using System;
using System.Linq;
using UnitTestSharp;
using Vellum;

namespace Ariadne.Vellum.UnitTests
{
    /// <summary>
    /// Saves an arc paused inside a passage of another arc, whose locals are saved with the caller's.
    /// </summary>
    public class ForeignCallSaveTests : TestFixture
    {
        public static OperatorScript PausedInside(Gates gates, int ticks)
        {
            var returnMe = new OperatorScript { Plant = new PlantScript() };
            for (int i = 0; i < ticks; ++i)
            {
                returnMe.Tick(gates, TestTicks.Fresh());
            }

            return returnMe;
        }

        public class ToNodeTests : TestFixture
        {
            public void CalleesLocals_AreSavedInATableInsideTheCallersNamedForTheCall()
            {
                SaveSession session = ArcConverterTests.Session();
                OperatorScript paused = PausedInside(new Gates(), ticks: 2);

                SaveNode node = session.ToNode(paused, typeof(OperatorScript));

                SaveNode locals = node.RequireEntry(ArcRecord.LocalsKey);
                CheckEqual(new[] { "Run.before", "Run.update/" },
                    locals.Entries.Keys.OrderBy(key => key, StringComparer.Ordinal).ToArray());
                SaveNode call = locals.RequireEntry("Run.update/");
                CheckEqual(new[] { "Update.waited", "receiver" },
                    call.Entries.Keys.OrderBy(key => key, StringComparer.Ordinal).ToArray());
                CheckEqual("2", call.RequireEntry("Update.waited").Text);
            }
        }

        public class FromNodeTests : TestFixture
        {
            public void Reloaded_ResumesTheCallWithItsLocalsOnTheSameArc()
            {
                SaveSession session = ArcConverterTests.Session();
                var gates = new Gates();
                OperatorScript paused = PausedInside(gates, ticks: 2);

                var loaded = (OperatorScript)session.FromNode(
                    session.ToNode(paused, typeof(OperatorScript)), typeof(OperatorScript));
                gates.Open.Add("go");
                loaded.Tick(gates, TestTicks.Fresh());

                CheckEqual("done 7 2", loaded.Result);
                CheckEqual("updated after 2", loaded.Plant.Note);
                CheckEqual(0, paused.Plant.Updates);
                CheckTrue(loaded.Finished);
            }

            public void ReloadedAndSavedAgainBeforeTicking_KeepsTheCallsLocals()
            {
                SaveSession session = ArcConverterTests.Session();
                var gates = new Gates();
                SaveNode once = session.ToNode(PausedInside(gates, ticks: 2), typeof(OperatorScript));

                var loaded = (OperatorScript)session.FromNode(once, typeof(OperatorScript));
                var again = (OperatorScript)session.FromNode(
                    session.ToNode(loaded, typeof(OperatorScript)), typeof(OperatorScript));
                gates.Open.Add("go");
                again.Tick(gates, TestTicks.Fresh());

                CheckEqual("updated after 2", again.Plant.Note);
            }
        }
    }
}