using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using UnitTestSharp;

namespace Vellum.UnitTests
{
    public class SortedSetConverterTests : TestFixture
    {
        public static SaveSession Session()
        {
            return SaveConvertersTests.TestConverters().CreateSession();
        }

        public class WriteTests : TestFixture
        {
            public void Set_IsATableOfItsItemsInOrder()
            {
                SaveNode node = Session().ToNode(new SortedSet<int> { 3, 1, 2 }, typeof(SortedSet<int>));

                CheckEqual(SaveNode.Kinds.Table, node.Kind);
                CheckEqual(new[] { "1", "2", "3" },
                    node.RequireEntry("items").Items.Select(item => item.Text).ToArray());
            }

            public void DefaultOrdering_IsLeftOut()
            {
                SaveNode node = Session().ToNode(new SortedSet<string> { "a" }, typeof(SortedSet<string>));

                CheckEqual(new[] { "items" }, node.Entries.Keys.ToArray());
            }

            public void NamedOrdering_IsSavedBesideTheItems()
            {
                var value = new SortedSet<string>(StringComparer.OrdinalIgnoreCase) { "a" };
                SaveNode node = Session().ToNode(value, typeof(SortedSet<string>));

                CheckEqual("OrdinalIgnoreCase", node.RequireEntry("comparer").Text);
            }

            public void OrderingThatCantBeSaved_Throws()
            {
                var value = new SortedSet<string>(StringComparer.CurrentCulture) { "a" };

                CheckThrow(typeof(NotSupportedException));
                Session().ToNode(value, typeof(SortedSet<string>));
            }

            public void NullSet_IsNull()
            {
                CheckEqual(SaveNode.Kinds.Null, Session().ToNode(null, typeof(SortedSet<int>)).Kind);
            }
        }

        public class ReadTests : TestFixture
        {
            public void SetHoldingItself_ReadsAsASetHoldingItself()
            {
                SaveNode node = SaveNode.NewTable();
                SaveNode items = SaveNode.NewList();
                items.Items.Add(node);
                node.Entries[HashSetConverter<object>.ItemsKey] = items;
                var loaded = (SortedSet<object>)new SaveConverters(new SaveConverter[0])
                    .CreateSession()
                    .FromNode(node, typeof(SortedSet<object>));

                CheckTrue(ReferenceEquals(loaded, loaded.Min));
            }

            public void Set_RoundTrips()
            {
                SaveSession session = Session();
                SaveNode node = session.ToNode(new SortedSet<int> { 3, 1, 2 }, typeof(SortedSet<int>));
                var loaded = (SortedSet<int>)session.FromNode(node, typeof(SortedSet<int>));

                CheckEqual(new[] { 1, 2, 3 }, loaded.ToArray());
            }

            public void Ordering_RoundTrips()
            {
                SaveSession session = Session();
                var value = new SortedSet<string>(StringComparer.OrdinalIgnoreCase) { "b", "A" };
                SaveNode node = session.ToNode(value, typeof(SortedSet<string>));
                var loaded = (SortedSet<string>)session.FromNode(node, typeof(SortedSet<string>));

                CheckEqual(new[] { "A", "b" }, loaded.ToArray());
                CheckTrue(loaded.Contains("B"));
            }

            public void SetThroughLuaText_RoundTrips()
            {
                SaveSession session = Session();
                var value = new SortedSet<string> { "b", "a" };
                SaveNode node = SaveConvertersTests.ThroughLuaText(session.ToNode(value, typeof(SortedSet<string>)));
                var loaded = (SortedSet<string>)session.FromNode(node, typeof(SortedSet<string>));

                CheckEqual(new[] { "a", "b" }, loaded.ToArray());
            }

            public void NullForASet_IsNull()
            {
                CheckNull(Session().FromNode(SaveNode.Null, typeof(SortedSet<int>)));
            }

            public void SameItemTwice_RecordsTheSecond()
            {
                SaveNode node = SaveNode.NewTable();
                node.Entries["items"] = SavedItems.ToNode(new[] { 1, 2, 1 }, Session());

                SaveSession session = Session();
                var loaded = (SortedSet<int>)session.FromNode(node, typeof(SortedSet<int>));

                CheckEqual(2, loaded.Count);
                CheckEqual(1, session.Sandbox.Issues.Count);
            }

            public void MissingItems_Throws()
            {
                CheckThrow(typeof(InvalidDataException));
                Session().FromNode(SaveNode.NewTable(), typeof(SortedSet<int>));
            }
        }

        public class TryListChildrenTests : TestFixture
        {
            public void EachItem_IsListedAsTheItemType()
            {
                SaveNode node = Session().ToNode(new SortedSet<string> { "b", "a" }, typeof(SortedSet<string>));
                var children = new ChildList();

                CheckTrue(new SortedSetConverter<string>().TryListChildren(node, children));
                CheckEqual(2, children.Count);
                CheckTrue(ReferenceEquals(node.RequireEntry("items").Items[0], children.NodeAt(0)));
                CheckEqual(typeof(string), children.TypeAt(1));
            }

            public void MissingItems_ReturnsFalse()
            {
                CheckFalse(new SortedSetConverter<int>().TryListChildren(SaveNode.NewTable(), new ChildList()));
            }

            public void ItemsThatAreNotAList_ReturnsFalse()
            {
                SaveNode node = SaveNode.NewTable();
                node.Entries["items"] = SaveNode.OfText("3");

                CheckFalse(new SortedSetConverter<int>().TryListChildren(node, new ChildList()));
            }
        }

        public class AllocateTests : TestFixture
        {
            public void SavedValue_GivesAnEmptyCollection()
            {
                SaveSession session = SaveConvertersTests.Session();
                SaveNode node = session.ToNode(new SortedSet<int> { 3, 1, 2 });

                CheckEqual(0, new SortedSetConverter<int>().Allocate(node, session).Count);
            }

            public void NodeOfTheWrongShape_Throws()
            {
                CheckThrow(typeof(InvalidDataException));
                new SortedSetConverter<int>().Allocate(SaveNode.OfText("3"), SaveConvertersTests.Session());
            }
        }

        public class FillTests : TestFixture
        {
            public void SavedValue_AddsWhatReadLoads()
            {
                SaveSession session = SaveConvertersTests.Session();
                SaveNode node = session.ToNode(new SortedSet<int> { 3, 1, 2 });
                var converter = new SortedSetConverter<int>();
                SortedSet<int> filled = converter.Allocate(node, session);
                converter.Fill(filled, node, session);

                CheckTrue(converter.Read(node, SaveConvertersTests.Session()).SequenceEqual(filled));
            }
        }

        public class FillNeedsFilledPartTests : TestFixture
        {
            public void TheHashedOrSortedType_IsTrue()
            {
                CheckTrue(new SortedSetConverter<int>().FillNeedsFilledPart(typeof(int)));
            }

            public void AnotherType_IsFalse()
            {
                CheckFalse(new SortedSetConverter<int>().FillNeedsFilledPart(typeof(string)));
            }
        }
    }
}