From 7a07398275abf496e3bf30d0097f8c263b398cc4 Mon Sep 17 00:00:00 2001
From: Nick Gasson <nick@nickg.me.uk>
Date: Fri, 12 Aug 2011 18:58:07 +0100
Subject: [PATCH] Further track graph work in progress

---
 src/TrackGraph.cpp | 65 ++++++++++++++++++++++++++++++++++++++++++++++
 1 file changed, 65 insertions(+)

diff --git a/src/TrackGraph.cpp b/src/TrackGraph.cpp
index 95212ba..f0d805e 100644
--- a/src/TrackGraph.cpp
+++ b/src/TrackGraph.cpp
@@ -17,6 +17,7 @@
 
 #include "ITrackGraph.hpp"
 #include "ILogger.hpp"
+#include "IterateTrack.hpp"
 
 #include <stdexcept>
 
@@ -24,12 +25,76 @@ class TrackGraph : public ITrackGraph {
 public:
    TrackGraph(IMapPtr map);
 
+   // ITrackGraph interface
    void write_dot_file(const string& file) const;
+   const graph::Node& root() const;
+   const graph::Node& node(unsigned n) const;
+
+private:
+   void walk_track(TrackIterator it,
+                   set<ITrackSegmentPtr>& visited,
+                   graph::Node& where);
+   graph::Node& add_node(graph::NodeType type);
+   
+   vector<graph::Node> nodes;
 };
 
 TrackGraph::TrackGraph(IMapPtr map)
 {
+   track::Position p;
+   track::Direction d;
+   tie(p, d) = map->start();
+
+   graph::Node& root = add_node(graph::NODE_ROOT);
+
+   set<ITrackSegmentPtr> visited;
+   walk_track(iterate_track(map, p, d), visited, root);
+}
+
+void TrackGraph::walk_track(TrackIterator it,
+                            set<ITrackSegmentPtr>& visited,
+                            graph::Node& where)
+{
+   if (visited.find(it.track) != visited.end()) {
+      // TODO: connect up with arc         
+   }
+
+   visited.insert(it.track);
+
+   switch (it.status) {
+   case TRACK_STATION:
+      // TODO
+   case TRACK_OK:
+      walk_track(it.next(), visited, where);
+      break;
+
+   case TRACK_NO_MORE:
+      break;
+
+   case TRACK_CHOICE:
+      throw runtime_error("can't graph track with choice yet!");
+      
+   }
+}
+
+graph::Node& TrackGraph::add_node(graph::NodeType type)
+{
+   unsigned id = nodes.size();
+   graph::Node n = { id, type };
+   nodes.push_back(n);
+   return nodes.at(id);
+}
    
+const graph::Node& TrackGraph::root() const
+{
+   assert(nodes.size() > 0);
+   return nodes.at(0);
+}
+
+const graph::Node& TrackGraph::node(unsigned n) const
+{
+   assert(n < nodes.size());
+   return nodes.at(n);
 }
 
 void TrackGraph::write_dot_file(const string& file) const
-- 
2.39.2