using Amphora;
using System;
using System.Collections.Generic;
using UnitTestSharp;

namespace Ariadne.UnitTests
{
    public class FrameTests : TestFixture
    {
        public class ResumeKeyTests : TestFixture
        {
            private Frame frame;

            public override void TestSetup()
            {
                frame = new Frame();
            }

            public void EmptyCursor_IsNull()
            {
                CheckNull(frame.ResumeKey);
            }

            public void DepthWithinTheCursor_IsTheKeyThere()
            {
                frame.Cursor.AddRange(new[] { "outer", "inner" });
                frame.Depth = 1;

                CheckEqual("inner", frame.ResumeKey);
            }

            public void DepthPastTheCursor_IsNull()
            {
                frame.Cursor.Add("outer");
                frame.Depth = 1;

                CheckNull(frame.ResumeKey);
            }
        }

        public class MarkTests : TestFixture
        {
            private Frame frame;

            public override void TestSetup()
            {
                frame = new Frame();
            }

            public void PastTheCursor_AppendsTheKey()
            {
                frame.Mark("wait");

                CheckEqual(new[] { "wait" }, frame.Cursor);
            }

            public void WithinTheCursor_ReplacesTheKeyAndDropsDeeperOnes()
            {
                frame.Cursor.AddRange(new[] { "outer", "inner", "innermost" });
                frame.Depth = 1;
                frame.Mark("elsewhere");

                CheckEqual(new[] { "outer", "elsewhere" }, frame.Cursor);
            }
        }

        public class EnterTests : TestFixture
        {
            private Frame frame;

            public override void TestSetup()
            {
                frame = new Frame();
            }

            public void PastTheCursor_AppendsTheKeyAndGoesDeeper()
            {
                frame.Enter("act");

                CheckEqual(new[] { "act" }, frame.Cursor);
                CheckEqual(1, frame.Depth);
            }

            public void TheKeyAlreadyThere_KeepsTheKeysBelowIt()
            {
                frame.Cursor.AddRange(new[] { "act", "wait" });
                frame.Enter("act");

                CheckEqual(new[] { "act", "wait" }, frame.Cursor);
                CheckEqual(1, frame.Depth);
            }

            public void ADifferentKey_ReplacesItAndDropsDeeperOnes()
            {
                frame.Cursor.AddRange(new[] { "act", "wait" });
                frame.Enter("other");

                CheckEqual(new[] { "other" }, frame.Cursor);
                CheckEqual(1, frame.Depth);
            }
        }

        public class PassageTests : TestFixture
        {
            public void Dispose_ReturnsToTheOuterDepth()
            {
                var frame = new Frame();
                Frame.Passage passage = frame.Enter("act");
                passage.Dispose();

                CheckEqual(0, frame.Depth);
            }
        }

        public class LendTests : TestFixture
        {
            public void Callee_SharesThePathAndDepth()
            {
                var lender = new Frame();
                lender.Cursor.Add("outer");
                lender.Depth = 1;
                var callee = new Frame();

                CheckTrue(ReferenceEquals(callee, lender.Lend(callee)));
                CheckTrue(ReferenceEquals(lender.Cursor, callee.Cursor));
                CheckEqual(1, callee.Depth);
            }

            public void CalleesKeys_JoinTheLendersPath()
            {
                var lender = new Frame();
                lender.Cursor.Add("outer");
                lender.Depth = 1;
                lender.Lend(new Frame()).Mark("inner");

                CheckEqual(new[] { "outer", "inner" }, lender.Cursor);
            }

            public void Callee_SharesTheWakeSlot()
            {
                var lender = new Frame { Wake = new WakeSlot() };
                var callee = lender.Lend(new Frame());

                CheckTrue(ReferenceEquals(lender.Wake, callee.Wake));
            }

            public void CalleeWithoutAWakeSlotOnTheLender_HasNone()
            {
                var callee = new Frame().Lend(new Frame { Wake = new WakeSlot() });

                CheckNull(callee.Wake);
            }

            public void CalleesSleep_ReachesTheLendersSlot()
            {
                var lender = new Frame { Wake = new WakeSlot() };
                lender.Lend(new Frame()).Sleep(TimeSpan.FromSeconds(3));

                CheckTrue(lender.Wake.Sleeping);
                CheckEqual(Duration.FromSeconds(3), lender.Wake.Deadline);
            }
        }

        public class SleepTests : TestFixture
        {
            public void WithAWakeSlot_RecordsTheDeadline()
            {
                var frame = new Frame { Wake = new WakeSlot() };
                frame.Sleep(TimeSpan.FromSeconds(5));

                CheckTrue(frame.Wake.Sleeping);
                CheckEqual(Duration.FromSeconds(5), frame.Wake.Deadline);
            }

            public void LaterSleep_ReplacesTheDeadline()
            {
                var frame = new Frame { Wake = new WakeSlot() };
                frame.Sleep(TimeSpan.FromSeconds(5));
                frame.Sleep(TimeSpan.FromSeconds(8));

                CheckEqual(Duration.FromSeconds(8), frame.Wake.Deadline);
            }

            public void WithoutAWakeSlot_DoesNothing()
            {
                var frame = new Frame();
                frame.Sleep(TimeSpan.FromSeconds(5));

                CheckNull(frame.Wake);
            }
        }

        public class SuspendTests : TestFixture
        {
            public void WithAWakeSlot_MarksItSuspended()
            {
                var frame = new Frame { Wake = new WakeSlot() };
                frame.Suspend();

                CheckTrue(frame.Wake.Suspended);
                CheckFalse(frame.Wake.Sleeping);
            }

            public void WithoutAWakeSlot_DoesNothing()
            {
                var frame = new Frame();
                frame.Suspend();

                CheckNull(frame.Wake);
            }

            public void CalleesSuspend_ReachesTheLendersSlot()
            {
                var lender = new Frame { Wake = new WakeSlot() };
                lender.Lend(new Frame()).Suspend();

                CheckTrue(lender.Wake.Suspended);
            }
        }

        public class RequireWakeTests : TestFixture
        {
            public void WithAWakeSlot_ReturnsIt()
            {
                var slot = new WakeSlot();
                var frame = new Frame { Wake = slot };

                CheckTrue(ReferenceEquals(slot, frame.RequireWake()));
            }

            public void WithoutAWakeSlot_Throws()
            {
                CheckThrow(typeof(InvalidOperationException));
                new Frame().RequireWake();
            }

            public void Callee_ReturnsTheLendersSlot()
            {
                var slot = new WakeSlot();
                var lender = new Frame { Wake = slot };

                CheckTrue(ReferenceEquals(slot, lender.Lend(new Frame()).RequireWake()));
            }
        }

        public class LocalsTests : TestFixture
        {
            public void SaveLocal_ThrowsForAKeyNoFrameHolds()
            {
                CheckThrow(typeof(InvalidOperationException));
                new Frame().SaveLocal("Run.ghost", new ArcRecord());
            }

            public void LoadLocals_ChangesNothing()
            {
                var record = new ArcRecord();
                record.Locals.Add("Run.ghost", 1);
                new Frame().LoadLocals(record);

                CheckEqual(1, record.Locals.Count);
            }
        }

        public class ExitTests : TestFixture
        {
            private Frame frame;

            public override void TestSetup()
            {
                frame = new Frame();
            }

            public void WithinTheCursor_DropsTheRunningPassagesKeysAndDeeperOnes()
            {
                frame.Cursor.AddRange(new[] { "outer", "inner", "innermost" });
                frame.Depth = 1;
                frame.Exit();

                CheckEqual(new[] { "outer" }, frame.Cursor);
            }

            public void PastTheCursor_ChangesNothing()
            {
                frame.Cursor.Add("outer");
                frame.Depth = 1;
                frame.Exit();

                CheckEqual(new[] { "outer" }, frame.Cursor);
            }
        }
    }
}