OpenStatement.cs

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// 
//  Copyright 2010-2015 Deveel
// 
//    Licensed under the Apache License, Version 2.0 (the "License");
//    you may not use this file except in compliance with the License.
//    You may obtain a copy of the License at
// 
//        http://www.apache.org/licenses/LICENSE-2.0
// 
//    Unless required by applicable law or agreed to in writing, software
//    distributed under the License is distributed on an "AS IS" BASIS,
//    WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
//    See the License for the specific language governing permissions and
//    limitations under the License.
//

using System;
using System.Linq;

using Deveel.Data.Serialization;
using Deveel.Data.Sql.Cursors;
using Deveel.Data.Sql.Expressions;

namespace Deveel.Data.Sql.Statements {
    [Serializable]
    public sealed class OpenStatement : SqlStatement, IPreparable, IPreparableStatement {
        public OpenStatement(string cursorName) 
            : this(cursorName, new SqlExpression[] {}) {
        }

        public OpenStatement(string cursorName, SqlExpression[] arguments) {
            CursorName = cursorName;
            Arguments = arguments;
        }

        private OpenStatement(ObjectData data) {
            CursorName = data.GetString("CursorName");
            Arguments = data.GetValue<SqlExpression[]>("Arguments");
        }

        public string CursorName { get; private set; }

        public SqlExpression[] Arguments { get; set; }

        object IPreparable.Prepare(IExpressionPreparer preparer) {
            SqlExpression[] args = null;
            if (Arguments != null) {
                args = (SqlExpression[])Arguments.Clone();

                for (int i = 0; i < args.Length; i++) {
                    args[i] = args[i].Prepare(preparer);
                }
            }

            return new OpenStatement(CursorName, args);
        }

        IStatement IPreparableStatement.Prepare(IRequest context) {
            SqlExpression[] args = Arguments;

            var cursor = context.Query.FindCursor(CursorName);
            if (cursor == null)
                throw new StatementPrepareException(String.Format("Cursor '{0}' was not found.", CursorName));

            if (args != null) {
                var orderedParams = cursor.CursorInfo.Parameters.OrderBy(x => x.Offset).ToArray();

                if (args.Length != orderedParams.Length)
                    throw new StatementPrepareException(String.Format("Invalid number of arguments for cursor '{0}' OPEN statement.", CursorName));

                // TODO: Cast to the parameter type here?
            }


            return new OpenStatement(CursorName, args);
        }

        protected override void GetData(SerializeData data) {
            data.SetValue("CursorName", CursorName);
            data.SetValue("Arguments", Arguments);
        }

        protected override void ExecuteStatement(ExecutionContext context) {
            var cursor = context.Request.Query.FindCursor(CursorName);
            if (cursor == null)
                throw new StatementException(String.Format("Cursor '{0}' was not found in the context.", CursorName));

            cursor.Open(context.Request, Arguments);
        }
    }
}