//
// SQLiteStatementImpl.h
//
// $Id: //poco/Main/Data/SQLite/include/Poco/Data/SQLite/SQLiteStatementImpl.h#4 $
//
// Library: SQLite
// Package: SQLite
// Module:  SQLiteStatementImpl
//
// Definition of the SQLiteStatementImpl class.
//
// Copyright (c) 2006, Applied Informatics Software Engineering GmbH.
// and Contributors.
//
// Permission is hereby granted, free of charge, to any person or organization
// obtaining a copy of the software and accompanying documentation covered by
// this license (the "Software") to use, reproduce, display, distribute,
// execute, and transmit the Software, and to prepare derivative works of the
// Software, and to permit third-parties to whom the Software is furnished to
// do so, all subject to the following:
// 
// The copyright notices in the Software and this entire statement, including
// the above license grant, this restriction and the following disclaimer,
// must be included in all copies of the Software, in whole or in part, and
// all derivative works of the Software, unless such copies or derivative
// works are solely in the form of machine-executable object code generated by
// a source language processor.
// 
// THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
// IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
// FITNESS FOR A PARTICULAR PURPOSE, TITLE AND NON-INFRINGEMENT. IN NO EVENT
// SHALL THE COPYRIGHT HOLDERS OR ANYONE DISTRIBUTING THE SOFTWARE BE LIABLE
// FOR ANY DAMAGES OR OTHER LIABILITY, WHETHER IN CONTRACT, TORT OR OTHERWISE,
// ARISING FROM, OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER
// DEALINGS IN THE SOFTWARE.
//


#ifndef Data_SQLite_SQLiteStatementImpl_INCLUDED
#define Data_SQLite_SQLiteStatementImpl_INCLUDED


#include "Poco/Data/SQLite/SQLite.h"
#include "Poco/Data/SQLite/Binder.h"
#include "Poco/Data/SQLite/Extractor.h"
#include "Poco/Data/StatementImpl.h"
#include "Poco/Data/MetaColumn.h"
#include "Poco/SharedPtr.h"


struct sqlite3;
struct sqlite3_stmt;


namespace Poco {
namespace Data {
namespace SQLite {


class SQLite_API SQLiteStatementImpl: public Poco::Data::StatementImpl
	/// Implements statement functionality needed for SQLite
{
public:
	SQLiteStatementImpl(Poco::Data::SessionImpl& rSession, sqlite3* pDB);
		/// Creates the SQLiteStatementImpl.

	~SQLiteStatementImpl();
		/// Destroys the SQLiteStatementImpl.

protected:
	std::size_t columnsReturned() const;
		/// Returns number of columns returned by query.

	std::size_t affectedRowCount() const;
		/// Returns the number of affected rows.
		/// Used to find out the number of rows affected by insert, delete or update.
		/// All changes are counted, even if they are later undone by a ROLLBACK or ABORT. 
		/// Changes associated with creating and dropping tables are not counted.
		/// SQLite implements the command "DELETE FROM table" without a WHERE clause by 
		/// dropping and recreating the table. Because of this optimization, the change count 
		/// for "DELETE FROM table" will be zero regardless of the number of elements that 
		/// were originally in the table. To get an accurate count of the number of rows deleted, 
		/// use "DELETE FROM table WHERE 1".

	const MetaColumn& metaColumn(std::size_t pos) const;
		/// Returns column meta data.

	bool hasNext();
		/// Returns true if a call to next() will return data.

	std::size_t next();
		/// Retrieves the next row from the resultset and returns 1.
		/// Will throw, if the resultset is empty.

	bool canBind() const;
		/// Returns true if a valid statement is set and we can bind.

	bool canCompile() const;
		/// Returns true if statement can compile.

	void compileImpl();
		/// Compiles the statement, doesn't bind yet.
		/// Returns true if the statement was succesfully compiled.
		/// The way SQLite handles batches of statmeents is by compiling
		/// one at a time and returning a pointer to the next one.
		/// The remainder of the statement is kept in a string
		/// buffer pointed to by _pLeftover member.

	void bindImpl();
		/// Binds parameters

	AbstractExtractor& extractor();
		/// Returns the concrete extractor used by the statement.

	AbstractBinder& binder();
		/// Returns the concrete binder used by the statement.

private:
	void clear();
		/// Removes the _pStmt

	typedef Poco::SharedPtr<Binder>             BinderPtr;
	typedef Poco::SharedPtr<Extractor>          ExtractorPtr;
	typedef Poco::Data::AbstractBindingVec      Bindings;
	typedef Poco::Data::AbstractExtractionVec   Extractions;
	typedef std::vector<Poco::Data::MetaColumn> MetaColumnVec;
	typedef std::vector<MetaColumnVec>          MetaColumnVecVec;
	typedef Poco::SharedPtr<std::string>        StrPtr;
	typedef Bindings::iterator                  BindIt;

	sqlite3*         _pDB;
	sqlite3_stmt*    _pStmt;
	bool             _stepCalled;
	int              _nextResponse;
	BinderPtr        _pBinder;
	ExtractorPtr     _pExtractor;
	MetaColumnVecVec _columns;
	std::size_t      _affectedRowCount;
	StrPtr           _pLeftover;
	BindIt           _bindBegin;
	bool             _canBind;
	bool             _isExtracted;
	bool             _canCompile;
};


//
// inlines
//
inline AbstractExtractor& SQLiteStatementImpl::extractor()
{
	return *_pExtractor;
}


inline AbstractBinder& SQLiteStatementImpl::binder()
{
	return *_pBinder;
}


inline bool SQLiteStatementImpl::canBind() const
{
	return _canBind;
}


inline bool SQLiteStatementImpl::canCompile() const
{
	return _canCompile;
}


} } } // namespace Poco::Data::SQLite


#endif // Data_SQLite_SQLiteStatementImpl_INCLUDED
