using System;
using System.Collections.Generic;
using System.Diagnostics.CodeAnalysis;

namespace ScreenConnect;

public static class FunctionalExtensions
{
	public static T? As<T>(this object? @this) where T : class
	{
		return @this as T;
	}

	public static T? AsNullable<T>(this T @this) where T : struct
	{
		return @this;
	}

	public static T? AsNullable<T>(this object? @this) where T : struct
	{
		return @this as T?;
	}

	public static T? ToNullable<T>(this T @this) where T : class?
	{
		return @this;
	}

	[return: NotNullIfNotNull("this")]
	public static T? To<T>(this object? @this)
	{
		return (T)@this;
	}

	public static T? If<T>(this T @this, Func<T, bool> predicate) where T : class
	{
		if (!predicate(@this))
		{
			return null;
		}
		return @this;
	}

	public static T? IfNullable<T>(this T @this, Func<T, bool> predicate) where T : struct
	{
		if (!predicate(@this))
		{
			return null;
		}
		return @this;
	}

	public static string? IfNotNullOrEmpty(this string? @this)
	{
		return @this?.IfNotEmpty();
	}

	public static string? IfNotEmpty(this string? @this)
	{
		return @this?.If((string s) => s != string.Empty);
	}

	public static ICollection<T>? IfNotEmpty<T>(this ICollection<T>? @this)
	{
		if (!@this.IsNullOrEmpty())
		{
			return @this;
		}
		return null;
	}

	public static T? IfNotDefault<T>(this T @this) where T : struct
	{
		if (!@this.EqualsDefault())
		{
			return @this;
		}
		return null;
	}

	public static T? SafeIf<T>(this T? @this, Func<T, bool> predicate) where T : class
	{
		if (@this == null)
		{
			return null;
		}
		return @this.If<T>(predicate);
	}

	public static T Else<T>(this T? @this, Func<T> creator) where T : class
	{
		return @this ?? creator();
	}

	public static T Else<T>(this T? @this, Func<T> creator) where T : struct
	{
		return @this ?? creator();
	}

	public static T Else<T>(this T? @this, T otherObj) where T : class
	{
		return @this ?? otherObj;
	}

	public static T Else<T>(this T? @this, T otherObj) where T : struct
	{
		return @this ?? otherObj;
	}

	[return: NotNullIfNotNull("this")]
	public static T? ElseDo<T>(this T? @this, Proc proc) where T : class
	{
		if (@this == null)
		{
			proc();
		}
		return @this;
	}

	public static T SafeDo<T>(this T obj, Proc<T> action)
	{
		if (obj != null)
		{
			action(obj);
		}
		return obj;
	}

	public static U? SafeNav<T, U>(this T obj, Func<T, U> selector)
	{
		if (obj != null)
		{
			return selector(obj);
		}
		return default(U);
	}

	[Obsolete("Use SafePipe")]
	public static U SafeNav<T, U>(this T obj, Func<T, U> selector, U defaultValue)
	{
		if (obj != null)
		{
			return selector(obj);
		}
		return defaultValue;
	}

	public static U Pipe<T, U>(this T @this, Func<T, U> func)
	{
		return func(@this);
	}

	public static T PipeIf<T>(this T @this, Func<T, T> func, bool shouldInvoke)
	{
		if (!shouldInvoke)
		{
			return @this;
		}
		return func(@this);
	}

	public static T PipeIf<T>(this T @this, Func<T, T> func, Func<T, bool> predicate)
	{
		if (!predicate(@this))
		{
			return @this;
		}
		return func(@this);
	}

	public static U? SafePipe<T, U>(this T? @this, Func<T, U> func) where T : class
	{
		if (@this != null)
		{
			return func(@this);
		}
		return default(U);
	}

	public static U? SafePipe<T, U>(this T? @this, Func<T, U> func) where T : struct
	{
		if (@this.HasValue)
		{
			return func(@this.Value);
		}
		return default(U);
	}

	public static U SafePipe<T, U>(this T? @this, Func<T, U> func, U defaultValue) where T : class
	{
		if (@this != null)
		{
			return func(@this);
		}
		return defaultValue;
	}

	public static U SafePipe<T, U>(this T? @this, Func<T, U> func, U defaultValue) where T : struct
	{
		if (@this.HasValue)
		{
			return func(@this.Value);
		}
		return defaultValue;
	}

	public static U? TryPipe<T, U>(this T @this, Func<T, U> func, U? defaultValue = default(U?))
	{
		return Extensions.TryGet((Func<U>)(() => @this.Pipe(func)), defaultValue, true);
	}

	public static U? TrySafePipe<T, U>(this T? @this, Func<T, U> func, U? defaultValue = default(U?)) where T : class
	{
		return @this.SafePipe<T, U>((T it) => it.TryPipe(func, defaultValue), defaultValue);
	}

	public static U? TrySafePipe<T, U>(this T? @this, Func<T, U> func, U? defaultValue = default(U?)) where T : struct
	{
		return @this.SafePipe<T, U>((T it) => it.TryPipe(func, defaultValue), defaultValue);
	}

	public static T Pass<T>(this T @this, Proc<T> interceptor)
	{
		interceptor(@this);
		return @this;
	}

	public static T PassIf<T>(this T @this, Proc<T> interceptor, bool shouldIntercept)
	{
		if (!shouldIntercept)
		{
			return @this;
		}
		return @this.Pass(interceptor);
	}

	public static T PassIf<T>(this T @this, Proc<T> interceptor, Func<T, bool> predicate)
	{
		return @this.PassIf(interceptor, predicate(@this));
	}

	[return: NotNullIfNotNull("this")]
	public static T? SafePass<T>(this T? @this, Proc<T> interceptor) where T : class
	{
		if (@this == null)
		{
			return @this;
		}
		return @this.Pass<T>(interceptor);
	}

	public static T? TryPass<T>(this T @this, Proc<T> interceptor)
	{
		return Extensions.TryGet(() => @this.Pass(interceptor), @this);
	}

	public static T? TrySafePass<T>(this T? @this, Proc<T> interceptor) where T : class
	{
		return @this.SafePass(delegate(T it)
		{
			it.TryPass(interceptor);
		});
	}

	public static T Mutate<T>(this T @this, Proc<T> mutator)
	{
		mutator(@this);
		return @this;
	}

	public static T MutateIf<T>(this T @this, Proc<T> mutator, bool shouldMutate)
	{
		if (!shouldMutate)
		{
			return @this;
		}
		return @this.Mutate(mutator);
	}

	public static T MutateIf<T>(this T @this, Proc<T> mutator, Func<T, bool> predicate)
	{
		return @this.MutateIf(mutator, predicate(@this));
	}

	[return: NotNullIfNotNull("this")]
	public static T? SafeMutate<T>(this T? @this, Proc<T> mutator) where T : class
	{
		if (@this == null)
		{
			return @this;
		}
		return @this.Mutate<T>(mutator);
	}

	public static T TryMutate<T>(this T @this, Proc<T> mutator)
	{
		return Extensions.TryGet(() => @this.Mutate(mutator), @this);
	}

	public static T? TrySafeMutate<T>(this T? @this, Proc<T> mutator) where T : class
	{
		return @this.SafeMutate(delegate(T it)
		{
			it.TryMutate(mutator);
		});
	}
}