cleaner(ish) code, support for rules

Bank.cs

@@ -1,6 +1,7 @@
 namespace BunyMuny {
 	public enum Bank {
 		ME,
-		NAB
+		NAB,
+		Other
 	}
 }

Program.cs

@@ -2,64 +2,98 @@
 using System.Collections.Generic;
 using System.Globalization;
 using System.IO;
+using System.Text.Json;
 using System.CommandLine.DragonFruit;
+using System.Text.Json.Serialization;
 using CsvHelper;
-using CsvHelper.Configuration.Attributes;
 
 namespace BunyMuny {
-	class Program {
+	internal class Program {
 		/// <summary>
 		/// BunyMuny parses the CSV output of various bank statement listings and converts it to something more human readable with nice visualisations.
 		/// </summary>
 		/// <param name="file">The CSV file to read</param>
-		/// <param name="rules">The JSON file to use for rules when parsing statement descriptions</param>
+		/// <param name="ruleFile">The JSON file to use for rules when parsing statement descriptions</param>
 		/// <returns></returns>
-		static int Main(string file = "test.csv", string rules = "rules.json") {
-			Bank bank = Bank.ME;
+		static int Main(string file = "test.csv", string ruleFile = "rules.json") {
+			var bank = Bank.Other;
 			var statements = new List<Statement>();
+			List<Rule> rules;
 
-			using (var sr = new StreamReader(file)) {
-				using (var csv = new CsvReader(sr, CultureInfo.InvariantCulture)) {
-					csv.Read();
-					csv.ReadHeader();
-					// get the first line of the CSV file (the header) as a string
-					string header = csv.Parser.Context.RawRecord;
-					if (header == null) {
-						Console.WriteLine("File is empty 0uo");
+			using (var ruleStreamReader = new StreamReader(ruleFile)) {
+				var jsonOptions = new JsonSerializerOptions();
+				jsonOptions.Converters.Add(new JsonStringEnumConverter(JsonNamingPolicy.CamelCase));
+				jsonOptions.WriteIndented = true;
+				rules = JsonSerializer.Deserialize<List<Rule>>(ruleStreamReader.ReadToEnd(), jsonOptions);
+			}
+
+			using var sr = new StreamReader(file);
+			using var csv = new CsvReader(sr, CultureInfo.InvariantCulture);
+
+			csv.Read();
+			csv.ReadHeader();
+
+			// get the first line of the CSV file (the header) as a string
+			var header = csv.Parser.Context.RawRecord.Trim();
+			switch (header) {
+				case null:
+					Console.WriteLine("File is empty 0uo");
+					return 1;
+				case "Date,Description,Debits and credits,Balance":
+					bank = Bank.ME;
+					break;
+				case "Whatever NAB uses I guess":
+					bank = Bank.NAB;
+					break;
+				default:
+					Console.WriteLine($"Unknown header: [{header}]");
+					break;
+			}
+
+			while (csv.Read()) {
+				switch (bank) {
+					case Bank.ME:
+						var value = double.Parse(csv.GetField("Debits and credits").TrimStart().Replace("$", ""));
+						var ruleValues = MatchAgainstRules(rules, csv.GetField("Description"));
+
+						statements.Add(new Statement() {
+							Date = DateTime.ParseExact(csv.GetField("Date"), "dd/MM/yyyy", CultureInfo.InvariantCulture),
+							OriginalDescription = csv.GetField("Description"),
+							Description = ruleValues.Description,
+							Category = ruleValues.Category,
+							Value = value
+						});
+						break;
+
+					case Bank.NAB:
+						Console.WriteLine("Unimplemented");
 						return 1;
-					}
-					else if (header == "Date,Description,Debits and credits,Balance") {
-						bank = Bank.ME;
-					}
-					else if (header == "Whatever NAB uses I guess") {
-						bank = Bank.NAB;
-					}
 
-					while (csv.Read()) {
-						switch (bank) {
-							case Bank.ME:
-								double value = double.Parse(csv.GetField("Debits and credits").TrimStart().Replace("$", ""));
-								statements.Add(new Statement() {
-									Date = DateTime.ParseExact(csv.GetField("Date"), "dd/MM/yyyy", CultureInfo.InvariantCulture),
-									Description = csv.GetField("Description"),
-									Category = "Unknown",
-									Value = value
-								});
-								break;
+					case Bank.Other:
+						Console.WriteLine("Unknown bank!");
+						return 1;
 
-							default:
-								Console.WriteLine(":(");
-								return 1;
-						}
-					}
-
-					foreach (var statement in statements) {
-						Console.WriteLine(statement);
-					}
+					default:
+						Console.WriteLine(":(");
+						return 1;
 				}
 			}
 
+			foreach (var statement in statements) {
+				Console.WriteLine(statement);
+			}
+
 			return 0;
 		}
+
+		private static (string Category, string Description) MatchAgainstRules(List<Rule> rules, string value) {
+			foreach (var rule in rules) {
+				if (rule.Check(value)) {
+					return (rule.Category, rule.Description);
+				}
+			}
+
+			return (null, null);
+		}
 	}
 }

Statement.cs

@@ -1,4 +1,5 @@
 using System;
+using System.Text;
 
 namespace BunyMuny {
 	public class Statement {
@@ -14,7 +15,16 @@ namespace BunyMuny {
 		public string Category;
 
 		public override string ToString() {
-			return $"${Math.Abs(Value)} {(Value < 0 ? "to" : "from")} {(Description)} on {Date.ToString("MMM d yyyy")}";
+			// e.g.: Debit:  $5.00 --> Lynnear Software (Personal) on Apr 2 2020
+			return String.Format(
+				"{0} ${1:0.##} {2} {3} ({4}) on {5:MMM d yyyy}",
+				Value < 0 ? "Credit:" : "Debit: ",
+				Math.Abs(Value),
+				Value < 0 ? "-->" : "<--",
+				Description,
+				Category ?? "Unknown",
+				Date
+				);
 		}
 	}
 }