using Microsoft.EntityFrameworkCore; using Microsoft.Extensions.Logging; using SixLabors.ImageSharp; using System; using System.Collections.Generic; using System.Globalization; using System.Linq; using System.Threading.Tasks; using Timeline.Entities; using Timeline.Helpers; using Timeline.Models; using Timeline.Models.Validation; using static Timeline.Resources.Services.TimelineService; namespace Timeline.Services { public enum TimelineUserRelationshipType { Own = 0b1, Join = 0b10, Default = Own | Join } public class TimelineUserRelationship { public TimelineUserRelationship(TimelineUserRelationshipType type, long userId) { Type = type; UserId = userId; } public TimelineUserRelationshipType Type { get; set; } public long UserId { get; set; } } public class PostData : ICacheableData { #pragma warning disable CA1819 // Properties should not return arrays public byte[] Data { get; set; } = default!; #pragma warning restore CA1819 // Properties should not return arrays public string Type { get; set; } = default!; public string ETag { get; set; } = default!; public DateTime? LastModified { get; set; } } /// /// This define the common interface of both personal timeline and normal timeline. /// /// /// The "name" parameter in each method has different meaning. /// => name of the ordinary timeline /// => username of the owner of the personal timeline /// => username if begin with '@' otherwise timeline name /// /// is thrown when name is illegal. /// For ordinary timeline, it means the name is not a valid timeline name. /// For personal timeline, it means the name is not a valid username. /// /// is thrown when timeline does not exist. /// For ordinary timeline, it means the timeline of the name does not exist. /// For personal timeline, it means the user with the username does not exist and the inner exception should be a . /// public interface IBaseTimelineService { /// /// Get the timeline info. /// /// See remarks of . /// The timeline info. /// Thrown when is null. /// See remarks of . /// See remarks of . Task GetTimeline(string name); /// /// Set the properties of a timeline. /// /// See remarks of . /// The new properties. Null member means not to change. /// Thrown when or is null. /// See remarks of . /// See remarks of . Task ChangeProperty(string name, TimelineChangePropertyRequest newProperties); /// /// Get all the posts in the timeline. /// /// See remarks of . /// A list of all posts. /// Thrown when is null. /// See remarks of . /// See remarks of . Task> GetPosts(string name); /// /// Get the etag of data of a post. /// /// See remarks of . /// The id of the post. /// The etag of the data. /// Thrown when is null. /// See remarks of . /// See remarks of . /// Thrown when post of does not exist or has been deleted. /// Thrown when post has no data. See remarks. /// Task GetPostDataETag(string name, long postId); /// /// Get the data of a post. /// /// See remarks of . /// The id of the post. /// The data and its type. /// Thrown when is null. /// See remarks of . /// See remarks of . /// Thrown when post of does not exist or has been deleted. /// Thrown when post has no data. See remarks. /// /// Use this method to retrieve the image of image post. /// /// Task GetPostData(string name, long postId); /// /// Create a new text post in timeline. /// /// See remarks of . /// The author's user id. /// The content text. /// The time of the post. If null, then use current time. /// The info of the created post. /// Thrown when or is null. /// See remarks of . /// See remarks of . /// Thrown if user with does not exist. Task CreateTextPost(string name, long authorId, string text, DateTime? time); /// /// Create a new image post in timeline. /// /// See remarks of . /// The author's user id. /// The image data. /// The time of the post. If null, then use current time. /// The info of the created post. /// Thrown when or is null. /// See remarks of . /// See remarks of . /// Thrown if user with does not exist. /// Thrown if data is not a image. Validated by . Task CreateImagePost(string name, long authorId, byte[] data, DateTime? time); /// /// Delete a post. /// /// See remarks of . /// The id of the post to delete. /// Thrown when is null. /// See remarks of . /// See remarks of . /// /// Thrown when the post with given id does not exist or is deleted already. /// /// /// First use /// to check the permission. /// Task DeletePost(string name, long id); /// /// Remove members to a timeline. /// /// See remarks of . /// A list of usernames of members to add. May be null. /// A list of usernames of members to remove. May be null. /// Thrown when is null. /// See remarks of . /// See remarks of . /// Thrown when names in or is not a valid username. /// /// Thrown when one of the user to change does not exist. /// /// /// Operating on a username that is of bad format or does not exist always throws. /// Add a user that already is a member has no effects. /// Remove a user that is not a member also has not effects. /// Add and remove an identical user results in no effects. /// More than one same usernames are regarded as one. /// Task ChangeMember(string name, IList? add, IList? remove); /// /// Check whether a user can manage(change timeline info, member, ...) a timeline. /// /// See remarks of . /// The user id. /// True if the user can manage the timeline, otherwise false. /// Thrown when is null. /// See remarks of . /// See remarks of . /// /// This method does not check whether visitor is administrator. /// Return false if user with user id does not exist. /// Task HasManagePermission(string name, long userId); /// /// Verify whether a visitor has the permission to read a timeline. /// /// See remarks of . /// The id of the user to check on. Null means visitor without account. /// True if can read, false if can't read. /// Thrown when is null. /// See remarks of . /// See remarks of . /// /// This method does not check whether visitor is administrator. /// Return false if user with visitor id does not exist. /// Task HasReadPermission(string name, long? visitorId); /// /// Verify whether a user has the permission to modify a post. /// /// See remarks of . /// The id of the user to check on. /// True if you want it to throw . Default false. /// True if can modify, false if can't modify. /// Thrown when is null. /// See remarks of . /// See remarks of . /// Thrown when the post with given id does not exist or is deleted already and is true. /// /// This method does not check whether the user is administrator. /// It only checks whether he is the author of the post or the owner of the timeline. /// Return false when user with modifier id does not exist. /// Task HasPostModifyPermission(string name, long id, long modifierId, bool throwOnPostNotExist = false); /// /// Verify whether a user is member of a timeline. /// /// See remarks of . /// The id of user to check on. /// True if it is a member, false if not. /// Thrown when is null. /// See remarks of . /// See remarks of . /// /// Timeline owner is also considered as a member. /// Return false when user with user id does not exist. /// Task IsMemberOf(string name, long userId); } /// /// Service for normal timeline. /// public interface ITimelineService : IBaseTimelineService { /// /// Get all timelines including personal timelines. /// /// Filter timelines related (own or is a member) to specific user. /// Filter timelines with given visibility. If null or empty, all visibilities are returned. Duplicate value are ignored. /// The list of timelines. /// /// If user with related user id does not exist, empty list will be returned. /// Task> GetTimelines(TimelineUserRelationship? relate = null, List? visibility = null); /// /// Create a timeline. /// /// The name of the timeline. /// The id of owner of the timeline. /// The info of the new timeline. /// Thrown when is null. /// Thrown when timeline name is invalid. /// Thrown when the timeline already exists. /// Thrown when the owner user does not exist. Task CreateTimeline(string name, long owner); /// /// Delete a timeline. /// /// The name of the timeline. /// Thrown when is null. /// Thrown when timeline name is invalid. /// Thrown when the timeline does not exist. Task DeleteTimeline(string name); } public interface IOrdinaryTimelineService : IBaseTimelineService { } public interface IPersonalTimelineService : IBaseTimelineService { } public abstract class BaseTimelineService : IBaseTimelineService { protected BaseTimelineService(ILoggerFactory loggerFactory, DatabaseContext database, IImageValidator imageValidator, IDataManager dataManager, IUserService userService, IClock clock) { _logger = loggerFactory.CreateLogger(); Clock = clock; Database = database; ImageValidator = imageValidator; DataManager = dataManager; UserService = userService; } private ILogger _logger; protected IClock Clock { get; } protected UsernameValidator UsernameValidator { get; } = new UsernameValidator(); protected DatabaseContext Database { get; } protected IImageValidator ImageValidator { get; } protected IDataManager DataManager { get; } protected IUserService UserService { get; } /// /// Find the timeline id by the name. /// For details, see remarks. /// /// The username or the timeline name. See remarks. /// The id of the timeline entity. /// Thrown when is null. /// Thrown when is illegal. It is not a valid timeline name (for normal timeline service) or a valid username (for personal timeline service). /// /// Thrown when timeline does not exist. /// For normal timeline, it means the name does not exist. /// For personal timeline, it means the user of that username does not exist /// and the inner exception should be a . /// /// /// This is the common but different part for both types of timeline service. /// For class that implements , this method should /// find the timeline entity id by the given as the username of the owner. /// For class that implements , this method should /// find the timeline entity id by the given as the timeline name. /// This method should be called by many other method that follows the contract. /// protected abstract Task FindTimelineId(string name); protected abstract string GenerateName(string name); public async Task GetTimeline(string name) { if (name == null) throw new ArgumentNullException(nameof(name)); var timelineId = await FindTimelineId(name); var timelineEntity = await Database.Timelines.Where(t => t.Id == timelineId).SingleAsync(); var timelineMemberEntities = await Database.TimelineMembers.Where(m => m.TimelineId == timelineId).Select(m => new { m.UserId }).ToListAsync(); var owner = await UserService.GetUserById(timelineEntity.OwnerId); var members = new List(); foreach (var memberEntity in timelineMemberEntities) { members.Add(await UserService.GetUserById(memberEntity.UserId)); } return new Models.Timeline { Name = GenerateName(name), Description = timelineEntity.Description ?? "", Owner = owner, Visibility = timelineEntity.Visibility, Members = members }; } public async Task> GetPosts(string name) { if (name == null) throw new ArgumentNullException(nameof(name)); var timelineId = await FindTimelineId(name); var postEntities = await Database.TimelinePosts.OrderBy(p => p.Time).Where(p => p.TimelineId == timelineId && p.Content != null).ToListAsync(); var posts = new List(); foreach (var entity in postEntities) { if (entity.Content != null) // otherwise it is deleted { var author = await UserService.GetUserById(entity.AuthorId); var type = entity.ContentType; ITimelinePostContent content = type switch { TimelinePostContentTypes.Text => new TextTimelinePostContent(entity.Content), TimelinePostContentTypes.Image => new ImageTimelinePostContent(entity.Content), _ => throw new DatabaseCorruptedException(string.Format(CultureInfo.InvariantCulture, ExceptionDatabaseUnknownContentType, type)) }; posts.Add(new TimelinePost( id: entity.LocalId, content: content, time: entity.Time, author: author, lastUpdated: entity.LastUpdated, timelineName: GenerateName(name) )); } } return posts; } public async Task GetPostDataETag(string name, long postId) { if (name == null) throw new ArgumentNullException(nameof(name)); var timelineId = await FindTimelineId(name); var postEntity = await Database.TimelinePosts.Where(p => p.TimelineId == timelineId && p.LocalId == postId).SingleOrDefaultAsync(); if (postEntity == null) throw new TimelinePostNotExistException(name, postId); if (postEntity.Content == null) throw new TimelinePostNotExistException(name, postId, true); if (postEntity.ContentType != TimelinePostContentTypes.Image) throw new BadPostTypeException(postEntity.ContentType, TimelinePostContentTypes.Image, ExceptionGetDataNonImagePost); var tag = postEntity.Content; return tag; } public async Task GetPostData(string name, long postId) { if (name == null) throw new ArgumentNullException(nameof(name)); var timelineId = await FindTimelineId(name); var postEntity = await Database.TimelinePosts.Where(p => p.TimelineId == timelineId && p.LocalId == postId).SingleOrDefaultAsync(); if (postEntity == null) throw new TimelinePostNotExistException(name, postId); if (postEntity.Content == null) throw new TimelinePostNotExistException(name, postId, true); if (postEntity.ContentType != TimelinePostContentTypes.Image) throw new BadPostTypeException(postEntity.ContentType, TimelinePostContentTypes.Image, ExceptionGetDataNonImagePost); var tag = postEntity.Content; byte[] data; try { data = await DataManager.GetEntry(tag); } catch (InvalidOperationException e) { throw new DatabaseCorruptedException(ExceptionGetDataDataEntryNotExist, e); } if (postEntity.ExtraContent == null) { _logger.LogWarning(LogGetDataNoFormat); var format = Image.DetectFormat(data); postEntity.ExtraContent = format.DefaultMimeType; await Database.SaveChangesAsync(); } return new PostData { Data = data, Type = postEntity.ExtraContent, ETag = tag, LastModified = postEntity.LastUpdated }; } public async Task CreateTextPost(string name, long authorId, string text, DateTime? time) { if (name == null) throw new ArgumentNullException(nameof(name)); if (text == null) throw new ArgumentNullException(nameof(text)); var timelineId = await FindTimelineId(name); var timelineEntity = await Database.Timelines.Where(t => t.Id == timelineId).SingleAsync(); var author = await UserService.GetUserById(authorId); var currentTime = Clock.GetCurrentTime(); var finalTime = time ?? currentTime; timelineEntity.CurrentPostLocalId += 1; var postEntity = new TimelinePostEntity { LocalId = timelineEntity.CurrentPostLocalId, ContentType = TimelinePostContentTypes.Text, Content = text, AuthorId = authorId, TimelineId = timelineId, Time = finalTime, LastUpdated = currentTime }; Database.TimelinePosts.Add(postEntity); await Database.SaveChangesAsync(); return new TimelinePost( id: postEntity.LocalId, content: new TextTimelinePostContent(text), time: finalTime, author: author, lastUpdated: currentTime, timelineName: GenerateName(name) ); } public async Task CreateImagePost(string name, long authorId, byte[] data, DateTime? time) { if (name == null) throw new ArgumentNullException(nameof(name)); if (data == null) throw new ArgumentNullException(nameof(data)); var timelineId = await FindTimelineId(name); var timelineEntity = await Database.Timelines.Where(t => t.Id == timelineId).SingleAsync(); var author = await UserService.GetUserById(authorId); var imageFormat = await ImageValidator.Validate(data); var imageFormatText = imageFormat.DefaultMimeType; var tag = await DataManager.RetainEntry(data); var currentTime = Clock.GetCurrentTime(); var finalTime = time ?? currentTime; timelineEntity.CurrentPostLocalId += 1; var postEntity = new TimelinePostEntity { LocalId = timelineEntity.CurrentPostLocalId, ContentType = TimelinePostContentTypes.Image, Content = tag, ExtraContent = imageFormatText, AuthorId = authorId, TimelineId = timelineId, Time = finalTime, LastUpdated = currentTime }; Database.TimelinePosts.Add(postEntity); await Database.SaveChangesAsync(); return new TimelinePost( id: postEntity.LocalId, content: new ImageTimelinePostContent(tag), time: finalTime, author: author, lastUpdated: currentTime, timelineName: GenerateName(name) ); } public async Task DeletePost(string name, long id) { if (name == null) throw new ArgumentNullException(nameof(name)); var timelineId = await FindTimelineId(name); var post = await Database.TimelinePosts.Where(p => p.TimelineId == timelineId && p.LocalId == id).SingleOrDefaultAsync(); if (post == null || post.Content == null) throw new TimelinePostNotExistException(name, id); string? dataTag = null; if (post.ContentType == TimelinePostContentTypes.Image) { dataTag = post.Content; } post.Content = null; post.LastUpdated = Clock.GetCurrentTime(); await Database.SaveChangesAsync(); if (dataTag != null) { await DataManager.FreeEntry(dataTag); } } public async Task ChangeProperty(string name, TimelineChangePropertyRequest newProperties) { if (name == null) throw new ArgumentNullException(nameof(name)); if (newProperties == null) throw new ArgumentNullException(nameof(newProperties)); var timelineId = await FindTimelineId(name); var timelineEntity = await Database.Timelines.Where(t => t.Id == timelineId).SingleAsync(); if (newProperties.Description != null) { timelineEntity.Description = newProperties.Description; } if (newProperties.Visibility.HasValue) { timelineEntity.Visibility = newProperties.Visibility.Value; } await Database.SaveChangesAsync(); } public async Task ChangeMember(string name, IList? add, IList? remove) { if (name == null) throw new ArgumentNullException(nameof(name)); List? RemoveDuplicateAndCheckFormat(IList? list, string paramName) { if (list != null) { List result = new List(); var count = list.Count; for (var index = 0; index < count; index++) { var username = list[index]; if (result.Contains(username)) { continue; } var (validationResult, message) = UsernameValidator.Validate(username); if (!validationResult) throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, ExceptionChangeMemberUsernameBadFormat, index), nameof(paramName)); result.Add(username); } return result; } else { return null; } } var simplifiedAdd = RemoveDuplicateAndCheckFormat(add, nameof(add)); var simplifiedRemove = RemoveDuplicateAndCheckFormat(remove, nameof(remove)); // remove those both in add and remove if (simplifiedAdd != null && simplifiedRemove != null) { var usersToClean = simplifiedRemove.Where(u => simplifiedAdd.Contains(u)).ToList(); foreach (var u in usersToClean) { simplifiedAdd.Remove(u); simplifiedRemove.Remove(u); } } var timelineId = await FindTimelineId(name); async Task?> CheckExistenceAndGetId(List? list) { if (list == null) return null; List result = new List(); foreach (var username in list) { result.Add(await UserService.GetUserIdByUsername(username)); } return result; } var userIdsAdd = await CheckExistenceAndGetId(simplifiedAdd); var userIdsRemove = await CheckExistenceAndGetId(simplifiedRemove); if (userIdsAdd != null) { var membersToAdd = userIdsAdd.Select(id => new TimelineMemberEntity { UserId = id, TimelineId = timelineId }).ToList(); Database.TimelineMembers.AddRange(membersToAdd); } if (userIdsRemove != null) { var membersToRemove = await Database.TimelineMembers.Where(m => m.TimelineId == timelineId && userIdsRemove.Contains(m.UserId)).ToListAsync(); Database.TimelineMembers.RemoveRange(membersToRemove); } await Database.SaveChangesAsync(); } public async Task HasManagePermission(string name, long userId) { if (name == null) throw new ArgumentNullException(nameof(name)); var timelineId = await FindTimelineId(name); var timelineEntity = await Database.Timelines.Where(t => t.Id == timelineId).Select(t => new { t.OwnerId }).SingleAsync(); return userId == timelineEntity.OwnerId; } public async Task HasReadPermission(string name, long? visitorId) { if (name == null) throw new ArgumentNullException(nameof(name)); var timelineId = await FindTimelineId(name); var timelineEntity = await Database.Timelines.Where(t => t.Id == timelineId).Select(t => new { t.Visibility }).SingleAsync(); if (timelineEntity.Visibility == TimelineVisibility.Public) return true; if (timelineEntity.Visibility == TimelineVisibility.Register && visitorId != null) return true; if (visitorId == null) { return false; } else { var memberEntity = await Database.TimelineMembers.Where(m => m.UserId == visitorId && m.TimelineId == timelineId).SingleOrDefaultAsync(); return memberEntity != null; } } public async Task HasPostModifyPermission(string name, long id, long modifierId, bool throwOnPostNotExist = false) { if (name == null) throw new ArgumentNullException(nameof(name)); var timelineId = await FindTimelineId(name); var timelineEntity = await Database.Timelines.Where(t => t.Id == timelineId).Select(t => new { t.OwnerId }).SingleAsync(); var postEntity = await Database.TimelinePosts.Where(p => p.Id == id).Select(p => new { p.AuthorId }).SingleOrDefaultAsync(); if (postEntity == null && throwOnPostNotExist) { throw new TimelinePostNotExistException(name, id, false); } return timelineEntity.OwnerId == modifierId || postEntity == null || postEntity.AuthorId == modifierId; } public async Task IsMemberOf(string name, long userId) { if (name == null) throw new ArgumentNullException(nameof(name)); var timelineId = await FindTimelineId(name); var timelineEntity = await Database.Timelines.Where(t => t.Id == timelineId).Select(t => new { t.OwnerId }).SingleAsync(); if (userId == timelineEntity.OwnerId) return true; return await Database.TimelineMembers.AnyAsync(m => m.TimelineId == timelineId && m.UserId == userId); } } public class OrdinaryTimelineService : BaseTimelineService, IOrdinaryTimelineService { private readonly TimelineNameValidator _timelineNameValidator = new TimelineNameValidator(); private void ValidateTimelineName(string name, string paramName) { if (!_timelineNameValidator.Validate(name, out var message)) { throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, ExceptionTimelineNameBadFormat, message), paramName); } } public OrdinaryTimelineService(ILoggerFactory loggerFactory, DatabaseContext database, IImageValidator imageValidator, IDataManager dataManager, IUserService userService, IClock clock) : base(loggerFactory, database, imageValidator, dataManager, userService, clock) { } protected override async Task FindTimelineId(string name) { if (name == null) throw new ArgumentNullException(nameof(name)); ValidateTimelineName(name, nameof(name)); var timelineEntity = await Database.Timelines.Where(t => t.Name == name).Select(t => new { t.Id }).SingleOrDefaultAsync(); if (timelineEntity == null) { throw new TimelineNotExistException(name); } else { return timelineEntity.Id; } } protected override string GenerateName(string name) { return name; } } public class PersonalTimelineService : BaseTimelineService, IPersonalTimelineService { public PersonalTimelineService(ILoggerFactory loggerFactory, DatabaseContext database, IImageValidator imageValidator, IDataManager dataManager, IUserService userService, IClock clock) : base(loggerFactory, database, imageValidator, dataManager, userService, clock) { } protected override async Task FindTimelineId(string name) { if (name == null) throw new ArgumentNullException(nameof(name)); long userId; try { userId = await UserService.GetUserIdByUsername(name); } catch (ArgumentException e) { throw new ArgumentException(ExceptionFindTimelineUsernameBadFormat, nameof(name), e); } catch (UserNotExistException e) { throw new TimelineNotExistException(name, e); } var timelineEntity = await Database.Timelines.Where(t => t.OwnerId == userId && t.Name == null).Select(t => new { t.Id }).SingleOrDefaultAsync(); if (timelineEntity != null) { return timelineEntity.Id; } else { var newTimelineEntity = new TimelineEntity { CurrentPostLocalId = 0, Name = null, OwnerId = userId, Visibility = TimelineVisibility.Register, CreateTime = Clock.GetCurrentTime() }; Database.Timelines.Add(newTimelineEntity); await Database.SaveChangesAsync(); return newTimelineEntity.Id; } } protected override string GenerateName(string name) { return "@" + name; } } public class TimelineService : ITimelineService { private readonly TimelineNameValidator _timelineNameValidator = new TimelineNameValidator(); private readonly DatabaseContext _database; private readonly IUserService _userService; private readonly IClock _clock; private readonly IOrdinaryTimelineService _ordinaryTimelineService; private readonly IPersonalTimelineService _personalTimelineService; public TimelineService(DatabaseContext database, IUserService userService, IClock clock, IOrdinaryTimelineService ordinaryTimelineService, IPersonalTimelineService personalTimelineService) { _database = database; _userService = userService; _clock = clock; _ordinaryTimelineService = ordinaryTimelineService; _personalTimelineService = personalTimelineService; } private void ValidateTimelineName(string name, string paramName) { if (!_timelineNameValidator.Validate(name, out var message)) { throw new ArgumentException(string.Format(CultureInfo.CurrentCulture, ExceptionTimelineNameBadFormat, message), paramName); } } public async Task> GetTimelines(TimelineUserRelationship? relate = null, List? visibility = null) { List entities; IQueryable ApplyTimelineVisibilityFilter(IQueryable query) { if (visibility != null && visibility.Count != 0) { return query.Where(t => visibility.Contains(t.Visibility)); } return query; } bool allVisibilities = visibility == null || visibility.Count == 0; if (relate == null) { entities = await ApplyTimelineVisibilityFilter(_database.Timelines).Include(t => t.Members).ToListAsync(); } else { entities = new List(); if ((relate.Type & TimelineUserRelationshipType.Own) != 0) { entities.AddRange(await ApplyTimelineVisibilityFilter(_database.Timelines.Where(t => t.OwnerId == relate.UserId)).Include(t => t.Members).ToListAsync()); } if ((relate.Type & TimelineUserRelationshipType.Join) != 0) { entities.AddRange(await ApplyTimelineVisibilityFilter(_database.TimelineMembers.Where(m => m.UserId == relate.UserId).Include(m => m.Timeline).ThenInclude(t => t.Members).Select(m => m.Timeline)).ToListAsync()); } } var result = new List(); foreach (var entity in entities) { var owner = await _userService.GetUserById(entity.OwnerId); var timeline = new Models.Timeline { Name = entity.Name ?? ("@" + owner.Username), Description = entity.Description ?? "", Owner = owner, Visibility = entity.Visibility, Members = new List() }; foreach (var m in entity.Members) { timeline.Members.Add(await _userService.GetUserById(m.UserId)); } result.Add(timeline); } return result; } public async Task CreateTimeline(string name, long owner) { if (name == null) throw new ArgumentNullException(nameof(name)); ValidateTimelineName(name, nameof(name)); var user = await _userService.GetUserById(owner); var conflict = await _database.Timelines.AnyAsync(t => t.Name == name); if (conflict) throw new ConflictException(ExceptionTimelineNameConflict); var newEntity = new TimelineEntity { CurrentPostLocalId = 0, Name = name, OwnerId = owner, Visibility = TimelineVisibility.Register, CreateTime = _clock.GetCurrentTime() }; _database.Timelines.Add(newEntity); await _database.SaveChangesAsync(); return new Models.Timeline { Name = name, Description = "", Owner = user, Visibility = newEntity.Visibility, Members = new List() }; } public async Task DeleteTimeline(string name) { if (name == null) throw new ArgumentNullException(nameof(name)); ValidateTimelineName(name, nameof(name)); var entity = await _database.Timelines.Where(t => t.Name == name).SingleOrDefaultAsync(); if (entity == null) throw new TimelineNotExistException(name); _database.Timelines.Remove(entity); await _database.SaveChangesAsync(); } private IBaseTimelineService BranchName(string name, out string realName) { if (name == null) throw new ArgumentNullException(nameof(name)); if (name.StartsWith('@')) { realName = name.Substring(1); return _personalTimelineService; } else { realName = name; return _ordinaryTimelineService; } } public Task GetTimeline(string name) { var s = BranchName(name, out var realName); return s.GetTimeline(realName); } public Task ChangeProperty(string name, TimelineChangePropertyRequest newProperties) { var s = BranchName(name, out var realName); return s.ChangeProperty(realName, newProperties); } public Task> GetPosts(string name) { var s = BranchName(name, out var realName); return s.GetPosts(realName); } public Task GetPostDataETag(string name, long postId) { var s = BranchName(name, out var realName); return s.GetPostDataETag(realName, postId); } public Task GetPostData(string name, long postId) { var s = BranchName(name, out var realName); return s.GetPostData(realName, postId); } public Task CreateTextPost(string name, long authorId, string text, DateTime? time) { var s = BranchName(name, out var realName); return s.CreateTextPost(realName, authorId, text, time); } public Task CreateImagePost(string name, long authorId, byte[] data, DateTime? time) { var s = BranchName(name, out var realName); return s.CreateImagePost(realName, authorId, data, time); } public Task DeletePost(string name, long id) { var s = BranchName(name, out var realName); return s.DeletePost(realName, id); } public Task ChangeMember(string name, IList? add, IList? remove) { var s = BranchName(name, out var realName); return s.ChangeMember(realName, add, remove); } public Task HasManagePermission(string name, long userId) { var s = BranchName(name, out var realName); return s.HasManagePermission(realName, userId); } public Task HasReadPermission(string name, long? visitorId) { var s = BranchName(name, out var realName); return s.HasReadPermission(realName, visitorId); } public Task HasPostModifyPermission(string name, long id, long modifierId, bool throwOnPostNotExist = false) { var s = BranchName(name, out var realName); return s.HasPostModifyPermission(realName, id, modifierId, throwOnPostNotExist); } public Task IsMemberOf(string name, long userId) { var s = BranchName(name, out var realName); return s.IsMemberOf(realName, userId); } } }