<?php
/**
 * Store and access key value pairs
 *
 * $Id$
 *
 * @author gERD Schaufelberger <gerd@php-tools.net>
 * @license PHP License
 * @package WB
 * @subpackage db
 */

WBClass::load('WBDatasource_Callback'
    , 'patI18n');

/**
 * Store and access key value pairs
 *
 * Use database to store key value pairs in a normalized form.
 * Microcache is used to shortcut DB queries for repetitive loading
 *
 * @version 1.0.0
 * @package WB
 * @subpackage db
 */
class WBDatasource_KeyValuePair extends WBStdClass implements WBDatasource_Callback
{
    /**
     * Table name: key
     */
    const TABLE_KEY     =   'keyvaluepairkey';

    /**
     * Table name: value
     */
    const TABLE_VALUE   =   'keyvaluepairvalue';

    /**
     * Table name: valueid
     */
    const TABLE_RELID   =   'keyvaluepairkeyvalueid';

    /**
     * Table name: key value relation
     */
    const TABLE_REL     =   'keyvaluepairkeyvalue';

    /**
     * datasource
     * @var WBDatasource_Table
     */
    private $table;

    /**
     * microcache
     * @var WBDatasource_TableMicroCache
     */
    private $mc;

    /**
     * Key domain
     * @var string
     */
    private $domain =   '';

    /**
     * Use translation
     *
     * @var bool
     */
    private $doTranslation  =   true;

    /**
     * Constructor
     *
     * @param array $parameter
     */
    public function __construct($parameter = array())
    {
        $this->table        =   WBClass::create('WBDatasource_Table', $parameter);
        $parameter['name']  =   $this->table->getDbName();
        //$this->mc           =   WBClass::create('WBDatasource_TableMicroCache', $parameter);
        //$this->mc->setTable(self::TABLE_REL);
    }

    /**
     * Switch on/off translation feature
     *
     * @param bool $switch
     */
    public function switchTranslation($switch = false)
    {
        $this->doTranslation    =   $switch;
        $this->table->switchTranslation($switch);
    }

    /**
     * Set domain
     *
     * Optionally define domain for keys. Using domains, allows you store keys separately.
     * The default text domain ist empty.
     *
     * @param string $domain
     */
    public function setDomain($domain = '')
    {
        $this->domain   =   $domain;
    }

    /**
     * Fetch key values pairs by id
     *
     * @param string $id
     * @param bool $asList
     * @return array
     */
    public function get($id, $asList = false)
    {
        if (empty($id)) {
            return array();
        }

        $list   =   $this->getListFromDb($id);
        if ($asList) {
            return $list;
        }

        $data   =   array();
        foreach ($list as $l) {
            $data[$l['key']]  =   $l['value'];
        }

        return $data;
    }

    /**
     * Fetch key values pairs from database
     *
     * @param array $id list of ids
     * @return array
     */
    private function getListFromDb($id)
    {
        if (!is_array($id)) {
            $id =   array($id);
        }

        /*
         * Build query
          SELECT k.word AS key, v.word AS value, kv.keyvalueid AS id
               FROM unittestkeyvaluepairkeyvalue kv
                     JOIN unittestkeyvaluepairkey k USING (keyid)
                     JOIN unittestkeyvaluepairvalue v USING (valueid)
               WHERE kv.keyvalueid IN ($id)
         */

        // sort by keys as defined in config
        $tInfo  =   $this->table->getTableInfo(self::TABLE_KEY);
        $order  =   array(
                        array(
                            'table' =>  self::TABLE_KEY,
                            'field' =>  'word',
                            'asc'   =>  1
                        )
                    );
        if (isset($tInfo['order']) && is_array($tInfo['order'])) {
            $order  =   array();
            foreach ($tInfo['order'] as $o) {
                $o['table'] =   self::TABLE_KEY;
                $order[]    =   $o;
            }
        }

        $clause     =   array();
        $clause[]   =   array(
                            'field'     =>  $this->table->getIdentifier(self::TABLE_RELID),
                            'relation'  =>  'in',
                            'value'     =>  $id
                        );
        $options            =   array();
        $options['order']   =   $order;
        $options['join']    =   array();
        $options['join'][]  =   array(
                                        'table' =>  self::TABLE_KEY,
                                        'using' =>  $this->table->getIdentifier(self::TABLE_KEY)
                                    );
        $options['join'][]  =   array(
                                        'table' =>  self::TABLE_VALUE,
                                        'using' =>  $this->table->getIdentifier(self::TABLE_VALUE)
                                    );
        $options['column']  =   array();
        $options['column'][]=   array(
                                        'table' =>  self::TABLE_KEY,
                                        'field' =>  'word',
                                        'as'    =>  'key'
                                    );
        $options['column'][]=   array(
                                        'table' =>  self::TABLE_VALUE,
                                        'field' =>  'word',
                                        'as'    =>  'value'
                                    );
        $options['column'][]=   array(
                                        'field' =>  $this->table->getIdentifier(self::TABLE_RELID),
                                        'as'    =>  'id'
                                    );
        if ($this->doTranslation) {
            $options['callback']    =   $this;
        }

        $list   =   $this->table->get(self::TABLE_REL, null, null, $clause, $options);
        //$this->mc->add($id, $list);
        return $list;
    }

    /**
     * Save list of key value pairs
     *
     * Save new list or add list
     *
     * @param array $data associative array (the actual key value pairs)
     * @param string $id
     * @return string
     */
    public function set($data = array(), $id = '__new')
    {
        if (!is_array($data)) {
            WBClass::load('WBException_Call');
            throw new WBException_Call('Invalid call, data parameter must be an array');
        }

        if (isset($data[0])) {
            WBClass::load('WBException_Call');
            throw new WBException_Call('Invalid call, data must be an associative array');
        }

        $kPrimary   =   $this->table->getIdentifier(self::TABLE_KEY);
        $vPrimary   =   $this->table->getIdentifier(self::TABLE_VALUE);
        $kvPrimary  =   $this->table->getIdentifier(self::TABLE_RELID);

        // use existing id or add new one
        if ('__new' == $id) {
            $id =   $this->table->save(self::TABLE_RELID, '__new', array('created' => gmdate('Y-m-d H:i:s')));
        } else {
            $clause     =   array();
            $clause[]   =   array(
                                'field' =>  $kvPrimary,
                                'value' =>  $id
                                );
            $this->table->delete(self::TABLE_REL, null, null, $clause);
        }

        if (empty($data)) {
            //$this->mc->add($id, array());
            return $id;
        }

        $save   =   array();
        $cache  =   array();
        foreach ($data as $key => $value) {
            $s  =   array(
                        $kvPrimary  =>  $id
                        );
            $s[$kPrimary]   =   $this->findOrAddWord(self::TABLE_KEY, $key);
            $s[$vPrimary]   =   $this->findOrAddWord(self::TABLE_VALUE, $value);
            $save[] =   $s;

            $cache[]    =   array(
                                'key'   =>  $key,
                                'value' =>  $value
                            );
        }

        $this->table->save(self::TABLE_REL, '__new', $save);
        //$this->mc->add($id, $cache);
        return $id;
    }

    /**
     * Remove key value pair list
     *
     * Delete rows from TABLE_REL and TABLE_RELID
     *
     * @param string $id
     */
    public function delete($id)
    {
        $clause     =   array();
        $clause[]   =   array(
                            'field' =>  $this->table->getIdentifier(self::TABLE_RELID),
                            'value' =>  $id
                            );
        $this->table->delete(self::TABLE_REL, null, null, $clause);
        $this->table->delete(self::TABLE_RELID, $id);
        //$this->mc->add($id, array());
    }

    /**
     * Get all known keys
     *
     * @return array
     */
    public function getKeys()
    {
        $clause     =   array();
        $clause[]   =   array(
                                'field' =>  'domain',
                                'value' =>  $this->domain
                            );
        $options    =   array(
                            'column'    =>  'word'
                        );
        return $this->table->getColumn(self::TABLE_KEY, null, $clause, $options);
    }

    /**
     * Find word in table
     *
     * Look up word in table. If it is not there, yet, add it.
     * Return word's id of found or added record
     *
     * @param string $table
     * @param string $word
     * @return string $id
     */
    private function findOrAddWord($table, $word)
    {
        // Look up for word
        $clause     =   array();
        $clause[]   =   array(
                            'field' =>  'word',
                            'value' =>  $word
                            );

        if (self::TABLE_KEY == $table) {
            $clause[]   =   array(
                            'field' =>  'domain',
                            'value' =>  $this->domain
                            );

        }
        $old    =   $this->table->getIds($table, null, $clause);
        if (count($old)) {
            return $old[0];
        }

        // add word if it was not found
        $save   =   array(
                        'word'  =>  $word
                        );
        if (self::TABLE_KEY == $table) {
            $save['domain'] =   $this->domain;
        }
        return $this->table->save($table, '__new', $save);
    }

   /**
    * callback when receive whole entry
    *
    * @param string $src name of source
    * @param string $key
    * @param array $data loaded data
    * @return bool true on success
    */
    public function onDatasourceGet($src, $key, &$data)
    {
        if (self::TABLE_REL != $src) {
            return true;
        }

        $data['value']  =   patI18n::gettext($data['value']);
        $data['key']    =   patI18n::gettext($data['key']);
        return true;
    }
}