using System.Collections.Generic;

namespace Robust.Shared.Serialization.Manager.Result
{
    public sealed class DeserializedDictionary<TDict, TKey, TValue> :
        DeserializationResult<TDict>
        where TKey : notnull
        where TDict : IReadOnlyDictionary<TKey, TValue>
    {
        public delegate TDict Create(Dictionary<TKey, TValue> elements);

        public DeserializedDictionary(
            TDict value,
            IReadOnlyDictionary<DeserializationResult, DeserializationResult> mappings,
            Create createDelegate)
        {
            Value = value;
            Mappings = mappings;
            CreateDelegate = createDelegate;
        }

        public override TDict Value { get; }

        public IReadOnlyDictionary<DeserializationResult, DeserializationResult> Mappings { get; }

        public Create CreateDelegate { get; }

        public override object RawValue => Value;

        public override DeserializationResult PushInheritanceFrom(DeserializationResult source)
        {
            var sourceRes = source.Cast<DeserializedDictionary<TDict, TKey, TValue>>();
            var valueDict = new Dictionary<TKey, TValue>();
            var mappingDict = new Dictionary<DeserializationResult, DeserializationResult>();

            foreach (var (keyRes, valRes) in sourceRes.Mappings)
            {
                var newKeyRes = keyRes.Copy();
                var newValueRes = valRes.Copy();

                valueDict.Add((TKey)newKeyRes.RawValue!, (TValue)newValueRes.RawValue!);
                mappingDict.Add(newKeyRes, newValueRes);
            }

            foreach (var (keyRes, valRes) in Mappings)
            {
                var newKeyRes = keyRes.Copy();
                var newValueRes = valRes.Copy();

                valueDict.Add((TKey) newKeyRes.RawValue!, (TValue)newValueRes.RawValue!);
                mappingDict.Add(newKeyRes, newValueRes);
            }

            return new DeserializedDictionary<TDict, TKey, TValue>(CreateDelegate(valueDict), mappingDict, CreateDelegate);
        }

        public override DeserializationResult Copy()
        {
            var valueDict = new Dictionary<TKey, TValue>();
            var mappingDict = new Dictionary<DeserializationResult, DeserializationResult>();

            foreach (var (keyRes, valRes) in Mappings)
            {
                var newKeyRes = keyRes.Copy();
                var newValueRes = valRes.Copy();

                valueDict.Add((TKey)newKeyRes.RawValue!, (TValue)newValueRes.RawValue!);
                mappingDict.Add(newKeyRes, newValueRes);
            }

            return new DeserializedDictionary<TDict, TKey, TValue>(CreateDelegate(valueDict), mappingDict, CreateDelegate);
        }

        public override void CallAfterDeserializationHook()
        {
            foreach (var (key, val) in Mappings)
            {
                key.CallAfterDeserializationHook();
                val.CallAfterDeserializationHook();
            }
        }
    }
}