using System;
using System.Linq;
using System.Threading.Tasks;

using Microsoft.AspNetCore.Authorization;

using Icarus.Authorization;

namespace Icarus.Authorization.Handlers
{
    public class HasScopeHandler : AuthorizationHandler<HasScopeRequirement>
    {
        protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, HasScopeRequirement requirement)
	{
	    if (!context.User.HasClaim(c => c.Type == "scope" && c.Issuer == requirement.Issuer))
	    {
	        return Task.CompletedTask;
	    }

	    var scopes = context.User.FindFirst(c =>
	        c.Type == "scope" && c.Issuer == requirement.Issuer).Value.Split(' ');

	    if (scopes.Any(s => s == requirement.Scope))
	    {
	        context.Succeed(requirement);
	    }

	    return Task.CompletedTask;
	}
    }
}