Kyoo/Kyoo.CommonAPI/DatabaseContext.cs
2021-05-08 17:55:22 +02:00

520 lines
18 KiB
C#

using System;
using System.Linq;
using System.Linq.Expressions;
using System.Threading;
using System.Threading.Tasks;
using Kyoo.Controllers;
using Kyoo.Models;
using Kyoo.Models.Exceptions;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.ChangeTracking;
using Microsoft.EntityFrameworkCore.Diagnostics;
namespace Kyoo
{
/// <summary>
/// The database handle used for all local repositories.
/// This is an abstract class. It is meant to be implemented by plugins. This allow the core to be database agnostic.
/// </summary>
/// <remarks>
/// It should not be used directly, to access the database use a <see cref="ILibraryManager"/> or repositories.
/// </remarks>
public abstract class DatabaseContext : DbContext
{
/// <summary>
/// All libraries of Kyoo. See <see cref="Library"/>.
/// </summary>
public DbSet<Library> Libraries { get; set; }
/// <summary>
/// All collections of Kyoo. See <see cref="Collection"/>.
/// </summary>
public DbSet<Collection> Collections { get; set; }
/// <summary>
/// All shows of Kyoo. See <see cref="Show"/>.
/// </summary>
public DbSet<Show> Shows { get; set; }
/// <summary>
/// All seasons of Kyoo. See <see cref="Season"/>.
/// </summary>
public DbSet<Season> Seasons { get; set; }
/// <summary>
/// All episodes of Kyoo. See <see cref="Episode"/>.
/// </summary>
public DbSet<Episode> Episodes { get; set; }
/// <summary>
/// All tracks of Kyoo. See <see cref="Track"/>.
/// </summary>
public DbSet<Track> Tracks { get; set; }
/// <summary>
/// All genres of Kyoo. See <see cref="Genres"/>.
/// </summary>
public DbSet<Genre> Genres { get; set; }
/// <summary>
/// All people of Kyoo. See <see cref="People"/>.
/// </summary>
public DbSet<People> People { get; set; }
/// <summary>
/// All studios of Kyoo. See <see cref="Studio"/>.
/// </summary>
public DbSet<Studio> Studios { get; set; }
/// <summary>
/// All providers of Kyoo. See <see cref="Provider"/>.
/// </summary>
public DbSet<Provider> Providers { get; set; }
/// <summary>
/// All metadataIDs (ExternalIDs) of Kyoo. See <see cref="MetadataID"/>.
/// </summary>
public DbSet<MetadataID> MetadataIds { get; set; }
/// <summary>
/// The list of registered users.
/// </summary>
public DbSet<User> Users { get; set; }
/// <summary>
/// All people's role. See <see cref="PeopleRole"/>.
/// </summary>
public DbSet<PeopleRole> PeopleRoles { get; set; }
/// <summary>
/// Episodes with a watch percentage. See <see cref="WatchedEpisode"/>
/// </summary>
public DbSet<WatchedEpisode> WatchedEpisodes { get; set; }
/// <summary>
/// Get a generic link between two resource types.
/// </summary>
/// <remarks>Types are order dependant. You can't inverse the order. Please always put the owner first.</remarks>
/// <typeparam name="T1">The first resource type of the relation. It is the owner of the second</typeparam>
/// <typeparam name="T2">The second resource type of the relation. It is the contained resource.</typeparam>
/// <returns>All links between the two types.</returns>
public DbSet<Link<T1, T2>> Links<T1, T2>()
where T1 : class, IResource
where T2 : class, IResource
{
return Set<Link<T1, T2>>();
}
/// <summary>
/// The default constructor
/// </summary>
protected DatabaseContext() { }
/// <summary>
/// Create a new <see cref="DatabaseContext"/> using specific options
/// </summary>
/// <param name="options">The options to use.</param>
protected DatabaseContext(DbContextOptions options)
: base(options)
{ }
/// <summary>
/// Set basic configurations (like preventing query tracking)
/// </summary>
/// <param name="optionsBuilder">An option builder to fill.</param>
protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
{
base.OnConfiguring(optionsBuilder);
optionsBuilder.UseQueryTrackingBehavior(QueryTrackingBehavior.NoTracking);
}
/// <summary>
/// Set database parameters to support every types of Kyoo.
/// </summary>
/// <param name="modelBuilder">The database's model builder.</param>
protected override void OnModelCreating(ModelBuilder modelBuilder)
{
base.OnModelCreating(modelBuilder);
modelBuilder.Entity<Track>()
.Property(t => t.IsDefault)
.ValueGeneratedNever();
modelBuilder.Entity<Track>()
.Property(t => t.IsForced)
.ValueGeneratedNever();
modelBuilder.Entity<Provider>()
.HasMany(x => x.Libraries)
.WithMany(x => x.Providers)
.UsingEntity<Link<Library, Provider>>(
y => y
.HasOne(x => x.First)
.WithMany(x => x.ProviderLinks),
y => y
.HasOne(x => x.Second)
.WithMany(x => x.LibraryLinks),
y => y.HasKey(Link<Library, Provider>.PrimaryKey));
modelBuilder.Entity<Collection>()
.HasMany(x => x.Libraries)
.WithMany(x => x.Collections)
.UsingEntity<Link<Library, Collection>>(
y => y
.HasOne(x => x.First)
.WithMany(x => x.CollectionLinks),
y => y
.HasOne(x => x.Second)
.WithMany(x => x.LibraryLinks),
y => y.HasKey(Link<Library, Collection>.PrimaryKey));
modelBuilder.Entity<Show>()
.HasMany(x => x.Libraries)
.WithMany(x => x.Shows)
.UsingEntity<Link<Library, Show>>(
y => y
.HasOne(x => x.First)
.WithMany(x => x.ShowLinks),
y => y
.HasOne(x => x.Second)
.WithMany(x => x.LibraryLinks),
y => y.HasKey(Link<Library, Show>.PrimaryKey));
modelBuilder.Entity<Show>()
.HasMany(x => x.Collections)
.WithMany(x => x.Shows)
.UsingEntity<Link<Collection, Show>>(
y => y
.HasOne(x => x.First)
.WithMany(x => x.ShowLinks),
y => y
.HasOne(x => x.Second)
.WithMany(x => x.CollectionLinks),
y => y.HasKey(Link<Collection, Show>.PrimaryKey));
modelBuilder.Entity<Genre>()
.HasMany(x => x.Shows)
.WithMany(x => x.Genres)
.UsingEntity<Link<Show, Genre>>(
y => y
.HasOne(x => x.First)
.WithMany(x => x.GenreLinks),
y => y
.HasOne(x => x.Second)
.WithMany(x => x.ShowLinks),
y => y.HasKey(Link<Show, Genre>.PrimaryKey));
modelBuilder.Entity<User>()
.HasMany(x => x.Watched)
.WithMany("users")
.UsingEntity<Link<User, Show>>(
y => y
.HasOne(x => x.Second)
.WithMany(),
y => y
.HasOne(x => x.First)
.WithMany(x => x.ShowLinks),
y => y.HasKey(Link<User, Show>.PrimaryKey));
modelBuilder.Entity<MetadataID>()
.HasOne(x => x.Show)
.WithMany(x => x.ExternalIDs)
.OnDelete(DeleteBehavior.Cascade);
modelBuilder.Entity<MetadataID>()
.HasOne(x => x.Season)
.WithMany(x => x.ExternalIDs)
.OnDelete(DeleteBehavior.Cascade);
modelBuilder.Entity<MetadataID>()
.HasOne(x => x.Episode)
.WithMany(x => x.ExternalIDs)
.OnDelete(DeleteBehavior.Cascade);
modelBuilder.Entity<MetadataID>()
.HasOne(x => x.People)
.WithMany(x => x.ExternalIDs)
.OnDelete(DeleteBehavior.Cascade);
modelBuilder.Entity<MetadataID>()
.HasOne(x => x.Provider)
.WithMany(x => x.MetadataLinks)
.OnDelete(DeleteBehavior.Cascade);
modelBuilder.Entity<WatchedEpisode>()
.HasKey(x => new {First = x.FirstID, Second = x.SecondID});
modelBuilder.Entity<Collection>().Property(x => x.Slug).IsRequired();
modelBuilder.Entity<Genre>().Property(x => x.Slug).IsRequired();
modelBuilder.Entity<Library>().Property(x => x.Slug).IsRequired();
modelBuilder.Entity<People>().Property(x => x.Slug).IsRequired();
modelBuilder.Entity<Provider>().Property(x => x.Slug).IsRequired();
modelBuilder.Entity<Show>().Property(x => x.Slug).IsRequired();
modelBuilder.Entity<Studio>().Property(x => x.Slug).IsRequired();
modelBuilder.Entity<User>().Property(x => x.Slug).IsRequired();
modelBuilder.Entity<Collection>()
.HasIndex(x => x.Slug)
.IsUnique();
modelBuilder.Entity<Genre>()
.HasIndex(x => x.Slug)
.IsUnique();
modelBuilder.Entity<Library>()
.HasIndex(x => x.Slug)
.IsUnique();
modelBuilder.Entity<People>()
.HasIndex(x => x.Slug)
.IsUnique();
modelBuilder.Entity<Show>()
.HasIndex(x => x.Slug)
.IsUnique();
modelBuilder.Entity<Studio>()
.HasIndex(x => x.Slug)
.IsUnique();
modelBuilder.Entity<Provider>()
.HasIndex(x => x.Slug)
.IsUnique();
modelBuilder.Entity<Season>()
.HasIndex(x => new {x.ShowID, x.SeasonNumber})
.IsUnique();
modelBuilder.Entity<Episode>()
.HasIndex(x => new {x.ShowID, x.SeasonNumber, x.EpisodeNumber, x.AbsoluteNumber})
.IsUnique();
modelBuilder.Entity<Track>()
.HasIndex(x => new {x.EpisodeID, x.Type, x.Language, x.TrackIndex, x.IsForced})
.IsUnique();
modelBuilder.Entity<User>()
.HasIndex(x => x.Slug)
.IsUnique();
}
/// <summary>
/// Return a new or an in cache temporary object wih the same ID as the one given
/// </summary>
/// <param name="model">If a resource with the same ID is found in the database, it will be used.
/// <see cref="model"/> will be used otherwise</param>
/// <typeparam name="T">The type of the resource</typeparam>
/// <returns>A resource that is now tracked by this context.</returns>
public T GetTemporaryObject<T>(T model)
where T : class, IResource
{
T tmp = Set<T>().Local.FirstOrDefault(x => x.ID == model.ID);
if (tmp != null)
return tmp;
Entry(model).State = EntityState.Unchanged;
return model;
}
/// <summary>
/// Save changes that are applied to this context.
/// </summary>
/// <exception cref="DuplicatedItemException">A duplicated item has been found.</exception>
/// <returns>The number of state entries written to the database.</returns>
public override int SaveChanges()
{
try
{
return base.SaveChanges();
}
catch (DbUpdateException ex)
{
DiscardChanges();
if (IsDuplicateException(ex))
throw new DuplicatedItemException();
throw;
}
}
/// <summary>
/// Save changes that are applied to this context.
/// </summary>
/// <param name="acceptAllChangesOnSuccess">Indicates whether AcceptAllChanges() is called after the changes
/// have been sent successfully to the database.</param>
/// <exception cref="DuplicatedItemException">A duplicated item has been found.</exception>
/// <returns>The number of state entries written to the database.</returns>
public override int SaveChanges(bool acceptAllChangesOnSuccess)
{
try
{
return base.SaveChanges(acceptAllChangesOnSuccess);
}
catch (DbUpdateException ex)
{
DiscardChanges();
if (IsDuplicateException(ex))
throw new DuplicatedItemException();
throw;
}
}
/// <summary>
/// Save changes that are applied to this context.
/// </summary>
/// <param name="duplicateMessage">The message that will have the <see cref="DuplicatedItemException"/>
/// (if a duplicate is found).</param>
/// <exception cref="DuplicatedItemException">A duplicated item has been found.</exception>
/// <returns>The number of state entries written to the database.</returns>
public int SaveChanges(string duplicateMessage)
{
try
{
return base.SaveChanges();
}
catch (DbUpdateException ex)
{
DiscardChanges();
if (IsDuplicateException(ex))
throw new DuplicatedItemException(duplicateMessage);
throw;
}
}
/// <summary>
/// Save changes that are applied to this context.
/// </summary>
/// <param name="acceptAllChangesOnSuccess">Indicates whether AcceptAllChanges() is called after the changes
/// have been sent successfully to the database.</param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> to observe while waiting for the task to complete</param>
/// <exception cref="DuplicatedItemException">A duplicated item has been found.</exception>
/// <returns>The number of state entries written to the database.</returns>
public override async Task<int> SaveChangesAsync(bool acceptAllChangesOnSuccess,
CancellationToken cancellationToken = new())
{
try
{
return await base.SaveChangesAsync(acceptAllChangesOnSuccess, cancellationToken);
}
catch (DbUpdateException ex)
{
DiscardChanges();
if (IsDuplicateException(ex))
throw new DuplicatedItemException();
throw;
}
}
/// <summary>
/// Save changes that are applied to this context.
/// </summary>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> to observe while waiting for the task to complete</param>
/// <exception cref="DuplicatedItemException">A duplicated item has been found.</exception>
/// <returns>The number of state entries written to the database.</returns>
public override async Task<int> SaveChangesAsync(CancellationToken cancellationToken = new())
{
try
{
return await base.SaveChangesAsync(cancellationToken);
}
catch (DbUpdateException ex)
{
DiscardChanges();
if (IsDuplicateException(ex))
throw new DuplicatedItemException();
throw;
}
}
/// <summary>
/// Save changes that are applied to this context.
/// </summary>
/// <param name="duplicateMessage">The message that will have the <see cref="DuplicatedItemException"/>
/// (if a duplicate is found).</param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> to observe while waiting for the task to complete</param>
/// <exception cref="DuplicatedItemException">A duplicated item has been found.</exception>
/// <returns>The number of state entries written to the database.</returns>
public async Task<int> SaveChangesAsync(string duplicateMessage,
CancellationToken cancellationToken = new())
{
try
{
return await base.SaveChangesAsync(cancellationToken);
}
catch (DbUpdateException ex)
{
DiscardChanges();
if (IsDuplicateException(ex))
throw new DuplicatedItemException(duplicateMessage);
throw;
}
}
/// <summary>
/// Save changes if no duplicates are found. If one is found, no change are saved but the current changes are no discarded.
/// The current context will still hold those invalid changes.
/// </summary>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> to observe while waiting for the task to complete</param>
/// <returns>The number of state entries written to the database or -1 if a duplicate exist.</returns>
public async Task<int> SaveIfNoDuplicates(CancellationToken cancellationToken = new())
{
try
{
return await SaveChangesAsync(cancellationToken);
}
catch (DuplicatedItemException)
{
return -1;
}
}
/// <summary>
/// Save items or retry with a custom method if a duplicate is found.
/// </summary>
/// <param name="obj">The item to save (other changes of this context will also be saved)</param>
/// <param name="onFail">A function to run on fail, the <see cref="obj"/> param wil be mapped.
/// The second parameter is the current retry number.</param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> to observe while waiting for the task to complete</param>
/// <typeparam name="T">The type of the item to save</typeparam>
/// <returns>The number of state entries written to the database.</returns>
public Task<T> SaveOrRetry<T>(T obj, Func<T, int, T> onFail, CancellationToken cancellationToken = new())
{
return SaveOrRetry(obj, onFail, 0, cancellationToken);
}
/// <summary>
/// Save items or retry with a custom method if a duplicate is found.
/// </summary>
/// <param name="obj">The item to save (other changes of this context will also be saved)</param>
/// <param name="onFail">A function to run on fail, the <see cref="obj"/> param wil be mapped.
/// The second parameter is the current retry number.</param>
/// <param name="recurse">The current retry number.</param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> to observe while waiting for the task to complete</param>
/// <typeparam name="T">The type of the item to save</typeparam>
/// <returns>The number of state entries written to the database.</returns>
private async Task<T> SaveOrRetry<T>(T obj,
Func<T, int, T> onFail,
int recurse,
CancellationToken cancellationToken = new())
{
try
{
await base.SaveChangesAsync(true, cancellationToken);
return obj;
}
catch (DbUpdateException ex) when (IsDuplicateException(ex))
{
recurse++;
return await SaveOrRetry(onFail(obj, recurse), onFail, recurse, cancellationToken);
}
catch (DbUpdateException)
{
DiscardChanges();
throw;
}
}
/// <summary>
/// Check if the exception is a duplicated exception.
/// </summary>
/// <param name="ex">The exception to check</param>
/// <returns>True if the exception is a duplicate exception. False otherwise</returns>
protected abstract bool IsDuplicateException(Exception ex);
/// <summary>
/// Delete every changes that are on this context.
/// </summary>
private void DiscardChanges()
{
foreach (EntityEntry entry in ChangeTracker.Entries().Where(x => x.State != EntityState.Unchanged
&& x.State != EntityState.Detached))
{
entry.State = EntityState.Detached;
}
}
/// <summary>
/// Perform a case insensitive like operation.
/// </summary>
/// <param name="query">An accessor to get the item that will be checked.</param>
/// <param name="format">The second operator of the like format.</param>
/// <typeparam name="T">The type of the item to query</typeparam>
/// <returns>An expression representing the like query. It can directly be passed to a where call.</returns>
public abstract Expression<Func<T, bool>> Like<T>(Expression<Func<T, string>> query, string format);
}
}