gaemstone/src/gaemstone/ECS/Module+Attributes.cs

using System;
using static gaemstone.Flecs.Core;

namespace gaemstone.ECS;

/// <summary>
/// Use a custom name or path for this entity instead of the type's name.
/// </summary>
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum)]
public class PathAttribute : Attribute
{
	public string Value { get; }
	public PathAttribute(string value) => Value = value;
}

/// <summary>
/// Register the entity under a globally unique symbol.
/// Uses the type's name by default.
/// </summary>
// TODO: Remove [Symbol], introduce [Public] for modules and [Private] or so.
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum)]
public class SymbolAttribute : Attribute {  }


/// <summary>
/// Marked entity automatically has the specified entity added to it when
/// automatically registered. Equivalent to <see cref="EntityBase.Add{T}"/>.
/// </summary>
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum, AllowMultiple = true)]
public class AddAttribute<TEntity> : Attribute {  }

/// <summary>
/// Marked entity automatically has the specified relationship pair added to it when
/// automatically registered. Equivalent to <see cref="EntityBase.Add{TRelation, TTarget}"/>.
/// </summary>
[AttributeUsage(AttributeTargets.Class | AttributeTargets.Struct | AttributeTargets.Enum, AllowMultiple = true)]
public class AddAttribute<TRelation, TTarget> : Attribute {  }


/// <seealso cref="IsA"/>
public class IsAAttribute<TTarget> : AddAttribute<IsA, TTarget> {  }

/// <seealso cref="ChildOf"/>
public class ChildOfAttribute<TTarget> : AddAttribute<ChildOf, TTarget> {  }

/// <seealso cref="DependsOn"/>
public class DependsOnAttribute<TTarget> : AddAttribute<DependsOn, TTarget> {  }

/// <seealso cref="Exclusive"/>
public class ExclusiveAttribute : AddAttribute<Exclusive> {  }

/// <seealso cref="With"/>
public class WithAttribute<TTarget> : AddAttribute<With, TTarget> {  }