using System;
using System.Collections.Generic;
using System.Collections.Immutable;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.CodeAnalysis.CodeFixes;
using Microsoft.CodeAnalysis.CSharp.Testing;
using Microsoft.CodeAnalysis.Diagnostics;
using Microsoft.CodeAnalysis.Testing;
using Microsoft.CodeAnalysis.Testing.Verifiers;

namespace Spectre.Console.Analyzer.Tests
{
    public static class SpectreAnalyzerVerifier<TAnalyzer>
        where TAnalyzer : DiagnosticAnalyzer, new()
    {
        public static Task VerifyCodeFixAsync(string source, DiagnosticResult expected, string fixedSource)
            => VerifyCodeFixAsync(source, new[] { expected }, fixedSource);

        private static Task VerifyCodeFixAsync(string source, IEnumerable<DiagnosticResult> expected, string fixedSource)
        {
            // Roslyn fixers always use \r\n for newlines, regardless of OS environment settings, so we normalize
            // the source as it typically comes from multi-line strings with varying newlines.
            if (Environment.NewLine != "\r\n")
            {
                source = source.Replace(Environment.NewLine, "\r\n");
                fixedSource = fixedSource.Replace(Environment.NewLine, "\r\n");
            }

            var test = new Test
            {
                TestCode = source,
                FixedCode = fixedSource,
            };

            test.ExpectedDiagnostics.AddRange(expected);
            return test.RunAsync();
        }

        public static Task VerifyAnalyzerAsync(string source, params DiagnosticResult[] expected)
        {
            var test = new Test
            {
                TestCode = source,
                CompilerDiagnostics = CompilerDiagnostics.All,
            };

            test.ExpectedDiagnostics.AddRange(expected);
            return test.RunAsync();
        }

        // Code fix tests support both analyzer and code fix testing. This test class is derived from the code fix test
        // to avoid the need to maintain duplicate copies of the customization work.
        private class Test : CSharpCodeFixTest<TAnalyzer, EmptyCodeFixProvider, XUnitVerifier>
        {
            public Test()
            {
                ReferenceAssemblies = CodeAnalyzerHelper.CurrentSpectre;
                TestBehaviors |= TestBehaviors.SkipGeneratedCodeCheck;
            }

            protected override IEnumerable<CodeFixProvider> GetCodeFixProviders()
            {
                var analyzer = new TAnalyzer();
                foreach (var provider in CodeFixProviderDiscovery.GetCodeFixProviders(Language))
                {
                    if (analyzer.SupportedDiagnostics.Any(diagnostic => provider.FixableDiagnosticIds.Contains(diagnostic.Id)))
                    {
                        yield return provider;
                    }
                }
            }
        }
    }

    internal static class CodeAnalyzerHelper
    {
        internal static ReferenceAssemblies CurrentSpectre { get; }

        static CodeAnalyzerHelper()
        {
            CurrentSpectre = ReferenceAssemblies.Net.Net50.AddAssemblies(
                ImmutableArray.Create(typeof(AnsiConsole).Assembly.Location.Replace(".dll", string.Empty)));
        }
    }
}