<?php
require_once( "class.debug.php" );

class cMySql
{
	//Needed MySql connection fields to be set from the constructor for connecting to MySql
	private $mysql_user;					
	private $mysql_pass;
	private $mysql_server;
	private $mysql_database;
	
	private $mysql_connection;
	private $mysql_connection_link;
	private $mysql_db_connection_link;

	
	private $mysql_columns = array( );			//Array to store columns that are retrieved from the SHOW COLUMNS command
	private $mysql_parsed_columns = array( );		//Array to store columns parsed from a SELECT query (see: parseColumnNames()/executeSelectQuery() )
	private $mysql_parsed_databases = array( );		//Array to store databases parsed from a SELECT query (see: executeSelectQuery() ) TODO: IMPLEMENT
	private $mysql_row_results = array( );			//Array to store the row results of a SELECT query (see: executeSelectQuery()/getSelectResult() )

	
	/*
	Function to read a private field from above.
	Was mainly used for debugging purposes
	*/
	function readMySqlVar( $field )
	{
		return $this->$field;
	}

	/*
	Check if we are connected to the database.
	Used for simple connection checking later on
	*/
	function isConnected( )
	{
		if( $this->mysql_connection_link && $this->mysql_db_connection_link ) return true;
		else return false;
	}

	/*
	Return the result of the mysql_connect function call or die and return the error
	*/
	function getConnectLink( )
	{
		return ( mysql_connect( $this->server, $this->mysql_user, $this->mysql_pass ) or die( "MySql Connect Error: " . mysql_error( ) ) );
	}

	/*
	Same as above except executed on the database
	*/
	function getDbConnectLink( )
	{
		return ( mysql_select_db( $this->mysql_database ) or die( "MySql Select Db Error: " . mysql_error( ) ) );
	}
	
	/*
	Executes a MySQL query.  Can also be used simply for an INSERT query.
	*/
	function executeQuery( $query )
	{
		$result = mysql_query( $query );
		$err = mysql_error( );
		if( $err != "" ) return $err;
		return $result;
	}

	/*
	Dynamically retrieves all the column names from a table and then pushes the
	results of the query (SHOW COLUMNS FROM $table ) onto the mysql_columns array
	*/
	function getTableColumns( $table )
	{
		$query = $this->executeQuery( "SHOW COLUMNS FROM $table" );
		while( $obj = mysql_fetch_object( $query ) )
		{
			array_push( $this->mysql_columns, $obj->Field );
		}
	}
	
	/*
	Counts the columns in the table
	*/
	function countColumnsInTable( $table )
	{
		$query = $this->executeQuery( "SHOW COLUMNS FROM $table" );
		return mysql_num_rows( $query );
	}
	
	/*
	Get a table name at a specific index in the mysql_columns array
	*/	
	function getTableColumnAtIdx( $table, $idx )
	{
		//Fill it if its empty.  Checking if it is empty so it is only done on the first
		//time rather than every single call to the function
		if( empty( $this->mysql_columns ) ) 
			$this->getTableColumns( $table );
	
		return $this->mysql_columns[$idx];
	}

	/*
	Checks if a column exists.  This is quite buggy and needs fixing
	*/
	function checkIfColumnsExist( $table, $columns_from_table, $columns_from_query )
	{
		for( $i = 0; $i < $this->countColumnsInTable( $table ); $i++ )
		{
			for( $j = 0; $j < sizeof( $columns_from_query ); $j++ )
			{
				if( $columns_from_query[ $i ] == "*" ) return true;
				if( $columns_from_table[ $i ] == $columns_from_query[ $j ] ) return true;
				else continue;
			}
		}
		return false;
	}

	/*
	Parses the column names from a SELECT query
	*/
	function parseColumnNamesFromQuery( $query )
	{
		$query = strtolower( $query );
		if( ( sizeof( $this->mysql_parsed_columns ) > 0 ) || ( sizeof( $this->mysql_row_results ) > 0 ) ) 
		{
			$size = sizeof( $this->mysql_parsed_columns );
			for( $i = 0; $i < $size; $i++ )
				array_pop( $this->mysql_parsed_columns );

			$size = sizeof( $this->mysql_row_results );
			for( $i = 0; $i < $size; $i++ )
				array_pop( $this->mysql_row_results );
		}
		
		$fmt = explode( "from", $query );
		$select = $fmt[0];
		$select = preg_replace('/\s/', '',$select );
		$select = preg_replace( '/select/', '', $select );
		$select_fmt = explode( ",", $select );
		$count = count( $select_fmt );

		if( $select_fmt[0] == "*" )
		{
			$debug = new cDebug( );
			$debug->enableDebugging( true );
			$debug->debugBuffer( "Wild cards are currently unsupported (TODO: Implement this feature )", 3 );
		}
		for( $i = 0; $i < $count; $i++ ) {
			array_push( $this->mysql_parsed_columns, $select_fmt[ $i ] );
		}
	}
	/*
	Executes the SELECT query, parses the names, and stores the results of
	the SELECT query in the mysql_row_results array
	*/
	function executeSelectQuery( $query )
	{
		$res = $this->executeQuery( $query );
		$this->parseColumnNamesFromQuery( $query );
		while( $row = mysql_fetch_assoc( $res ) ) 
		{
			for( $i = 0; $i < sizeof( $this->mysql_parsed_columns ); $i++ )
			{
				array_push( $this->mysql_row_results, $row[ $this->mysql_parsed_columns[ $i ] ] );
			}
		}
	}

	/*
	Returns the result set stored in a specific index number 
	in the mysql_row_result array.  This will only retrieve information
	of the last query executed with executeSelectQuery()
	*/
	function getSelectResult( $idx )
	{
		return $this->mysql_row_results[ $idx ];
	}

	/*
	Returns the size of the mysql_row_results array which in turn
	also returns the size of the result set of the previous SELECT query
	executed with executeSelectQuery()
	*/
	function getSelectResultSize( )
	{
		return sizeof( $this->mysql_row_results );
	}

	/*
	Constructor for setting up the mysql connection
	*/
	function __construct( $user, $pass, $server, $database )
	{
		$this->mysql_user = $user;
		$this->mysql_pass = $pass;
		$this->mysql_server = $server;
		$this->mysql_database = $database;
		$this->mysql_connection_link = $this->getConnectLink( );
		$this->mysql_db_connection_link = $this->getDbConnectLink( );
	}
}

?>