using System;
using UnitTestSharp;

namespace Glass.UnitTests
{
    public class InMemoryKeyValueStoreTests : TestFixture
    {
        public class GetKeysTests : TestFixture
        {
            public void Empty_GivesNothing()
            {
                CheckEqual(0, new InMemoryKeyValueStore().GetKeys().Count);
            }

            public void GivesEveryKeySet()
            {
                var store = new InMemoryKeyValueStore();
                store.Set("a", "1");
                store.Set("b", "2");

                CheckEqual(2, store.GetKeys().Count);
                CheckTrue(((System.Collections.Generic.List<string>)store.GetKeys()).Contains("a"));
                CheckTrue(((System.Collections.Generic.List<string>)store.GetKeys()).Contains("b"));
            }

            public void ListIsACopy()
            {
                var store = new InMemoryKeyValueStore();
                store.Set("a", "1");
                var keys = (System.Collections.Generic.List<string>)store.GetKeys();

                keys.Clear();

                CheckEqual(1, store.GetKeys().Count);
            }
        }

        public class GetTests : TestFixture
        {
            public void SetKey_GivesItsValue()
            {
                var store = new InMemoryKeyValueStore();
                store.Set("a", "1");

                CheckEqual("1", store.Get("a"));
            }

            public void MissingKey_GivesNull()
            {
                CheckNull(new InMemoryKeyValueStore().Get("a"));
            }

            public void Null_Throws()
            {
                var store = new InMemoryKeyValueStore();

                CheckThrow(typeof(ArgumentNullException));
                store.Get(null);
            }
        }

        public class SetTests : TestFixture
        {
            public void ExistingKey_IsReplaced()
            {
                var store = new InMemoryKeyValueStore();
                store.Set("a", "1");

                store.Set("a", "2");

                CheckEqual("2", store.Get("a"));
                CheckEqual(1, store.GetKeys().Count);
            }

            public void EmptyValue_IsKept()
            {
                var store = new InMemoryKeyValueStore();

                store.Set("a", "");

                CheckEqual("", store.Get("a"));
            }

            public void NullKey_Throws()
            {
                var store = new InMemoryKeyValueStore();

                CheckThrow(typeof(ArgumentNullException));
                store.Set(null, "1");
            }

            public void NullValue_Throws()
            {
                var store = new InMemoryKeyValueStore();

                CheckThrow(typeof(ArgumentNullException));
                store.Set("a", null);
            }
        }

        public class RemoveTests : TestFixture
        {
            public void ExistingKey_Forgets()
            {
                var store = new InMemoryKeyValueStore();
                store.Set("a", "1");

                store.Remove("a");

                CheckNull(store.Get("a"));
                CheckEqual(0, store.GetKeys().Count);
            }

            public void MissingKey_DoesNothing()
            {
                var store = new InMemoryKeyValueStore();
                store.Set("a", "1");

                store.Remove("b");

                CheckEqual(1, store.GetKeys().Count);
            }

            public void Null_Throws()
            {
                var store = new InMemoryKeyValueStore();

                CheckThrow(typeof(ArgumentNullException));
                store.Remove(null);
            }
        }
    }
}