// <copyright file="ComposableAttributeTests.cs" company="MUnique">
// Licensed under the MIT License. See LICENSE file in the project root for full license information.
// </copyright>

namespace MUnique.OpenMU.AttributeSystem.Tests;

/// <summary>
/// Tests for the <see cref="ComposableAttribute"/>.
/// </summary>
[TestFixture]
public class ComposableAttributeTests
{
    private ComposableAttribute _composableAttribute = null!;

    /// <summary>
    /// Sets up each test case.
    /// </summary>
    [SetUp]
    public void Setup()
    {
        var attributeDefinition = new AttributeDefinition(new Guid("52263EA9-F309-475D-B10B-352D3BFD7650"), "Test attribute", "Test attribute");
        this._composableAttribute = new ComposableAttribute(attributeDefinition);
    }

    /// <summary>
    /// Tests if the value is 0 after creation.
    /// </summary>
    [Test]
    public void ValueIsNullAfterCreation()
    {
        Assert.That(this._composableAttribute.Value, Is.EqualTo(0));
    }

    /// <summary>
    /// Tests if the value is updated after adding an element.
    /// </summary>
    [Test]
    public void ValueAfterAddedElement()
    {
        var element = new ConstantElement(4711);
        this._composableAttribute.AddElement(element);
        Assert.That(this._composableAttribute.Value, Is.EqualTo(element.Value));
    }

    /// <summary>
    /// Tests if the value of multiple elements is combined in <see cref="ComposableAttribute.Value"/> by using <see cref="AggregateType.AddRaw"/>.
    /// </summary>
    [Test]
    public void ValueOfMultipleRawElements()
    {
        var element1 = new ConstantElement(3000);
        var element2 = new ConstantElement(5000);
        this._composableAttribute.AddElement(element1);
        this._composableAttribute.AddElement(element2);
        Assert.That(this._composableAttribute.Value, Is.EqualTo(element1.Value + element2.Value));
    }

    /// <summary>
    /// Tests if the value of multiple elements is combined in <see cref="ComposableAttribute.Value"/>
    /// by using <see cref="AggregateType.AddRaw"/> in the first element and
    /// by using <see cref="AggregateType.Multiplicate"/> in the second element.
    /// </summary>
    [Test]
    public void ValueWithRawAndMultiplierElements()
    {
        var element1 = new ConstantElement(3000);
        var element2 = new SimpleElement { Value = 5, AggregateType = AggregateType.Multiplicate };
        this._composableAttribute.AddElement(element1);
        this._composableAttribute.AddElement(element2);
        Assert.That(this._composableAttribute.Value, Is.EqualTo(element1.Value * element2.Value));
    }

    /// <summary>
    /// Tests if the value of multiple elements is combined in <see cref="ComposableAttribute.Value"/>
    /// by using <see cref="AggregateType.AddRaw"/> in the first element,
    /// by using <see cref="AggregateType.Multiplicate"/> in the second element and
    /// by using <see cref="AggregateType.AddFinal"/> in the last element.
    /// </summary>
    [Test]
    public void ValueWithRawMultiplierAndFinalElements()
    {
        var element1 = new ConstantElement(3000);
        var element2 = new SimpleElement { Value = 5, AggregateType = AggregateType.Multiplicate };
        var element3 = new SimpleElement { Value = 1000, AggregateType = AggregateType.AddFinal };
        this._composableAttribute.AddElement(element1);
        this._composableAttribute.AddElement(element2);
        this._composableAttribute.AddElement(element3);
        Assert.That(this._composableAttribute.Value, Is.EqualTo((element1.Value * element2.Value) + element3.Value));
    }

    /// <summary>
    /// Tests if the value of multiple elements is combined in <see cref="ComposableAttribute.Value"/>
    /// by using one <see cref="AggregateType.AddRaw"/> element and
    /// by using several <see cref="AggregateType.Maximum"/> elements.
    /// </summary>
    [Test]
    public void ValueWithRawAndMultipleMaximumElements()
    {
        var element1 = new ConstantElement(3000);
        var element2 = new SimpleElement { Value = 5, AggregateType = AggregateType.Maximum };
        var element3 = new SimpleElement { Value = 1000, AggregateType = AggregateType.Maximum };
        this._composableAttribute.AddElement(element1);
        this._composableAttribute.AddElement(element2);
        this._composableAttribute.AddElement(element3);
        Assert.That(this._composableAttribute.Value, Is.EqualTo(element1.Value + Math.Max(element2.Value, element3.Value)));
    }

    /// <summary>
    /// Tests if the value of multiple elements is combined in <see cref="ComposableAttribute.Value"/>
    /// by using <see cref="AggregateType.Multiplicate"/> elements exclusively.
    /// A <see cref="AggregateType.AddRaw"/> element of value 1 should be assumed.
    /// </summary>
    [Test]
    public void ValueWithMultiplierElementsOnly()
    {
        var element1 = new SimpleElement { Value = 5, AggregateType = AggregateType.Multiplicate };
        var element2 = new SimpleElement { Value = 1000, AggregateType = AggregateType.Multiplicate };
        this._composableAttribute.AddElement(element1);
        this._composableAttribute.AddElement(element2);
        Assert.That(this._composableAttribute.Value, Is.EqualTo(element1.Value * element2.Value));
    }

    /// <summary>
    /// Tests if the value of multiple elements is combined in <see cref="ComposableAttribute.Value"/>
    /// by using <see cref="AggregateType.Multiplicate"/> in the first element and
    /// by using <see cref="AggregateType.AddFinal"/> in the second element.
    /// </summary>
    [Test]
    public void ValueWithMultiplierAndFinalElements()
    {
        var element1 = new SimpleElement { Value = 5, AggregateType = AggregateType.Multiplicate };
        var element2 = new SimpleElement { Value = 1000, AggregateType = AggregateType.AddFinal };
        this._composableAttribute.AddElement(element1);
        this._composableAttribute.AddElement(element2);
        Assert.That(this._composableAttribute.Value, Is.EqualTo(1000));
    }

    /// <summary>
    /// Tests if the updated correctly after an element got removed.
    /// </summary>
    [Test]
    public void ValueCorrectAfterElementRemoved()
    {
        var element1 = new ConstantElement(3000);
        var element2 = new SimpleElement { Value = 5, AggregateType = AggregateType.Multiplicate };
        var element3 = new SimpleElement { Value = 1000, AggregateType = AggregateType.AddFinal };
        this._composableAttribute.AddElement(element1);
        this._composableAttribute.AddElement(element2);
        this._composableAttribute.AddElement(element3);
        Assert.That(this._composableAttribute.Value, Is.EqualTo((element1.Value * element2.Value) + element3.Value));
        this._composableAttribute.RemoveElement(element2);
        Assert.That(this._composableAttribute.Value, Is.EqualTo(element1.Value + element3.Value));
    }

    /// <summary>
    /// Tests if the <see cref="BaseAttribute.ValueChanged"/> is called when the depending element value changed.
    /// </summary>
    [Test]
    public void ValueChangedEvent()
    {
        var element = new SimpleElement { Value = 5 };
        this._composableAttribute.AddElement(element);

        var eventCalled = false;
        this._composableAttribute.ValueChanged += (_, _) => eventCalled = true;
        element.Value = 6;

        Assert.That(eventCalled, Is.True);
    }

    /// <summary>
    /// Tests if the <see cref="BaseAttribute.ValueChanged"/> is called when a new depending element was added.
    /// </summary>
    [Test]
    public void ValueChangedEventWhenElementAdded()
    {
        var element = new SimpleElement { Value = 5 };
        bool eventCalled = false;
        this._composableAttribute.ValueChanged += (_, _) => eventCalled = true;
        this._composableAttribute.AddElement(element);
        Assert.That(eventCalled, Is.True);
    }

    /// <summary>
    /// Tests if the <see cref="BaseAttribute.ValueChanged"/> is called when a new depending element was removed.
    /// </summary>
    [Test]
    public void ValueChangedEventWhenElementRemoved()
    {
        var element = new SimpleElement { Value = 5 };
        this._composableAttribute.AddElement(element);

        bool eventCalled = false;
        this._composableAttribute.ValueChanged += (_, _) => eventCalled = true;
        this._composableAttribute.RemoveElement(element);
        Assert.That(eventCalled, Is.True);
    }
}