using System.Collections.Generic;
using System.Linq;
using System.Security.Claims;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Authorization.Policy;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.SignalR;

namespace Notesnook.API.Authorization
{
    public class SyncRequirement : AuthorizationHandler<SyncRequirement>, IAuthorizationRequirement
    {
        private Dictionary<string, string> pathErrorPhraseMap = new Dictionary<string, string>
        {
            ["/sync/attachments"] = "use attachments",
            ["/sync"] = "sync your notes",
            ["/hubs/sync"] = "sync your notes",
            ["/monographs"] = "publish monographs"
        };

        private string[] allowedClaims = { "trial", "premium", "premium_canceled" };
        protected override Task HandleRequirementAsync(AuthorizationHandlerContext context, SyncRequirement requirement)
        {
            PathString path = context.Resource is DefaultHttpContext httpContext ? httpContext.Request.Path : null;
            var result = this.IsAuthorized(context.User, path);
            if (result.Succeeded) context.Succeed(requirement);
            else
            {
                var hasReason = result.AuthorizationFailure.FailureReasons.Count() > 0;
                if (hasReason)
                    context.Fail(result.AuthorizationFailure.FailureReasons.First());
                else context.Fail();
            }

            return Task.CompletedTask;
        }

        public PolicyAuthorizationResult IsAuthorized(ClaimsPrincipal User, PathString requestPath)
        {
            var id = User.FindFirstValue("sub");

            if (string.IsNullOrEmpty(id))
            {
                var reason = new AuthorizationFailureReason[]
                {
                    new AuthorizationFailureReason(this, "Invalid token.")
                };
                return PolicyAuthorizationResult.Forbid(AuthorizationFailure.Failed(reason));
            }

            var hasSyncScope = User.HasClaim("scope", "notesnook.sync");
            var isInAudience = User.HasClaim("aud", "notesnook");
            var hasRole = User.HasClaim("role", "notesnook");

            var isEmailVerified = User.HasClaim("verified", "true");

            if (!isEmailVerified)
            {
                var phrase = "continue";

                foreach (var item in pathErrorPhraseMap)
                {
                    if (requestPath != null && requestPath.StartsWithSegments(item.Key))
                        phrase = item.Value;
                }

                var error = $"Please confirm your email to {phrase}.";
                var reason = new AuthorizationFailureReason[]
                {
                    new AuthorizationFailureReason(this, error)
                };
                return PolicyAuthorizationResult.Forbid(AuthorizationFailure.Failed(reason));
                //  context.Fail(new AuthorizationFailureReason(this, error));
            }

            var isProOrTrial = User.HasClaim((c) => c.Type == "notesnook:status" && allowedClaims.Contains(c.Value));
            if (hasSyncScope && isInAudience && hasRole && isEmailVerified)
                return PolicyAuthorizationResult.Success(); //(requirement);
            return PolicyAuthorizationResult.Forbid();
        }

        public override Task HandleAsync(AuthorizationHandlerContext context)
        {
            return this.HandleRequirementAsync(context, this);
        }

    }
}