<?php
/* vim: set expandtab tabstop=4 shiftwidth=4 softtabstop=4 foldmethod=marker: */
// +---------------------------------------------------------------------------
// | SWAN [ $_SWANBR_SLOGAN_$ ]
// +---------------------------------------------------------------------------
// | Copyright $_SWANBR_COPYRIGHT_$
// +---------------------------------------------------------------------------
// | Version  $_SWANBR_VERSION_$
// +---------------------------------------------------------------------------
// | Licensed ( $_SWANBR_LICENSED_URL_$ )
// +---------------------------------------------------------------------------
// | $_SWANBR_WEB_DOMAIN_$
// +---------------------------------------------------------------------------

namespace Kafka\Protocol;

/**
+------------------------------------------------------------------------------
* Kafka protocol for join group api
+------------------------------------------------------------------------------
*
* @package
* @version $_SWANBR_VERSION_$
* @copyright Copyleft
* @author $_SWANBR_AUTHOR_$
+------------------------------------------------------------------------------
*/

class JoinGroup extends Protocol
{
    // {{{ functions
    // {{{ public function encode()

    /**
     * join group request encode
     *
     * @param array $payloads
     * @access public
     * @return string
     */
    public function encode($payloads)
    {
        if (!isset($payloads['group_id'])) {
            throw new \Kafka\Exception\Protocol('given join group data invalid. `group_id` is undefined.');
        }
        if (!isset($payloads['session_timeout'])) {
            throw new \Kafka\Exception\Protocol('given join group data invalid. `session_timeout` is undefined.');
        }
        if (!isset($payloads['member_id'])) {
            throw new \Kafka\Exception\Protocol('given join group data invalid. `member_id` is undefined.');
        }
        if (!isset($payloads['data'])) {
            throw new \Kafka\Exception\Protocol('given join group data invalid. `data` is undefined.');
        }
        if (!isset($payloads['protocol_type'])) {
            $payloads['protocol_type'] = 'consumer';
        }
        if (!isset($payloads['rebalance_timeout'])) {
            $payloads['rebalance_timeout'] = $payloads['session_timeout'];
        }

        $header = $this->requestHeader('kafka-php', self::JOIN_GROUP_REQUEST, self::JOIN_GROUP_REQUEST);
        $data   = self::encodeString($payloads['group_id'], self::PACK_INT16);
        $data   .= self::pack(self::BIT_B32, $payloads['session_timeout']);
        if ($this->getApiVersion(self::JOIN_GROUP_REQUEST) == self::API_VERSION1) {
            $data .= self::pack(self::BIT_B32, $payloads['rebalance_timeout']);
        }
        $data .= self::encodeString($payloads['member_id'], self::PACK_INT16);
        $data .= self::encodeString($payloads['protocol_type'], self::PACK_INT16);
        $data .= self::encodeArray($payloads['data'], array($this, 'encodeGroupProtocol'));
        $data = self::encodeString($header . $data, self::PACK_INT32);

        return $data;
    }

    // }}}
    // {{{ public function decode()

    /**
     * decode join group response
     *
     * @access public
     * @return array
     */
    public function decode($data)
    {
        $offset = 0;
        $errorCode = self::unpack(self::BIT_B16_SIGNED, substr($data, $offset, 2));
        $offset += 2;
        $generationId = self::unpack(self::BIT_B32, substr($data, $offset, 4));
        $offset += 4;
        $groupProtocol = $this->decodeString(substr($data, $offset), self::BIT_B16);
        $offset += $groupProtocol['length'];
        $leaderId = $this->decodeString(substr($data, $offset), self::BIT_B16);
        $offset += $leaderId['length'];
        $memberId = $this->decodeString(substr($data, $offset), self::BIT_B16);
        $offset += $memberId['length'];

        $members = $this->decodeArray(substr($data, $offset), array($this, 'joinGroupMember'));
        $offset += $memberId['length'];

        return array(
            'errorCode' => $errorCode,
            'generationId' => $generationId,
            'groupProtocol' => $groupProtocol['data'],
            'leaderId' => $leaderId['data'],
            'memberId' => $memberId['data'],
            'members' => $members['data'],
        );
    }

    // }}}
    // {{{ protected function encodeGroupProtocol()

    /**
     * encode group protocol
     *
     * @param partions
     * @access protected
     * @return string
     */
    protected function encodeGroupProtocol($values)
    {
        if (!isset($values['protocol_name'])) {
            throw new \Kafka\Exception\Protocol('given join group data invalid. `protocol_name` is undefined.');
        }

        $protocolName = self::encodeString($values['protocol_name'], self::PACK_INT16);

        if (!isset($values['version'])) {
            throw new \Kafka\Exception\Protocol('given data invalid. `version` is undefined.');
        }

        if (!isset($values['subscription']) || empty($values['subscription'])) {
            throw new \Kafka\Exception\Protocol('given data invalid. `subscription` is undefined.');
        }
        if (!isset($values['user_data'])) {
            $values['user_data'] = '';
        }

        $data = self::pack(self::BIT_B16, 0);
        $data .= self::encodeArray($values['subscription'], array($this, 'encodeGroupProtocolMetaTopic'));
        $data .= self::encodeString($values['user_data'], self::PACK_INT32);

        return $protocolName . self::encodeString($data, self::PACK_INT32);
    }

    // }}}
    // {{{ protected function encodeGroupProtocolMetaTopic()

    /**
     * encode group protocol metadata topic
     *
     * @param partions
     * @access protected
     * @return string
     */
    protected function encodeGroupProtocolMetaTopic($values)
    {
        $topic = self::encodeString($values, self::PACK_INT16);
        return $topic;
    }

    // }}}
    // {{{ protected function joinGroupMember()

    /**
     * decode join group member response
     *
     * @access protected
     * @return array
     */
    protected function joinGroupMember($data)
    {
        $offset = 0;
        $memberId = $this->decodeString(substr($data, $offset), self::BIT_B16);
        $offset += $memberId['length'];
        $memberMeta = $this->decodeString(substr($data, $offset), self::BIT_B32);
        $offset += $memberMeta['length'];

        $metaData = $memberMeta['data'];
        $metaOffset = 0;
        $version = self::unpack(self::BIT_B16, substr($metaData, $metaOffset, 2));
        $metaOffset += 2;
        $topics = $this->decodeArray(substr($metaData, $metaOffset), array($this, 'decodeString'), self::BIT_B16);
        $metaOffset += $topics['length'];
        $userData = $this->decodeString(substr($metaData, $metaOffset), self::BIT_B32);

        return array(
            'length' => $offset,
            'data' => array(
                'memberId' => $memberId['data'],
                'memberMeta' => array(
                    'version' => $version,
                    'topics'  => $topics['data'],
                    'userData' => $userData['data'],
                ),
            )
        );
    }

    // }}}
    // }}}
}