<?php

WB::loadClass( 'WBDaemon' );

class WBDaemon_ShootingStar extends WBDaemon
{
    protected $_env =   array(
                                'DISPLAY'   =>  ':2'
                            );

    protected $_xvfbPid     =   null; 
    protected $_mozillaPid  =   null; 
    protected $_star        =   null;
    protected $_sleep       =   15;
    protected $_shotPerChild    =   10;
    protected $_shotCount   =   0;
    
    
    protected $_tmpDir      =   '/tmp';
    
    public function setTmpDir( $tmp = '/tmp' )
    {
        if( !is_dir( $tmp ) || !is_writable( $tmp ) ) {
            throw new Exception( $tmp . ' is no directory or not writable!' );
        }        
        $this->_tmpDir =   $tmp;
        return true;
    }
    
    protected function _init()
    {
        WB::loadClass( 'WBShootingStar' );        
        $this->_star   =   new WBShootingStar();

        $this->_startX();
        $this->_startMozilla();
        
        return true;
    }
    
    protected function _startX()
    {
        $pid    =   pcntl_fork();
        if( $pid == -1 ) {
            WBLog::debug( 'Failed to fork' );
            return false;
        }
        
        if( !$pid ) {
            // to child stuff here
            $args   =   array(
                            $this->_env['DISPLAY'],
                            '-screen', '0', '1024x1024x24'
                        );
            pcntl_exec( '/usr/bin/Xvfb', $args );
            WBLog::debug( 'Failed to start Xvfb' );
        }
        
        // remember chid's pid
        $this->_xvfbPid =   $pid;
        WBLog::debug( 'Xvfb PID ' . $pid );
                
        // wait for the X-Server
        sleep( 2 );
        return true;
    }
    
    protected function _startMozilla()
    {
        // start browser
        $pid    =   pcntl_fork();        
        if( $pid == -1 ) {
            WBLog::debug( 'Failed to fork' );
            return false;
        }
        
        // to child stuff 
        if( !$pid ) {
            $args   =   array( 'about:' );
            pcntl_exec( '/usr/bin/firefox', $args, $this->_env );
            WBLog::debug( 'Failed to start browser' );
        }
        
        // remember mozilla
        $this->_mozillaPid = $pid;
        WBLog::debug( 'Firefox PID ' . $pid );
        
        // wait for thw browser
        sleep( 2 );
        return true;
    }
    
    protected function _run()
    {
        $ids    =   $this->_star->getQueue();
        foreach( $ids as $id ) {
            WBLog::debug( 'Extracted from queue ' . $id );
            
            $data   =   $this->_star->get( $id );
            $file   =   $this->_snapshot( $data['url'] );
            
            $this->_star->addScreenShot( $id, $file );
            $this->_star->unQueue( $id );
            
            ++$this->_shotCount;
            if( ( $this->_shotCount % $this->_shotPerChild ) == 0 ) {
                $this->_stopMozilla();
                $this->_startMozilla();
            }
        }
        
        sleep( $this->_sleep );
        return true;
    }
    
    protected function _snapshot( $url )
    {        
        WBLog::debug( 'Snapshot ' . $url );
        
        // surf to URL
        exec( 'DISPLAY='. $this->_env['DISPLAY'] .' /usr/bin/firefox -a firefox -remote "openurl('.$url.')"' );
        sleep( ( $this->_sleep * 3 ) );
        
        // take screenshot
        $file   =   tempnam( $this->_tmpDir, 'shot' );
        exec( 'xwd -display '. $this->_env['DISPLAY'] .' -root -silent >' . $file . '.xwd' );
        exec( 'mogrify -format jpg ' . $file . '.xwd' );

        // go back
        exec( 'DISPLAY='. $this->_env['DISPLAY'] .' /usr/bin/firefox -a firefox -remote "openurl(about:)"' );
        
        // remove temporary files
        unlink( $file );
        unlink( $file . '.xwd' );
        WBLog::debug( 'Snapshot done' . $file . ' ' . filesize( $file . '.jpg' ) );
        return $file . '.jpg';
    }
        
    protected function hangUp()
    {
        $this->_stopMozilla();
        $this->_stopX();
        
        $this->_startX();
        $this->_startMozilla();
        return true;
    }
    
    protected function _stop()
    {
        $this->_stopMozilla();
        $this->_stopX();
        return true;
    }
    
    protected function _stopMozilla()
    {
        // first kill X application
        if( !$this->_mozillaPid ) {
            return false;
        }
        
        WBLog::debug( 'Kill Firefox' );
        posix_kill( $this->_mozillaPid, SIGTERM );
        $status = null;
        pcntl_waitpid( $this->_mozillaPid, $status );
        $this->_mozillaPid  =   null;
        return true;
    }
    
    protected function _stopX()
    {
        // kill the X server
        if( !$this->_xvfbPid ) {
            return false;
        }
        
        WBLog::debug( 'Kill Xvfb' );
        posix_kill( $this->_xvfbPid, SIGTERM );
        
        $status = null;
        pcntl_waitpid( $this->_xvfbPid, $status );
        $this->_xvfbPid =   null;
        return true;
    }
}     
?>