using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Umbraco.Cms.Core;
using Umbraco.Cms.Core.Cache;
using Umbraco.Cms.Core.Mapping;
using Umbraco.Cms.Core.Models.ContentEditing;
using Umbraco.Cms.Core.Models.Membership;
using Umbraco.Cms.Core.Security;
using Umbraco.Cms.Core.Services;
using Umbraco.Cms.Core.Strings;
using Umbraco.Cms.Web.BackOffice.Filters;
using Umbraco.Cms.Web.Common.Attributes;
using Umbraco.Cms.Web.Common.Authorization;
using Umbraco.Extensions;

namespace Umbraco.Cms.Web.BackOffice.Controllers;

[PluginController(Constants.Web.Mvc.BackOfficeApiArea)]
[Authorize(Policy = AuthorizationPolicies.SectionAccessUsers)]
[PrefixlessBodyModelValidator]
public class UserGroupsController : BackOfficeNotificationsController
{
    private readonly AppCaches _appCaches;
    private readonly IBackOfficeSecurityAccessor _backofficeSecurityAccessor;
    private readonly IContentService _contentService;
    private readonly IEntityService _entityService;
    private readonly ILocalizedTextService _localizedTextService;
    private readonly IMediaService _mediaService;
    private readonly IShortStringHelper _shortStringHelper;
    private readonly IUmbracoMapper _umbracoMapper;
    private readonly IUserService _userService;

    public UserGroupsController(
        IUserService userService,
        IContentService contentService,
        IEntityService entityService,
        IMediaService mediaService,
        IBackOfficeSecurityAccessor backofficeSecurityAccessor,
        IUmbracoMapper umbracoMapper,
        ILocalizedTextService localizedTextService,
        IShortStringHelper shortStringHelper,
        AppCaches appCaches)
    {
        _userService = userService ?? throw new ArgumentNullException(nameof(userService));
        _contentService = contentService ?? throw new ArgumentNullException(nameof(contentService));
        _entityService = entityService ?? throw new ArgumentNullException(nameof(entityService));
        _mediaService = mediaService ?? throw new ArgumentNullException(nameof(mediaService));
        _backofficeSecurityAccessor = backofficeSecurityAccessor ??
                                      throw new ArgumentNullException(nameof(backofficeSecurityAccessor));
        _umbracoMapper = umbracoMapper ?? throw new ArgumentNullException(nameof(umbracoMapper));
        _localizedTextService =
            localizedTextService ?? throw new ArgumentNullException(nameof(localizedTextService));
        _shortStringHelper = shortStringHelper ?? throw new ArgumentNullException(nameof(shortStringHelper));
        _appCaches = appCaches ?? throw new ArgumentNullException(nameof(appCaches));
    }

    [UserGroupValidate]
    public ActionResult<UserGroupDisplay?> PostSaveUserGroup(UserGroupSave userGroupSave)
    {
        if (userGroupSave == null)
        {
            throw new ArgumentNullException(nameof(userGroupSave));
        }

        //authorize that the user has access to save this user group
        var authHelper = new UserGroupEditorAuthorizationHelper(
            _userService, _contentService, _mediaService, _entityService, _appCaches);

        Attempt<string?> isAuthorized =
            authHelper.AuthorizeGroupAccess(_backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser, userGroupSave.Alias);
        if (isAuthorized == false)
        {
            return Unauthorized(isAuthorized.Result);
        }

        //if sections were added we need to check that the current user has access to that section
        isAuthorized = authHelper.AuthorizeSectionChanges(
            _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser,
            userGroupSave.PersistedUserGroup?.AllowedSections,
            userGroupSave.Sections);
        if (isAuthorized == false)
        {
            return Unauthorized(isAuthorized.Result);
        }

        //if start nodes were changed we need to check that the current user has access to them
        isAuthorized = authHelper.AuthorizeStartNodeChanges(
            _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser,
            userGroupSave.PersistedUserGroup?.StartContentId,
            userGroupSave.StartContentId,
            userGroupSave.PersistedUserGroup?.StartMediaId,
            userGroupSave.StartMediaId);
        if (isAuthorized == false)
        {
            return Unauthorized(isAuthorized.Result);
        }

        //need to ensure current user is in a group if not an admin to avoid a 401
        EnsureNonAdminUserIsInSavedUserGroup(userGroupSave);

        //map the model to the persisted instance
        _umbracoMapper.Map(userGroupSave, userGroupSave.PersistedUserGroup);

        if (userGroupSave.PersistedUserGroup is not null)
        {
            //save the group
            _userService.Save(userGroupSave.PersistedUserGroup, userGroupSave.Users?.ToArray());
        }

        //deal with permissions

        //remove ones that have been removed
        var existing = _userService.GetPermissions(userGroupSave.PersistedUserGroup, true)
            .ToDictionary(x => x.EntityId, x => x);
        if (userGroupSave.AssignedPermissions is not null)
        {
            IEnumerable<int> toRemove = existing.Keys.Except(userGroupSave.AssignedPermissions.Select(x => x.Key));
            foreach (var contentId in toRemove)
            {
                _userService.RemoveUserGroupPermissions(userGroupSave.PersistedUserGroup?.Id ?? default, contentId);
            }

            //update existing
            foreach (KeyValuePair<int, IEnumerable<string>> assignedPermission in userGroupSave.AssignedPermissions)
            {
                _userService.ReplaceUserGroupPermissions(
                    userGroupSave.PersistedUserGroup?.Id ?? default,
                    assignedPermission.Value.Select(x => x[0]),
                    assignedPermission.Key);
            }
        }

        UserGroupDisplay? display = _umbracoMapper.Map<UserGroupDisplay>(userGroupSave.PersistedUserGroup);

        display?.AddSuccessNotification(
            _localizedTextService.Localize("speechBubbles", "operationSavedHeader"),
            _localizedTextService.Localize("speechBubbles", "editUserGroupSaved"));
        return display;
    }

    private void EnsureNonAdminUserIsInSavedUserGroup(UserGroupSave userGroupSave)
    {
        if (_backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.IsAdmin() ?? false)
        {
            return;
        }

        var userIds = userGroupSave.Users?.ToList();
        if (_backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser is null ||
            userIds is null ||
            userIds.Contains(_backofficeSecurityAccessor.BackOfficeSecurity.CurrentUser.Id))
        {
            return;
        }

        userIds.Add(_backofficeSecurityAccessor.BackOfficeSecurity.CurrentUser.Id);
        userGroupSave.Users = userIds;
    }

    /// <summary>
    ///     Returns the scaffold for creating a new user group
    /// </summary>
    /// <returns></returns>
    public UserGroupDisplay? GetEmptyUserGroup() =>
        _umbracoMapper.Map<UserGroupDisplay>(new UserGroup(_shortStringHelper));

    /// <summary>
    ///     Returns all user groups
    /// </summary>
    /// <returns></returns>
    public IEnumerable<UserGroupBasic> GetUserGroups(bool onlyCurrentUserGroups = true)
    {
        var allGroups = _umbracoMapper.MapEnumerable<IUserGroup, UserGroupBasic>(_userService.GetAllUserGroups())
            .ToList();

        var isAdmin = _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.IsAdmin() ?? false;
        if (isAdmin)
        {
            return allGroups;
        }

        if (onlyCurrentUserGroups == false)
        {
            //this user is not an admin so in that case we need to exclude all admin users
            allGroups.RemoveAt(
                allGroups.IndexOf(allGroups.Find(basic => basic.Alias == Constants.Security.AdminGroupAlias)!));
            return allGroups;
        }

        //we cannot return user groups that this user does not have access to
        var currentUserGroups = _backofficeSecurityAccessor.BackOfficeSecurity?.CurrentUser?.Groups.Select(x => x.Alias)
            .ToArray();
        return allGroups.WhereNotNull().Where(x => currentUserGroups?.Contains(x.Alias) ?? false).ToArray();
    }

    /// <summary>
    ///     Return a user group
    /// </summary>
    /// <returns></returns>
    [Authorize(Policy = AuthorizationPolicies.UserBelongsToUserGroupInRequest)]
    public ActionResult<UserGroupDisplay?> GetUserGroup(int id)
    {
        IUserGroup? found = _userService.GetUserGroupById(id);
        if (found == null)
        {
            return NotFound();
        }

        UserGroupDisplay? display = _umbracoMapper.Map<UserGroupDisplay>(found);

        return display;
    }

    [HttpPost]
    [HttpDelete]
    [Authorize(Policy = AuthorizationPolicies.UserBelongsToUserGroupInRequest)]
    public IActionResult PostDeleteUserGroups([FromQuery] int[] userGroupIds)
    {
        IUserGroup[] userGroups = _userService.GetAllUserGroups(userGroupIds)
            //never delete the admin group, sensitive data or translators group
            .Where(x => !x.IsSystemUserGroup())
            .ToArray();
        foreach (IUserGroup userGroup in userGroups)
        {
            _userService.DeleteUserGroup(userGroup);
        }

        if (userGroups.Length > 1)
        {
            return Ok(_localizedTextService.Localize("speechBubbles", "deleteUserGroupsSuccess", new[] { userGroups.Length.ToString() }));
        }

        return Ok(_localizedTextService.Localize("speechBubbles", "deleteUserGroupSuccess", new[] { userGroups[0].Name }));
    }
}