// 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 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
			};
	}
}