Connected.Common/Common/Documents/Validators.cs

using Connected.Middleware;
using Connected.Security.Identity;
using Connected.Validation;

namespace Common.Documents;
public abstract class InsertDocumentValidator<TDocumentArgs> : MiddlewareComponent, IValidator<TDocumentArgs>
	where TDocumentArgs : InsertDocumentArgs
{
	public InsertDocumentValidator(IUserService users)
	{
		Users = users;
	}
	protected IUserService Users { get; }
	protected TDocumentArgs Arguments { get; private set; }
	public async Task Validate(TDocumentArgs args)
	{
		Arguments = args;

		await ValidateAuthor();
	}

	protected virtual async Task OnValidating()
	{
		await Task.CompletedTask;
	}

	private async Task ValidateAuthor()
	{
		if (Arguments.Author is null)
			return;

		if (await Users.Select(Arguments.Author) is null)
			throw new ArgumentException(nameof(Arguments.Author));
	}
}

public abstract class UpdateDocumentValidator<TDocumentArgs, TPrimaryKey> : MiddlewareComponent, IValidator<TDocumentArgs>
	where TDocumentArgs : UpdateDocumentArgs<TPrimaryKey>
	where TPrimaryKey : notnull
{
	public UpdateDocumentValidator(IUserService users)
	{
		Users = users;
	}

	protected IUserService Users { get; }

	public async Task Validate(TDocumentArgs args)
	{
		await ValidateOwner(args);
	}

	private async Task ValidateOwner(TDocumentArgs args)
	{
		if (args.Owner is null)
			return;

		if (await Users.Select(args.Owner) is null)
			throw new ArgumentException(nameof(args.Owner));
	}
}