// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT license.
// See the LICENSE file in the project root for more information.
 
#nullable disable
 
using Microsoft.CodeAnalysis.CSharp.Symbols;
using Microsoft.CodeAnalysis.CSharp.UnitTests;
using Xunit;
 
namespace Microsoft.CodeAnalysis.CSharp.Semantic.UnitTests.Semantics
{
    public class ValueTupleTests : CompilingTestBase
    {
        [Fact]
        public void TestWellKnownMembersForValueTuple()
        {
            var source = @"
namespace System
{
    struct ValueTuple<T1>
    {
        public T1 Item1;
    }
    struct ValueTuple<T1, T2>
    {
        public T1 Item1;
        public T2 Item2;
    }
    struct ValueTuple<T1, T2, T3>
    {
        public T1 Item1;
        public T2 Item2;
        public T3 Item3;
    }
    struct ValueTuple<T1, T2, T3, T4>
    {
        public T1 Item1;
        public T2 Item2;
        public T3 Item3;
        public T4 Item4;
    }
    struct ValueTuple<T1, T2, T3, T4, T5>
    {
        public T1 Item1;
        public T2 Item2;
        public T3 Item3;
        public T4 Item4;
        public T5 Item5;
    }
    struct ValueTuple<T1, T2, T3, T4, T5, T6>
    {
        public T1 Item1;
        public T2 Item2;
        public T3 Item3;
        public T4 Item4;
        public T5 Item5;
        public T6 Item6;
    }
    struct ValueTuple<T1, T2, T3, T4, T5, T6, T7>
    {
        public T1 Item1;
        public T2 Item2;
        public T3 Item3;
        public T4 Item4;
        public T5 Item5;
        public T6 Item6;
        public T7 Item7;
    }
    struct ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>
    {
        public T1 Item1;
        public T2 Item2;
        public T3 Item3;
        public T4 Item4;
        public T5 Item5;
        public T6 Item6;
        public T7 Item7;
        public TRest Rest;
    }
}";
            var comp = CreateCompilation(source);
            Assert.Equal("T1 System.ValueTuple<T1>.Item1",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T1__Item1).ToTestDisplayString());
 
            Assert.Equal("T1 (T1, T2).Item1",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T2__Item1).ToTestDisplayString());
            Assert.Equal("T2 (T1, T2).Item2",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T2__Item2).ToTestDisplayString());
 
            Assert.Equal("T1 (T1, T2, T3).Item1",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T3__Item1).ToTestDisplayString());
            Assert.Equal("T2 (T1, T2, T3).Item2",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T3__Item2).ToTestDisplayString());
            Assert.Equal("T3 (T1, T2, T3).Item3",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T3__Item3).ToTestDisplayString());
 
            Assert.Equal("T1 (T1, T2, T3, T4).Item1",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T4__Item1).ToTestDisplayString());
            Assert.Equal("T2 (T1, T2, T3, T4).Item2",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T4__Item2).ToTestDisplayString());
            Assert.Equal("T3 (T1, T2, T3, T4).Item3",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T4__Item3).ToTestDisplayString());
            Assert.Equal("T4 (T1, T2, T3, T4).Item4",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T4__Item4).ToTestDisplayString());
 
            Assert.Equal("T1 (T1, T2, T3, T4, T5).Item1",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item1).ToTestDisplayString());
            Assert.Equal("T2 (T1, T2, T3, T4, T5).Item2",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item2).ToTestDisplayString());
            Assert.Equal("T3 (T1, T2, T3, T4, T5).Item3",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item3).ToTestDisplayString());
            Assert.Equal("T4 (T1, T2, T3, T4, T5).Item4",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item4).ToTestDisplayString());
            Assert.Equal("T5 (T1, T2, T3, T4, T5).Item5",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item5).ToTestDisplayString());
 
            Assert.Equal("T1 (T1, T2, T3, T4, T5, T6).Item1",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item1).ToTestDisplayString());
            Assert.Equal("T2 (T1, T2, T3, T4, T5, T6).Item2",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item2).ToTestDisplayString());
            Assert.Equal("T3 (T1, T2, T3, T4, T5, T6).Item3",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item3).ToTestDisplayString());
            Assert.Equal("T4 (T1, T2, T3, T4, T5, T6).Item4",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item4).ToTestDisplayString());
            Assert.Equal("T5 (T1, T2, T3, T4, T5, T6).Item5",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item5).ToTestDisplayString());
            Assert.Equal("T6 (T1, T2, T3, T4, T5, T6).Item6",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item6).ToTestDisplayString());
 
            Assert.Equal("T1 (T1, T2, T3, T4, T5, T6, T7).Item1",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item1).ToTestDisplayString());
            Assert.Equal("T2 (T1, T2, T3, T4, T5, T6, T7).Item2",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item2).ToTestDisplayString());
            Assert.Equal("T3 (T1, T2, T3, T4, T5, T6, T7).Item3",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item3).ToTestDisplayString());
            Assert.Equal("T4 (T1, T2, T3, T4, T5, T6, T7).Item4",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item4).ToTestDisplayString());
            Assert.Equal("T5 (T1, T2, T3, T4, T5, T6, T7).Item5",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item5).ToTestDisplayString());
            Assert.Equal("T6 (T1, T2, T3, T4, T5, T6, T7).Item6",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item6).ToTestDisplayString());
            Assert.Equal("T7 (T1, T2, T3, T4, T5, T6, T7).Item7",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item7).ToTestDisplayString());
 
            Assert.Equal("T1 System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>.Item1",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item1).ToTestDisplayString());
            Assert.Equal("T2 System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>.Item2",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item2).ToTestDisplayString());
            Assert.Equal("T3 System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>.Item3",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item3).ToTestDisplayString());
            Assert.Equal("T4 System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>.Item4",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item4).ToTestDisplayString());
            Assert.Equal("T5 System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>.Item5",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item5).ToTestDisplayString());
            Assert.Equal("T6 System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>.Item6",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item6).ToTestDisplayString());
            Assert.Equal("T7 System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>.Item7",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item7).ToTestDisplayString());
            Assert.Equal("TRest System.ValueTuple<T1, T2, T3, T4, T5, T6, T7, TRest>.Rest",
                comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Rest).ToTestDisplayString());
        }
 
        [Fact]
        public void TestMissingWellKnownMembersForValueTuple()
        {
            var comp = CreateCompilationWithMscorlib40("");
            Assert.True(comp.GetWellKnownType(WellKnownType.System_ValueTuple_T1).IsErrorType());
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T1__Item1));
 
            Assert.True(comp.GetWellKnownType(WellKnownType.System_ValueTuple_T2).IsErrorType());
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T2__Item1));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T2__Item2));
 
            Assert.True(comp.GetWellKnownType(WellKnownType.System_ValueTuple_T3).IsErrorType());
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T3__Item1));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T3__Item2));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T3__Item3));
 
            Assert.True(comp.GetWellKnownType(WellKnownType.System_ValueTuple_T4).IsErrorType());
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T4__Item1));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T4__Item2));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T4__Item3));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T4__Item4));
 
            Assert.True(comp.GetWellKnownType(WellKnownType.System_ValueTuple_T5).IsErrorType());
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item1));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item2));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item3));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item4));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T5__Item5));
 
            Assert.True(comp.GetWellKnownType(WellKnownType.System_ValueTuple_T6).IsErrorType());
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item1));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item2));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item3));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item4));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T6__Item6));
 
            Assert.True(comp.GetWellKnownType(WellKnownType.System_ValueTuple_T7).IsErrorType());
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item1));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item2));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item3));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item4));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item6));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_T7__Item7));
 
            Assert.True(comp.GetWellKnownType(WellKnownType.System_ValueTuple_TRest).IsErrorType());
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item1));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item2));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item3));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item4));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item6));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Item7));
            Assert.Null(comp.GetWellKnownTypeMember(WellKnownMember.System_ValueTuple_TRest__Rest));
        }
    }
}