/// <summary>
/// Get connected nodes for node specified (directed)
/// </summary>
/// <param name="node">node to search for</param>
/// <returns>list of connected nodes</returns>
public IReadOnlyList <TNode> GetConnectedNodes(TNode node)
{
var list = _edges.Values
.Where(x => KeyCompare.Equals(x.FromNodeKey, node.Key))
.Join(_nodes.Values, x => x.ToNodeKey, x => x.Key, (o, i) => i)
.ToList();
return(list);
}
/// <summary>
/// Return list of nodes by key(s)
/// </summary>
/// <param name="nodeKeys">list of node keys</param>
/// <returns>nodes matching set</returns>
public IReadOnlyList <TNode> FindNodesByKey(IEnumerable <TKey> nodeKeys)
{
if (nodeKeys == null || !nodeKeys.Any())
{
return(new List <TNode>());
}
return(Nodes.Values
.Where(x => nodeKeys.Any(y => KeyCompare.Equals(x.Key, y)))
.ToList());
}
/// <summary>
/// Remove node, will remove all edges associated
/// </summary>
/// <param name="nodeKey"></param>
/// <returns></returns>
public GraphMap <TKey, TNode, TEdge> RemoveNode(TKey nodeKey)
{
// Remove edges associated with node
_edges.Values
.Where(x => KeyCompare.Equals(x.FromNodeKey, nodeKey) || KeyCompare.Equals(x.ToNodeKey, nodeKey))
.Select(x => x.Key)
.ToList()
.ForEach(x => _edges.Remove(x));
_nodes.Remove(nodeKey);
return(this);
}
/// <summary>
/// Remove edge
/// </summary>
/// <param name="fromNodeKey">from node key</param>
/// <param name="toNodeKey">to node key</param>
/// <returns></returns>
public GraphMap <TKey, TNode, TEdge> RemoveEdge(TKey fromNodeKey, TKey toNodeKey)
{
Guid?edgeKey = _edges.Values
.Where(x => KeyCompare.Equals(x.FromNodeKey, fromNodeKey) && KeyCompare.Equals(x.ToNodeKey, toNodeKey))
.Select(x => x.Key)
.FirstOrDefault();
if (edgeKey != null)
{
_edges.Remove((Guid)edgeKey);
}
return(this);
}
/// <summary>
/// Test edge and return error message
/// </summary>
/// <param name="edge"></param>
/// <returns>error message</returns>
private string TestEdge(TEdge edge)
{
if (!_nodes.ContainsKey(edge.FromNodeKey))
{
return($"Parent {edge.FromNodeKey} is not found in nodes");
}
if (!_nodes.ContainsKey(edge.ToNodeKey))
{
return($"Child {edge.ToNodeKey} is not found in nodes");
}
if (KeyCompare.Equals(edge.FromNodeKey, edge.ToNodeKey))
{
return($"From node {edge.FromNodeKey} cannot be the same as the to {edge.ToNodeKey}.");
}
return(null);
}