persistence/DD.Persistence.Client/TimestampedSetMapper.cs

using DD.Persistence.Models;
using System.Collections.Concurrent;
using System.Reflection;
using System.Runtime.CompilerServices;
using System.Text.Json;

namespace DD.Persistence.Client;

internal abstract class TimestampedSetMapperBase
{
    public abstract object Map(TimestampedSetDto data);

}
internal class TimestampedSetMapper<T> : TimestampedSetMapperBase
{
    private readonly Type entityType = typeof(T);
    public Guid IdDiscriminator { get; }
    private readonly ConcurrentDictionary<string, PropertyInfo?> PropertyCache = new();

    public TimestampedSetMapper(Guid idDiscriminator)
    {
        IdDiscriminator = idDiscriminator;
    }

    public override object Map(TimestampedSetDto data)
    {
        return DeserializeTimeStampedData(data)!;
    }

    public T DeserializeTimeStampedData(TimestampedSetDto data)
    {

        if (entityType.IsValueType)
            return MapStruct(data);
        else
            return MapClass(data);
    }

    private T MapClass(TimestampedSetDto data)
    {
        var entity = (T)RuntimeHelpers.GetUninitializedObject(typeof(T));
        foreach (var (propertyName, value) in data.Set)
        {
            if (value is JsonElement jsonElement)
                SetPropertyValueFromJson(ref entity, propertyName, jsonElement);
        }
        SetPropertyValue(ref entity, "Timestamp", data.Timestamp);
        return entity;
    }

    private T MapStruct(TimestampedSetDto data)
    {
        var entity = Activator.CreateInstance<T>();
        object boxedEntity = entity!;
        foreach (var (propertyName, value) in data.Set)
        {
            if (value is JsonElement jsonElement)
                SetPropertyValueForStructFromJson(ref boxedEntity, propertyName, jsonElement);
        }
        SetPropertyValueForStruct(ref boxedEntity, "Timestamp", data.Timestamp);

        return (T)boxedEntity;
    }

    private void SetPropertyValueForStructFromJson(ref object entity, string propertyName, JsonElement element)
    {
        var property = GetPropertyInfo(propertyName);
        if (property is null)
            return;

        try
        {
            var value = element.Deserialize(property.PropertyType);
            property.SetValue(entity, value);
        }
        catch (Exception ex)
        {
        }
    }
    private void SetPropertyValueForStruct(ref object entity, string propertyName, object value)
    {
        var property = GetPropertyInfo(propertyName);
        if (property is null)
            return;

        try
        {
            var convertedValue = Convert.ChangeType(value, property.PropertyType);
            property.SetValue(entity, convertedValue);
        }
        catch (Exception ex)
        {
        }
    }


    private void SetPropertyValueFromJson(ref T entity, string propertyName, JsonElement jsonElement)
    {
        var property = GetPropertyInfo(propertyName);

        if (property is null)
            return;

        try
        {
            var value = jsonElement.Deserialize(property.PropertyType);
            property.SetValue(entity, value);
        }
        catch (Exception ex)
        {

        }
    }

    private void SetPropertyValue(ref T entity, string propertyName, object value)
    {
        var property = GetPropertyInfo(propertyName);
        if (property is null)
            return;

        try
        {
            var convertedValue = Convert.ChangeType(value, property.PropertyType);
            property.SetValue(entity, convertedValue);
        }
        catch (Exception ex)
        {
        }
    }

    private PropertyInfo? GetPropertyInfo(string propertyName)
    {
        return PropertyCache.GetOrAdd(propertyName, name => entityType.GetProperty(name));
    }
}