using System.Linq;
using Microsoft.CodeAnalysis;
using Microsoft.CodeAnalysis.CSharp;
using Microsoft.CodeAnalysis.CSharp.Syntax;
using UnitTestSharp;

namespace Ariadne.Generator.UnitTests
{
    public class ScriptClassTests : TestFixture
    {
        public const string Mission = @"
public partial class Mission : Arc<World>
{
    protected override void Run(World world)
    {
    step:
        while (!world.Open.Contains(""go""))
        {
            Yield();
        }

        Helper();
    }
}";

        public const string Helper = "public partial class Mission { private void Helper() { Yield(); } }";

        public static ScriptClass Script()
        {
            CSharpCompilation compilation = GeneratorRun.Compile(("Mission.cs", Mission), ("Helper.cs", Helper));

            return ScriptClass.Create(compilation.GetTypeByMetadataName("Mission"), compilation);
        }

        public static MethodDeclarationSyntax Method(ScriptClass script, string name)
        {
            return script.Methods.Values.Single(method => method.Identifier.Text == name);
        }

        public class ModelForTests : TestFixture
        {
            public void NodesOfOneTree_ShareOneModel()
            {
                ScriptClass script = Script();
                SyntaxList<StatementSyntax> statements = script.RunSyntax.Body.Statements;

                CheckTrue(script.ModelFor(statements[0]) == script.ModelFor(statements[1]));
                CheckTrue(script.ModelFor(statements[0]) == script.ModelFor(script.RunSyntax));
            }

            public void NodesOfDifferentTrees_GetTheirOwnModels()
            {
                ScriptClass script = Script();
                MethodDeclarationSyntax helper = Method(script, "Helper");

                CheckTrue(script.ModelFor(script.RunSyntax) != script.ModelFor(helper));
                CheckTrue(script.ModelFor(helper).SyntaxTree == helper.SyntaxTree);
            }
        }

        public class IsYieldTests : TestFixture
        {
            public void InvocationAskedAboutTwice_AnswersTheSameBothTimes()
            {
                ScriptClass script = Script();
                InvocationExpressionSyntax yield = script.RunSyntax.DescendantNodes()
                    .OfType<InvocationExpressionSyntax>().Single(call => call.Expression.ToString() == "Yield");
                InvocationExpressionSyntax helper = script.RunSyntax.DescendantNodes()
                    .OfType<InvocationExpressionSyntax>().Single(call => call.Expression.ToString() == "Helper");

                CheckTrue(script.IsYield(yield));
                CheckTrue(script.IsYield(yield));
                CheckFalse(script.IsYield(helper));
                CheckFalse(script.IsYield(helper));
            }
        }

        public class PassageCalledTests : TestFixture
        {
            public void InvocationAskedAboutTwice_AnswersTheSameBothTimes()
            {
                ScriptClass script = Script();
                InvocationExpressionSyntax helper = script.RunSyntax.DescendantNodes()
                    .OfType<InvocationExpressionSyntax>().Single(call => call.Expression.ToString() == "Helper");

                CheckEqual("Helper", script.PassageCalled(helper).Name);
                CheckEqual("Helper", script.PassageCalled(helper).Name);
            }
        }
    }
}