1 files changed, 115 insertions, 1 deletions

diff --git a/src/Program/Program.cs b/src/Program/Program.cs
index 426284a..90e80bd 100644
--- a/src/Program/Program.cs
+++ b/src/Program/Program.cs
@@ -1,4 +1,8 @@
 using System;
+using System.Collections.Generic;
+using System.IO;
+using System.Linq;
+using Graph = NetworkFlow.Graph;
 
 namespace Program
 {
@@ -6,7 +10,117 @@ namespace Program
     {
         static void Main(string[] args)
         {
-            Console.WriteLine("Hello World!");
+            // attempt to read file from command line args, otherwise asks for a file
+            FileInfo inputFile = (args.Length > 0) ? new FileInfo(args[0]) : ReadFileName();
+
+            // attempt to get source and terminal nodes from command line args
+            string source = (args.Length >= 2) ? args[1] : default(string);
+            string terminal = (args.Length >= 3) ? args[2] : default(string);
+
+
+            if (!inputFile.Exists)
+            {
+                Console.WriteLine($"Failed to open {inputFile}: File does not exist.");
+                return;
+            }
+
+            // read file into graph
+            Graph graph = ReadFile(inputFile.FullName);
+
+            // verify command line source and terminal values or gets new values from the user
+            (int s, int t) = ReadSourceAndTerminal(graph, source, terminal);
+
+            // call maxFlow
+            double maxFlow = graph.MaxFlow(s, t);
+            Console.WriteLine($"The max flow is {maxFlow}");
+        }
+
+        public static (int s, int t) ReadSourceAndTerminal(Graph graph, string source, string terminal)
+        {
+            int s, t;
+            // retries until it succeeds
+            while (true)
+            {
+                // try to parse supplied values
+                bool isSetSource = int.TryParse(source, out s);
+                bool isSetTerminal = int.TryParse(terminal, out t);
+
+                // validates the values are ints and the graph contains the corresponding node
+                if (!(isSetSource && graph.Nodes.ContainsKey(s)))
+                {
+                    if (source != default(string))
+                        Console.WriteLine($"Invalid Source Node: {source}");
+                    Console.Write($"Enter the Source Node: ");
+                    // asks for a new value
+                    source = Console.ReadLine();
+                }
+                // validates the values are ints and the graph contains the corresponding node
+                if (!(isSetTerminal && graph.Nodes.ContainsKey(t)))
+                {
+                    if (terminal != default(string))
+                        Console.WriteLine($"Invalid Terminal Node: {terminal}");
+                    Console.Write($"Enter the Terminal Node: ");
+                    // asks for a new value
+                    terminal = Console.ReadLine();
+                }
+                // if everything is correct then we can return
+                if (isSetSource && isSetTerminal && graph.Nodes.ContainsKey(s) && graph.Nodes.ContainsKey(t))
+                    break;
+            }
+
+
+            return (s, t);
+        }
+
+        public static FileInfo ReadFileName()
+        {
+            string filePath;
+
+            // continues to ask for a valid filepath until obtained
+            while (true)
+            {
+                Console.Write("Enter a path to a points file: ");
+                filePath = Console.ReadLine();
+
+                if (String.IsNullOrEmpty(filePath))
+                    Console.WriteLine("File path cannot be empty!");
+                else if (!System.IO.File.Exists(filePath))
+                    Console.WriteLine($"{filePath} does not exist.");
+                else
+                    break;
+            }
+
+            FileInfo file = new FileInfo(filePath);
+
+            return file;
+        }
+
+        public static Graph ReadFile(string file)
+        {
+            // create default Graph object
+            Graph graph = new Graph();
+
+            // Read in graph file
+            foreach (string line in File.ReadLines(file))
+            {
+                // each file line is a Node with optional edges
+                // line format:
+                // vertex:int optional[ connected-vertex:int edge-weight:double optional[..] ]
+                List<string> vals = line.Split(' ').ToList();
+                int u, v;
+                double weight;
+                int.TryParse(vals[0], out u);
+                graph.AddNode(u);
+                for (int i = 1; i < vals.Count - 1; i += 2)
+                {
+                    // AddEdge(int u, int v, double weight)
+                    int.TryParse(vals[i], out v);
+                    double.TryParse(vals[i + 1], out weight);
+                    graph.AddEdge(u, v, weight);
+                }
+            }
+            // return object when done
+            return graph;
         }
     }
 }