using System.Data;
using Database.Common;
using Insight.Database;

namespace Database.Core.DataControlLanguage
{

	/// <summary>
	/// Only a superadmin or similar can create Application Users
	/// </summary>
	public class SetupApplicationUser
	{

		IDbConnection _db;
		string _schema;
		string _user;
		string _password;

		public SetupApplicationUser(IDbConnection db)
		{
			_db = db;
		}

		public void CreateUserWithSchemaInDatabase(string schema, string user, string password)
		{
			_schema = schema;
			_password = password;
			_user = user;

			if (!Validations.IsValidSchemaName(_schema))
				throw new ArgumentException("Invalid schema name", _schema);

			using (var transaction = _db.BeginTransaction())
			{
				try
				{
					CreateSchema();
					CreateRole();
					GrantSchemaRights();

					transaction.Commit();
				}
				catch (Exception ex)
				{
					transaction.Rollback();
					throw new InvalidOperationException("Failed to SetupApplicationUser in Database", ex);
				}
			}

		}
		private void ExecuteSql(string sql)
		{
			_db.ExecuteSql(sql);
		}

		private void CreateSchema()
		{
			var sql = $"CREATE SCHEMA IF NOT EXISTS {_schema}";
			ExecuteSql(sql);
		}

		private void CreateRole()
		{
			var sql = $"CREATE ROLE {_user} WITH CREATEDB CREATEROLE LOGIN PASSWORD '{_password}';";
			ExecuteSql(sql);

			var sql1 = $"ALTER ROLE {_user} SET search_path='{_schema}';";
			ExecuteSql(sql1);

		}

		private void GrantSchemaRights()
		{
			var sql = $"GRANT USAGE ON SCHEMA {_schema} TO {_user};";
			ExecuteSql(sql);

			var sql1 = $"ALTER DEFAULT PRIVILEGES IN SCHEMA {_schema} " +
					$"GRANT INSERT, SELECT, UPDATE PRIVILEGES ON TABLES TO {_user};";
			ExecuteSql(sql1);

			var sql2 = $"GRANT ALL PRIVILEGES ON ALL SEQUENCES IN SCHEMA {_schema} TO {_user};";
			ExecuteSql(sql2);

		}
	}
}