// CRecordset.h: interface for the CConnection class.
//
//////////////////////////////////////////////////////////////////////

#if !defined(AFX_CONNECTION_H__FF5ED1A8_ECAE_4A7F_8CFE_44F22F9A2FDA__INCLUDED_)
#define AFX_CONNECTION_H__FF5ED1A8_ECAE_4A7F_8CFE_44F22F9A2FDA__INCLUDED_

#if _MSC_VER > 1000
#pragma once
#endif // _MSC_VER > 1000

class CServerConnection;

namespace scdriver
{
// forward declaration
class CRecordset;
class CCommand;

/**************************************
 *
 *    enum: D A T A _ T Y P E
 *
 **************************************
 *
 * Functional description
 *
 *	data types of the field
 **************************************/
enum DATA_TYPE
{
	DB_TINYINT			= 2,
	DB_SMALLINT			= 2,
	DB_INT				= 3,
	DB_BIGINT			= 32769,
	DB_UNIQUEIDENTIFIER	= 32768,
	DB_DOUBLE			= 5,
	DB_FLOAT			= 4,
	DB_DATETIME			= 7,
	DB_CHAR				= 8,
	DB_VARCHAR			= 8,
	DB_TEXT				= 32770,
	DB_NCHAR			= 25,
	DB_NVARCHAR			= 25,
	DB_NTEXT			= 32772,
	DB_BLOB				= 32771,
	DB_GUID				= 72,
	DB_NULL				= 1,
	DB_DECIMAL			= 2048, // decimal data type
	DB_BIT				= 102,
};

#ifdef DELPHI
class CAbstractFieldStream
{
public:
	virtual int __stdcall GetFieldSize() const = 0;
	virtual bool __stdcall IsNull() const = 0;
	virtual bool __stdcall ReadField(void *data, int *size) = 0;
};
#endif

/**************************************
 *
 *    class: C F i e l d S t r e a m
 *
 **************************************
 *
 * Functional description
 *
 *	Interface for reading column's value
 **************************************/
#ifdef DELPHI
class CFieldStream : public CAbstractFieldStream
#else
class __declspec( dllexport ) CFieldStream
#endif
{
public:
	CFieldStream();
	virtual ~CFieldStream();

	/**************************************
	 *
	 *    function: G e t F i e l d S i z e
	 *
	 **************************************
	 *
	 * Functional description
	 *
	 *	return number of bytes of the content of the column's data
	 *	NOTE: for the BLOB type columns it will return bigger size
	 *	of the BLOB than actual.
	 *	The function is especially usefull to read BLOB's data in a single
	 *	ReadField() call.
	 **************************************/
#ifdef DELPHI
	int __stdcall GetFieldSize() const;
#else
	int GetFieldSize()const;
#endif

	/**************************************
	 *
	 *    function: I s N u l l
	 *
	 **************************************
	 *
	 * Functional description
	 *
	 *	return TRUE if column is null, otherwise - FALSE
	 **************************************/
#ifdef DELPHI
	bool __stdcall IsNull() const;
#else
	bool IsNull();
#endif

	/**************************************
	 *
	 *    function: R e a d F i e l d
	 *
	 **************************************
	 *
	 * Functional description
	 *
	 *	fill ouput buffer with the data column's data
	 *	parameters: 
	 *		[in] data - buffer to write column's content
	 *		[in,out] size - [in] max buffer's size, [out] - number of bytes readed
	 *	return:
	 *		false - more data to read left
	 *		true  - all content of the column has been read
	 **************************************/
#ifdef DELPHI
	bool __stdcall ReadField(void *data, int *size);
#else
	bool ReadField(void *data, int *size);
#endif

protected:
	friend class CRecordset;
	void SetField(const int &_type, void *data);

private:
	CConnection		*m_conn;
	DATA_TYPE		m_type;
	byte			*m_data;
	byte			*m_blob;
	long			m_ichunk;
	long			m_chunks;
	int				m_isize;
	int				m_size;
};

/**************************************
 *
 *    struct: F I E L D _ I N F O
 *
 **************************************
 *
 * Functional description
 *
 *	detailed information of the column int the output row
 **************************************/
struct FIELD_INFO
{
	char			name[128];
	int				id;
	DATA_TYPE		type;
	unsigned char	m_prec;		// DECIMAL precision
	unsigned char	m_scale;	// DECIMAL fraction
	byte			vtype; // visibility mask. Used to gennerate SQL for update/delete/insert when modifyning recordset in DB grid
						// 0 - normal column (show always), 
						// 4 - RID (columns belong to row ID or primary key), show always
						// 6 - RID column, hide from output
	unsigned __int64 table_id; // unique table_id the column belongs to: select table_id from system.systables		
	CFieldStream	data;

	bool operator() (const char *f1,const char *f2) const 
	{
		return stricmp(f1,f2) < 0; 
	};
};

#ifdef DELPHI
class CAbstractRecordset
{
public:
	virtual void __stdcall Open(CConnection *conn, const char *cmd) = 0;
	virtual void __stdcall Next() = 0;
	virtual int __stdcall GetFieldCount() const = 0;
	virtual FIELD_INFO* __stdcall GetFieldInfoByIndex(const int iCol) = 0;
	virtual FIELD_INFO* __stdcall GetFieldInfoByName(const char *name) = 0;
	virtual CFieldStream* __stdcall GetFieldStreamByIndex(const int iCol) = 0;
	virtual CFieldStream* __stdcall GetFieldStreamByName(const char *name) = 0;
	virtual bool __stdcall IsEOF() const = 0;
	virtual void __stdcall Free() = 0;
};

extern "C" CAbstractRecordset* __stdcall NewRecordset();
#endif

/**************************************
 *
 *    class: C R e c o r d s e t
 *
 **************************************
 *
 * Functional description
 *
 *	manage recordsets. single threaded
 **************************************/
#ifdef DELPHI
class CRecordset : public CAbstractRecordset
#else
class __declspec( dllexport ) CRecordset
#endif
{
public:
	
	CRecordset();
	virtual ~CRecordset();

	/**************************************
	 *
	 *    function: g e t _ c a l l _ s i z e
	 *
	 **************************************
	 *
	 * Functional description
	 *
	 *	return the size of the class
	 **************************************/
	static int get_class_size();

	/**************************************
	 *
	 *    function: O p e n
	 *
	 **************************************
	 *
	 * Functional description
	 *
	 *	execute SQL/DQL statement and receive status
	 *	(has output, columns schema & rows)
	 **************************************/
#ifdef DELPHI
	void __stdcall Open(CConnection *conn, const char *cmd);
#else
	void Open(CConnection *conn, const char *cmd);
#endif

	/**************************************
	*
	*	function: N e x t
	* 
	**************************************
	*
	* Functional description
	*	Move to the next row in the recordset
	**************************************/
#ifdef DELPHI
	void __stdcall Next();
#else
	void Next();
#endif

	/**************************************
	*
	*	function: G e t F i e l d C o u n t
	* 
	**************************************
	*
	* Functional description
	*	Return number of columns in the output row(s)
	**************************************/
#ifdef DELPHI
	int __stdcall GetFieldCount() const;
#else
	int GetFieldCount();
#endif

	/**************************************
	*
	*	function: G e t V i s i b l e F i e l d C o u n t
	* 
	**************************************
	*
	* Functional description
	*	Return number of visible columns
	**************************************/
	int GetVisibleFieldCount();

	/**************************************
	*
	*	function: G e t F i e l d I n f o
	* 
	**************************************
	*
	* Functional description
	*	Get field's info structure by the its 
	*	position in the row [0,nFields[
	**************************************/
#ifdef DELPHI
	FIELD_INFO* __stdcall GetFieldInfoByIndex(const int iCol);
	CFieldStream* __stdcall GetFieldStreamByIndex(const int iCol);
#else
	FIELD_INFO *GetFieldInfo(const int iCol);
#endif

	/**************************************
	*
	*	function: G e t F i e l d I n f o
	* 
	**************************************
	*
	* Functional description
	*	Get field's info structure by the its 
	*	name
	**************************************/
#ifdef DELPHI
	FIELD_INFO* __stdcall GetFieldInfoByName(const char *name);
	CFieldStream* __stdcall GetFieldStreamByName(const char *name);
#else
	FIELD_INFO *GetFieldInfo(const char *name);
#endif

	/**************************************
	 *
	 *    function: E O F
	 *
	 **************************************
	 *
	 * Functional description
	 *
	 *	return TRUE if end of recordset reached
	 **************************************/
#ifdef DELPHI
	bool __stdcall IsEOF();
#else
	bool IsEOF();
#endif

#ifdef DELPHI
	void __stdcall Free();
#endif

	/**************************************
	 *
	 *    function: O p e n
	 *
	 **************************************
	 *
	 * Functional description
	 *
	 *	execute SQL/DQL inside server (for UDI procedures)
	 **************************************/
	void Open(CServerConnection *conn, const char *cmd);

	/**************************************
	*
	*	function: G e t S c h e m a I n f o
	* 
	**************************************
	*
	* Functional description
	*	
	*	set the number of rows affected by insert/update/delete
	*	and if select statement can update rows
	**************************************/
	void GetSchemaInfo(int *_recodset, unsigned __int64 *_affected_row, bool *_allow_add, bool *_allow_edit,bool *_allow_delete)
	{
		*_recodset		= m_recordset;
		*_affected_row	= m_affected_row;
		*_allow_add		= m_allow_add;
		*_allow_edit	= m_allow_edit;
		*_allow_delete	= m_allow_delete;
	};

protected:
	/**************************************
	*
	*	function: r e a d _ s c h e m a
	* 
	**************************************
	*
	* Functional description
	*	called then query has completed to read
	*	column's definition in output recordset
	**************************************/
	static void __stdcall read_schema(CConnection *conn, void *recordset);

	/**************************************
	*
	*    function: a l l o c _ f i e l d s
	*
	**************************************
	*
	* Functional description
	*
	*	reallocate fields buffer if it is too
	*	small
	**************************************/
	void alloc_fields(const unsigned int &iallocate);

private:
	/**************************************
	*
	*	function: f e t c h _ p r o j e c t
	* 
	**************************************
	*
	* Functional description
	*	read columns info
	**************************************/
	void fetch_project();

	/**************************************
	*
	*	function: f e t c h _ r o w s e t
	* 
	**************************************
	*
	* Functional description
	*	read rows
	**************************************/
	void fetch_rowset();

private:
	short		m_eof;		// end of recordset
	int			m_index;	// current row position in the precached rows chunk buffer
	CConnection *m_conn;	// connection instance 
	CServerConnection *m_server_conn; // server side connection instance. used by UDI applications
	int			m_nfields;  // number of the fields/columns in the output row
	FIELD_INFO  *m_fields;	// columns type info 
	void		*m_fmap;		// for fast access to the field by its name
	byte		*m_rows;	// rows fitting to the single IO page
	bool		m_first;	// true - if first package from db received
	int			m_ifields;  // number of preallocated fields
	
	int			m_recordset;
	bool		m_allow_add;
	bool		m_allow_edit;
	bool		m_allow_delete;
	unsigned __int64 m_affected_row; // number of rows affected by insert/update/delete

	friend class CCommand;
};
}

#endif // !defined(AFX_CONNECTION_H__FF5ED1A8_ECAE_4A7F_8CFE_44F22F9A2FDA__INCLUDED_)