           Message formatting parameters.
 * @return              -1 on failure, anything else on success.
 *                      This function fails if the mod does not support it.
 * @error               Client not in-game, or sync object not valid.
 */
native int ShowSyncHudText(int client, Handle sync, const char[] message, any ...);

/**
 * Clears the text on a synchronized HUD channel.
 *
 * This is not the same as sending "" because it guarantees that it won't
 * overwrite text on another channel.  For example, consider the scenario:
 *
 * 1. Your synchronized message goes to channel 3.
 * 2. Someone else's non-synchronized message goes to channel 3.
 *
 * If you were to simply send "" on your synchronized message,
 * then someone else's text could be overwritten.
 *
 * @param client        Client index to send the message to.
 * @param sync          Synchronization object.
 * @error               Client not in-game, or sync object not valid.
 */
native void ClearSyncHud(int client, Handle sync);

/**
 * Shows a HUD message to a client on the given channel.
 *
 * As of this writing, only TF, HL2MP, and SourceForts support HUD Text.
 *
 * @param client        Client index to send the message to.
 * @param channel       A channel number.
 *                      If -1, then a channel will automatically be selected
 *                      based on the least-recently-used channel.  If the
 *                      channel is any other number, it will be modulo'd with
 *                      the channel count to get a final channel number.
 * @param message       Message text or formatting rules.
 * @param ...           Message formatting parameters.
 * @return              -1 on failure (lack of mod support).
 *                      Any other return value is the channel number that was
 *                      used to render the text.
 */
native int ShowHudText(int client, int channel, const char[] message, any ...);

/**
 * Shows a MOTD panel to a specific client.
 *
 * @param client        Client index.
 * @param title         Title of the panel (printed on the top border of the window).
 * @param msg           Contents of the panel, it can be treated as an url, filename or plain text
 *                      depending on the type parameter (WARNING: msg has to be 192 bytes maximum!)
 * @param type          Determines the way to treat the message body of the panel.
 * @error               If the client is not connected an error will be thrown.
 */
stock void ShowMOTDPanel(int client, const char[] title, const char[] msg, int type=MOTDPANEL_TYPE_INDEX)
{
	char num[3];
	IntToString(type, num, sizeof(num));

	KeyValues kv = new KeyValues("data");
	kv.SetString("title", title);
	kv.SetString("type", num);
	kv.SetString("msg", msg);
	ShowVGUIPanel(client, "info", kv);
	delete kv;
}

/**
 * Displays a panel asking the client to connect to a specified IP.
 *
 * @param client        Client index.
 * @param time          Duration to hold the panel on the client's screen.
 * @param ip            Destination IP.
 * @param password      Password to connect to the destination IP. The client will be able to see this.
 */
stock void DisplayAskConnectBox(int client, float time, const char[] ip, const char[] password = "")
{
	char destination[288];
	FormatEx(destination, sizeof(destination), "%s/%s", ip, password);

	KeyValues kv = new KeyValues("data");
	kv.SetFloat("time", time);
	kv.SetString("title", destination);
	CreateDialog(client, kv, DialogType_AskConnect);
	delete kv;
}

/**
 * Converts an entity index into a serial encoded entity reference.
 *
 * @param entity        Entity index.
 * @return              Entity reference.
 */
native int EntIndexToEntRef(int entity);

/**
 * Retrieves the entity index from a reference.
 *
 * @param ref           Entity reference.
 * @return              Entity index.
 */
native int EntRefToEntIndex(int ref);

/**
 * Converts a reference into a backwards compatible version.
 *
 * @param ref           Entity reference.
 * @return              Bcompat reference.
 */
native int MakeCompatEntRef(int ref);

enum ClientRangeType
{
	RangeType_Visibility = 0,
	RangeType_Audibility
}

/**
 * Find clients that are potentially in range of a position.
 *
 * @param origin        Coordinates from which to test range.
 * @param rangeType     Range type to use for filtering clients.
 * @param clients       Array to which found client indexes will be written.
 * @param size          Maximum size of clients array.
 * @return              Number of client indexes written to clients array.
 */
native int GetClientsInRange(float origin[3], ClientRangeType rangeType, int[] clients, int size);

/**
 * Retrieves the server's authentication string (SteamID).
 *
 * Note: If called before server is connected to Steam, auth id
 * will be invalid ([I:0:1], 1, etc.)
 *
 * @param authType      Auth id type and format to use.
 *                      (Only AuthId_Steam3 and AuthId_SteamID64 are supported)
 * @param auth          Buffer to store the server's auth id.
 * @param maxlen        Maximum length of string buffer (includes NULL terminator).
 * @error               Invalid AuthIdType given.
 */
native void GetServerAuthId(AuthIdType authType, char[] auth, int maxlen);

/**
 * Returns the server's Steam account ID.
 *
 * @return              Steam account ID or 0 if not available.
 */
native int GetServerSteamAccountId();