using System;
using System.Linq;
using MongoDB.Bson.Serialization;
using MongoDB.Bson.Serialization.Serializers;
using MongoDB.Driver;
using NUnit.Framework;

namespace TPP.Persistence.MongoDB.Tests.Repos
{
    public enum TestEnum { Foo, Bar, Baz }
    public record TestEntity(string Id, string Category, TestEnum EnumValue);

    public class TestEnumSerializer : SerializerBase<TestEnum>
    {
        public override TestEnum Deserialize(BsonDeserializationContext context, BsonDeserializationArgs args)
        {
            return context.Reader.ReadString() switch
            {
                "my_foo" => TestEnum.Foo,
                "my_bar" => TestEnum.Bar,
                "my_baz" => TestEnum.Baz,
                _ => throw new ArgumentOutOfRangeException()
            };
        }

        public override void Serialize(BsonSerializationContext context, BsonSerializationArgs args, TestEnum value)
        {
            context.Writer.WriteString(value switch
            {
                TestEnum.Foo => "my_foo",
                TestEnum.Bar => "my_bar",
                TestEnum.Baz => "my_baz",
                _ => throw new ArgumentOutOfRangeException()
            });
        }
    }

    public class MongoEnumTest
    {
        [Test]
        public void Foo()
        {
            BsonClassMap.RegisterClassMap<TestEntity>(cm =>
            {
                cm.MapIdProperty(e => e.Id);
                cm.MapProperty(e => e.Category)
                    .SetElementName("category");
                cm.MapProperty(e => e.EnumValue)
                    .SetElementName("enum_value")
                    .SetSerializer(new TestEnumSerializer());
            });

            IMongoClient client = new MongoClient();
            IMongoDatabase db = client.GetDatabase("test_database");
            db.CreateCollection("test_collection");

            IMongoCollection<TestEntity> collection = db.GetCollection<TestEntity>("test_collection");
            collection.InsertOne(new TestEntity("1", "cat1", TestEnum.Foo));
            collection.InsertOne(new TestEntity("2", "cat1", TestEnum.Bar));
            collection.InsertOne(new TestEntity("3", "cat2", TestEnum.Bar));

            var bars = collection.Aggregate()
                .Group(
                    e => e.Category,
                    group => new { NumBars = group.Count(e2 => e2.EnumValue == TestEnum.Bar) })
                .ToList();
            Assert.AreEqual(2, bars.Count);
            foreach (var wrapperObject in bars)
                Assert.AreEqual(1, wrapperObject.NumBars);
        }
    }
}