//-----------------------------------------------------------------------------
// Computes the link type
//-----------------------------------------------------------------------------
Navigation_t CAI_Pathfinder::ComputeWaypointType( CAI_Node **ppNodes, int parentID, int destID )
{
	Navigation_t navType = NAV_NONE;

	CAI_Node *pNode = ppNodes[parentID];
	for (int link=0; link < pNode->NumLinks();link++) 
	{
		if (pNode->GetLinkByIndex(link)->DestNodeID(parentID) == destID)
		{
			// BRJ 10/1/02
			// FIXME: pNPC->CapabilitiesGet() is actually the mechanism by which fliers
			// filter out the bitfields in the waypoint type (most importantly, bits_MOVE_CAP_GROUND)
			// that would cause the waypoint distance to be computed in a 2D, as opposed to 3D fashion
			// This is a super-scary weak link if you ask me.
			int linkMoveTypeBits = pNode->GetLinkByIndex(link)->m_iAcceptedMoveTypes[GetHullType()];
			int moveTypeBits = ( linkMoveTypeBits & CapabilitiesGet());
			if ( !moveTypeBits && linkMoveTypeBits == bits_CAP_MOVE_JUMP )
			{
				Assert( pNode->GetHint() && pNode->GetHint()->HintType() == HINT_JUMP_OVERRIDE );
				ppNodes[destID]->Lock(0.3);
				moveTypeBits = linkMoveTypeBits;
			}
			Navigation_t linkType = MoveBitsToNavType( moveTypeBits );

			// This will only trigger if the links disagree about their nav type
			Assert( (navType == NAV_NONE) || (navType == linkType) );
			navType = linkType; 
			break;
		}
	}

	// @TODO (toml 10-15-02): one would not expect to come out of the above logic
	// with NAV_NONE. However, if a graph is newly built, it can contain malformed
	// links that are referred to by the destination node, not the source node.
	// This has to be fixed
	if ( navType == NAV_NONE )
	{
		pNode = ppNodes[destID];
		for (int link=0; link < pNode->NumLinks();link++) 
		{
			if (pNode->GetLinkByIndex(link)->DestNodeID(parentID) == destID)
			{
				int npcMoveBits = CapabilitiesGet();
				int nodeMoveBits = pNode->GetLinkByIndex(link)->m_iAcceptedMoveTypes[GetHullType()];
				int moveTypeBits = ( npcMoveBits & nodeMoveBits );
				Navigation_t linkType = MoveBitsToNavType( moveTypeBits );

				Assert( (navType == NAV_NONE) || (navType == linkType) );
				navType = linkType; 

				DevMsg( "Note: Strange link found between nodes in AI node graph\n" );
				break;
			}
		}
	}

	AssertMsg( navType != NAV_NONE, "Pathfinder appears to have output a path with consecutive nodes thate are not actually connected\n" );

	return navType;
}
int CAI_TacticalServices::FindLosNode(const Vector &vThreatPos, const Vector &vThreatEyePos, float flMinThreatDist, float flMaxThreatDist, float flBlockTime, FlankType_t eFlankType, const Vector &vecFlankRefPos, float flFlankParam )
{
	if ( !CAI_NetworkManager::NetworksLoaded() )
		return NO_NODE;

	AI_PROFILE_SCOPE( CAI_TacticalServices_FindLosNode );

	MARK_TASK_EXPENSIVE();

	int iMyNode	= GetPathfinder()->NearestNodeToNPC();
	if ( iMyNode == NO_NODE )
	{
		Vector pos = GetOuter()->GetAbsOrigin();
		DevWarning( 2, "FindCover() - %s has no nearest node! (Check near %f %f %f)\n", GetEntClassname(), pos.x, pos.y, pos.z);
		return NO_NODE;
	}

	// ------------------------------------------------------------------------------------
	// We're going to search for a shoot node by expanding to our current node's neighbors
	// and then their neighbors, until a shooting position is found, or all nodes are beyond MaxDist
	// ------------------------------------------------------------------------------------
	AI_NearNode_t *pBuffer = (AI_NearNode_t *)stackalloc( sizeof(AI_NearNode_t) * GetNetwork()->NumNodes() );
	CNodeList list( pBuffer, GetNetwork()->NumNodes() );
	CVarBitVec wasVisited(GetNetwork()->NumNodes());	// Nodes visited

	// mark start as visited
	wasVisited.Set( iMyNode );
	list.Insert( AI_NearNode_t(iMyNode, 0) );

	static int nSearchRandomizer = 0;		// tries to ensure the links are searched in a different order each time;

	while ( list.Count() )
	{
		int nodeIndex = list.ElementAtHead().nodeIndex;
		// remove this item from the list
		list.RemoveAtHead();

		const Vector &nodeOrigin = GetNetwork()->GetNode(nodeIndex)->GetPosition(GetHullType());

		// HACKHACK: Can't we rework this loop and get rid of this?
		// skip the starting node, or we probably wouldn't have called this function.
		if ( nodeIndex != iMyNode )
		{
			bool skip = false;

			// See if the node satisfies the flanking criteria.
			switch ( eFlankType )
			{
				case FLANKTYPE_NONE:
					break;
					
				case FLANKTYPE_RADIUS:
				{
					Vector vecDist = nodeOrigin - vecFlankRefPos;
					if ( vecDist.Length() < flFlankParam )
					{
						skip = true;
					}
					
					break;
				}
				
				case FLANKTYPE_ARC:
				{
					Vector vecEnemyToRef = vecFlankRefPos - vThreatPos;
					VectorNormalize( vecEnemyToRef );

					Vector vecEnemyToNode = nodeOrigin - vThreatPos;
					VectorNormalize( vecEnemyToNode );
					
					float flDot = DotProduct( vecEnemyToRef, vecEnemyToNode );
					
					if ( RAD2DEG( acos( flDot ) ) < flFlankParam )
					{
						skip = true;
					}
					
					break;
				}
			}

			// Don't accept climb nodes, and assume my nearest node isn't valid because
			// we decided to make this check in the first place.  Keep moving
			if ( !skip && !GetNetwork()->GetNode(nodeIndex)->IsLocked() &&
				GetNetwork()->GetNode(nodeIndex)->GetType() != NODE_CLIMB )
			{
				// Now check its distance and only accept if in range
				float flThreatDist = ( nodeOrigin - vThreatPos ).Length();

				if ( flThreatDist < flMaxThreatDist &&
					 flThreatDist > flMinThreatDist )
				{
					CAI_Node *pNode = GetNetwork()->GetNode(nodeIndex);
					if ( GetOuter()->IsValidShootPosition( nodeOrigin, pNode, pNode->GetHint() ) )
					{
						if (GetOuter()->TestShootPosition(nodeOrigin,vThreatEyePos))
						{
							// Note when this node was used, so we don't try 
							// to use it again right away.
							GetNetwork()->GetNode(nodeIndex)->Lock( flBlockTime );

#if 0
							if ( GetOuter()->GetHintNode() )
							{
								GetOuter()->GetHintNode()->Unlock(GetOuter()->GetHintDelay(GetOuter()->GetHintNode()->HintType()));
								GetOuter()->SetHintNode( NULL );
							}

							// This used to not be set, why? (kenb)
							// @Note (toml 05-19-04): I think because stomping  the hint can lead to
							// unintended side effects. The hint node is primarily a high level
							// tool, and certain NPCs break if it gets slammed here. If we need
							// this, we should propagate it out and let the schedule selector
							// or task decide to set the hint node
							GetOuter()->SetHintNode( GetNetwork()->GetNode(nodeIndex)->GetHint() );
#endif
							if ( ShouldDebugLos( nodeIndex ) )
							{
								NDebugOverlay::Text( nodeOrigin, CFmtStr( "%d:los!", nodeIndex), false, 1 );
							}

							// The next NPC who searches should use a slight different pattern
							nSearchRandomizer = nodeIndex;
							return nodeIndex;
						}
						else
						{
							if ( ShouldDebugLos( nodeIndex ) )
							{
								NDebugOverlay::Text( nodeOrigin, CFmtStr( "%d:!shoot", nodeIndex), false, 1 );
							}
						}
					}
					else
					{
						if ( ShouldDebugLos( nodeIndex ) )
						{
							NDebugOverlay::Text( nodeOrigin, CFmtStr( "%d:!valid", nodeIndex), false, 1 );
						}
					}
				}
				else
				{
					if ( ShouldDebugLos( nodeIndex ) )
					{
						CFmtStr msg( "%d:%s", nodeIndex, ( flThreatDist < flMaxThreatDist ) ? "too close" : "too far" );
						NDebugOverlay::Text( nodeOrigin, msg, false, 1 );
					}
				}
			}
		}

		// Go through each link and add connected nodes to the list
		for (int link=0; link < GetNetwork()->GetNode(nodeIndex)->NumLinks();link++) 
		{
			int index = (link + nSearchRandomizer) % GetNetwork()->GetNode(nodeIndex)->NumLinks();
			CAI_Link *nodeLink = GetNetwork()->GetNode(nodeIndex)->GetLinkByIndex(index);

			if ( !m_pPathfinder->IsLinkUsable( nodeLink, iMyNode ) )
				continue;

			int newID = nodeLink->DestNodeID(nodeIndex);

			// If not already visited, add to the list
			if (!wasVisited.IsBitSet(newID))
			{
				float dist = (GetLocalOrigin() - GetNetwork()->GetNode(newID)->GetPosition(GetHullType())).LengthSqr();
				list.Insert( AI_NearNode_t(newID, dist) );
				wasVisited.Set( newID );
			}
		}
	}
	// We failed.  No range attack node node was found
	return NO_NODE;
}
int CAI_TacticalServices::FindCoverNode(const Vector &vNearPos, const Vector &vThreatPos, const Vector &vThreatEyePos, float flMinDist, float flMaxDist )
{
	if ( !CAI_NetworkManager::NetworksLoaded() )
		return NO_NODE;

	AI_PROFILE_SCOPE( CAI_TacticalServices_FindCoverNode );

	MARK_TASK_EXPENSIVE();

	DebugFindCover( NO_NODE, GetOuter()->EyePosition(), vThreatEyePos, 0, 255, 255 );

	int iMyNode = GetPathfinder()->NearestNodeToPoint( vNearPos );

	if ( iMyNode == NO_NODE )
	{
		Vector pos = GetOuter()->GetAbsOrigin();
		DevWarning( 2, "FindCover() - %s has no nearest node! (Check near %f %f %f)\n", GetEntClassname(), pos.x, pos.y, pos.z);
		return NO_NODE;
	}

	if ( !flMaxDist )
	{
		// user didn't supply a MaxDist, so work up a crazy one.
		flMaxDist = 784;
	}

	if ( flMinDist > 0.5 * flMaxDist)
	{
		flMinDist = 0.5 * flMaxDist;
	}

	// ------------------------------------------------------------------------------------
	// We're going to search for a cover node by expanding to our current node's neighbors
	// and then their neighbors, until cover is found, or all nodes are beyond MaxDist
	// ------------------------------------------------------------------------------------
	AI_NearNode_t *pBuffer = (AI_NearNode_t *)stackalloc( sizeof(AI_NearNode_t) * GetNetwork()->NumNodes() );
	CNodeList list( pBuffer, GetNetwork()->NumNodes() );
	CVarBitVec wasVisited(GetNetwork()->NumNodes());	// Nodes visited

	// mark start as visited
	list.Insert( AI_NearNode_t(iMyNode, 0) ); 
	wasVisited.Set( iMyNode );
	float flMinDistSqr = flMinDist*flMinDist;
	float flMaxDistSqr = flMaxDist*flMaxDist;

	static int nSearchRandomizer = 0;		// tries to ensure the links are searched in a different order each time;

	// Search until the list is empty
	while( list.Count() )
	{
		// Get the node that is closest in the number of steps and remove from the list
		int nodeIndex = list.ElementAtHead().nodeIndex;
		list.RemoveAtHead();

		CAI_Node *pNode = GetNetwork()->GetNode(nodeIndex);
		Vector nodeOrigin = pNode->GetPosition(GetHullType());

		float dist = (vNearPos - nodeOrigin).LengthSqr();
		if (dist >= flMinDistSqr && dist < flMaxDistSqr)
		{
			Activity nCoverActivity = GetOuter()->GetCoverActivity( pNode->GetHint() );
			Vector vEyePos = nodeOrigin + GetOuter()->EyeOffset(nCoverActivity);

			if ( GetOuter()->IsValidCover( nodeOrigin, pNode->GetHint() ) )
			{
				// Check if this location will block the threat's line of sight to me
				if (GetOuter()->IsCoverPosition(vThreatEyePos, vEyePos))
				{
					// --------------------------------------------------------
					// Don't let anyone else use this node for a while
					// --------------------------------------------------------
					pNode->Lock( 1.0 );

					if ( pNode->GetHint() && ( pNode->GetHint()->HintType() == HINT_TACTICAL_COVER_MED || pNode->GetHint()->HintType() == HINT_TACTICAL_COVER_LOW ) )
					{
						if ( GetOuter()->GetHintNode() )
						{
							GetOuter()->GetHintNode()->Unlock(GetOuter()->GetHintDelay(GetOuter()->GetHintNode()->HintType()));
							GetOuter()->SetHintNode( NULL );
						}

						GetOuter()->SetHintNode( pNode->GetHint() );
					}

					// The next NPC who searches should use a slight different pattern
					nSearchRandomizer = nodeIndex;
					DebugFindCover( pNode->GetId(), vEyePos, vThreatEyePos, 0, 255, 0 );
					return nodeIndex;
				}
				else
				{
					DebugFindCover( pNode->GetId(), vEyePos, vThreatEyePos, 255, 0, 0 );
				}
			}
			else
			{
				DebugFindCover( pNode->GetId(), vEyePos, vThreatEyePos, 0, 0, 255 );
			}
		}

		// Add its children to the search list
		// Go through each link
		// UNDONE: Pass in a cost function to measure each link?
		for ( int link = 0; link < GetNetwork()->GetNode(nodeIndex)->NumLinks(); link++ ) 
		{
			int index = (link + nSearchRandomizer) % GetNetwork()->GetNode(nodeIndex)->NumLinks();
			CAI_Link *nodeLink = GetNetwork()->GetNode(nodeIndex)->GetLinkByIndex(index);

			if ( !m_pPathfinder->IsLinkUsable( nodeLink, iMyNode ) )
				continue;

			int newID = nodeLink->DestNodeID(nodeIndex);

			// If not already on the closed list, add to it and set its distance
			if (!wasVisited.IsBitSet(newID))
			{
				// Don't accept climb nodes or nodes that aren't ready to use yet
				if ( GetNetwork()->GetNode(newID)->GetType() != NODE_CLIMB && !GetNetwork()->GetNode(newID)->IsLocked() )
				{
					// UNDONE: Shouldn't we really accumulate the distance by path rather than
					// absolute distance.  After all, we are performing essentially an A* here.
					nodeOrigin = GetNetwork()->GetNode(newID)->GetPosition(GetHullType());
					dist = (vNearPos - nodeOrigin).LengthSqr();

					// use distance to threat as a heuristic to keep AIs from running toward
					// the threat in order to take cover from it.
					float threatDist = (vThreatPos - nodeOrigin).LengthSqr();

					// Now check this node is not too close towards the threat
					if ( dist < threatDist * 1.5 )
					{
						list.Insert( AI_NearNode_t(newID, dist) );
					}
				}
				// mark visited
				wasVisited.Set(newID);
			}
		}
	}

	// We failed.  Not cover node was found
	// Clear hint node used to set ducking
	GetOuter()->ClearHintNode();
	return NO_NODE;
}