<?php
/**
 * Class for Database Table management
 *
 * PHP version 5
 *
 * Copyright © 2010 Remi Collet
 *
 * This file is part of rpmphp.
 *
 * rpmphp is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as published by
 * the Free Software Foundation, either version 3 of the License, or
 * (at your option) any later version.
 *
 * rpmphp is distributed in the hope that it will be useful,
 * but WITHOUT ANY WARRANTY; without even the implied warranty of
 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
 * GNU Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with rpmphp.  If not, see <http://www.gnu.org/licenses/>.
 *
 * @category  Main
 * @package   RPMPHP
 *
 * @author    Remi Collet <unknown@unknwown.com>
 * @author    Johan Cwiklinski <johan@x-tnd.be>
 * @copyright 2010 Remi Collet
 * @license   http://www.gnu.org/licenses/agpl-3.0-standalone.html AGPL License 3.0 or (at your option) any later version
 * @link      http://github.com/remicollet/rpmphp/
 * @since     The begining of times.
*/

abstract class CommonTable
{
    protected $db;
    protected $table;

    /**
     * Instanciate a CommonTable
     *
     * @param object $db    PDO instance of the DB connection
     * @param string $table with table name
     */
    function __construct(PDO $db, $table)
    {
        $this->db = $db;
        $this->table = $table;

        if (!$this->existsTable($table)) {
            $this->createTable($table);
        }
    }

    /**
     * Check if the table already exists
     *
     * @param string $table with table name
     *
     * @return boolean
     */
    public function existsTable($table)
    {
        $req = new TableIterator($this->db, "SHOW TABLES LIKE '$table'");
        foreach ($req as $data) {
            return true;
        }
        return false;
    }

    /**
     * Execute an SQL statement (INSERT, DELETE, ...)
     *
     * @param string $sql The SQL clause
     */
    protected function exec($sql)
    {
        $res = $this->db->exec($sql);
        if ($res===false) {
            $err = $this->db->errorInfo();
            throw new Exception($err[2]);
        }
    }

    /**
     * Add a new row in the table
     *
     * @param hashtable $fields hashtable of fieldname => value
     */
    protected function add(array $fields)
    {
        $col = array();
        $val = array();
        foreach ($fields as $name => $value) {
            $col[] = "`$name`";
            if (is_null($value)) {
                $val[] = 'NULL';
            } else if (is_numeric($value)) {
                $val[] = $value;
            } else {
                $val[] = "'$value'";
            }
        }
        $sql = "INSERT INTO `".$this->table."` (".implode(',', $col).")
                VALUE (".implode(',', $val).")";
        $this->exec($sql);
    }

    /**
     * Create the table
     */
    abstract protected function createTable();

    /**
     * Instanciate a Simple TableIterator on the current table
     *
     * Examples =
     *  foreach ($DB->request() as $ID => $data) { ... }
     *  foreach ($DB->request("ID=1") as $ID => $data) { ... }
     *  foreach ($DB->request("", "name") as $ID => $data) { ... }
     *  foreach ($DB->request(array("name"=>"SBEI003W","entities_id"=>1),array("serial","otherserial")) { ... }
     *
     * @param string|array $crit string or array of field/values,
     *                           ex array("id"=>1), if empty => all rows
     *
     * Examples =
     *  array("id"=>NULL)
     *  array("OR"=>array("id"=>1, "NOT"=>array("state"=>3)));
     *  array(
     *      "AND"=>array(
     *          "id"=>1,array(
     *              "NOT"=>array(
     *                  "state"=>array(3,4,5),
     *                  "toto"=>2
     *              )
     *          )
     *      )
     *  )
     *
     * param 'FIELDS' name or array of field names
     * param 'ORDER' filed name or array of field names
     * param 'LIMIT' max of row to retrieve
     * param 'START' first row to retrieve
     *
     * @return DBIterator
     **/
    public function request ($crit='')
    {
        return new TableIterator ($this->db, $this->table, $crit);
    }

    /**
     * Retrieve 2 columns of all the table's row in a hashtable
     *
     * @param string $fieldkey   name of the field to use as index
     * @param string $fieldvalue name of the field to use as value
     *
     * @return hashtable
     */
    public function getAllArray($fieldkey, $fieldvalue)
    {
        $crit = array('FIELDS'  => array($fieldkey, $fieldvalue),
                      'ORDER'   => $fieldkey);
        $tab = array();
        foreach ($this->request($crit) as $data) {
            $tab[$data[$fieldkey]] = $data[$fieldvalue];
        }
        return $tab;
    }
}

?>