<?php
/**
 * Akeeba Engine
 * The modular PHP5 site backup engine
 * @copyright Copyright (c)2009-2014 Nicholas K. Dionysopoulos
 * @license GNU GPL version 3 or, at your option, any later version
 * @package ALICE
 *
 */

// Protection against direct access
defined('AKEEBAENGINE') or die();

/**
 * Checks if the user is trying to backup too much databases, causing the system to fail
 */
class AliceCoreDomainChecksRuntimeerrorsToomuchdbs extends AliceCoreDomainChecksAbstract
{
    public function __construct($logFile = null)
    {
        parent::__construct(40, JText::_('ALICE_ANALYZE_RUNTIME_ERRORS_TOOMUCHDBS'), $logFile);
    }

	public function check()
	{
        $handle = @fopen($this->logFile, 'r');

        if($handle === false)
        {
            AliceUtilLogger::WriteLog(_AE_LOG_ERROR, $this->checkName.' Test error, could not open backup log file.');
            return false;
        }

        $prev_data = '';
        $buffer    = 65536;
        $tables    = array();
		$ex_tables = array();

        while (!feof($handle))
        {
            $data = $prev_data.fread($handle, $buffer);

            // Let's find the last occurrence of a new line
            $newLine = strrpos($data, "\n");

            // I didn't hit any EOL char, let's keep reading
            if($newLine === false)
            {
                $prev_data = $data;
                continue;
            }
            else
            {
                // Gotcha! Let's roll back to its position
                $prev_data = '';
                $rollback  = strlen($data) - $newLine + 1;
                $len       = strlen($data);

                $data      = substr($data, 0, $newLine);

                // I have to rollback only if I read the whole buffer (ie I'm not at the end of the file)
                // Using this trick should be much more faster than calling ftell to know where we are
                if($len == $buffer)
                {
                    fseek($handle, -$rollback, SEEK_CUR);
                }
            }

	        // Let's save every scanned table
	        preg_match_all('#AEDumpNativeMysql :: Adding.*?\(internal name (.*?)\)#i', $data, $matches);

	        if(isset($matches[1]))
	        {
		        $tables = array_merge($tables, $matches[1]);
	        }
        }

        fclose($handle);

		// Let's loop on saved tables and look at their prefixes
		foreach($tables as $table)
		{
			preg_match('/^(.*?_)/', $table, $matches);


			if($matches[1] !== '#_' && !in_array($matches[1], $ex_tables))
			{
				$ex_tables[] = $matches[1];
			}
		}

		if(count($ex_tables))
		{
			if(count($ex_tables) > 0 && count($ex_tables) <= 3)
			{
				$this->setResult(0);
			}
			else
			{
				$this->setResult(-1);
			}

			AliceUtilLogger::WriteLog(_AE_LOG_INFO, $this->checkName.' Test failed, user is trying to backup '.count($ex_tables).' different databases at once.');

			throw new Exception(JText::_('ALICE_ANALYZE_RUNTIME_ERRORS_TOOMUCHDBS_ERROR'));
		}

        AliceUtilLogger::WriteLog(_AE_LOG_INFO, $this->checkName.' Test passed, there are no issues while creating the backup archive ');

        return true;
	}

	public function getSolution()
	{
		return JText::_('ALICE_ANALYZE_RUNTIME_ERRORS_TOOMUCHDBS_SOLUTION');
	}
}
