AList Edges = new AList();
class Edge extends Base {
  Node n0, n1;
  AgentProgressComparator agentComparator = new AgentProgressComparator();
  int trampled = 0;

   //Edge properties
   float weight = 1.0f; 
   float edgeLength;
   float normalLength;
   float edgeWidth;
   float density = 0;
  
  Edge(Node n0, Node n1, color c, String label, String type) {
    super(c, label, type, Edges);
    this.n0 = n0;
    this.n1 = n1;
    n0.addEdge(this);
    n1.addEdge(this);
    update();
  }
  
  boolean isFull() {
    return getAgentsHere().size() * Graph.singleFileWidth > edgeLength;
  }
  
  float placeAgent() {
    return (getAgentsHere().size() + 1) * Graph.singleFileWidth / edgeLength;
  } 
  
  void placeAgentsUniform() {
    Agent agent;
    float numAgents = float(getAgentsHere().size()); 
    for (int i = 0; i < numAgents; i++) {
      agent = (Agent)getAgentsHere().get(i);
      agent.percent = i/numAgents;
      agent.speed = (agent.percent < 0.5) ? -abs(agent.speed) : abs(agent.speed);      
    }
  }
  
  void setWeight(float weight) {
    this.weight=weight;
  }
  void modifyWeight(float delta) {
    this.weight+=delta;
  }
  void paint(){
    color crowdColor;
    if (isCrowded()) {
      crowdColor = color(red(c),green(c)+255,blue(c),alpha(c)+100); //blend (c, color(0, 255, 0, 200), ADD);
    } else if (showPeople && getAgentsHere().size()>0) {
      crowdColor = color(255);
    } else {
      crowdColor = c;
    }
    stroke(crowdColor);
    
    if (subtype != "" && !showPeople) stroke(255);
    line(n0.x, n0.y, n0.z, n1.x, n1.y, n1.z);
    paintLabel(CENTER,(n0.x+n1.x)/2,(n0.y+n1.y)/2,(n0.z+n1.z)/2);
    if (showTrampled && trampled>0) {
        stroke(255,0,0);
        line(n0.x, n0.y-trampled/4, n0.z, n1.x, n1.y-trampled/4, n1.z);
        line(n0.x, n0.y-trampled/4, n0.z, n0.x, n0.y, n0.z);
        line(n1.x, n1.y-trampled/4, n1.z, n1.x, n1.y, n1.z);
        
    }
    
  }
  float len() {
    //return sqrt(sq(n0.x-n1.x)+sq(n0.y-n1.y)+sq(n0.z-n1.z));
    //return isCrowded() ? weight*edgeLength*3.0 : weight*edgeLength;
    return weight*edgeLength;

    }
  
  float getWidth() {
    return edgeWidth;
  }  
  
  float normalX() {
    return dz() / normalLength;
  }

  float normalZ() {
    return -dx() / normalLength;
  }
  
    
  float dx() {
    return n1.x-n0.x;
  }
  float dy() {
    return n1.y-n0.y;
  }
  float dz() {
    return n1.z-n0.z;
  }
  Node n0() {
    return n0;
  }
  Node n1() {
    return n1;
  }
  Node nOther(Node n) {
    return (n0==n)?n1:n0; // could use ID
  }

  void update() { // adjusts x,y,z to be middle of node locations.
    x=(n0.x+n1.x)/2;
    y=(n0.y+n1.y)/2;
    z=(n0.z+n1.z)/2;
    edgeLength = sqrt(sq(n0.x-n1.x)+sq(n0.y-n1.y)+sq(n0.z-n1.z));
    normalLength = sqrt(sq(dx()) + sq(dz()));
    if (getData(Base.Type) == graph.Row)
      edgeWidth = Graph.widthOfRow;
    else if (getData(Base.Type) == graph.Aisle)
      edgeWidth = Graph.widthOfAisle;
    else
      edgeWidth = Graph.widthOfCorridor;
  }

   float getCurrentDensity() {
     return calcCurrentDensity();
     //return density; 
   }
 
   float calcCurrentDensity() {
     density = getAgentsHere().size() / edgeLength / edgeWidth  ;
     
     return density;
   }
 
   boolean isCrowded() {
     if (graph != null) {
       return (getCurrentDensity() > graph.crowdedDensity);
     }
     
     return false;
   }
 
   void step() {
     float D =  calcCurrentDensity();
     //java.util.Collections.sort(Agents, agentComparator);
    
      }
   
   boolean twoNeighborRows() {
     int n = 0;
     
     AList neighbors = new AList();
     neighbors.addAll(n0.edges);
     neighbors.addAll(n1.edges);
     Iterator it = neighbors.iterator();
     while (it.hasNext()) {
       if (((Edge) it.next()).getType() == Graph.Row)
         n++;
       if (n>=2) return true;
     }
      return false; 
   }


}
// ---- Utils ----
class ModifyWeight implements Ask {
  float delta;
  ModifyWeight(float delta) {
    this.delta = delta;
  }
  void ask(Object o) {
    ((Edge)o).modifyWeight(delta);
  }
}
class ModifyWeightByRadius implements Ask {
  Node center;
  float maxDelta;
  ModifyWeightByRadius(Node center, float maxDelta) {
    this.center = center;
    this.maxDelta = maxDelta;
  }
  void ask(Object o) {
    float radius = ((Edge)o).lenTo(center);
    float delta = maxDelta/radius;
    ((Edge)o).modifyWeight(delta);
  }
}

public class AgentProgressComparator implements java.util.Comparator {
    int compare (Object o1, Object o2) {
      Agent a1 = (Agent) o1, a2 = (Agent) o2;
      if (a1.percent == a2.percent)
        return 0;
      
      return (a1.percent < a2.percent) ? -1 : 1;
    }
}