using System;

using System.Collections.Generic;

using System.Linq;

namespace Simplify.Web.System;

/// <summary>

/// Provides the <see cref="Type" /> extensions.

/// </summary>

public static class TypeExtensions

{

/// <summary>

/// Determines whether one type is derivative of another.

/// </summary>

/// <param name="t">The type.</param>

/// <param name="type">The type.</param>

public static bool IsTypeOf(this Type t, Type type)

{

switch (t.IsGenericType)

{

case false when t == type:

case true when t.GetGenericTypeDefinition() == type:

return true;

default:

return false;

}

}

/// <summary>

/// Determines whether the type is derived from one of the specified types.

/// </summary>

/// <param name="t">The t.</param>

/// <param name="types">The types.</param>

/// <returns>

/// <c>true</c> if the type is derived from one of the specified types; otherwise, <c>false</c>.

/// </returns>

public static bool IsDerivedFrom(this Type t, params Type[] types) => Array.Exists(types, t.IsDerivedFrom);

/// <summary>

/// Determines whether the type is derived from other type.

/// </summary>

/// <param name="t">The t.</param>

/// <param name="type">The type.</param>

/// <returns>

/// <c>true</c> if the type is derived from other type; otherwise, <c>false</c>.

/// </returns>

public static bool IsDerivedFrom(this Type t, Type type)

{

if (t.IsAbstract)

return false;

if (t.BaseType == null)

return false;

if (t.BaseType.IsTypeOf(type))

return true;

if (t.BaseType.BaseType == null)

return false;

if (t.BaseType.BaseType.IsTypeOf(type))

return true;

return false;

}

/// <summary>

/// Gets the type names as string.

/// </summary>

/// <param name="types">The types.</param>

public static string GetTypeNamesAsString(this IEnumerable<Type> types) => string.Join(", ", types.Select(type => type.Name));

}