/* 
 * File:   LPQResultSet.h
 * Author: Saleem Edah-Tally - nmset@yandex.com
 * License : LGPL version 2.1
 * Copyright Saleem Edah-Tally, M. D. - © 2014
 *
 * Created on 29 mai 2014, 16:16
 */

#ifdef USE_LIBPQ
#ifndef LPQRESULTSET_H
#define LPQRESULTSET_H

#include "LResultSet.h"
#include <libpq-fe.h>

/**
 * PostgreSQL namespace.
 * 
 * Please note USE_LIBPQ pre-processor directive must be defined to include the PostgreSQL backend.
 */
namespace PQ
{
#define RSPQMC wxString(_T("RSPQM"))
#define RS000C wxString(_T("RS000"))
#define RS000M wxString(_T("Result set is NULL."))
#define RS001C wxString(_T("RS001"))
#define RS001M wxString(_("Insert started\nPlease SAVE or CANCEL first"))
#define RS002C wxString(_T("RS002"))
#define RS002M wxString(_("Unknown error"))
#define RS003C wxString(_T("RS003"))
#define RS003M wxString(_("Data altered\nPlease SAVE or CANCEL first"))
#define RS004C wxString(_T("RS004"))
#define RS004M wxString(_T("Invalid column name :\n"))

/**
 * Scrollable resultset for the PostgreSQL backend.
 * 
 * This class allows data modification through GUI elements.
 * The underlying SQL query must not contain table aliases.
 * 
 * A column alias must still be a real column name of the table specified in SetTableName.
 * 
 * Ex : SELECT tbl1.pk1, tbl1.text1, list2.text2 AS num1 FROM tbl1 LEFT JOIN list2 ON tbl1.num1 = list2.pk2
 */
class LPQResultSet : public LResultSet
{
public:
    LPQResultSet();
    LPQResultSet(LConnection * newConnection);
    virtual ~LPQResultSet();

    /**
     * Updates and runs the SQL string.
     * @param newSql
     * @return 
     */
    bool SetSQL(const wxString& newSql);
    bool HasData() const;
    bool Absolute(const unsigned int newRowIndex);
    bool IsFirst() const;
    bool IsLast() const;
    bool First();
    bool Next();
    bool Previous();
    bool Last();
    const unsigned int GetRowCount() const;
    const unsigned int GetColumnCount() const;
    const wxString GetColumnName(const unsigned int colIndex) const;
    const int GetColumnIndex(const wxString& colName) const;
    const wxAny GetData(const unsigned int rowIdx, const unsigned int colIdx) const;
    /**
     * At current row.
     * @param colName
     * @return database table value or wxEmptyString.
     */
    const wxAny GetData(const wxString& colName) const;
    /**
     * Updates registered controls on screen.
     */
    void Display();
    bool Save();

    inline void InformInserting() const
    {
        InformLibMessage(LInformation(RS001C, RS001M));
    }

    inline void InformDirty() const
    {
        InformLibMessage(LInformation(RS003C, RS003M));
    };

    /**
     * Replaces a single quote ' by two single quotes '' .
     * @param literal
     * @return the number of single quotes replaced
     */
    static int EscapeChar(wxString& literal)
    {
        return literal.Replace(_T("'"), _T("''"));
    }

private:
    bool RunSQL();
    const wxString MakeUpdateSQL() const;
    const wxString MakeDeleteSQL() const;
    /**
     * Locates a row by the primary key value and returns its index.
     * @param pkValue
     * @return row index or -1 if not found.
     */
    const int GetRowByPKValue(const wxAny& pkValue) const;
};

}
#endif /* LPQRESULTSET_H */
#endif