From 86fda4a81f662eac7876bb72ec0295fc42ee200c Mon Sep 17 00:00:00 2001
From: Stevan Freeborn <65925598+StevanFreeborn@users.noreply.github.com>
Date: Sat, 9 Dec 2023 12:17:56 -0600
Subject: [PATCH] feat: start working on part 1 solution

---
 .../OasisReportTests.cs                       | 35 +++++++++
 09/MirageMaintenance.Tests/UnitTest1.cs       | 10 ---
 .../ValueHistoryTests.cs                      | 76 +++++++++++++++++++
 09/MirageMaintenance/Program.cs               | 73 +++++++++++++++++-
 4 files changed, 182 insertions(+), 12 deletions(-)
 create mode 100644 09/MirageMaintenance.Tests/OasisReportTests.cs
 delete mode 100644 09/MirageMaintenance.Tests/UnitTest1.cs
 create mode 100644 09/MirageMaintenance.Tests/ValueHistoryTests.cs

diff --git a/09/MirageMaintenance.Tests/OasisReportTests.cs b/09/MirageMaintenance.Tests/OasisReportTests.cs
new file mode 100644
index 0000000..13b68cc
--- /dev/null
+++ b/09/MirageMaintenance.Tests/OasisReportTests.cs
@@ -0,0 +1,35 @@
+namespace MirageMaintenance.Tests;
+
+public class UnitTest1
+{
+  [Theory]
+  [MemberData(nameof(TestData.OasisReportParseTestData), MemberType = typeof(TestData))]
+  public void Parse_GivenAReportInput_ItShouldReturnExpectedOasisReportInstance(string[] input, OasisReport expected)
+  {
+    OasisReport.Parse(input).Should().BeEquivalentTo(expected);
+  }
+
+  public static class TestData
+  {
+    public static IEnumerable<object[]> OasisReportParseTestData =>
+      new List<object[]>
+      {
+          new object[]
+          {
+            new string[]
+            {
+              "0 3 6 9 12 15",
+              "1 3 6 10 15 21",
+              "10 13 16 21 30 45",
+            },
+            new OasisReport(
+              [
+                new([0, 3, 6, 9, 12, 15]),
+                new([1, 3, 6, 10, 15, 21]),
+                new([10, 13, 16, 21, 30, 45]),
+              ]
+            )
+          }
+      };
+  }
+}
\ No newline at end of file
diff --git a/09/MirageMaintenance.Tests/UnitTest1.cs b/09/MirageMaintenance.Tests/UnitTest1.cs
deleted file mode 100644
index 561193c..0000000
--- a/09/MirageMaintenance.Tests/UnitTest1.cs
+++ /dev/null
@@ -1,10 +0,0 @@
-namespace MirageMaintenance.Tests;
-
-public class UnitTest1
-{
-    [Fact]
-    public void Test1()
-    {
-
-    }
-}
\ No newline at end of file
diff --git a/09/MirageMaintenance.Tests/ValueHistoryTests.cs b/09/MirageMaintenance.Tests/ValueHistoryTests.cs
new file mode 100644
index 0000000..e2c2e8f
--- /dev/null
+++ b/09/MirageMaintenance.Tests/ValueHistoryTests.cs
@@ -0,0 +1,76 @@
+namespace MirageMaintenance.Tests;
+
+public class ValueHistoryTests
+{
+  [Theory]
+  [MemberData(nameof(TestData.CalculateDifferencesTestData), MemberType = typeof(TestData))]
+  public void CalculateDifferences_GivenAListOfValues_ItShouldReturnAListOfDifferences(List<long> values, List<long> expected)
+  {
+    new ValueHistory([]).CalculateDifferences(values).Should().BeEquivalentTo(expected);
+  }
+
+  [Theory]
+  [MemberData(nameof(TestData.CalculateHistoryTest), MemberType = typeof(TestData))]
+  public void CalculateHistory_GivenAListOfValues_ItShouldReturnAListOfHistoricalValues(List<long> values, List<List<long>> expected)
+  {
+    new ValueHistory(values).CalculateHistory().Should().BeEquivalentTo(expected);
+  }
+
+  public static class TestData
+  {
+    public static IEnumerable<object[]> CalculateHistoryTest =>
+      new List<object[]>
+      {
+          new object[]
+          {
+            new List<long> { 0, 3, 6, 9, 12, 15 },
+            new List<List<long>>
+            {
+              new() { 3, 3, 3, 3, 3 },
+              new() { 0, 0, 0, 0 },
+            },
+          },
+          new object[]
+          {
+            new List<long> { 1, 3, 6, 10, 15, 21 },
+            new List<List<long>>
+            {
+              new() { 2, 3, 4, 5, 6 },
+              new() { 1, 1, 1, 1 },
+              new() { 0, 0, 0 },
+            },
+          },
+          new object[]
+          {
+            new List<long> { 10, 13, 16, 21, 30, 45 },
+            new List<List<long>>
+            {
+              new() { 3, 3, 5, 9, 15 },
+              new() { 0, 2, 4, 6 },
+              new() { 2, 2, 2 },
+              new() { 0, 0 },
+            },
+          },
+      };
+
+    public static IEnumerable<object[]> CalculateDifferencesTestData =>
+      new List<object[]>
+      {
+          new object[]
+          {
+            new List<long> { 0, 3, 6, 9, 12, 15 },
+            new List<long> { 3, 3, 3, 3, 3 },
+          },
+          new object[]
+          {
+            new List<long> { 1, 3, 6, 10, 15, 21 },
+            new List<long> { 2, 3, 4, 5, 6 },
+          },
+          new object[]
+          {
+            new List<long> { 10, 13, 16, 21, 30, 45 },
+            new List<long> { 3, 3, 5, 9, 15 },
+          },
+      };
+  }
+}
\ No newline at end of file
diff --git a/09/MirageMaintenance/Program.cs b/09/MirageMaintenance/Program.cs
index 3751555..3a825bd 100644
--- a/09/MirageMaintenance/Program.cs
+++ b/09/MirageMaintenance/Program.cs
@@ -1,2 +1,71 @@
-// See https://aka.ms/new-console-template for more information
-Console.WriteLine("Hello, World!");
+namespace MirageMaintenance;
+
+class Program
+{
+  public static async Task<int> Main(string[] args)
+  {
+    return await Task.FromResult(0);
+  }
+}
+
+public class OasisReport(
+  List<ValueHistory> valueHistories
+)
+{
+  public List<ValueHistory> ValueHistories { get; init; } = valueHistories;
+
+  public static OasisReport Parse(string[] oasisReportInput)
+  {
+    var valueHistories = new List<ValueHistory>();
+
+    foreach (var line in oasisReportInput)
+    {
+      var values = line
+        .Split(' ', StringSplitOptions.TrimEntries | StringSplitOptions.RemoveEmptyEntries)
+        .Select(long.Parse)
+        .ToList();
+
+      var valueHistory = new ValueHistory(values);
+      valueHistories.Add(valueHistory);
+    }
+
+    return new OasisReport(valueHistories);
+  }
+}
+
+public class ValueHistory(
+  List<long> values
+)
+{
+  List<long> Values { get; init; } = values;
+
+  public List<long> CalculateDifferences(List<long> values) => Enumerable
+    .Range(0, values.Count - 1)
+    .Select(i => values[i + 1] - values[i])
+    .ToList();
+
+  public List<List<long>> CalculateHistory()
+  {
+    var allHistoricalValues = new List<List<long>>();
+    var currentValues = Values;
+
+    while (
+      allHistoricalValues.Count is 0 ||
+      allHistoricalValues.Last().Sum() is not 0
+    )
+    {
+      var historicalValues = CalculateDifferences(currentValues);
+      allHistoricalValues.Add(historicalValues);
+      currentValues = historicalValues;
+    }
+
+    return allHistoricalValues;
+  }
+
+  public long CalculateNextValue()
+  {
+    var historicalValues = CalculateHistory();
+    var values = historicalValues.Prepend(Values).ToList();
+    return 0;
+  }
+}
\ No newline at end of file