Refactor: Make Connectd a directional graph (#19)

src/connectd/digraph.mo

@@ -0,0 +1,32 @@
+import Array "mo:stdlib/array";
+import Iter "mo:stdlib/iter";
+import Types "./types";
+
+module {
+  type Vertex = Types.Vertex;
+
+  public class Digraph() {
+
+    var vertexList : [Vertex] = [];
+    var edgeList : [(Vertex, Vertex)] = [];
+
+    public func addVertex(vertex : Vertex) {
+      vertexList := Array.append<Vertex>(vertexList, [vertex]);
+    };
+
+    public func addEdge(fromVertex : Vertex, toVertex : Vertex) {
+      edgeList := Array.append<(Vertex, Vertex)>(edgeList, [(fromVertex, toVertex)]);
+    };
+
+    public func getAdjacent(vertex : Vertex) : [Vertex] {
+      var adjacencyList : [Vertex] = [];
+      for ((fromVertex, toVertex) in Iter.fromArray<(Vertex, Vertex)>(edgeList)) {
+        if (fromVertex == vertex) {
+          adjacencyList := Array.append<Vertex>(adjacencyList, [toVertex]);
+        };
+      };
+      adjacencyList
+    };
+
+  };
+};

src/connectd/main.mo

@@ -1,23 +1,19 @@
-import Database "./database";
+import Digraph "./digraph";
 import Types "./types";
 
-type Entry = Types.Entry;
-type EntryId = Types.EntryId;
+type Vertex = Types.Vertex;
 
-actor Graph {
-  var entries : Database.Entries = Database.Entries();
+actor Connectd {
+  var graph : Digraph.Digraph = Digraph.Digraph();
 
   public func healthcheck() : async Bool { true };
 
-  // Connections
-
-  // "public" makes this method available as Graph.connect
-  public func connect(caller : Nat32, userId : Nat32) : async () {
-    entries.addConnection(caller, userId);
+  public func connect(userA : Vertex, userB : Vertex) : async () {
+    graph.addEdge(userA, userB);
   };
 
-  public func getConnections(userId : EntryId) : async [EntryId] {
-    entries.getConnections(userId)
+  public func getConnections(user : Vertex) : async [Vertex] {
+    graph.getAdjacent(user)
   };
 
 };

src/connectd/types.mo

@@ -1,11 +1,5 @@
 import Hash "mo:stdlib/hash";
 
 module {
-  public type EntryId = Nat32;
-
-  public type Entry = {
-    id : EntryId;
-    connections : [EntryId];
-    invitations : [EntryId];
-  };
+  public type Vertex = Nat32;
 };