<?php
/**
 * Created by PhpStorm.
 * User: stanley-king
 * Date: 2016/10/5
 * Time: 下午11:39
 */

namespace search;

interface IProcessor
{
    public function handle_input($body);
}

class CentraHelper
{
    const body_header_len = 10;
    const time_out = 3600;

    private $socket;
    private $ev_base;
    private $ev;
    private $connections;
    private $buffers;
    private $contents;
    private $connect_id;

    private $processor;
    private static $stInstance;

    public static function instance()
    {
        if(self::$stInstance == null) {
            self::$stInstance = new CentraHelper();
        }
        return self::$stInstance;
    }

    private function __construct()
    {
        $this->connect_id = 0;
        $this->connections = array();
        $this->buffers = array();
    }
    public function init(IProcessor $processor)
    {
        $this->processor = $processor;
    }

    public function run_loop($sockfd)
    {
        $this->socket = $sockfd;
        //$this->socket = stream_socket_server ($this->remote_addr(), $errno, $errstr);
        stream_set_blocking($this->socket, 0);
        $this->ev_base = event_base_new();
        $this->ev = event_new();
        event_set($this->ev, $this->socket, EV_READ | EV_PERSIST, 'ev_accept', $this->ev_base);
        event_base_set($this->ev, $this->ev_base);
        event_add($this->ev);
        event_base_loop($this->ev_base);
    }

    public function ev_accept($socket, $flag, $base)
    {
        $this->connect_id += 1;
        $connection = stream_socket_accept($socket);
        if($connection == false) return;

        stream_set_blocking($connection, 0);
        $buffer = event_buffer_new($connection, 'ev_read', NULL, 'ev_error', $this->connect_id);
        if($buffer == false) {
            fclose($connection);
            return;
        }

        event_buffer_base_set($buffer, $base);
        event_buffer_timeout_set($buffer, self::time_out, self::time_out);
        event_buffer_watermark_set($buffer, EV_READ, 0, 0xffffff);
        event_buffer_priority_set($buffer, 10);
        event_buffer_enable($buffer, EV_READ | EV_PERSIST);

        // we need to save both buffer and connection outside
        $this->connections[$this->connect_id] = $connection;
        $this->buffers[$this->connect_id] = $buffer;
        $this->contents[$this->connect_id] = "";
    }

    public function ev_read($buffer, $id)
    {
        $content = &$this->contents[$id];
        while ($read = event_buffer_read($buffer, 256)) {
            $content .= $read;
        }

        $start = 0;
        $left = strlen($content);
        do
        {
            if($left > self::body_header_len)
            {
                $len = substr($content,$start,self::body_header_len);
                $len = intval($len);
                if($left >= self::body_header_len + $len)
                {
                    $body = substr($content,$start + self::body_header_len,$len);
                    if($this->processor != null) {
                        $data = $this->processor->handle_input($body);
                        $header = sprintf("%010d",strlen($data));
                        $data = $header . $data;
                        event_buffer_write($buffer,$data,strlen($data));
                    }
                    $start += self::body_header_len + $len;
                    $left = $left - self::body_header_len - $len;
                }
                else {
                    break;
                }
            }
            else {
                break;
            }
        } while ($left > 0);

        if($start > 0) {
            $content = substr($content,$start);
        }
    }

    public function ev_error($buffer, $error, $id)
    {
        event_buffer_disable($this->buffers[$id], EV_READ | EV_WRITE);
        event_buffer_free($this->buffers[$id]);
        fclose($this->connections[$id]);
        unset($this->connections[$id]);
        unset($this->buffers[$id]);
        unset($this->contents[$id]);
    }

    private function remote_addr()
    {
        global $config;

        $host = $config['searcher']['host'];
        $port = $config['searcher']['port'];

        return "{$host}:{$port}";
    }
}