trail-into-darkness/Assets/Code/GameState/Entities/CharacterStatsFactory.cs

using System;
using System.Collections.Generic;
using System.Linq;

namespace Nox.Game {
    public interface ICharacterStatsFactory {
        EntityStats Create(IEntityDefinition entityDefinition);
    }

    public sealed class CharacterStatsFactory : ICharacterStatsFactory {
        private readonly CharacterRegistry characterRegistry;

        public CharacterStatsFactory(CharacterRegistry characterRegistry) {
            this.characterRegistry = characterRegistry;
        }

        public EntityStats Create(IEntityDefinition entityDefinition) {
            var attributes = entityDefinition.Attributes;
            var stats = entityDefinition.Stats;
            var perks = entityDefinition.Perks;
            var modifiers = entityDefinition.Modifiers;

            if(attributes.attributes.Any(a => a.value <= 0)) {
                throw new ArgumentOutOfRangeException( "attributes cannot be zero or negative.", new ArgumentException() );
            }

            var healthModifiers = modifiers.modifiers.Where(m => m.StatType == StatType.Health);
            var health = stats.GetValue(StatType.Health) + attributes.GetValue(AttributeType.Might) * ResolveModifiersValue(healthModifiers, attributes);

            return new EntityStats {
                stats = new[] {
                    new Stat(StatType.Health, health)
                }
            };
        }
        private int ResolveModifiersValue(IEnumerable<ModifierDefinition> healthModifiers, EntityAttributes attributes) {
            throw new NotImplementedException();
        }
    }
}