+/* $Id$
+
+This file is part of the MSP Märklin suite
+Copyright © 2007-2010 Mikkosoft Productions, Mikko Rasa
+Distributed under the GPL
+*/
+
+#include <queue>
+#include <msp/strings/formatter.h>
+#include "layout.h"
#include "route.h"
+#include "track.h"
+#include "trackiter.h"
+#include "tracktype.h"
+
+using namespace std;
+using namespace Msp;
+
+namespace {
+
+using namespace Marklin;
+
+typedef std::pair<Track *, unsigned> Key;
+
+struct Node
+{
+ Track *track;
+ unsigned ep;
+ Node *prev;
+ float dist;
+
+ Node():
+ track(0), ep(0), prev(0), dist(0)
+ { }
+
+ Node(Track &t, unsigned e):
+ track(&t), ep(e), prev(0), dist(0)
+ { }
+
+ Node(Track &t, unsigned e, Node &r, float d):
+ track(&t), ep(e), prev(&r), dist(prev->dist+d)
+ { }
+
+ bool operator<(const Node &other) const
+ { return dist>other.dist; }
+};
+
+struct TrackMatch
+{
+ Track &track;
+
+ TrackMatch(Track &t): track(t) { }
+
+ bool operator()(Track &t) const { return &t==&track; }
+};
+
+struct TrackInSet
+{
+ const set<Track *> &tracks;
+
+ TrackInSet(const set<Track *> &t): tracks(t) { }
+
+ bool operator()(Track &t) const { return tracks.count(&t); }
+};
+
+template<typename Pred>
+list<Track *> dijkstra(Track &from, unsigned ep, const Pred &goal)
+{
+ map<Key, Node> track_nodes;
+ priority_queue<Node> nodes;
+ Node *final = 0;
+
+ nodes.push(Node(from, ep));
+
+ while(!nodes.empty())
+ {
+ Node lowest = nodes.top();
+ nodes.pop();
+
+ Key key(lowest.track, lowest.ep);
+ if(track_nodes.count(key))
+ continue;
+
+ Node &ref = track_nodes[key] = lowest;
+ if(goal(*lowest.track))
+ {
+ final = &ref;
+ break;
+ }
+
+ const TrackType &type = lowest.track->get_type();
+ const vector<Endpoint> &eps = type.get_endpoints();
+ const vector<Track *> &links = lowest.track->get_links();
+ for(unsigned i=0; i<eps.size(); ++i)
+ {
+ if(i==lowest.ep || !links[i])
+ continue;
+
+ unsigned link_ep = links[i]->get_endpoint_by_link(*lowest.track);
+ if(track_nodes.count(Key(links[i], link_ep)))
+ continue;
+
+ unsigned mask = eps[i].paths&eps[lowest.ep].paths;
+ if(!mask)
+ continue;
+
+ unsigned path=0;
+ for(; !(mask&1); ++path, mask>>=1) ;
+ nodes.push(Node(*links[i], links[i]->get_endpoint_by_link(*lowest.track), ref, type.get_path_length(path)));
+ }
+ }
+
+ if(!final)
+ throw InvalidParameterValue("Could not find a route");
+
+ list<Track *> result;
+ for(Node *node=final; node; node=node->prev)
+ result.push_front(node->track);
+
+ return result;
+}
+
+template<typename Pred>
+Route *create_route(Track &from, unsigned ep, const Pred &goal)
+{
+ list<Track *> tracks = dijkstra(from, ep, goal);
+
+ Route *route = new Route(from.get_layout());
+ for(list<Track *>::iterator i=tracks.begin(); i!=tracks.end(); ++i)
+ route->add_track(**i);
+
+ route->set_name("Pathfinder");
+ route->set_temporary(true);
+
+ return route;
+}
+
+}
+
namespace Marklin {
+Route::Route(Layout &l):
+ layout(l),
+ temporary(false)
+{
+ layout.add_route(*this);
+ layout.signal_track_removed.connect(sigc::mem_fun(this, &Route::track_removed));
+}
+
+Route::~Route()
+{
+ layout.remove_route(*this);
+}
+
+void Route::set_name(const string &n)
+{
+ name = n;
+ signal_name_changed.emit(name);
+}
+
+void Route::set_temporary(bool t)
+{
+ temporary = t;
+}
+
+void Route::set_turnout(unsigned addr, unsigned path)
+{
+ if(!addr)
+ throw InvalidParameterValue("Invalid turnout address");
+ map<unsigned, int>::iterator i = turnouts.find(addr);
+ if(i==turnouts.end())
+ throw KeyError("Turnout is not in this route");
+ if(i->second>=0 && path!=static_cast<unsigned>(i->second))
+ throw InvalidState("Setting conflicts with route");
+ i->second = path;
+}
+
+void Route::update_turnouts()
+{
+ set<unsigned> found;
+ for(set<Track *>::const_iterator i=tracks.begin(); i!=tracks.end(); ++i)
+ if(unsigned tid = (*i)->get_turnout_id())
+ {
+ found.insert(tid);
+
+ const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
+ const vector<Track *> &links = (*i)->get_links();
+
+ // Build a combined path mask from linked endpoints
+ unsigned mask = 15;
+ for(unsigned j=0; j<endpoints.size(); ++j)
+ {
+ if(!tracks.count(links[j]))
+ continue;
+
+ if(unsigned tid2 = links[j]->get_turnout_id())
+ {
+ const Endpoint &ep = links[j]->get_type().get_endpoints()[links[j]->get_endpoint_by_link(**i)];
+ int p = get_turnout(tid2);
+ if(p>=0 && !(ep.paths&(1<<p)))
+ {
+ // The linked track is a turnout and has a path which is incompatible with this endpoint
+ mask &= ~endpoints[j].paths;
+ continue;
+ }
+ }
+ mask &= endpoints[j].paths;
+ }
+
+ if(mask && !(mask&(mask-1)))
+ {
+ // Exactly one possible choice, set the path accordingly
+ unsigned path = 0;
+ for(; (mask && !(mask&1)); mask>>=1, ++path) ;
+ turnouts[tid] = path;
+ }
+ else if(!turnouts.count(tid))
+ // More than one possible choice, and no existing entry - set as undecided
+ turnouts[tid] = -1;
+ }
+
+ // Remove any turnouts that do not exist in the route
+ for(map<unsigned, int>::iterator i=turnouts.begin(); i!=turnouts.end();)
+ {
+ if(!found.count(i->first))
+ turnouts.erase(i++);
+ else
+ ++i;
+ }
+}
+
+int Route::get_turnout(unsigned id) const
+{
+ map<unsigned, int>::const_iterator i = turnouts.find(id);
+ if(i!=turnouts.end())
+ return i->second;
+ return -1;
+}
+
+void Route::add_track(Track &trk)
+{
+ if(tracks.count(&trk))
+ return;
+
+ if(!tracks.empty())
+ {
+ unsigned valid = check_validity(trk);
+ if(!(valid&1))
+ throw Exception("Not linked to existing tracks");
+ else if(!(valid&2))
+ throw Exception("Branching routes not allowed");
+ else if(!(valid&4))
+ throw Exception("Route must be smooth");
+ }
+
+ tracks.insert(&trk);
+ update_turnouts();
+}
+
+void Route::add_tracks(const set<Track *> &trks)
+{
+ set<Track *> pending;
+ for(set<Track *>::const_iterator i=trks.begin(); i!=trks.end(); ++i)
+ if(!tracks.count(*i))
+ pending.insert(*i);
+
+ while(!pending.empty())
+ {
+ bool found = false;
+ for(set<Track *>::const_iterator i=pending.begin(); i!=pending.end(); ++i)
+ if(tracks.empty() || check_validity(**i)==7)
+ {
+ tracks.insert(*i);
+ pending.erase(*i);
+ found = true;
+ break;
+ }
+
+ if(!found)
+ throw Exception("Could not add all tracks to route");
+ }
+
+ update_turnouts();
+}
+
+void Route::add_track_chain(Track &start, unsigned ep, const TurnoutMap &trnts)
+{
+ TrackIter iter(&start, ep);
+ while(iter)
+ {
+ if(iter->get_type().is_dead_end())
+ break;
+
+ if(has_track(*iter))
+ break;
+
+ int path = 0;
+ if(iter->get_turnout_id())
+ {
+ TurnoutMap::const_iterator i = trnts.find(iter->get_turnout_id());
+ if(i==trnts.end())
+ break;
+
+ path = i->second;
+ }
+
+ add_track(*iter);
+
+ iter = iter.next(path);
+ }
+}
+
+bool Route::has_track(Track &t) const
+{
+ return tracks.count(&t);
+}
+
+void Route::save(list<DataFile::Statement> &st) const
+{
+ st.push_back((DataFile::Statement("name"), name));
+ for(map<unsigned, int>::const_iterator i=turnouts.begin(); i!=turnouts.end(); ++i)
+ st.push_back((DataFile::Statement("turnout"), i->first, i->second));
+}
+
+unsigned Route::check_validity(Track &trk) const
+{
+ unsigned result = 4;
+ for(set<Track *>::const_iterator i=tracks.begin(); i!=tracks.end(); ++i)
+ {
+ int epi=(*i)->get_endpoint_by_link(trk);
+ if(epi>=0)
+ {
+ // Linked to an existing track - good
+ result |= 1;
+ const vector<Endpoint> &endpoints = (*i)->get_type().get_endpoints();
+ if(unsigned tid=(*i)->get_turnout_id())
+ {
+ int r = get_turnout(tid);
+ if(r>=0)
+ {
+ // Linking to a turnout with path set is only good if we're continuing that path
+ if(endpoints[epi].paths&(1<<r))
+ result |= 2;
+ }
+ else
+ {
+ // Linked to a turnout with no path set - find out other linked tracks
+ unsigned count = 0;
+ const vector<Track *> &links = (*i)->get_links();
+ int epj = -1;
+ for(unsigned k=0; k<endpoints.size(); ++k)
+ if(tracks.count(links[k]))
+ {
+ ++count;
+ epj = k;
+ }
+
+ // Only good if at most one other track is linked to the turnout
+ if(count<=1)
+ {
+ result |= 2;
+ if(epj>=0 && !(endpoints[epi].paths&endpoints[epj].paths))
+ // Impossible path through the turnout - not good
+ result &= 3;
+ }
+ }
+ }
+ else
+ // Linked to something linear - good
+ result |= 2;
+ }
+ }
+
+ return result;
+}
+
+void Route::track_removed(Track &t)
+{
+ tracks.erase(&t);
+}
+
+Route *Route::find(Track &from, unsigned ep, Track &to)
+{
+ return create_route(from, ep, TrackMatch(to));
+}
+
+Route *Route::find(Track &from, unsigned ep, const Route &to)
+{
+ return create_route(from, ep, TrackInSet(to.get_tracks()));
+}
+
+Route *Route::find(Track &from, unsigned ep, const set<Track *> &to)
+{
+ return create_route(from, ep, TrackInSet(to));
+}
+
+
+Route::Loader::Loader(Route &r):
+ DataFile::BasicLoader<Route>(r)
+{
+ add("name", &Route::name);
+ add("turnout", &Loader::turnout);
+}
+
+void Route::Loader::finish()
+{
+ const set<Track *> <racks = obj.layout.get_tracks();
+ for(set<Track *>::const_iterator i=ltracks.begin(); i!=ltracks.end(); ++i)
+ {
+ unsigned tid = (*i)->get_turnout_id();
+ if(!tid)
+ continue;
+
+ TurnoutMap::iterator j = turnouts.find(tid);
+ if(j==turnouts.end())
+ continue;
+
+ unsigned path_mask = 1<<j->second;
+ const vector<Endpoint> &eps = (*i)->get_type().get_endpoints();
+ for(unsigned k=0; k<eps.size(); ++k)
+ if(eps[k].paths&path_mask)
+ {
+ Track *link = (*i)->get_link(k);
+ if(!obj.tracks.count(link))
+ obj.add_track_chain(*link, link->get_endpoint_by_link(**i), turnouts);
+ if(!obj.tracks.count(*i))
+ obj.add_track_chain(**i, k, turnouts);
+ break;
+ }
+
+ break;
+ }
+}
+void Route::Loader::turnout(unsigned id, unsigned path)
+{
+ turnouts[id] = path;
+}
} // namespace Marklin