#include <sourcemod>
#include <sdktools>
#include <dhooks>
#pragma semicolon 1
#pragma newdecls required

#define PLUGIN_VERSION "1.0"

public Plugin myinfo = 
{
	name = "Fix func_physbox_multiplayer collision",
	author = "xen",
	description = "Sets the collision to weapons only whenever a func_physbox_multiplayer gets parented",
	version = PLUGIN_VERSION,
	url = ""
}

Handle g_hSetParent;

// Entity collision groups
enum
{
	COLLISION_GROUP_NONE = 0,			// 0 
	COLLISION_GROUP_DEBRIS,				// 1 - Collides with nothing but world and static stuff
	COLLISION_GROUP_DEBRIS_TRIGGER, 	// 2 - Same as debris, but hits triggers
	COLLISION_GROUP_INTERACTIVE_DEBRIS,	// 3 - Collides with everything except other interactive debris or debris
	COLLISION_GROUP_INTERACTIVE,		// 4 - Collides with everything except interactive debris or debris
	COLLISION_GROUP_PLAYER,             // 5 
	COLLISION_GROUP_BREAKABLE_GLASS,    // 6 
	COLLISION_GROUP_VEHICLE,            // 7 
	COLLISION_GROUP_PLAYER_MOVEMENT,  	// 8 - For HL2, same as Collision_Group_Player, for
										//     TF2, this filters out other players and CBaseObjects
	COLLISION_GROUP_NPC,				// 9 - Generic NPC group
	COLLISION_GROUP_IN_VEHICLE,			// 10 - for any entity inside a vehicle
	COLLISION_GROUP_WEAPON,				// 11 - for any weapons that need collision detection
	COLLISION_GROUP_VEHICLE_CLIP,		// 12 - vehicle clip brush to restrict vehicle movement
	COLLISION_GROUP_PROJECTILE,			// 13 - Projectiles!
	COLLISION_GROUP_DOOR_BLOCKER,		// 14 - Blocks entities not permitted to get near moving doors
	COLLISION_GROUP_PASSABLE_DOOR,		// 15 - Doors that the player shouldn't collide with
	COLLISION_GROUP_DISSOLVING,			// 16 - Things that are dissolving are in this group
	COLLISION_GROUP_PUSHAWAY,			// 17 - Nonsolid on client and server, pushaway in player code

	COLLISION_GROUP_NPC_ACTOR,			// 18 - Used so NPCs in scripts ignore the player.
	COLLISION_GROUP_NPC_SCRIPTED,		// 19 - USed for NPCs in scripts that should not collide with each other

	LAST_SHARED_COLLISION_GROUP
};

// Physbox spawnflags
enum
{
	SF_PHYSBOX_ASLEEP						= 0x01000,
	SF_PHYSBOX_IGNOREUSE					= 0x02000,
	SF_PHYSBOX_DEBRIS						= 0x04000,
	SF_PHYSBOX_MOTIONDISABLED				= 0x08000,
	SF_PHYSBOX_USEPREFERRED					= 0x10000,
	SF_PHYSBOX_ENABLE_ON_PHYSCANNON			= 0x20000,
	SF_PHYSBOX_NO_ROTORWASH_PUSH			= 0x40000,		// The rotorwash doesn't push these
	SF_PHYSBOX_ENABLE_PICKUP_OUTPUT			= 0x80000,
	SF_PHYSBOX_ALWAYS_PICK_UP		    	= 0x100000,		// Physcannon can always pick this up, no matter what mass or constraints may apply.
	SF_PHYSBOX_NEVER_PICK_UP				= 0x200000,		// Physcannon will never be able to pick this up.
	SF_PHYSBOX_NEVER_PUNT					= 0x400000,		// Physcannon will never be able to punt this object.
	SF_PHYSBOX_PREVENT_PLAYER_TOUCH_ENABLE 	= 0x800000		// If set, the player will not cause the object to enable its motion when bumped into
};

public void OnPluginStart()
{
	Handle hGameConf = LoadGameConfigFile("FixPhysboxMultiplayer.games");
	if(!hGameConf)
	{
		SetFailState("Can't find FixPhysBoxMultiplayers.games.txt gamedata.");
		return;
	}

	int offset = GameConfGetOffset(hGameConf, "CBaseEntity::SetParent");
	if (offset == -1)
		SetFailState("Failed to find CBaseEntity::SetParent offset");

	// DHooks
	g_hSetParent = DHookCreate(offset, HookType_Entity, ReturnType_Void, ThisPointer_CBaseEntity, Hook_SetParent);
	DHookAddParam(g_hSetParent, HookParamType_CBaseEntity);
	DHookAddParam(g_hSetParent, HookParamType_Int);
	
	CloseHandle(hGameConf);
}

public void OnEntityCreated(int iEntity, const char[] sClassname)
{
	if(StrEqual(sClassname, "func_physbox_multiplayer", false))
		DHookEntity(g_hSetParent, true, iEntity);
}

public MRESReturn Hook_SetParent(int iEntity)
{
	SetDebrisCollisionGroup(iEntity);
	return MRES_Ignored;
}

public void SetDebrisCollisionGroup(int iEntity)
{
	// Set collisiongroup to WEAPON to replicate CS:S behavior when parented
	char parent[64];
	if(GetEntPropString(iEntity, Prop_Data, "m_iParent", parent, sizeof(parent)))
		SetEntProp(iEntity, Prop_Data, "m_CollisionGroup", COLLISION_GROUP_WEAPON);
}