package fr.uge.graph;


/// An oriented graph with values on edges and not on nodes.
public interface Graph {
  /// Returns the number of nodes of this graph.
  /// @return the number of nodes of this graph.
  //nodeCount()

  /// Create a graph implementation based on a matrix.
  ///
  /// @param <T> type of the edge weight.
  /// @param nodeCount the number of nodes.
  /// @return a new implementation of Graph.
  //createMatrixGraph(nodeCount)

  /// Add an edge between two nodes or replace it if an edge already exists.
  ///
  /// @param src source node.
  /// @param dst destination node.
  /// @param weight weight of the edge.
  /// @throws NullPointerException if weight is `null`.
  /// @throws IndexOutOfBoundsException if src or dst is not a valid node number.
  //addEdge(src, dst, weight)

  /// Return the weight of an edge.
  ///
  /// @param src source ndoe.
  /// @param dst destination nde.
  /// @return the weight of the edge between `src`and `dst` or Optional.empty().
  /// @throws IndexOutOfBoundsException if src or dst is not a valid node number.
  //getWeight(src, dst)

  /// Adds all the edge values of the graph taken as parameter to the current graph,
  /// uses the `merger` if there is already a value to merge the value.
  ///
  /// @param graph a graph
  /// @param merger the function to call if there are two values to merge.
  /// @throws NullPointerException if either graph or merger is null.
  /// @throws IllegalArgumentException if the graphs do not have the same number of nodes.
  //mergeAll(graph, merger)

  /// Returns all the nodes that are connected to the node taken as parameter.
  /// The order of the nodes may be different that the insertion order.
  /// @param src a node.
  /// @return an iterator on all nodes connected to the specified source node.
  /// @throws IndexOutOfBoundsException if src is not a valid node number.
  //neighborIterator(src)

  /// An edge of the graph.
  ///
  /// @param src the index of the source node.
  /// @param dst the index of the destination node.
  /// @param weight the weight associated to the edge.
  /// @param <T> the type of the weight
  // Edge

  /// Call the consumer for each edge associated to the source node.
  ///
  /// @param src the source node.
  /// @param function the function called for all edge that have src as source node.
  /// @throws NullPointerException if consumer is null.
  /// @throws IndexOutOfBoundsException if src is not a valid index for a node.
  // forEachEdge(src, function)

  /// Returns all the edges of the graph that have a value.
  ///
  /// @return all the edges of the graph that have a value in any order.
  //edges()

  /// Create a graph implementation based on a node map.
  /// @param nodeCount the number of nodes
  /// @return a new graph implementation
  /// @param <T> type of the edge weight
  //createNodeMapGraph(nodeCount)
}