Kavita/API/Controllers/ReaderController.cs

using System;
using System.Collections.Generic;
using System.IO;
using System.Linq;
using System.Threading.Tasks;
using API.Data;
using API.Data.Repositories;
using API.DTOs;
using API.DTOs.Filtering;
using API.DTOs.Reader;
using API.Entities;
using API.Entities.Enums;
using API.Extensions;
using API.Services;
using API.Services.Tasks;
using Hangfire;
using Microsoft.AspNetCore.Authorization;
using Microsoft.AspNetCore.Mvc;
using Microsoft.Extensions.Logging;
using Microsoft.IdentityModel.Tokens;

namespace API.Controllers;

/// <summary>
/// For all things regarding reading, mainly focusing on non-Book related entities
/// </summary>
public class ReaderController : BaseApiController
{
    private readonly ICacheService _cacheService;
    private readonly IUnitOfWork _unitOfWork;
    private readonly ILogger<ReaderController> _logger;
    private readonly IReaderService _readerService;
    private readonly IBookmarkService _bookmarkService;
    private readonly IAccountService _accountService;

    /// <inheritdoc />
    public ReaderController(ICacheService cacheService,
        IUnitOfWork unitOfWork, ILogger<ReaderController> logger,
        IReaderService readerService, IBookmarkService bookmarkService,
        IAccountService accountService)
    {
        _cacheService = cacheService;
        _unitOfWork = unitOfWork;
        _logger = logger;
        _readerService = readerService;
        _bookmarkService = bookmarkService;
        _accountService = accountService;
    }

    /// <summary>
    /// Returns the PDF for the chapterId.
    /// </summary>
    /// <param name="chapterId"></param>
    /// <returns></returns>
    [HttpGet("pdf")]
    [ResponseCache(CacheProfileName = "Hour")]
    public async Task<ActionResult> GetPdf(int chapterId)
    {
        var chapter = await _cacheService.Ensure(chapterId);
        if (chapter == null) return BadRequest("There was an issue finding pdf file for reading");

        // Validate the user has access to the PDF
        var series = await _unitOfWork.SeriesRepository.GetSeriesForChapter(chapter.Id,
            await _unitOfWork.UserRepository.GetUserIdByUsernameAsync(User.GetUsername()));
        if (series == null) return BadRequest("Invalid Access");

        try
        {

            var path = _cacheService.GetCachedFile(chapter);
            if (string.IsNullOrEmpty(path) || !System.IO.File.Exists(path)) return BadRequest($"Pdf doesn't exist when it should.");

            return PhysicalFile(path, "application/pdf", Path.GetFileName(path), true);
        }
        catch (Exception)
        {
            _cacheService.CleanupChapters(new []{ chapterId });
            throw;
        }
    }

    /// <summary>
    /// Returns an image for a given chapter. Side effect: This will cache the chapter images for reading.
    /// </summary>
    /// <param name="chapterId"></param>
    /// <param name="page"></param>
    /// <returns></returns>
    [HttpGet("image")]
    [ResponseCache(CacheProfileName = "Hour")]
    [AllowAnonymous]
    public async Task<ActionResult> GetImage(int chapterId, int page)
    {
        if (page < 0) page = 0;
        var chapter = await _cacheService.Ensure(chapterId);
        if (chapter == null) return BadRequest("There was an issue finding image file for reading");

        try
        {
            var path = _cacheService.GetCachedPagePath(chapter, page);
            if (string.IsNullOrEmpty(path) || !System.IO.File.Exists(path)) return BadRequest($"No such image for page {page}. Try refreshing to allow re-cache.");
            var format = Path.GetExtension(path).Replace(".", "");

            return PhysicalFile(path, "image/" + format, Path.GetFileName(path), true);
        }
        catch (Exception)
        {
            _cacheService.CleanupChapters(new []{ chapterId });
            throw;
        }
    }

    /// <summary>
    /// Returns an image for a given bookmark series. Side effect: This will cache the bookmark images for reading.
    /// </summary>
    /// <param name="seriesId"></param>
    /// <param name="apiKey">Api key for the user the bookmarks are on</param>
    /// <param name="page"></param>
    /// <remarks>We must use api key as bookmarks could be leaked to other users via the API</remarks>
    /// <returns></returns>
    [HttpGet("bookmark-image")]
    [ResponseCache(CacheProfileName = "Hour")]
    [AllowAnonymous]
    public async Task<ActionResult> GetBookmarkImage(int seriesId, string apiKey, int page)
    {
        if (page < 0) page = 0;
        var userId = await _unitOfWork.UserRepository.GetUserIdByApiKeyAsync(apiKey);

        // NOTE: I'm not sure why I need this flow here
        var totalPages = await _cacheService.CacheBookmarkForSeries(userId, seriesId);
        if (page > totalPages)
        {
            page = totalPages;
        }

        try
        {
            var path = _cacheService.GetCachedBookmarkPagePath(seriesId, page);
            if (string.IsNullOrEmpty(path) || !System.IO.File.Exists(path)) return BadRequest($"No such image for page {page}");
            var format = Path.GetExtension(path).Replace(".", "");

            return PhysicalFile(path, "image/" + format, Path.GetFileName(path));
        }
        catch (Exception)
        {
            _cacheService.CleanupBookmarks(new []{ seriesId });
            throw;
        }
    }

    /// <summary>
    /// Returns various information about a Chapter. Side effect: This will cache the chapter images for reading.
    /// </summary>
    /// <param name="chapterId"></param>
    /// <returns></returns>
    [HttpGet("chapter-info")]
    public async Task<ActionResult<ChapterInfoDto>> GetChapterInfo(int chapterId)
    {
        if (chapterId <= 0) return null; // This can happen occasionally from UI, we should just ignore
        var chapter = await _cacheService.Ensure(chapterId);
        if (chapter == null) return BadRequest("Could not find Chapter");

        var dto = await _unitOfWork.ChapterRepository.GetChapterInfoDtoAsync(chapterId);
        if (dto == null) return BadRequest("Please perform a scan on this series or library and try again");
        var mangaFile = (await _unitOfWork.ChapterRepository.GetFilesForChapterAsync(chapterId)).First();

        var info = new ChapterInfoDto()
        {
            ChapterNumber = dto.ChapterNumber,
            VolumeNumber = dto.VolumeNumber,
            VolumeId = dto.VolumeId,
            FileName = Path.GetFileName(mangaFile.FilePath),
            SeriesName = dto.SeriesName,
            SeriesFormat = dto.SeriesFormat,
            SeriesId = dto.SeriesId,
            LibraryId = dto.LibraryId,
            IsSpecial = dto.IsSpecial,
            Pages = dto.Pages,
            ChapterTitle = dto.ChapterTitle ?? string.Empty,
            Subtitle = string.Empty,
            Title = dto.SeriesName
        };

        if (info.ChapterTitle is {Length: > 0}) {
            info.Title += " - " + info.ChapterTitle;
        }

        if (info.IsSpecial && dto.VolumeNumber.Equals(Services.Tasks.Scanner.Parser.Parser.DefaultVolume))
        {
            info.Subtitle = info.FileName;
        } else if (!info.IsSpecial && info.VolumeNumber.Equals(Services.Tasks.Scanner.Parser.Parser.DefaultVolume))
        {
            info.Subtitle = _readerService.FormatChapterName(info.LibraryType, true, true) + info.ChapterNumber;
        }
        else
        {
            info.Subtitle = "Volume " + info.VolumeNumber;
            if (!info.ChapterNumber.Equals(Services.Tasks.Scanner.Parser.Parser.DefaultChapter))
            {
                info.Subtitle += " " + _readerService.FormatChapterName(info.LibraryType, true, true) +
                                 info.ChapterNumber;
            }
        }

        return Ok(info);
    }

    /// <summary>
    /// Returns various information about all bookmark files for a Series. Side effect: This will cache the bookmark images for reading.
    /// </summary>
    /// <param name="seriesId">Series Id for all bookmarks</param>
    /// <returns></returns>
    [HttpGet("bookmark-info")]
    public async Task<ActionResult<BookmarkInfoDto>> GetBookmarkInfo(int seriesId)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername());
        var totalPages = await _cacheService.CacheBookmarkForSeries(user.Id, seriesId);
        var series = await _unitOfWork.SeriesRepository.GetSeriesByIdAsync(seriesId, SeriesIncludes.None);

        return Ok(new BookmarkInfoDto()
        {
            SeriesName = series.Name,
            SeriesFormat = series.Format,
            SeriesId = series.Id,
            LibraryId = series.LibraryId,
            Pages = totalPages,
        });
    }


    /// <summary>
    /// Marks a Series as read. All volumes and chapters will be marked as read during this process.
    /// </summary>
    /// <param name="markReadDto"></param>
    /// <returns></returns>
    [HttpPost("mark-read")]
    public async Task<ActionResult> MarkRead(MarkReadDto markReadDto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);
        await _readerService.MarkSeriesAsRead(user, markReadDto.SeriesId);

        if (!await _unitOfWork.CommitAsync()) return BadRequest("There was an issue saving progress");

        return Ok();
    }


    /// <summary>
    /// Marks a Series as Unread. All volumes and chapters will be marked as unread during this process.
    /// </summary>
    /// <param name="markReadDto"></param>
    /// <returns></returns>
    [HttpPost("mark-unread")]
    public async Task<ActionResult> MarkUnread(MarkReadDto markReadDto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);
        await _readerService.MarkSeriesAsUnread(user, markReadDto.SeriesId);

        if (!await _unitOfWork.CommitAsync()) return BadRequest("There was an issue saving progress");

        return Ok();
    }

    /// <summary>
    /// Marks all chapters within a volume as unread
    /// </summary>
    /// <param name="markVolumeReadDto"></param>
    /// <returns></returns>
    [HttpPost("mark-volume-unread")]
    public async Task<ActionResult> MarkVolumeAsUnread(MarkVolumeReadDto markVolumeReadDto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);

        var chapters = await _unitOfWork.ChapterRepository.GetChaptersAsync(markVolumeReadDto.VolumeId);
        await _readerService.MarkChaptersAsUnread(user, markVolumeReadDto.SeriesId, chapters);

        _unitOfWork.UserRepository.Update(user);

        if (await _unitOfWork.CommitAsync())
        {
            return Ok();
        }

        return BadRequest("Could not save progress");
    }

    /// <summary>
    /// Marks all chapters within a volume as Read
    /// </summary>
    /// <param name="markVolumeReadDto"></param>
    /// <returns></returns>
    [HttpPost("mark-volume-read")]
    public async Task<ActionResult> MarkVolumeAsRead(MarkVolumeReadDto markVolumeReadDto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);

        var chapters = await _unitOfWork.ChapterRepository.GetChaptersAsync(markVolumeReadDto.VolumeId);
        await _readerService.MarkChaptersAsRead(user, markVolumeReadDto.SeriesId, chapters);

        _unitOfWork.UserRepository.Update(user);

        if (await _unitOfWork.CommitAsync())
        {
            return Ok();
        }

        return BadRequest("Could not save progress");
    }


    /// <summary>
    /// Marks all chapters within a list of volumes as Read. All volumes must belong to the same Series.
    /// </summary>
    /// <param name="dto"></param>
    /// <returns></returns>
    [HttpPost("mark-multiple-read")]
    public async Task<ActionResult> MarkMultipleAsRead(MarkVolumesReadDto dto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);
        user.Progresses ??= new List<AppUserProgress>();

        var chapterIds = await _unitOfWork.VolumeRepository.GetChapterIdsByVolumeIds(dto.VolumeIds);
        foreach (var chapterId in dto.ChapterIds)
        {
            chapterIds.Add(chapterId);
        }
        var chapters = await _unitOfWork.ChapterRepository.GetChaptersByIdsAsync(chapterIds);
        await _readerService.MarkChaptersAsRead(user, dto.SeriesId, chapters);

        _unitOfWork.UserRepository.Update(user);

        if (await _unitOfWork.CommitAsync())
        {
            return Ok();
        }

        return BadRequest("Could not save progress");
    }

    /// <summary>
    /// Marks all chapters within a list of volumes as Unread. All volumes must belong to the same Series.
    /// </summary>
    /// <param name="dto"></param>
    /// <returns></returns>
    [HttpPost("mark-multiple-unread")]
    public async Task<ActionResult> MarkMultipleAsUnread(MarkVolumesReadDto dto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);
        user.Progresses ??= new List<AppUserProgress>();

        var chapterIds = await _unitOfWork.VolumeRepository.GetChapterIdsByVolumeIds(dto.VolumeIds);
        foreach (var chapterId in dto.ChapterIds)
        {
            chapterIds.Add(chapterId);
        }
        var chapters = await _unitOfWork.ChapterRepository.GetChaptersByIdsAsync(chapterIds);
        await _readerService.MarkChaptersAsUnread(user, dto.SeriesId, chapters);

        _unitOfWork.UserRepository.Update(user);

        if (await _unitOfWork.CommitAsync())
        {
            return Ok();
        }

        return BadRequest("Could not save progress");
    }

    /// <summary>
    /// Marks all chapters within a list of series as Read.
    /// </summary>
    /// <param name="dto"></param>
    /// <returns></returns>
    [HttpPost("mark-multiple-series-read")]
    public async Task<ActionResult> MarkMultipleSeriesAsRead(MarkMultipleSeriesAsReadDto dto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);
        user.Progresses ??= new List<AppUserProgress>();

        var volumes = await _unitOfWork.VolumeRepository.GetVolumesForSeriesAsync(dto.SeriesIds.ToArray(), true);
        foreach (var volume in volumes)
        {
            await _readerService.MarkChaptersAsRead(user, volume.SeriesId, volume.Chapters);
        }

        _unitOfWork.UserRepository.Update(user);

        if (await _unitOfWork.CommitAsync())
        {
            return Ok();
        }

        return BadRequest("Could not save progress");
    }

    /// <summary>
    /// Marks all chapters within a list of series as Unread.
    /// </summary>
    /// <param name="dto"></param>
    /// <returns></returns>
    [HttpPost("mark-multiple-series-unread")]
    public async Task<ActionResult> MarkMultipleSeriesAsUnread(MarkMultipleSeriesAsReadDto dto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);
        user.Progresses ??= new List<AppUserProgress>();

        var volumes = await _unitOfWork.VolumeRepository.GetVolumesForSeriesAsync(dto.SeriesIds.ToArray(), true);
        foreach (var volume in volumes)
        {
            await _readerService.MarkChaptersAsUnread(user, volume.SeriesId, volume.Chapters);
        }

        _unitOfWork.UserRepository.Update(user);

        if (await _unitOfWork.CommitAsync())
        {
            return Ok();
        }

        return BadRequest("Could not save progress");
    }

    /// <summary>
    /// Returns Progress (page number) for a chapter for the logged in user
    /// </summary>
    /// <param name="chapterId"></param>
    /// <returns></returns>
    [HttpGet("get-progress")]
    public async Task<ActionResult<ProgressDto>> GetProgress(int chapterId)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);
        var progressBookmark = new ProgressDto()
        {
            PageNum = 0,
            ChapterId = chapterId,
            VolumeId = 0,
            SeriesId = 0
        };
        if (user.Progresses == null) return Ok(progressBookmark);
        var progress = user.Progresses.FirstOrDefault(x => x.AppUserId == user.Id && x.ChapterId == chapterId);

        if (progress != null)
        {
            progressBookmark.SeriesId = progress.SeriesId;
            progressBookmark.VolumeId = progress.VolumeId;
            progressBookmark.PageNum = progress.PagesRead;
            progressBookmark.BookScrollId = progress.BookScrollId;
        }
        return Ok(progressBookmark);
    }

    /// <summary>
    /// Save page against Chapter for logged in user
    /// </summary>
    /// <param name="progressDto"></param>
    /// <returns></returns>
    [HttpPost("progress")]
    public async Task<ActionResult> BookmarkProgress(ProgressDto progressDto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername());

        if (await _readerService.SaveReadingProgress(progressDto, user.Id)) return Ok(true);

        return BadRequest("Could not save progress");
    }

    /// <summary>
    /// Continue point is the chapter which you should start reading again from. If there is no progress on a series, then the first chapter will be returned (non-special unless only specials).
    /// Otherwise, loop through the chapters and volumes in order to find the next chapter which has progress.
    /// </summary>
    /// <returns></returns>
    [HttpGet("continue-point")]
    public async Task<ActionResult<ChapterDto>> GetContinuePoint(int seriesId)
    {
        var userId = await _unitOfWork.UserRepository.GetUserIdByUsernameAsync(User.GetUsername());

        return Ok(await _readerService.GetContinuePoint(seriesId, userId));
    }

    /// <summary>
    /// Returns if the user has reading progress on the Series
    /// </summary>
    /// <param name="seriesId"></param>
    /// <returns></returns>
    [HttpGet("has-progress")]
    public async Task<ActionResult<ChapterDto>> HasProgress(int seriesId)
    {
        var userId = await _unitOfWork.UserRepository.GetUserIdByUsernameAsync(User.GetUsername());
        return Ok(await _unitOfWork.AppUserProgressRepository.HasAnyProgressOnSeriesAsync(seriesId, userId));
    }

    /// <summary>
    /// Marks every chapter that is sorted below the passed number as Read. This will not mark any specials as read.
    /// </summary>
    /// <remarks>This is built for Tachiyomi and is not expected to be called by any other place</remarks>
    /// <returns></returns>
    [Obsolete("Deprecated. Use 'Tachiyomi/mark-chapter-until-as-read'")]
    [HttpPost("mark-chapter-until-as-read")]
    public async Task<ActionResult<bool>> MarkChaptersUntilAsRead(int seriesId, float chapterNumber)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Progress);
        user.Progresses ??= new List<AppUserProgress>();

        // Tachiyomi sends chapter 0.0f when there's no chapters read.
        // Due to the encoding for volumes this marks all chapters in volume 0 (loose chapters) as read so we ignore it
        if (chapterNumber == 0.0f) return true;

        if (chapterNumber < 1.0f)
        {
            // This is a hack to track volume number. We need to map it back by x100
            var volumeNumber = int.Parse($"{chapterNumber * 100f}");
            await _readerService.MarkVolumesUntilAsRead(user, seriesId, volumeNumber);
        }
        else
        {
            await _readerService.MarkChaptersUntilAsRead(user, seriesId, chapterNumber);
        }


        _unitOfWork.UserRepository.Update(user);

        if (!_unitOfWork.HasChanges()) return Ok(true);
        if (await _unitOfWork.CommitAsync()) return Ok(true);

        await _unitOfWork.RollbackAsync();
        return Ok(false);
    }


    /// <summary>
    /// Returns a list of bookmarked pages for a given Chapter
    /// </summary>
    /// <param name="chapterId"></param>
    /// <returns></returns>
    [HttpGet("chapter-bookmarks")]
    public async Task<ActionResult<IEnumerable<BookmarkDto>>> GetBookmarks(int chapterId)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Bookmarks);
        if (user.Bookmarks == null) return Ok(Array.Empty<BookmarkDto>());
        return Ok(await _unitOfWork.UserRepository.GetBookmarkDtosForChapter(user.Id, chapterId));
    }

    /// <summary>
    /// Returns a list of all bookmarked pages for a User
    /// </summary>
    /// <param name="filterDto">Only supports SeriesNameQuery</param>
    /// <returns></returns>
    [HttpPost("all-bookmarks")]
    public async Task<ActionResult<IEnumerable<BookmarkDto>>> GetAllBookmarks(FilterDto filterDto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Bookmarks);
        if (user.Bookmarks == null) return Ok(Array.Empty<BookmarkDto>());

        return Ok(await _unitOfWork.UserRepository.GetAllBookmarkDtos(user.Id, filterDto));
    }

    /// <summary>
    /// Removes all bookmarks for all chapters linked to a Series
    /// </summary>
    /// <param name="dto"></param>
    /// <returns></returns>
    [HttpPost("remove-bookmarks")]
    public async Task<ActionResult> RemoveBookmarks(RemoveBookmarkForSeriesDto dto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Bookmarks);
        if (user.Bookmarks == null) return Ok("Nothing to remove");

        try
        {
            var bookmarksToRemove = user.Bookmarks.Where(bmk => bmk.SeriesId == dto.SeriesId).ToList();
            user.Bookmarks = user.Bookmarks.Where(bmk => bmk.SeriesId != dto.SeriesId).ToList();
            _unitOfWork.UserRepository.Update(user);

            if (!_unitOfWork.HasChanges() || await _unitOfWork.CommitAsync())
            {
                try
                {
                    await _bookmarkService.DeleteBookmarkFiles(bookmarksToRemove);
                }
                catch (Exception ex)
                {
                    _logger.LogError(ex, "There was an issue cleaning up old bookmarks");
                }
                return Ok();
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "There was an exception when trying to clear bookmarks");
            await _unitOfWork.RollbackAsync();
        }

        return BadRequest("Could not clear bookmarks");
    }

    /// <summary>
    /// Removes all bookmarks for all chapters linked to a Series
    /// </summary>
    /// <param name="dto"></param>
    /// <returns></returns>
    [HttpPost("bulk-remove-bookmarks")]
    public async Task<ActionResult> BulkRemoveBookmarks(BulkRemoveBookmarkForSeriesDto dto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Bookmarks);
        if (user.Bookmarks == null) return Ok("Nothing to remove");

        try
        {
            foreach (var seriesId in dto.SeriesIds)
            {
                var bookmarksToRemove = user.Bookmarks.Where(bmk => bmk.SeriesId == seriesId).ToList();
                user.Bookmarks = user.Bookmarks.Where(bmk => bmk.SeriesId != seriesId).ToList();
                _unitOfWork.UserRepository.Update(user);
                await _bookmarkService.DeleteBookmarkFiles(bookmarksToRemove);
            }


            if (!_unitOfWork.HasChanges() || await _unitOfWork.CommitAsync())
            {
                return Ok();
            }
        }
        catch (Exception ex)
        {
            _logger.LogError(ex, "There was an exception when trying to clear bookmarks");
            await _unitOfWork.RollbackAsync();
        }

        return BadRequest("Could not clear bookmarks");
    }

    /// <summary>
    /// Returns all bookmarked pages for a given volume
    /// </summary>
    /// <param name="volumeId"></param>
    /// <returns></returns>
    [HttpGet("volume-bookmarks")]
    public async Task<ActionResult<IEnumerable<BookmarkDto>>> GetBookmarksForVolume(int volumeId)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Bookmarks);
        if (user.Bookmarks == null) return Ok(Array.Empty<BookmarkDto>());
        return Ok(await _unitOfWork.UserRepository.GetBookmarkDtosForVolume(user.Id, volumeId));
    }

    /// <summary>
    /// Returns all bookmarked pages for a given series
    /// </summary>
    /// <param name="seriesId"></param>
    /// <returns></returns>
    [HttpGet("series-bookmarks")]
    public async Task<ActionResult<IEnumerable<BookmarkDto>>> GetBookmarksForSeries(int seriesId)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Bookmarks);
        if (user.Bookmarks == null) return Ok(Array.Empty<BookmarkDto>());

        return Ok(await _unitOfWork.UserRepository.GetBookmarkDtosForSeries(user.Id, seriesId));
    }

    /// <summary>
    /// Bookmarks a page against a Chapter
    /// </summary>
    /// <remarks>This has a side effect of caching the chapter files to disk</remarks>
    /// <param name="bookmarkDto"></param>
    /// <returns></returns>
    [HttpPost("bookmark")]
    public async Task<ActionResult> BookmarkPage(BookmarkDto bookmarkDto)
    {
        // Don't let user save past total pages.
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Bookmarks);
        if (user == null) return new UnauthorizedResult();

        if (!await _accountService.HasBookmarkPermission(user))
            return BadRequest("You do not have permission to bookmark");

        var chapter = await _cacheService.Ensure(bookmarkDto.ChapterId);
        if (chapter == null) return BadRequest("Could not find cached image. Reload and try again.");

        bookmarkDto.Page = _readerService.CapPageToChapter(chapter, bookmarkDto.Page);
        var path = _cacheService.GetCachedPagePath(chapter, bookmarkDto.Page);

        if (!await _bookmarkService.BookmarkPage(user, bookmarkDto, path)) return BadRequest("Could not save bookmark");

        BackgroundJob.Enqueue(() => _cacheService.CleanupBookmarkCache(bookmarkDto.SeriesId));
        return Ok();
    }

    /// <summary>
    /// Removes a bookmarked page for a Chapter
    /// </summary>
    /// <param name="bookmarkDto"></param>
    /// <returns></returns>
    [HttpPost("unbookmark")]
    public async Task<ActionResult> UnBookmarkPage(BookmarkDto bookmarkDto)
    {
        var user = await _unitOfWork.UserRepository.GetUserByUsernameAsync(User.GetUsername(), AppUserIncludes.Bookmarks);
        if (user == null) return new UnauthorizedResult();
        if (user.Bookmarks.IsNullOrEmpty()) return Ok();

        if (!await _accountService.HasBookmarkPermission(user))
            return BadRequest("You do not have permission to unbookmark");

        if (!await _bookmarkService.RemoveBookmarkPage(user, bookmarkDto))
            return BadRequest("Could not remove bookmark");
        BackgroundJob.Enqueue(() => _cacheService.CleanupBookmarkCache(bookmarkDto.SeriesId));
        return Ok();
    }

    /// <summary>
    /// Returns the next logical chapter from the series.
    /// </summary>
    /// <example>
    /// V1 → V2 → V3 chapter 0 → V3 chapter 10 → SP 01 → SP 02
    /// </example>
    /// <param name="seriesId"></param>
    /// <param name="volumeId"></param>
    /// <param name="currentChapterId"></param>
    /// <returns>chapter id for next manga</returns>
    [HttpGet("next-chapter")]
    public async Task<ActionResult<int>> GetNextChapter(int seriesId, int volumeId, int currentChapterId)
    {
        var userId = await _unitOfWork.UserRepository.GetUserIdByUsernameAsync(User.GetUsername());
        return await _readerService.GetNextChapterIdAsync(seriesId, volumeId, currentChapterId, userId);
    }


    /// <summary>
    /// Returns the previous logical chapter from the series.
    /// </summary>
    /// <example>
    /// V1 ← V2 ← V3 chapter 0 ← V3 chapter 10 ← SP 01 ← SP 02
    /// </example>
    /// <param name="seriesId"></param>
    /// <param name="volumeId"></param>
    /// <param name="currentChapterId"></param>
    /// <returns>chapter id for next manga</returns>
    [HttpGet("prev-chapter")]
    public async Task<ActionResult<int>> GetPreviousChapter(int seriesId, int volumeId, int currentChapterId)
    {
        var userId = await _unitOfWork.UserRepository.GetUserIdByUsernameAsync(User.GetUsername());
        return await _readerService.GetPrevChapterIdAsync(seriesId, volumeId, currentChapterId, userId);
    }

    /// <summary>
    /// For the current user, returns an estimate on how long it would take to finish reading the series.
    /// </summary>
    /// <remarks>For Epubs, this does not check words inside a chapter due to overhead so may not work in all cases.</remarks>
    /// <param name="seriesId"></param>
    /// <returns></returns>
    [HttpGet("time-left")]
    public async Task<ActionResult<HourEstimateRangeDto>> GetEstimateToCompletion(int seriesId)
    {
        var userId = await _unitOfWork.UserRepository.GetUserIdByUsernameAsync(User.GetUsername());
        var series = await _unitOfWork.SeriesRepository.GetSeriesDtoByIdAsync(seriesId, userId);

        // Get all sum of all chapters with progress that is complete then subtract from series. Multiply by modifiers
        var progress = await _unitOfWork.AppUserProgressRepository.GetUserProgressForSeriesAsync(seriesId, userId);
        if (series.Format == MangaFormat.Epub)
        {
            var chapters =
                await _unitOfWork.ChapterRepository.GetChaptersByIdsAsync(progress.Select(p => p.ChapterId).ToList());
            // Word count
            var progressCount = chapters.Sum(c => c.WordCount);
            var wordsLeft = series.WordCount - progressCount;
            return _readerService.GetTimeEstimate(wordsLeft, 0, true);
        }

        var progressPageCount = progress.Sum(p => p.PagesRead);
        var pagesLeft = series.Pages - progressPageCount;
        return _readerService.GetTimeEstimate(0, pagesLeft, false);
    }

}