// Copyright (c) .NET Foundation. All rights reserved.
// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Analyzer.Testing;
using Microsoft.AspNetCore.Mvc.Analyzers.Infrastructure;
using Microsoft.CodeAnalysis;
using Xunit;

namespace Microsoft.AspNetCore.Mvc.Analyzers
{
    public class MvcFactsTest
    {
        private static readonly string ControllerAttribute = typeof(ControllerAttribute).FullName;
        private static readonly string NonControllerAttribute = typeof(NonControllerAttribute).FullName;
        private static readonly string NonActionAttribute = typeof(NonActionAttribute).FullName;
        private static readonly Type TestIsControllerActionType = typeof(TestIsControllerAction);

        #region IsController
        [Fact]
        public Task IsController_ReturnsFalseForInterfaces() => IsControllerReturnsFalse(typeof(ITestController));

        [Fact]
        public Task IsController_ReturnsFalseForAbstractTypes() => IsControllerReturnsFalse(typeof(AbstractController));

        [Fact]
        public Task IsController_ReturnsFalseForValueType() => IsControllerReturnsFalse(typeof(ValueTypeController));

        [Fact]
        public Task IsController_ReturnsFalseForGenericType() => IsControllerReturnsFalse(typeof(OpenGenericController<>));

        [Fact]
        public Task IsController_ReturnsFalseForPocoType() => IsControllerReturnsFalse(typeof(PocoType));

        [Fact]
        public Task IsController_ReturnsFalseForTypeDerivedFromPocoType() => IsControllerReturnsFalse(typeof(DerivedPocoType));

        [Fact]
        public Task IsController_ReturnsTrueForTypeDerivingFromController() => IsControllerReturnsTrue(typeof(TypeDerivingFromController));

        [Fact]
        public Task IsController_ReturnsTrueForTypeDerivingFromControllerBase() => IsControllerReturnsTrue(typeof(TypeDerivingFromControllerBase));

        [Fact]
        public Task IsController_ReturnsTrueForTypeDerivingFromController_WithoutSuffix() => IsControllerReturnsTrue(typeof(NoSuffix));

        [Fact]
        public Task IsController_ReturnsTrueForTypeWithSuffix_ThatIsNotDerivedFromController() => IsControllerReturnsTrue(typeof(PocoController));

        [Fact]
        public Task IsController_ReturnsTrueForTypeWithoutSuffix_WithControllerAttribute() => IsControllerReturnsTrue(typeof(CustomBase));

        [Fact]
        public Task IsController_ReturnsTrueForTypeDerivingFromCustomBaseThatHasControllerAttribute() => IsControllerReturnsTrue(typeof(ChildOfCustomBase));

        [Fact]
        public Task IsController_ReturnsFalseForTypeWithNonControllerAttribute() => IsControllerReturnsFalse(typeof(BaseNonController));

        [Fact]
        public Task IsController_ReturnsFalseForTypesDerivingFromTypeWithNonControllerAttribute() => IsControllerReturnsFalse(typeof(BasePocoNonControllerChildController));

        [Fact]
        public Task IsController_ReturnsFalseForTypesDerivingFromTypeWithNonControllerAttributeWithControllerAttribute() =>
            IsControllerReturnsFalse(typeof(ControllerAttributeDerivingFromNonController));

        private async Task IsControllerReturnsFalse(Type type)
        {
            var compilation = await GetIsControllerCompilation();
            var controllerAttribute = compilation.GetTypeByMetadataName(ControllerAttribute);
            var nonControllerAttribute = compilation.GetTypeByMetadataName(NonControllerAttribute);
            var typeSymbol = compilation.GetTypeByMetadataName(type.FullName);

            // Act
            var isController = MvcFacts.IsController(typeSymbol, controllerAttribute, nonControllerAttribute);

            // Assert
            Assert.False(isController);
        }

        private async Task IsControllerReturnsTrue(Type type)
        {
            var compilation = await GetIsControllerCompilation();
            var controllerAttribute = compilation.GetTypeByMetadataName(ControllerAttribute);
            var nonControllerAttribute = compilation.GetTypeByMetadataName(NonControllerAttribute);
            var typeSymbol = compilation.GetTypeByMetadataName(type.FullName);

            // Act
            var isController = MvcFacts.IsController(typeSymbol, controllerAttribute, nonControllerAttribute);

            // Assert
            Assert.True(isController);
        }

        #endregion

        #region IsControllerAction
        [Fact]
        public Task IsAction_ReturnsFalseForConstructor() => IsActionReturnsFalse(TestIsControllerActionType, ".ctor");

        [Fact]
        public Task IsAction_ReturnsFalseForStaticConstructor() => IsActionReturnsFalse(TestIsControllerActionType, ".cctor");

        [Fact]
        public Task IsAction_ReturnsFalseForPrivateMethod() => IsActionReturnsFalse(TestIsControllerActionType, "PrivateMethod");

        [Fact]
        public Task IsAction_ReturnsFalseForProtectedMethod() => IsActionReturnsFalse(TestIsControllerActionType, "ProtectedMethod");

        [Fact]
        public Task IsAction_ReturnsFalseForInternalMethod() => IsActionReturnsFalse(TestIsControllerActionType, nameof(TestIsControllerAction.InternalMethod));

        [Fact]
        public Task IsAction_ReturnsFalseForGenericMethod() => IsActionReturnsFalse(TestIsControllerActionType, nameof(TestIsControllerAction.GenericMethod));

        [Fact]
        public Task IsAction_ReturnsFalseForStaticMethod() => IsActionReturnsFalse(TestIsControllerActionType, nameof(TestIsControllerAction.StaticMethod));

        [Fact]
        public Task IsAction_ReturnsFalseForNonActionMethod() => IsActionReturnsFalse(TestIsControllerActionType, nameof(TestIsControllerAction.NonAction));

        [Fact]
        public Task IsAction_ReturnsFalseForOverriddenNonActionMethod() => IsActionReturnsFalse(TestIsControllerActionType, nameof(TestIsControllerAction.NonActionBase));

        [Fact]
        public Task IsAction_ReturnsFalseForDisposableDispose() => IsActionReturnsFalse(TestIsControllerActionType, nameof(TestIsControllerAction.Dispose));

        [Fact]
        public Task IsAction_ReturnsFalseForExplicitDisposableDispose() => IsActionReturnsFalse(typeof(ExplicitIDisposable), "System.IDisposable.Dispose");

        [Fact]
        public Task IsAction_ReturnsFalseForAbstractMethods() => IsActionReturnsFalse(typeof(TestIsControllerActionBase), nameof(TestIsControllerActionBase.AbstractMethod));

        [Fact]
        public Task IsAction_ReturnsFalseForObjectEquals() => IsActionReturnsFalse(typeof(object), nameof(object.Equals));

        [Fact]
        public Task IsAction_ReturnsFalseForObjectHashCode() => IsActionReturnsFalse(typeof(object), nameof(object.GetHashCode));

        [Fact]
        public Task IsAction_ReturnsFalseForObjectToString() => IsActionReturnsFalse(typeof(object), nameof(object.ToString));

        [Fact]
        public Task IsAction_ReturnsFalseForOverriddenObjectEquals() =>
            IsActionReturnsFalse(typeof(OverridesObjectMethods), nameof(OverridesObjectMethods.Equals));

        [Fact]
        public Task IsAction_ReturnsFalseForOverriddenObjectHashCode() =>
            IsActionReturnsFalse(typeof(OverridesObjectMethods), nameof(OverridesObjectMethods.GetHashCode));

        private async Task IsActionReturnsFalse(Type type, string methodName)
        {
            var compilation = await GetIsControllerActionCompilation();
            var nonActionAttribute = compilation.GetTypeByMetadataName(NonActionAttribute);
            var disposableDispose = GetDisposableDispose(compilation);
            var typeSymbol = compilation.GetTypeByMetadataName(type.FullName);
            var method = (IMethodSymbol)typeSymbol.GetMembers(methodName).First();

            // Act
            var isControllerAction = MvcFacts.IsControllerAction(method, nonActionAttribute, disposableDispose);

            // Assert
            Assert.False(isControllerAction);
        }

        [Fact]
        public Task IsAction_ReturnsTrueForNewMethodsOfObject() => IsActionReturnsTrue(typeof(OverridesObjectMethods), nameof(OverridesObjectMethods.ToString));

        [Fact]
        public Task IsAction_ReturnsTrueForNotDisposableDispose() => IsActionReturnsTrue(typeof(NotDisposable), nameof(NotDisposable.Dispose));

        [Fact]
        public Task IsAction_ReturnsTrueForNotDisposableDisposeOnTypeWithExplicitImplementation() =>
            IsActionReturnsTrue(typeof(NotDisposableWithExplicitImplementation), nameof(NotDisposableWithExplicitImplementation.Dispose));

        [Fact]
        public Task IsAction_ReturnsTrueForOrdinaryAction() => IsActionReturnsTrue(TestIsControllerActionType, nameof(TestIsControllerAction.Ordinary));

        [Fact]
        public Task IsAction_ReturnsTrueForOverriddenMethod() => IsActionReturnsTrue(TestIsControllerActionType, nameof(TestIsControllerAction.AbstractMethod));

        [Fact]
        public async Task IsAction_ReturnsTrueForNotDisposableDisposeOnTypeWithImplicitImplementation()
        {
            var compilation = await GetIsControllerActionCompilation();
            var nonActionAttribute = compilation.GetTypeByMetadataName(NonActionAttribute);
            var disposableDispose = GetDisposableDispose(compilation);
            var typeSymbol = compilation.GetTypeByMetadataName(typeof(NotDisposableWithDisposeThatIsNotInterfaceContract).FullName);
            var method = typeSymbol.GetMembers(nameof(IDisposable.Dispose)).OfType<IMethodSymbol>().First(f => !f.ReturnsVoid);

            // Act
            var isControllerAction = MvcFacts.IsControllerAction(method, nonActionAttribute, disposableDispose);

            // Assert
            Assert.True(isControllerAction);
        }

        private async Task IsActionReturnsTrue(Type type, string methodName)
        {
            var compilation = await GetIsControllerActionCompilation();
            var nonActionAttribute = compilation.GetTypeByMetadataName(NonActionAttribute);
            var disposableDispose = GetDisposableDispose(compilation);
            var typeSymbol = compilation.GetTypeByMetadataName(type.FullName);
            var method = (IMethodSymbol)typeSymbol.GetMembers(methodName).First();

            // Act
            var isControllerAction = MvcFacts.IsControllerAction(method, nonActionAttribute, disposableDispose);

            // Assert
            Assert.True(isControllerAction);
        }

        private IMethodSymbol GetDisposableDispose(Compilation compilation)
        {
            var type = compilation.GetSpecialType(SpecialType.System_IDisposable);
            return (IMethodSymbol)type.GetMembers(nameof(IDisposable.Dispose)).First();
        }
        #endregion


        private Task<Compilation> GetIsControllerCompilation() => GetCompilation("IsControllerTests");

        private Task<Compilation> GetIsControllerActionCompilation() => GetCompilation("IsControllerActionTests");

        private Task<Compilation> GetCompilation(string test)
        {
            var testSource = MvcTestSource.Read(GetType().Name, test);
            var project = DiagnosticProject.Create(GetType().Assembly, new[] { testSource.Source });

            return project.GetCompilationAsync();
        }
    }
}