feat: Implement bookmark service.

2 files changed, 124 insertions, 4 deletions

diff --git a/BackEnd/Timeline/Entities/DatabaseContext.cs b/BackEnd/Timeline/Entities/DatabaseContext.cs
index 4205c2cf..513cdc95 100644
--- a/BackEnd/Timeline/Entities/DatabaseContext.cs
+++ b/BackEnd/Timeline/Entities/DatabaseContext.cs
@@ -30,6 +30,7 @@ namespace Timeline.Entities
         public DbSet<TimelinePostEntity> TimelinePosts { get; set; } = default!;

         public DbSet<TimelineMemberEntity> TimelineMembers { get; set; } = default!;

         public DbSet<HighlightTimelineEntity> HighlightTimelines { get; set; } = default!;

+        public DbSet<BookmarkTimelineEntity> BookmarkTimelines { get; set; } = default!;

 

         public DbSet<JwtTokenEntity> JwtToken { get; set; } = default!;

         public DbSet<DataEntity> Data { get; set; } = default!;

diff --git a/BackEnd/Timeline/Services/BookmarkTimelineService.cs b/BackEnd/Timeline/Services/BookmarkTimelineService.cs
index 7eb691b7..f65a1ff0 100644
--- a/BackEnd/Timeline/Services/BookmarkTimelineService.cs
+++ b/BackEnd/Timeline/Services/BookmarkTimelineService.cs
@@ -1,6 +1,9 @@
-using System;

+using Microsoft.EntityFrameworkCore;

+using System;

 using System.Collections.Generic;

+using System.Linq;

 using System.Threading.Tasks;

+using Timeline.Entities;

 using Timeline.Models;

 using Timeline.Services.Exceptions;

 

@@ -59,16 +62,132 @@ namespace Timeline.Services
         /// </summary>

         /// <param name="userId">User id of bookmark owner.</param>

         /// <param name="timelineName">Timeline name.</param>

-        /// <param name="position">New position. Starts at 1.</param>

+        /// <param name="newPosition">New position. Starts at 1.</param>

         /// <exception cref="ArgumentNullException">Thrown when <paramref name="timelineName"/> is null.</exception>

         /// <exception cref="ArgumentException">Thrown when <paramref name="timelineName"/> is not a valid name.</exception>

         /// <exception cref="UserNotExistException">Thrown when user does not exist.</exception>

         /// <exception cref="TimelineNotExistException">Thrown when timeline does not exist.</exception>

         /// <exception cref="InvalidBookmarkException">Thrown when the timeline is not a bookmark.</exception>

-        Task MoveBookmark(long userId, string timelineName, long position);

+        Task MoveBookmark(long userId, string timelineName, long newPosition);

     }

 

-    public class BookmarkTimelineService

+    public class BookmarkTimelineService : IBookmarkTimelineService

     {

+        private readonly DatabaseContext _database;

+        private readonly IBasicUserService _userService;

+        private readonly ITimelineService _timelineService;

+

+        public BookmarkTimelineService(DatabaseContext database, IBasicUserService userService, ITimelineService timelineService)

+        {

+            _database = database;

+            _userService = userService;

+            _timelineService = timelineService;

+        }

+

+        public async Task AddBookmark(long userId, string timelineName)

+        {

+            if (timelineName is null)

+                throw new ArgumentNullException(nameof(timelineName));

+

+            if (!await _userService.CheckUserExistence(userId))

+                throw new UserNotExistException(userId);

+

+            var timelineId = await _timelineService.GetTimelineIdByName(timelineName);

+

+            _database.BookmarkTimelines.Add(new BookmarkTimelineEntity

+            {

+                TimelineId = timelineId,

+                UserId = userId,

+                Rank = (await _database.BookmarkTimelines.CountAsync(t => t.UserId == userId)) + 1

+            });

+

+            await _database.SaveChangesAsync();

+        }

+

+        public async Task<List<TimelineInfo>> GetBookmarks(long userId)

+        {

+            if (!await _userService.CheckUserExistence(userId))

+                throw new UserNotExistException(userId);

+

+            var entities = await _database.BookmarkTimelines.Where(t => t.UserId == userId).Select(t => new { t.TimelineId }).ToListAsync();

+

+            List<TimelineInfo> result = new();

+

+            foreach (var entity in entities)

+            {

+                result.Add(await _timelineService.GetTimelineById(entity.TimelineId));

+            }

+

+            return result;

+        }

+

+        public async Task MoveBookmark(long userId, string timelineName, long newPosition)

+        {

+            if (timelineName == null)

+                throw new ArgumentNullException(nameof(timelineName));

+

+            var timelineId = await _timelineService.GetTimelineIdByName(timelineName);

+

+            var entity = await _database.BookmarkTimelines.SingleOrDefaultAsync(t => t.TimelineId == timelineId && t.UserId == userId);

+

+            if (entity == null) throw new InvalidBookmarkException("You can't move a non-bookmark timeline.");

+

+            var oldPosition = entity.Rank;

+

+            if (newPosition < 1)

+            {

+                newPosition = 1;

+            }

+            else

+            {

+                var totalCount = await _database.HighlightTimelines.CountAsync();

+                if (newPosition > totalCount) newPosition = totalCount;

+            }

+

+            if (oldPosition == newPosition) return;

+

+            await using var transaction = await _database.Database.BeginTransactionAsync();

+

+            if (newPosition > oldPosition)

+            {

+                await _database.Database.ExecuteSqlRawAsync("UPDATE `bookmark_timelines` SET `rank` = `rank` - 1 WHERE `rank` BETWEEN {0} AND {1} AND `user` = {2}", oldPosition + 1, newPosition, userId);

+                await _database.Database.ExecuteSqlRawAsync("UPDATE `bookmark_timelines` SET `rank` = {0} WHERE `id` = {1}", newPosition, entity.Id);

+            }

+            else

+            {

+                await _database.Database.ExecuteSqlRawAsync("UPDATE `bookmark_timelines` SET `rank` = `rank` + 1 WHERE `rank` BETWEEN {0} AND {1} AND `user` = {2}", newPosition, oldPosition - 1, userId);

+                await _database.Database.ExecuteSqlRawAsync("UPDATE `bookmark_timelines` SET `rank` = {0} WHERE `id` = {1}", newPosition, entity.Id);

+            }

+

+            await transaction.CommitAsync();

+        }

+

+        public async Task<bool> RemoveBookmark(long userId, string timelineName)

+        {

+            if (timelineName is null)

+                throw new ArgumentNullException(nameof(timelineName));

+

+            if (!await _userService.CheckUserExistence(userId))

+                throw new UserNotExistException(userId);

+

+            var timelineId = await _timelineService.GetTimelineIdByName(timelineName);

+

+            var entity = await _database.BookmarkTimelines.SingleOrDefaultAsync(t => t.UserId == userId && t.TimelineId == timelineId);

+

+            if (entity == null) return false;

+

+            await using var transaction = await _database.Database.BeginTransactionAsync();

+

+            var rank = entity.Rank;

+

+            _database.BookmarkTimelines.Remove(entity);

+            await _database.SaveChangesAsync();

+

+            await _database.Database.ExecuteSqlRawAsync("UPDATE `bookmark_timelines` SET `rank` = `rank` - 1 WHERE `rank` > {0}", rank);

+

+            await transaction.CommitAsync();

+

+            return true;

+        }

     }

 }