/* $Id$ */

/** @file yapf_rail.cpp The rail pathfinding. */

#include "../stdafx.h"

#include "yapf.hpp"
#include "yapf_node_rail.hpp"
#include "yapf_costrail.hpp"
#include "yapf_destrail.hpp"
#include "../vehicle_func.h"

#define DEBUG_YAPF_CACHE 0

int _total_pf_time_us = 0;





template <class Types>
class CYapfFollowAnyDepotRailT
{
public:
	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
	typedef typename Types::TrackFollower TrackFollower;
	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
	typedef typename Node::Key Key;                      ///< key to hash tables

protected:
	/// to access inherited path finder
	FORCEINLINE Tpf& Yapf() {return *static_cast<Tpf*>(this);}

public:
	/** Called by YAPF to move from the given node to the next tile. For each
	 *  reachable trackdir on the new tile creates new node, initializes it
	 *  and adds it to the open list by calling Yapf().AddNewNode(n) */
	inline void PfFollowNode(Node& old_node)
	{
		TrackFollower F(Yapf().GetVehicle());
		if (F.Follow(old_node.GetLastTile(), old_node.GetLastTrackdir()))
			Yapf().AddMultipleNodes(&old_node, F);
	}

	/// return debug report character to identify the transportation type
	FORCEINLINE char TransportTypeChar() const {return 't';}

	static bool stFindNearestDepotTwoWay(Vehicle *v, TileIndex t1, Trackdir td1, TileIndex t2, Trackdir td2, int max_distance, int reverse_penalty, TileIndex* depot_tile, bool* reversed)
	{
		Tpf pf1;
		bool result1 = pf1.FindNearestDepotTwoWay(v, t1, td1, t2, td2, max_distance, reverse_penalty, depot_tile, reversed);

#if DEBUG_YAPF_CACHE
		Tpf pf2;
		TileIndex depot_tile2 = INVALID_TILE;
		bool reversed2 = false;
		pf2.DisableCache(true);
		bool result2 = pf2.FindNearestDepotTwoWay(v, t1, td1, t2, td2, max_distance, reverse_penalty, &depot_tile2, &reversed2);
		if (result1 != result2 || (result1 && (*depot_tile != depot_tile2 || *reversed != reversed2))) {
			DEBUG(yapf, 0, "CACHE ERROR: FindNearestDepotTwoWay() = [%s, %s]", result1 ? "T" : "F", result2 ? "T" : "F");
		}
#endif

		return result1;
	}

	FORCEINLINE bool FindNearestDepotTwoWay(Vehicle *v, TileIndex t1, Trackdir td1, TileIndex t2, Trackdir td2, int max_distance, int reverse_penalty, TileIndex* depot_tile, bool* reversed)
	{
		// set origin and destination nodes
		Yapf().SetOrigin(t1, td1, t2, td2, reverse_penalty, true);
		Yapf().SetDestination(v);
		Yapf().SetMaxCost(YAPF_TILE_LENGTH * max_distance);

		// find the best path
		bool bFound = Yapf().FindPath(v);
		if (!bFound) return false;

		// some path found
		// get found depot tile
		Node *n = Yapf().GetBestNode();
		*depot_tile = n->GetLastTile();

		// walk through the path back to the origin
		Node *pNode = n;
		while (pNode->m_parent != NULL) {
			pNode = pNode->m_parent;
		}

		// if the origin node is our front vehicle tile/Trackdir then we didn't reverse
		// but we can also look at the cost (== 0 -> not reversed, == reverse_penalty -> reversed)
		*reversed = (pNode->m_cost != 0);

		return true;
	}
};

template <class Types>
class CYapfFollowRailT
{
public:
	typedef typename Types::Tpf Tpf;                     ///< the pathfinder class (derived from THIS class)
	typedef typename Types::TrackFollower TrackFollower;
	typedef typename Types::NodeList::Titem Node;        ///< this will be our node type
	typedef typename Node::Key Key;                      ///< key to hash tables

protected:
	/// to access inherited path finder
	FORCEINLINE Tpf& Yapf() {return *static_cast<Tpf*>(this);}

public:
	/** Called by YAPF to move from the given node to the next tile. For each
	 *  reachable trackdir on the new tile creates new node, initializes it
	 *  and adds it to the open list by calling Yapf().AddNewNode(n) */
	inline void PfFollowNode(Node& old_node)
	{
		TrackFollower F(Yapf().GetVehicle());
		if (F.Follow(old_node.GetLastTile(), old_node.GetLastTrackdir()))
			Yapf().AddMultipleNodes(&old_node, F);
	}

	/// return debug report character to identify the transportation type
	FORCEINLINE char TransportTypeChar() const {return 't';}

	static Trackdir stChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found)
	{
		// create pathfinder instance
		Tpf pf1;
		Trackdir result1 = pf1.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found);

#if DEBUG_YAPF_CACHE
		Tpf pf2;
		pf2.DisableCache(true);
		Trackdir result2 = pf2.ChooseRailTrack(v, tile, enterdir, tracks, path_not_found);
		if (result1 != result2) {
			DEBUG(yapf, 0, "CACHE ERROR: ChooseRailTrack() = [%d, %d]", result1, result2);
			DumpTarget dmp1, dmp2;
			pf1.DumpBase(dmp1);
			pf2.DumpBase(dmp2);
			FILE *f1 = fopen("C:\\yapf1.txt", "wt");
			FILE *f2 = fopen("C:\\yapf2.txt", "wt");
			fwrite(dmp1.m_out.Data(), 1, dmp1.m_out.Size(), f1);
			fwrite(dmp2.m_out.Data(), 1, dmp2.m_out.Size(), f2);
			fclose(f1);
			fclose(f2);
		}
#endif

		return result1;
	}

	FORCEINLINE Trackdir ChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found)
	{
		// set origin and destination nodes
		Yapf().SetOrigin(v->tile, GetVehicleTrackdir(v), INVALID_TILE, INVALID_TRACKDIR, 1, true);
		Yapf().SetDestination(v);

		// find the best path
		bool path_found = Yapf().FindPath(v);
		if (path_not_found != NULL) {
			// tell controller that the path was only 'guessed'
			// treat the path as found if stopped on the first two way signal(s)
			*path_not_found = !(path_found || Yapf().m_stopped_on_first_two_way_signal);
		}

		// if path not found - return INVALID_TRACKDIR
		Trackdir next_trackdir = INVALID_TRACKDIR;
		Node *pNode = Yapf().GetBestNode();
		if (pNode != NULL) {
			// path was found or at least suggested
			// walk through the path back to the origin
			Node* pPrev = NULL;
			while (pNode->m_parent != NULL) {
				pPrev = pNode;
				pNode = pNode->m_parent;
			}
			// return trackdir from the best origin node (one of start nodes)
			Node& best_next_node = *pPrev;
			assert(best_next_node.GetTile() == tile);
			next_trackdir = best_next_node.GetTrackdir();
		}
		return next_trackdir;
	}

	static bool stCheckReverseTrain(Vehicle* v, TileIndex t1, Trackdir td1, TileIndex t2, Trackdir td2, int reverse_penalty)
	{
		Tpf pf1;
		bool result1 = pf1.CheckReverseTrain(v, t1, td1, t2, td2, reverse_penalty);

#if DEBUG_YAPF_CACHE
		Tpf pf2;
		pf2.DisableCache(true);
		bool result2 = pf2.CheckReverseTrain(v, t1, td1, t2, td2, reverse_penalty);
		if (result1 != result2) {
			DEBUG(yapf, 0, "CACHE ERROR: CheckReverseTrain() = [%s, %s]", result1 ? "T" : "F", result2 ? "T" : "F");
		}
#endif

		return result1;
	}

	FORCEINLINE bool CheckReverseTrain(Vehicle* v, TileIndex t1, Trackdir td1, TileIndex t2, Trackdir td2, int reverse_penalty)
	{
		// create pathfinder instance
		// set origin and destination nodes
		Yapf().SetOrigin(t1, td1, t2, td2, reverse_penalty, false);
		Yapf().SetDestination(v);

		// find the best path
		bool bFound = Yapf().FindPath(v);

		if (!bFound) return false;

		// path was found
		// walk through the path back to the origin
		Node *pNode = Yapf().GetBestNode();
		while (pNode->m_parent != NULL) {
			pNode = pNode->m_parent;
		}

		// check if it was reversed origin
		Node& best_org_node = *pNode;
		bool reversed = (best_org_node.m_cost != 0);
		return reversed;
	}
};

template <class Tpf_, class Ttrack_follower, class Tnode_list, template <class Types> class TdestinationT, template <class Types> class TfollowT>
struct CYapfRail_TypesT
{
	typedef CYapfRail_TypesT<Tpf_, Ttrack_follower, Tnode_list, TdestinationT, TfollowT>  Types;

	typedef Tpf_                                Tpf;
	typedef Ttrack_follower                     TrackFollower;
	typedef Tnode_list                          NodeList;
	typedef CYapfBaseT<Types>                   PfBase;
	typedef TfollowT<Types>                     PfFollow;
	typedef CYapfOriginTileTwoWayT<Types>       PfOrigin;
	typedef TdestinationT<Types>                PfDestination;
	typedef CYapfSegmentCostCacheGlobalT<Types> PfCache;
	typedef CYapfCostRailT<Types>               PfCost;
};

struct CYapfRail1         : CYapfT<CYapfRail_TypesT<CYapfRail1        , CFollowTrackRail    , CRailNodeListTrackDir, CYapfDestinationTileOrStationRailT, CYapfFollowRailT> > {};
struct CYapfRail2         : CYapfT<CYapfRail_TypesT<CYapfRail2        , CFollowTrackRailNo90, CRailNodeListTrackDir, CYapfDestinationTileOrStationRailT, CYapfFollowRailT> > {};

struct CYapfAnyDepotRail1 : CYapfT<CYapfRail_TypesT<CYapfAnyDepotRail1, CFollowTrackRail    , CRailNodeListTrackDir, CYapfDestinationAnyDepotRailT     , CYapfFollowAnyDepotRailT> > {};
struct CYapfAnyDepotRail2 : CYapfT<CYapfRail_TypesT<CYapfAnyDepotRail2, CFollowTrackRailNo90, CRailNodeListTrackDir, CYapfDestinationAnyDepotRailT     , CYapfFollowAnyDepotRailT> > {};


Trackdir YapfChooseRailTrack(Vehicle *v, TileIndex tile, DiagDirection enterdir, TrackBits tracks, bool *path_not_found)
{
	// default is YAPF type 2
	typedef Trackdir (*PfnChooseRailTrack)(Vehicle*, TileIndex, DiagDirection, TrackBits, bool*);
	PfnChooseRailTrack pfnChooseRailTrack = &CYapfRail1::stChooseRailTrack;

	// check if non-default YAPF type needed
	if (_settings.pf.forbid_90_deg) {
		pfnChooseRailTrack = &CYapfRail2::stChooseRailTrack; // Trackdir, forbid 90-deg
	}

	Trackdir td_ret = pfnChooseRailTrack(v, tile, enterdir, tracks, path_not_found);

	return td_ret;
}

bool YapfCheckReverseTrain(Vehicle* v)
{
	/* last wagon */
	Vehicle* last_veh = GetLastVehicleInChain(v);

	// get trackdirs of both ends
	Trackdir td = GetVehicleTrackdir(v);
	Trackdir td_rev = ReverseTrackdir(GetVehicleTrackdir(last_veh));

	/* tiles where front and back are */
	TileIndex tile = v->tile;
	TileIndex tile_rev = last_veh->tile;

	int reverse_penalty = 0;

	if (v->u.rail.track == TRACK_BIT_WORMHOLE) {
		/* front in tunnel / on bridge */
		DiagDirection dir_into_wormhole = GetTunnelBridgeDirection(tile);

		if (TrackdirToExitdir(td) == dir_into_wormhole) tile = GetOtherTunnelBridgeEnd(tile);
		/* Now 'tile' is the tunnel entry/bridge ramp the train will reach when driving forward */

		/* Current position of the train in the wormhole */
		TileIndex cur_tile = TileVirtXY(v->x_pos, v->y_pos);

		/* Add distance to drive in the wormhole as penalty for the forward path, i.e. bonus for the reverse path
		 * Note: Negative penalties are ok for the start tile. */
		reverse_penalty -= DistanceManhattan(cur_tile, tile) * YAPF_TILE_LENGTH;
	}

	if (last_veh->u.rail.track == TRACK_BIT_WORMHOLE) {
		/* back in tunnel / on bridge */
		DiagDirection dir_into_wormhole = GetTunnelBridgeDirection(tile_rev);

		if (TrackdirToExitdir(td_rev) == dir_into_wormhole) tile_rev = GetOtherTunnelBridgeEnd(tile_rev);
		/* Now 'tile_rev' is the tunnel entry/bridge ramp the train will reach when reversing */

		/* Current position of the last wagon in the wormhole */
		TileIndex cur_tile = TileVirtXY(last_veh->x_pos, last_veh->y_pos);

		/* Add distance to drive in the wormhole as penalty for the revere path. */
		reverse_penalty += DistanceManhattan(cur_tile, tile_rev) * YAPF_TILE_LENGTH;
	}

	typedef bool (*PfnCheckReverseTrain)(Vehicle*, TileIndex, Trackdir, TileIndex, Trackdir, int);
	PfnCheckReverseTrain pfnCheckReverseTrain = CYapfRail1::stCheckReverseTrain;

	// check if non-default YAPF type needed
	if (_settings.pf.forbid_90_deg) {
		pfnCheckReverseTrain = &CYapfRail2::stCheckReverseTrain; // Trackdir, forbid 90-deg
	}

	/* slightly hackish: If the pathfinders finds a path, the cost of the first node is tested to distinguish between forward- and reverse-path. */
	if (reverse_penalty == 0) reverse_penalty = 1;

	bool reverse = pfnCheckReverseTrain(v, tile, td, tile_rev, td_rev, reverse_penalty);

	return reverse;
}

bool YapfFindNearestRailDepotTwoWay(Vehicle *v, int max_distance, int reverse_penalty, TileIndex* depot_tile, bool* reversed)
{
	*depot_tile = INVALID_TILE;
	*reversed = false;

	Vehicle* last_veh = GetLastVehicleInChain(v);

	TileIndex tile = v->tile;
	TileIndex last_tile = last_veh->tile;

	// their trackdirs
	Trackdir td = GetVehicleTrackdir(v);
	Trackdir td_rev = ReverseTrackdir(GetVehicleTrackdir(last_veh));

	typedef bool (*PfnFindNearestDepotTwoWay)(Vehicle*, TileIndex, Trackdir, TileIndex, Trackdir, int, int, TileIndex*, bool*);
	PfnFindNearestDepotTwoWay pfnFindNearestDepotTwoWay = &CYapfAnyDepotRail1::stFindNearestDepotTwoWay;

	// check if non-default YAPF type needed
	if (_settings.pf.forbid_90_deg) {
		pfnFindNearestDepotTwoWay = &CYapfAnyDepotRail2::stFindNearestDepotTwoWay; // Trackdir, forbid 90-deg
	}

	bool ret = pfnFindNearestDepotTwoWay(v, tile, td, last_tile, td_rev, max_distance, reverse_penalty, depot_tile, reversed);
	return ret;
}

/** if any track changes, this counter is incremented - that will invalidate segment cost cache */
int CSegmentCostCacheBase::s_rail_change_counter = 0;

void YapfNotifyTrackLayoutChange(TileIndex tile, Track track) {CSegmentCostCacheBase::NotifyTrackLayoutChange(tile, track);}