using System;
using System.Collections.Generic;
using System.Globalization;
using System.Linq;
using System.Threading.Tasks;
using Microsoft.AspNetCore.Http;
using Microsoft.AspNetCore.Identity;
using Microsoft.Extensions.Logging;
using Microsoft.Extensions.Options;
using Umbraco.Cms.Core.Configuration.Models;
using Umbraco.Cms.Core.Models.PublishedContent;
using Umbraco.Cms.Core.Net;
using Umbraco.Cms.Core.Security;
using Umbraco.Cms.Core.Services;
using Umbraco.Extensions;

namespace Umbraco.Cms.Web.Common.Security
{

    public class MemberManager : UmbracoUserManager<MemberIdentityUser, MemberPasswordConfigurationSettings>, IMemberManager
    {
        private readonly IMemberUserStore _store;
        private readonly IPublicAccessService _publicAccessService;
        private readonly IHttpContextAccessor _httpContextAccessor;
        private MemberIdentityUser _currentMember;

        public MemberManager(
            IIpResolver ipResolver,
            IMemberUserStore store,
            IOptions<IdentityOptions> optionsAccessor,
            IPasswordHasher<MemberIdentityUser> passwordHasher,
            IEnumerable<IUserValidator<MemberIdentityUser>> userValidators,
            IEnumerable<IPasswordValidator<MemberIdentityUser>> passwordValidators,
            IdentityErrorDescriber errors,
            IServiceProvider services,
            ILogger<UserManager<MemberIdentityUser>> logger,
            IOptions<MemberPasswordConfigurationSettings> passwordConfiguration,
            IPublicAccessService publicAccessService,
            IHttpContextAccessor httpContextAccessor)
            : base(ipResolver, store, optionsAccessor, passwordHasher, userValidators, passwordValidators, errors,
                services, logger, passwordConfiguration)
        {
            _store = store;
            _publicAccessService = publicAccessService;
            _httpContextAccessor = httpContextAccessor;
        }

        /// <inheritdoc />
        public override bool SupportsUserTwoFactor => true;

        /// <inheritdoc />
        public async Task<bool> IsMemberAuthorizedAsync(IEnumerable<string> allowTypes = null, IEnumerable<string> allowGroups = null, IEnumerable<int> allowMembers = null)
        {
            if (allowTypes == null)
            {
                allowTypes = Enumerable.Empty<string>();
            }

            if (allowGroups == null)
            {
                allowGroups = Enumerable.Empty<string>();
            }

            if (allowMembers == null)
            {
                allowMembers = Enumerable.Empty<int>();
            }

            // Allow by default
            var allowAction = true;

            if (IsLoggedIn() == false)
            {
                // If not logged on, not allowed
                allowAction = false;
            }
            else
            {
                MemberIdentityUser currentMember = await GetCurrentMemberAsync();

                // If a member could not be resolved from the provider, we are clearly not authorized and can break right here
                if (currentMember == null)
                {
                    return false;
                }

                int memberId = int.Parse(currentMember.Id, CultureInfo.InvariantCulture);

                // If types defined, check member is of one of those types
                IList<string> allowTypesList = allowTypes as IList<string> ?? allowTypes.ToList();
                if (allowTypesList.Any(allowType => allowType != string.Empty))
                {
                    // Allow only if member's type is in list
                    allowAction = allowTypesList.Select(x => x.ToLowerInvariant()).Contains(currentMember.MemberTypeAlias.ToLowerInvariant());
                }

                // If specific members defined, check member is of one of those
                var allowMembersList = allowMembers.ToList();
                if (allowAction && allowMembersList.Any())
                {
                    // Allow only if member's Id is in the list
                    allowAction = allowMembersList.Contains(memberId);
                }

                // If groups defined, check member is of one of those groups
                IList<string> allowGroupsList = allowGroups as IList<string> ?? allowGroups.ToList();
                if (allowAction && allowGroupsList.Any(allowGroup => allowGroup != string.Empty))
                {
                    // Allow only if member is assigned to a group in the list
                    IList<string> groups = await GetRolesAsync(currentMember);
                    allowAction = allowGroupsList.Select(s => s.ToLowerInvariant()).Intersect(groups.Select(myGroup => myGroup.ToLowerInvariant())).Any();
                }
            }

            return allowAction;
        }

        /// <inheritdoc />
        public bool IsLoggedIn()
        {
            HttpContext httpContext = _httpContextAccessor.HttpContext;
            return httpContext?.User.Identity?.IsAuthenticated ?? false;
        }

        /// <inheritdoc />
        public async Task<bool> MemberHasAccessAsync(string path)
        {
            if (await IsProtectedAsync(path))
            {
                return await HasAccessAsync(path);
            }
            return true;
        }

        /// <inheritdoc />
        public async Task<IReadOnlyDictionary<string, bool>> MemberHasAccessAsync(IEnumerable<string> paths)
        {
            IReadOnlyDictionary<string, bool> protectedPaths = await IsProtectedAsync(paths);

            IEnumerable<string> pathsWithProtection = protectedPaths.Where(x => x.Value).Select(x => x.Key);
            IReadOnlyDictionary<string, bool> pathsWithAccess = await HasAccessAsync(pathsWithProtection);

            var result = new Dictionary<string, bool>();
            foreach (var path in paths)
            {
                pathsWithAccess.TryGetValue(path, out var hasAccess);
                // if it's not found it's false anyways
                result[path] = !pathsWithProtection.Contains(path) || hasAccess;
            }
            return result;
        }

        /// <inheritdoc />
        /// <remarks>
        /// this is a cached call
        /// </remarks>
        public Task<bool> IsProtectedAsync(string path) => Task.FromResult(_publicAccessService.IsProtected(path).Success);

        /// <inheritdoc />
        public Task<IReadOnlyDictionary<string, bool>> IsProtectedAsync(IEnumerable<string> paths)
        {
            var result = new Dictionary<string, bool>();
            foreach (var path in paths)
            {
                //this is a cached call
                result[path] = _publicAccessService.IsProtected(path);
            }
            return Task.FromResult((IReadOnlyDictionary<string, bool>)result);
        }

        /// <inheritdoc />
        public async Task<MemberIdentityUser> GetCurrentMemberAsync()
        {
            if (_currentMember == null)
            {
                if (!IsLoggedIn())
                {
                    return null;
                }
                _currentMember = await GetUserAsync(_httpContextAccessor.HttpContext.User);
            }
            return _currentMember;
        }

        /// <summary>
        /// This will check if the member has access to this path
        /// </summary>
        /// <param name="path"></param>
        /// <param name="roleProvider"></param>
        /// <returns></returns>
        private async Task<bool> HasAccessAsync(string path)
        {
            MemberIdentityUser currentMember = await GetCurrentMemberAsync();
            if (currentMember == null || !currentMember.IsApproved || currentMember.IsLockedOut)
            {
                return false;
            }

            return await _publicAccessService.HasAccessAsync(
                path,
                currentMember.UserName,
                async () => await GetRolesAsync(currentMember));
        }

        private async Task<IReadOnlyDictionary<string, bool>> HasAccessAsync(IEnumerable<string> paths)
        {
            var result = new Dictionary<string, bool>();
            MemberIdentityUser currentMember = await GetCurrentMemberAsync();

            if (currentMember == null || !currentMember.IsApproved || currentMember.IsLockedOut)
            {
                return result;
            }

            // ensure we only lookup user roles once
            IList<string> userRoles = null;
            async Task<IList<string>> getUserRolesAsync()
            {
                if (userRoles != null)
                {
                    return userRoles;
                }

                userRoles = await GetRolesAsync(currentMember);
                return userRoles;
            }

            foreach (var path in paths)
            {
                result[path] = await _publicAccessService.HasAccessAsync(
                    path,
                    currentMember.UserName,
                    async () => await getUserRolesAsync());
            }
            return result;
        }

        public IPublishedContent AsPublishedMember(MemberIdentityUser user) => _store.GetPublishedMember(user);
    }
}