// Licensed under the Apache License, Version 2.0. See License.txt in the project root for license information.

using System.Diagnostics;
using Microsoft.EntityFrameworkCore.Internal;
using Microsoft.EntityFrameworkCore.Migrations.Operations;
using Microsoft.EntityFrameworkCore.Scaffolding;
using Microsoft.EntityFrameworkCore.Scaffolding.Metadata;
using EntityFrameworkCore.Jet.Diagnostics.Internal;
using EntityFrameworkCore.Jet.Metadata.Internal;
using EntityFrameworkCore.Jet.Scaffolding.Internal;
using Microsoft.EntityFrameworkCore;
using Microsoft.EntityFrameworkCore.TestUtilities;
using Microsoft.Extensions.Logging;

namespace EntityFrameworkCore.Jet.FunctionalTests.TestUtilities
{
    public class JetDatabaseCleaner : RelationalDatabaseCleaner
    {
        protected override IDatabaseModelFactory CreateDatabaseModelFactory(ILoggerFactory loggerFactory)
            => new JetDatabaseModelFactory(
                new DiagnosticsLogger<DbLoggerCategory.Scaffolding>(
                    loggerFactory,
                    new LoggingOptions(),
                    new DiagnosticListener("Fake"),
                    new JetLoggingDefinitions()));

        protected override bool AcceptTable(DatabaseTable table) => !(table is DatabaseView);

        protected override bool AcceptIndex(DatabaseIndex index)
            => false;

        private readonly string _dropViewsSql = @"
DECLARE @name VARCHAR(MAX) = '__dummy__', @SQL VARCHAR(MAX) = '';

WHILE @name IS NOT NULL
BEGIN
    SELECT @name =
    (SELECT TOP 1 QUOTENAME(s.`name`) + '.' + QUOTENAME(o.`name`)
     FROM sysobjects o
     INNER JOIN sys.views v ON o.id = v.object_id
     INNER JOIN sys.schemas s ON s.schema_id = v.schema_id
     WHERE (s.name = 'dbo' OR s.principal_id <> s.schema_id) AND o.`type` = 'V' AND o.category = 0 AND o.`name` NOT IN
     (
        SELECT referenced_entity_name
        FROM sys.sql_expression_dependencies AS sed
        INNER JOIN sys.objects AS o ON sed.referencing_id = o.object_id
     )
     ORDER BY v.`name`)

    SELECT @SQL = 'DROP VIEW ' + @name
    EXEC (@SQL)
END";

        protected override string BuildCustomSql(DatabaseModel databaseModel)
            => _dropViewsSql;

        protected override string BuildCustomEndingSql(DatabaseModel databaseModel)
            => _dropViewsSql
                + @"
GO

DECLARE @SQL VARCHAR(MAX) = '';
SELECT @SQL = @SQL + 'DROP FUNCTION ' + QUOTENAME(ROUTINE_SCHEMA) + '.' + QUOTENAME(ROUTINE_NAME) + ';'
  FROM `INFORMATION_SCHEMA`.`ROUTINES` WHERE ROUTINE_TYPE = 'FUNCTION' AND ROUTINE_BODY = 'SQL';
EXEC (@SQL);

SET @SQL ='';
SELECT @SQL = @SQL + 'DROP AGGREGATE ' + QUOTENAME(ROUTINE_SCHEMA) + '.' + QUOTENAME(ROUTINE_NAME) + ';'
  FROM `INFORMATION_SCHEMA`.`ROUTINES` WHERE ROUTINE_TYPE = 'FUNCTION' AND ROUTINE_BODY = 'EXTERNAL';
EXEC (@SQL);

SET @SQL ='';
SELECT @SQL = @SQL + 'DROP PROC ' + QUOTENAME(schema_name(schema_id)) + '.' + QUOTENAME(name) + ';' FROM sys.procedures;
EXEC (@SQL);

SET @SQL ='';
SELECT @SQL = @SQL + 'DROP TYPE ' + QUOTENAME(schema_name(schema_id)) + '.' + QUOTENAME(name) + ';' FROM sys.types WHERE is_user_defined = 1;
EXEC (@SQL);

SET @SQL ='';
SELECT @SQL = @SQL + 'DROP SCHEMA ' + QUOTENAME(name) + ';' FROM sys.schemas WHERE principal_id <> schema_id;
EXEC (@SQL);";
    }
}