<?php
/**
 *
 *
 *
 * Example usage
$part   =   new DBPartitionMaker();

if (1 < count($_SERVER['argv'])) {
    array_shift($_SERVER['argv']);
    $min    =   array_shift($_SERVER['argv']);
    $max    =   null;
    if (!empty($_SERVER['argv'])) {
        $max    =   array_shift($_SERVER['argv']);
    }

    $part->setYear($min, $max);
}

$tables =   $part->getKnownTables();
foreach ($table as $t) {
    $part->partition($t);
}

*/

/**
 * Partition Maker
 *
 * Helper Tool
 */
class DBPartitionMaker
{
    private $sqlPart    = '';
    private $sqlRange   = '';
    private $yearMin    = 2010;
    private $yearMax    = 2020;

    private $knownTables    =   array();

    public function __construct()
    {
        $this->knownTables[]    =   'forwardtracking';
        $this->knownTables[]    =   'cookiepreferences';
        $this->knownTables[]    =   'sessionview';
        $this->knownTables[]    =   'pageview';
        $this->knownTables[]    =   'genericview';

        $this->yearMax  =   date('Y');

        $this->sqlRange =   '    PARTITION p%d VALUES LESS THAN (%d)';
        $this->sqlPart    =   <<<EOL
-- %1\$s
CREATE TABLE `w%1\$s` LIKE wb%1\$s;

ALTER TABLE w%1\$s
ENGINE=InnoDB
PARTITION BY RANGE (year(created)) (
%2\$s
);

ALTER TABLE wb%1\$s RENAME TO x%1\$s;
CREATE TABLE wb%1\$s LIKE x%1\$s;

ALTER TABLE w%1\$s DISABLE KEYS;
INSERT INTO w%1\$s SELECT * FROM x%1\$s;
ALTER TABLE w%1\$s ENABLE KEYS;

ALTER TABLE wb%1\$s RENAME TO y%1\$s;
ALTER TABLE w%1\$s RENAME TO wb%1\$s;

INSERT INTO wb%1\$s SELECT * FROM y%1\$s;

DROP TABLE x%1\$s;
DROP TABLE y%1\$s;

EOL;
    }

    /**
     * Get List Of Tables
     *
     * @return array
     */
    public function getKnownTables()
    {
        return $this->knownTables;
    }

    /**
     * Set Year
     *
     * @param int start year
     * @param int end year
     */
    public function setYear($min, $max = null)
    {
        $this->yearMin  =   $min;
        if (empty($max)) {
            return;
        }
        $this->yearMax  =   $max;
    }

    /**
     * Build Parttions SQL
     *
     * @return string
     */
    public function partition($table)
    {
        $range  =   array();
        for ($i = $this->yearMin; $i <= $this->yearMax; ++$i) {
            $range[]    =   sprintf($this->sqlRange, $i, $i + 1);
        }
        $range  =   implode(",\n", $range);
        return sprintf($this->sqlPart . "\n", $table, $range);
    }
}