using NUnit.Framework;
using FluentAssertions;

using Encompass;
using System.Collections.Generic;
using System;
using System.Linq;

namespace Tests
{
    public class ComponentTests
    {
        struct MockComponent : IComponent
        {
            public string myString;
            public int myInt;
        }

        struct EntityMessage : IMessage
        {
            public Entity entity;
        }

        static IEnumerable<(Guid, MockComponent)> gottenMockComponentIDPairs = Enumerable.Empty<(Guid, MockComponent)>();
        static (Guid, MockComponent) gottenMockComponentIDPair;

        [Reads(typeof(EntityMessage), typeof(MockComponent))]
        class GetMockComponentsEngine : Engine
        {
            public override void Update(double dt)
            {
                gottenMockComponentIDPairs = Enumerable.Empty<(Guid, MockComponent)>();

                foreach (var entityMessage in ReadMessages<EntityMessage>())
                {
                    gottenMockComponentIDPairs = GetComponents<MockComponent>(entityMessage.entity);
                }
            }
        }

        [Reads(typeof(EntityMessage), typeof(MockComponent))]
        class GetMockComponentEngine : Engine
        {
            public override void Update(double dt)
            {
                foreach (var entityMessage in ReadMessages<EntityMessage>())
                {
                    gottenMockComponentIDPair = GetComponent<MockComponent>(entityMessage.entity);
                }
            }
        }

        struct AddComponentTestMessage : IMessage
        {
            public Entity entity;
            public MockComponent mockComponent;
        }

        [Reads(typeof(AddComponentTestMessage), typeof(MockComponent))]
        class AddComponentEngine : Engine
        {
            public override void Update(double dt)
            {
                foreach (var addComponentTestMessage in ReadMessages<AddComponentTestMessage>())
                {
                    Assert.IsTrue(HasComponent<MockComponent>(addComponentTestMessage.entity));
                    Assert.That(GetComponent<MockComponent>(addComponentTestMessage.entity).Item2, Is.EqualTo(addComponentTestMessage.mockComponent));
                }
            }
        }

        [Test]
        public void AddComponent()
        {
            var worldBuilder = new WorldBuilder();
            worldBuilder.AddEngine(new AddComponentEngine());
            worldBuilder.AddEngine(new GetMockComponentEngine());

            var entity = worldBuilder.CreateEntity();

            MockComponent mockComponent;
            mockComponent.myInt = 3;
            mockComponent.myString = "hello";

            worldBuilder.AddComponent(entity, mockComponent);

            AddComponentTestMessage addComponentTestMessage;
            addComponentTestMessage.entity = entity;
            addComponentTestMessage.mockComponent = mockComponent;
            worldBuilder.EmitMessage(addComponentTestMessage);

            var world = worldBuilder.Build();

            world.Update(0.01);
        }

        [Test]
        public void GetComponents()
        {
            var worldBuilder = new WorldBuilder();
            worldBuilder.AddEngine(new GetMockComponentsEngine());

            var entity = worldBuilder.CreateEntity();

            MockComponent mockComponentA;
            mockComponentA.myInt = 3;
            mockComponentA.myString = "hello";

            MockComponent mockComponentB;
            mockComponentB.myInt = 5;
            mockComponentB.myString = "wassup";

            MockComponent mockComponentC;
            mockComponentC.myInt = 1;
            mockComponentC.myString = "howdy";

            var componentAID = worldBuilder.AddComponent(entity, mockComponentA);
            var componentBID = worldBuilder.AddComponent(entity, mockComponentB);
            var componentCID = worldBuilder.AddComponent(entity, mockComponentC);

            EntityMessage entityMessage;
            entityMessage.entity = entity;
            worldBuilder.EmitMessage(entityMessage);

            var world = worldBuilder.Build();

            world.Update(0.01);

            gottenMockComponentIDPairs.Should().Contain((componentAID, mockComponentA));
            gottenMockComponentIDPairs.Should().Contain((componentBID, mockComponentB));
            gottenMockComponentIDPairs.Should().Contain((componentCID, mockComponentC));
        }

        [Test]
        public void GetComponent()
        {
            var worldBuilder = new WorldBuilder();
            worldBuilder.AddEngine(new GetMockComponentEngine());

            var entity = worldBuilder.CreateEntity();

            MockComponent mockComponent;
            mockComponent.myInt = 3;
            mockComponent.myString = "hello";

            var componentID = worldBuilder.AddComponent<MockComponent>(entity, mockComponent);

            EntityMessage entityMessage;
            entityMessage.entity = entity;
            worldBuilder.EmitMessage(entityMessage);

            var world = worldBuilder.Build();

            world.Update(0.01);

            Assert.AreEqual((componentID, mockComponent), gottenMockComponentIDPair);
        }

        struct HasComponentTestMessage : IMessage
        {
            public Entity entity;
        }

        [Reads(typeof(HasComponentTestMessage), typeof(MockComponent))]
        class HasComponentTestEngine : Engine
        {
            public override void Update(double dt)
            {
                foreach (var hasComponentTestEngine in ReadMessages<HasComponentTestMessage>())
                {
                    Assert.IsTrue(HasComponent<MockComponent>(hasComponentTestEngine.entity));
                }
            }
        }

        [Test]
        public void HasComponent()
        {
            var worldBuilder = new WorldBuilder();
            worldBuilder.AddEngine(new HasComponentTestEngine());

            var entity = worldBuilder.CreateEntity();

            MockComponent mockComponent;
            mockComponent.myInt = 3;
            mockComponent.myString = "hello";

            worldBuilder.AddComponent(entity, mockComponent);

            HasComponentTestMessage hasComponentTestMessage;
            hasComponentTestMessage.entity = entity;
            worldBuilder.EmitMessage(hasComponentTestMessage);

            var world = worldBuilder.Build();

            world.Update(0.01);
        }

        struct HasComponentWhenInactiveTestMessage : IMessage
        {
            public Entity entity;
        }

        [Reads(typeof(HasComponentWhenInactiveTestMessage), typeof(MockComponent))]
        class HasComponentWhenInactiveTestEngine : Engine
        {
            public override void Update(double dt)
            {
                foreach (var hasComponentTestEngine in ReadMessages<HasComponentWhenInactiveTestMessage>())
                {
                    Assert.IsFalse(HasComponent<MockComponent>(hasComponentTestEngine.entity));
                }
            }
        }

        [Test]
        public void HasComponentWhenInactive()
        {
            var worldBuilder = new WorldBuilder();
            worldBuilder.AddEngine(new HasComponentWhenInactiveTestEngine());
            var entity = worldBuilder.CreateEntity();
            
            MockComponent mockComponent;
            mockComponent.myInt = 3;
            mockComponent.myString = "hello";

            var componentID = worldBuilder.AddComponent(entity, mockComponent);

            HasComponentWhenInactiveTestMessage testMessage;
            testMessage.entity = entity;
            worldBuilder.EmitMessage(testMessage);

            worldBuilder.DeactivateComponent(componentID);

            var world = worldBuilder.Build();

            world.Update(0.01f);
        }

        struct RemoveComponentTestMessage : IMessage
        {
            public Entity entity;
            public Guid componentID;
        }

        [Reads(typeof(RemoveComponentTestMessage), typeof(MockComponent))]
        [Writes(typeof(MockComponent))]
        class RemoveComponentTestEngine : Engine
        {
            public override void Update(double dt)
            {
                foreach (var removeComponentMessage in ReadMessages<RemoveComponentTestMessage>())
                {
                    RemoveComponent(removeComponentMessage.componentID);

                    Assert.IsFalse(HasComponent<MockComponent>(removeComponentMessage.entity));
                    Assert.IsEmpty(GetComponents<MockComponent>(removeComponentMessage.entity));
                }
            }
        }

        [Test]
        public void RemoveComponent()
        {
            var worldBuilder = new WorldBuilder();
            worldBuilder.AddEngine(new RemoveComponentTestEngine());

            var entity = worldBuilder.CreateEntity();

            MockComponent mockComponent;
            mockComponent.myInt = 3;
            mockComponent.myString = "hello";

            var componentID = worldBuilder.AddComponent(entity, mockComponent);

            RemoveComponentTestMessage removeComponentMessage;
            removeComponentMessage.entity = entity;
            removeComponentMessage.componentID = componentID;
            worldBuilder.EmitMessage(removeComponentMessage);

            var world = worldBuilder.Build();


            world.Update(0.01f);
        }

        struct ActivateComponentMessage : IMessage
        {
            public Entity entity;
            public Guid componentID;
        }

        [Reads(typeof(ActivateComponentMessage), typeof(MockComponent))]
        [Writes(typeof(MockComponent))]
        class ActivateComponentEngine : Engine
        {
            public override void Update(double dt)
            {
                foreach (var activateComponentMessage in ReadMessages<ActivateComponentMessage>())
                {
                    ActivateComponent(activateComponentMessage.componentID);
                    Assert.IsTrue(HasComponent<MockComponent>(activateComponentMessage.entity));
                }
            }
        }

        [Test]
        public void ActivateComponent()
        {
            var worldBuilder = new WorldBuilder();
            worldBuilder.AddEngine(new ActivateComponentEngine());

            var entity = worldBuilder.CreateEntity();

            MockComponent mockComponent;
            mockComponent.myInt = 3;
            mockComponent.myString = "hello";

            var componentID = worldBuilder.AddComponent(entity, mockComponent);

            worldBuilder.DeactivateComponent(componentID);

            ActivateComponentMessage activateMessage;
            activateMessage.entity = entity;
            activateMessage.componentID = componentID;
            worldBuilder.EmitMessage(activateMessage);

            var world = worldBuilder.Build();

            world.Update(0.01f);
        }

        struct DeactivateComponentMessage : IMessage
        {
            public Entity entity;
            public Guid componentID;
        }

        [Reads(typeof(DeactivateComponentMessage), typeof(MockComponent))]
        [Writes(typeof(MockComponent))]
        class DeactivateComponentEngine : Engine
        {
            public override void Update(double dt)
            {
                foreach (var deactivateComponentMessage in ReadMessages<DeactivateComponentMessage>())
                {
                    DeactivateComponent(deactivateComponentMessage.componentID);
                    Assert.IsFalse(HasComponent<MockComponent>(deactivateComponentMessage.entity));
                }
            }
        }

        [Test]
        public void DeactivateComponent()
        {
            var worldBuilder = new WorldBuilder();
            worldBuilder.AddEngine(new DeactivateComponentEngine());

            var entity = worldBuilder.CreateEntity();

            MockComponent mockComponent;
            mockComponent.myInt = 3;
            mockComponent.myString = "hello";

            var componentID = worldBuilder.AddComponent(entity, mockComponent);

            DeactivateComponentMessage deactivateComponentMessage;
            deactivateComponentMessage.entity = entity;
            deactivateComponentMessage.componentID = componentID;
            worldBuilder.EmitMessage(deactivateComponentMessage);

            var world = worldBuilder.Build();

            world.Update(0.01);
        }
    }
}