#region CPL License
/*
Nuclex Framework
Copyright (C) 2002-2014 Nuclex Development Labs

This library is free software; you can redistribute it and/or
modify it under the terms of the IBM Common Public License as
published by the IBM Corporation; either version 1.0 of the
License, or (at your option) any later version.

This library is distributed in the hope that it will be useful,
but WITHOUT ANY WARRANTY; without even the implied warranty of
MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
IBM Common Public License for more details.

You should have received a copy of the IBM Common Public
License along with this library
*/
#endregion

#if UNITTEST && WINDOWS

using System;
using System.Collections.Generic;
using System.Globalization;

using Microsoft.Win32;

using NUnit.Framework;

namespace Nuclex.Support.Settings {

  /// <summary>Unit tests for the windows registry settings store</summary>
  [TestFixture]
  internal class WindowsRegistryStoreTest {

    #region class TestContext

    /// <summary>Sets up a temporary registry key for the unit test</summary>
    private class TestContext : IDisposable {

      /// <summary>Initializes a new test context</summary>
      public TestContext() {
        this.keyName = Guid.NewGuid().ToString();
        this.registryKey = Registry.CurrentUser.CreateSubKey(this.keyName);
        this.store = new WindowsRegistryStore(this.registryKey, writable: true);
      }

      /// <summary>Immediately frees all resources owned by the test context</summary>
      public void Dispose() {
        if(this.store != null) {
          this.store.Dispose();
          this.store = null;
          this.registryKey = null;
        } else if(this.registryKey != null) {
          this.registryKey.Dispose();
          this.registryKey = null;
        }
        if(this.keyName != null) {
          Registry.CurrentUser.DeleteSubKeyTree(this.keyName);
          this.keyName = null;
        }
      }

      /// <summary>Store created on a temporary registry key</summary>
      public WindowsRegistryStore Store {
        get { return this.store; }
      }

      /// <summary>Name of the temporary registry key</summary>
      private string keyName;
      /// <summary>Registry key (ownership transfered to the store)</summary>
      private RegistryKey registryKey;
      /// <summary>Store that is accessing the registry key</summary>
      private WindowsRegistryStore store;

    }

    #endregion // class TestContext

    /// <summary>Verifies that new instances of the registry store can be created</summary>
    [Test]
    public void CanBeCreated() {
      Assert.That(
        () => { using(var context = new TestContext()) { } }, Throws.Nothing
      );
    }

    /// <summary>Verifies that new instances of the registry store can be created</summary>
    [Test]
    public void RegistryHivesCanBeOpened() {
      Assert.That(
        () => {
          using(
            var store = new WindowsRegistryStore(
              RegistryHive.LocalMachine, "SOFTWARE", writable: false
            )
          ) { }
        },
        Throws.Nothing
      );
    }

    /// <summary>Verifies that booleans can be stored in the registry</summary>
    [Test]
    public void BooleansCanBeStored() {
      using(var context = new TestContext()) {
        context.Store.Set(null, "test", true);
        Assert.That(context.Store.Get<bool>(null, "test"), Is.True);

        context.Store.Set(null, "test", false);
        Assert.That(context.Store.Get<bool>(null, "test"), Is.False);
      }
    }

    /// <summary>Verifies that integers can be stored in the registry</summary>
    [Test]
    public void IntegersCanBeStored() {
      using(var context = new TestContext()) {
        context.Store.Set(null, "test", 123);
        Assert.That(context.Store.Get<int>(null, "test"), Is.EqualTo(123));

        context.Store.Set(null, "test", 456);
        Assert.That(context.Store.Get<int>(null, "test"), Is.EqualTo(456));
      }
    }

    /// <summary>Verifies that floats can be stored in the registry</summary>
    [Test]
    public void FloatsCanBeStored() {
      float testValue = float.Parse("123.456", CultureInfo.InvariantCulture);

      using(var context = new TestContext()) {
        context.Store.Set(null, "test", testValue);
        Assert.That(context.Store.Get<float>(null, "test"), Is.EqualTo(testValue));

        testValue = float.Parse("654.321", CultureInfo.InvariantCulture);

        context.Store.Set(null, "test", testValue);
        Assert.That(context.Store.Get<float>(null, "test"), Is.EqualTo(testValue));
      }
    }

    /// <summary>Verifies that strings can be stored in the registry</summary>
    [Test]
    public void StringsCanBeStored() {
      using(var context = new TestContext()) {
        context.Store.Set(null, "test", "hello world");
        Assert.That(context.Store.Get<string>(null, "test"), Is.EqualTo("hello world"));

        context.Store.Set(null, "test", "world hello");
        Assert.That(context.Store.Get<string>(null, "test"), Is.EqualTo("world hello"));
      }
    }

    /// <summary>Verifies that long integers can be stored in the registry</summary>
    [Test]
    public void LongIntegersCanBeStored() {
      using(var context = new TestContext()) {
        context.Store.Set(null, "test", long.MaxValue);
        Assert.That(context.Store.Get<long>(null, "test"), Is.EqualTo(long.MaxValue));

        context.Store.Set(null, "test", long.MinValue);
        Assert.That(context.Store.Get<long>(null, "test"), Is.EqualTo(long.MinValue));
      }
    }

    /// <summary>Verifies that string arrays can be stored in the registry</summary>
    [Test]
    public void StringArraysCanBeStored() {
      string[] english = new string[] { "one", "two", "three" };
      string[] german = new string[] { "eins", "zwei", "drei" };

      using(var context = new TestContext()) {
        context.Store.Set(null, "test", english);
        Assert.That(context.Store.Get<string[]>(null, "test"), Is.EquivalentTo(english));

        context.Store.Set(null, "test", german);
        Assert.That(context.Store.Get<string[]>(null, "test"), Is.EquivalentTo(german));
      }
    }

    /// <summary>Verifies that byte arrays can be stored in the registry</summary>
    [Test]
    public void ByteArraysCanBeStored() {
      byte[] ascending = new byte[] { 1, 2, 3 };
      byte[] descending = new byte[] { 9, 8, 7 };

      using(var context = new TestContext()) {
        context.Store.Set(null, "test", ascending);
        Assert.That(context.Store.Get<byte[]>(null, "test"), Is.EquivalentTo(ascending));

        context.Store.Set(null, "test", descending);
        Assert.That(context.Store.Get<byte[]>(null, "test"), Is.EquivalentTo(descending));
      }
    }

    /// <summary>Verifies that strings can be stored in the registry</summary>
    [Test]
    public void ValuesCanBeStoredInCategories() {
      using(var context = new TestContext()) {
        context.Store.Set("main", "test", "hello world");

        string value;
        Assert.That(context.Store.TryGet<string>(null, "test", out value), Is.False);
        Assert.That(context.Store.Get<string>("main", "test"), Is.EqualTo("hello world"));
      }
    }

    /// <summary>Verifies that the subkeys of a registry key can be enumerated</summary>
    [Test]
    public void CategoriesCanBeEnumerated() {
      string[] names = new string[] { "one", "two", "three" };

      using(var context = new TestContext()) {
        context.Store.Set(names[0], "sol", 21);
        context.Store.Set(names[1], "sol", 42);
        context.Store.Set(names[2], "sol", 84);

        Assert.That(context.Store.EnumerateCategories(), Is.EquivalentTo(names));
      }
    }

    /// <summary>Verifies that the values under a registry subkey can be enumerated</summary>
    [Test]
    public void OptionsInCategoryCanBeEnumerated() {
      string[] names = new string[] { "one", "two", "three" };

      using(var context = new TestContext()) {
        context.Store.Set("test", names[0], 1);
        context.Store.Set("test", names[1], 2);
        context.Store.Set("test", names[2], 3);

        var optionInfos = new List<OptionInfo>(context.Store.EnumerateOptions("test"));
        Assert.That(optionInfos.Count, Is.EqualTo(3));
      }
    }

    /// <summary>Verifies that the values under a registry key can be enumerated</summary>
    [Test]
    public void RootOptionsCanBeEnumerated() {
      string[] names = new string[] { "one", "two", "three" };

      using(var context = new TestContext()) {
        context.Store.Set(null, names[0], 1);
        context.Store.Set(null, names[1], 2);
        context.Store.Set(null, names[2], 3);

        var optionInfos = new List<OptionInfo>(context.Store.EnumerateOptions(null));
        Assert.That(optionInfos.Count, Is.EqualTo(3));

        string[] actualNames = new string[] {
          optionInfos[0].Name, optionInfos[1].Name, optionInfos[2].Name
        };
        Assert.That(actualNames, Is.EquivalentTo(names));
      }
    }

    /// <summary>
    ///   Verifies that accessing an option that doesn't exist throws an exception
    /// </summary>
    [Test]
    public void AccessingNonExistingOptionThrowsException() {
      using(var context = new TestContext()) {
        Assert.That(
          () => context.Store.Get<string>(null, "doesn't exist"),
          Throws.Exception.AssignableTo<KeyNotFoundException>()
        );
      }
    }

    /// <summary>
    ///   Verifies that accessing a category that doesn't exist throws an exception
    /// </summary>
    [Test]
    public void AccessingNonExistingCategoryThrowsException() {
      using(var context = new TestContext()) {
        Assert.That(
          () => context.Store.Get<string>("doesn't exist", "test"),
          Throws.Exception.AssignableTo<KeyNotFoundException>()
        );
      }
    }

    /// <summary>
    ///   Verifies that values can be removed from a registry key
    /// </summary>
    [Test]
    public void ValuesCanBeRemovedFromRoot() {
      using(var context = new TestContext()) {
        context.Store.Set(null, "nothing", "short-lived");
        Assert.That(context.Store.Remove(null, "nothing"), Is.True);
        Assert.That(context.Store.Remove(null, "nothing"), Is.False);

        Assert.That(context.Store.EnumerateOptions(), Is.Empty);
      }
    }

    /// <summary>
    ///   Verifies that values can be removed from the subkey of a registry key
    /// </summary>
    [Test]
    public void ValuesCanBeRemovedFromCategory() {
      using(var context = new TestContext()) {
        context.Store.Set("limbo", "nothing", "short-lived");
        Assert.That(context.Store.Remove("limbo", "nothing"), Is.True);
        Assert.That(context.Store.Remove("limbo", "nothing"), Is.False);

        Assert.That(context.Store.EnumerateOptions("limbo"), Is.Empty);
      }
    }

    /// <summary>
    ///   Verifies that values can be removed from a non-existing subkey without
    ///   causing an error
    /// </summary>
    [Test]
    public void RemovingValueFromNonExistingCategoryCanBeHandled() {
      using(var context = new TestContext()) {
        Assert.That(context.Store.Remove("empty", "nothing"), Is.False);
      }
    }

    /// <summary>
    ///   Verifies that the store identifies the types of values stored in
    ///   a registry when they are enumerated
    /// </summary>
    [Test]
    public void ValueTypesAreIdentifiedWhenEnumerating() {
      Type[] types = new Type[] {
        typeof(int),
        typeof(long),
        typeof(byte[]),
        typeof(string),
        typeof(string[])
      };
      using(var context = new TestContext()) {
        context.Store.Set<int>(null, "0", 123);
        context.Store.Set<long>(null, "1", 456L);
        context.Store.Set<byte[]>(null, "2", new byte[] { 7, 8, 9 });
        context.Store.Set<string>(null, "3", "text");
        context.Store.Set<string[]>(null, "4", new string[] { "many", "words" });

        var optionInfos = new List<OptionInfo>(context.Store.EnumerateOptions());
        for(int index = 0; index < optionInfos.Count; ++index) {
          int typeIndex = int.Parse(optionInfos[index].Name);
          Assert.That(optionInfos[index].OptionType, Is.EqualTo(types[typeIndex]));
        }
      }
    }

  }

} // namespace Nuclex.Support.Settings

#endif // UNITTEST