// 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 System.Linq;
using System.Threading;
using System.Threading.Tasks;
using Roslyn.Test.Utilities;
using Xunit;
using Xunit.Abstractions;
using LSP = Roslyn.LanguageServer.Protocol;
 
namespace Microsoft.CodeAnalysis.LanguageServer.UnitTests.References;
 
public sealed class FindImplementationsTests : AbstractLanguageServerProtocolTests
{
    public FindImplementationsTests(ITestOutputHelper testOutputHelper) : base(testOutputHelper)
    {
    }
 
    [Theory, CombinatorialData]
    public async Task TestFindImplementationAsync(bool mutatingLspWorkspace)
    {
        var markup =
            """
            interface IA
            {
                void {|caret:|}M();
            }
            class A : IA
            {
                void IA.{|implementation:M|}()
                {
                }
            }
            """;
        await using var testLspServer = await CreateTestLspServerAsync(markup, mutatingLspWorkspace);
 
        var results = await RunFindImplementationAsync(testLspServer, testLspServer.GetLocations("caret").Single());
        AssertLocationsEqual(testLspServer.GetLocations("implementation"), results);
    }
 
    [Theory, CombinatorialData]
    public async Task TestFindImplementationAsync_DifferentDocument(bool mutatingLspWorkspace)
    {
        var markups = new string[]
        {
            """
            namespace One
            {
                interface IA
                {
                    void {|caret:|}M();
                }
            }
            """,
            """
            namespace One
            {
                class A : IA
                {
                    void IA.{|implementation:M|}()
                    {
                    }
                }
            }
            """
        };
 
        await using var testLspServer = await CreateTestLspServerAsync(markups, mutatingLspWorkspace);
 
        var results = await RunFindImplementationAsync(testLspServer, testLspServer.GetLocations("caret").Single());
        AssertLocationsEqual(testLspServer.GetLocations("implementation"), results);
    }
 
    [Theory, CombinatorialData]
    public async Task TestFindImplementationAsync_MappedFile(bool mutatingLspWorkspace)
    {
        await using var testLspServer = await CreateTestLspServerAsync(string.Empty, mutatingLspWorkspace);
 
        AddMappedDocument(testLspServer.TestWorkspace, """
            interface IA
            {
                void M();
            }
            class A : IA
            {
                void IA.M()
                {
                }
            }
            """);
 
        var position = new LSP.Position { Line = 2, Character = 9 };
        var results = await RunFindImplementationAsync(testLspServer, new LSP.Location
        {
            DocumentUri = ProtocolConversions.CreateAbsoluteDocumentUri($"C:\\{TestSpanMapper.GeneratedFileName}"),
            Range = new LSP.Range { Start = position, End = position }
        });
        AssertLocationsEqual([TestSpanMapper.MappedFileLocation], results);
    }
 
    [Theory, CombinatorialData]
    public async Task TestFindImplementationAsync_InvalidLocation(bool mutatingLspWorkspace)
    {
        var markup =
            """
            class A
            {
                void M()
                {
                    {|caret:|}
                }
            }
            """;
        await using var testLspServer = await CreateTestLspServerAsync(markup, mutatingLspWorkspace);
 
        var results = await RunFindImplementationAsync(testLspServer, testLspServer.GetLocations("caret").Single());
        Assert.Empty(results);
    }
 
    [Theory, CombinatorialData, WorkItem("https://github.com/dotnet/roslyn/issues/44846")]
    public async Task TestFindImplementationAsync_MultipleLocations(bool mutatingLspWorkspace)
    {
        var markup =
            """
            class {|caret:|}A { }
 
            class {|implementation:B|} : A { }
 
            class {|implementation:C|} : A { }
            """;
        await using var testLspServer = await CreateTestLspServerAsync(markup, mutatingLspWorkspace);
 
        var results = await RunFindImplementationAsync(testLspServer, testLspServer.GetLocations("caret").Single());
        AssertLocationsEqual(testLspServer.GetLocations("implementation"), results);
    }
 
    [Theory, CombinatorialData]
    public async Task TestFindImplementationAsync_NoMetadataResults(bool mutatingLspWorkspace)
    {
        var markup = """
            using System;
            class C : IDisposable
            {
                public void {|implementation:Dispose|}()
                {
                    IDisposable d;
                    d.{|caret:|}Dispose();
                }
            }
            """;
        await using var testLspServer = await CreateTestLspServerAsync(markup, mutatingLspWorkspace);
 
        var results = await RunFindImplementationAsync(testLspServer, testLspServer.GetLocations("caret").Single());
 
        // At the moment we only support source results here, so verify we haven't accidentally
        // broken that without work to make sure they display nicely
        AssertLocationsEqual(testLspServer.GetLocations("implementation"), results);
    }
 
    private static async Task<LSP.Location[]> RunFindImplementationAsync(TestLspServer testLspServer, LSP.Location caret)
    {
        return await testLspServer.ExecuteRequestAsync<LSP.TextDocumentPositionParams, LSP.Location[]>(LSP.Methods.TextDocumentImplementationName,
                       CreateTextDocumentPositionParams(caret), CancellationToken.None);
    }
}