<?php

namespace VfxApply\Plugin\Executor;

use VfxApply\Plugin;
use VfxApply\Input;
use VfxApply\Output;
use VfxApply\Preset;

class ExecutorPlugin extends Plugin
{
    public function getName()
    {
        return "executor";
    }
    
    public function applyPreset(Preset $preset, Input $input, Output $output)
    {
        
        $env = [
            'uinput' => $input->getFilename(),
            'uoutput' => $output->getFilename(),
            'frames' => $input->getVideoDuration()->frames,
            'seconds' => $input->getVideoDuration()->seconds,
        ];
        $env['input'] = escapeshellarg($env['uinput']);
        $env['output'] = escapeshellarg($env['uoutput']);
        
        $script = $this->loadScript($preset);
        $script->execute($env);
    }


    private function loadScript(Preset $preset)
    {
        $script = new Script();
        foreach ((array)$preset->get('set') as $k=>$v) {
            $script->set($k,$v);
        }
        foreach ((array)$preset->get('script') as $name=>$step) {
            $op = new Operation($name, $step);
            $script->addOperation($op);
        }
        return $script;
    }

}

class Script
{
    /** @var array Variables */
    protected $vars = [];

    public function set($k,$v)
    {
        $this->vars[$k] = $v;
    }

    public function addOperation(Operation $operation)
    {
        $operation->setScript($this);
        $this->operations[] = $operation;
    }

    public function execute(array $env)
    {
        $env = $this->buildEnvironment($env, $this->vars);
        //print_r($env);
        foreach ($this->operations as $operation) {
            //printf("Executing: %s\n", $operation->getInfo());
            $operation->execute($env);
        }
    }

    private function buildEnvironment(array $env, array $vars)
    {
        $vars = array_merge($env, $vars);
        foreach ($vars as $k=>$var) {
            if (is_array($var)) {
                $esc = empty($var['escape'])?false:$var['escape'];
                $var = preg_replace_callback('/\{\%([a-z]+?)\}/i', function ($match) use (&$vars,$var) {
                    $k = $match[1];
                    if (empty($vars[$k])) return null;
                    return $vars[$k];
                }, $var['value']);
                if ($esc) $var = escapeshellarg($var);
                $vars[$k] = $var;
            }
        }
        return $vars;
    }

    public function parseVariable($value, array $env)
    {
        return preg_replace_callback('/\{\%([a-z]+?)\}/i', function ($match) use (&$env) {
            $k = $match[1];
            if (empty($env[$k])) return null;
            return $env[$k];
        }, $value);
    }
}

class Operation
{
    protected $name;

    protected $info;

    protected $parser;

    protected $command;

    protected $script;

    public function __construct($name, array $data)
    {
        $_ = function($a,$k,$d=null) { return empty($a[$k])?$d:$a[$k]; };
        $this->name = $name;
        $this->info = $_($data,'info');
        $this->command = $_($data,'exec');
        $this->parser = new Parser($_($data,'parse'));
    }

    public function getName()
    {
        return $this->name;
    }

    public function getInfo()
    {
        return $this->info;
    }

    public function setScript(Script $script)
    {
        $this->script = $script;
    }

    public function execute(array $env)
    {
        $cmdl = $this->script->parseVariable($this->command, $env);
        //printf(" cmd: %s\n", $this->command);
        //printf("   eval: %s\n", $cmdl);

        $descr = [
            0 => [ 'pipe', 'r' ],
            1 => [ 'pipe', 'w' ],
            2 => [ 'pipe', 'w' ]
        ];
        echo "Exec: ".$cmdl."\n";
        $proc = proc_open($cmdl, $descr, $pipes);
        $tot = (int)$env['frames']-1;
        printf("\r%s [%s]", $this->info, $this->name);
        $this->parser->parse($pipes, function ($status) use ($tot) {
            $curr = (int)$status['frame'];
            $pc = min(100,100/$tot*$curr);
            printf("\r%s [%s]: %.1f%%", $this->info, $this->name, $pc);
        });
        proc_close($proc);
        printf("\n");

    }
}

class Parser
{
    const STDOUT = 1;
    const STDERR = 2;

    /** @var array Resources */
    protected $streams = [];
    /** @var string The expression to match (preg match) */
    protected $expression;
    /** @var int The stream to watch */
    protected $source;
    /** @var array Index to name mappings */
    protected $names = [];

    public function __construct(array $parser=null)
    {
        $_ = function($a,$k,$d=null) { return empty($a[$k])?$d:$a[$k]; };
        $this->expression = $_($parser,'regex');
        $this->source = $_($parser,'from');
        foreach ((array)$parser as $k=>$v) {
            if (is_numeric($v)) {
                $this->names[$k] = $v;
            }
        }
    }

    public function parse(array $streams, callable $callback)
    {
        $this->streams = $streams;
        $match = [ 'stdout' => 1, 'stderr' => 2 ];
        $source = $this->source?:'stdout';

        foreach ($this->streams as $stream)
            stream_set_blocking($stream, false);

        while (!feof($this->streams[1])) {
            $stdout = fread($this->streams[1],8192);
            $stderr = fread($this->streams[2],8192);
            //($stdout) && printf("OUT: <<%s>>\n", $stdout);
            //($stderr) && printf("ERR: <<%s>>\n", $stderr);
            if (($stdout && $this->expression) && ($source=='stdout'))
                if (preg_match($this->expression, $stdout, $match))
                    call_user_func($callback, $this->parseNames($match));
            if (($stderr && $this->expression) && ($source=='stderr'))
                if (preg_match($this->expression, $stderr, $match))
                    call_user_func($callback, $this->parseNames($match));
            usleep(10000);
        }

    }

    protected function parseNames(array $match)
    {
        $ret = [];
        foreach ($this->names as $k=>$index) {
            $ret[$k] = $match[$index];
        }
        return $ret;
    }

}

return new ExecutorPlugin();