Kyoo/back/src/Kyoo.Postgresql/PostgresContext.cs

// Kyoo - A portable and vast media library solution.
// Copyright (c) Kyoo.
//
// See AUTHORS.md and LICENSE file in the project root for full license information.
//
// Kyoo is free software: you can redistribute it and/or modify
// it under the terms of the GNU General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// any later version.
//
// Kyoo is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License
// along with Kyoo. If not, see <https://www.gnu.org/licenses/>.

using System;
using System.Globalization;
using EFCore.NamingConventions.Internal;
using Kyoo.Abstractions.Models;
using Kyoo.Utils;
using Microsoft.AspNetCore.Http;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.Query.SqlExpressions;
using Npgsql;

namespace Kyoo.Postgresql
{
	/// <summary>
	/// A postgresql implementation of <see cref="DatabaseContext"/>.
	/// </summary>
	public class PostgresContext : DatabaseContext
	{
		/// <summary>
		/// Is this instance in debug mode?
		/// </summary>
		private readonly bool _debugMode;

		/// <summary>
		/// Should the configure step be skipped? This is used when the database is created via DbContextOptions.
		/// </summary>
		private readonly bool _skipConfigure;

		// TODO: This needs ot be updated but ef-core still does not offer a way to use this.
		[Obsolete]
		static PostgresContext()
		{
			NpgsqlConnection.GlobalTypeMapper.MapEnum<Status>();
			NpgsqlConnection.GlobalTypeMapper.MapEnum<Genre>();
			NpgsqlConnection.GlobalTypeMapper.MapEnum<WatchStatus>();
		}

		/// <summary>
		/// Design time constructor (dotnet ef migrations add). Do not use
		/// </summary>
		public PostgresContext()
			: base(null!) { }

		public PostgresContext(DbContextOptions options, IHttpContextAccessor accessor)
			: base(options, accessor)
		{
			_skipConfigure = true;
		}

		public PostgresContext(string connection, bool debugMode, IHttpContextAccessor accessor)
			: base(accessor)
		{
			_debugMode = debugMode;
		}

		/// <summary>
		/// Set connection information for this database context
		/// </summary>
		/// <param name="optionsBuilder">An option builder to fill.</param>
		protected override void OnConfiguring(DbContextOptionsBuilder optionsBuilder)
		{
			if (!_skipConfigure)
			{
				optionsBuilder.UseNpgsql();
				if (_debugMode)
					optionsBuilder.EnableDetailedErrors().EnableSensitiveDataLogging();
			}

			optionsBuilder.UseSnakeCaseNamingConvention();
			base.OnConfiguring(optionsBuilder);
		}

		/// <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)
		{
			modelBuilder.HasPostgresEnum<Status>();
			modelBuilder.HasPostgresEnum<Genre>();
			modelBuilder.HasPostgresEnum<WatchStatus>();

			modelBuilder
				.HasDbFunction(typeof(DatabaseContext).GetMethod(nameof(MD5))!)
				.HasTranslation(
					args =>
						new SqlFunctionExpression(
							"md5",
							args,
							nullable: true,
							argumentsPropagateNullability: new[] { false },
							type: args[0].Type,
							typeMapping: args[0].TypeMapping
						)
				);

			base.OnModelCreating(modelBuilder);
		}

		/// <inheritdoc />
		protected override string LinkName<T, T2>()
		{
			SnakeCaseNameRewriter rewriter = new(CultureInfo.InvariantCulture);
			return rewriter.RewriteName("Link" + typeof(T).Name + typeof(T2).Name);
		}

		/// <inheritdoc />
		protected override string LinkNameFk<T>()
		{
			SnakeCaseNameRewriter rewriter = new(CultureInfo.InvariantCulture);
			return rewriter.RewriteName(typeof(T).Name + "ID");
		}

		/// <inheritdoc />
		protected override bool IsDuplicateException(Exception ex)
		{
			return ex.InnerException
				is PostgresException
				{
					SqlState: PostgresErrorCodes.UniqueViolation
						or PostgresErrorCodes.ForeignKeyViolation
				};
		}
	}
}