<?php
namespace ATF;

use Exception;
use Amp;

class Cmd
{
  public string $module;
  public string $func;

  function __construct(string $module, string $func)
  {
    $this->module = $module;
    $this->func = $func;
  }

  function __toString()
  {
    return $this->module.':'.$this->func;
  }
}

class Task 
{
  const CODE_MESSAGE   = 0;
  const CODE_EXCEPTION = 1;
  const CODE_WARN      = 2;
  const CODE_NSTART    = 124;
  const CODE_STUCK     = 125;
  const CODE_GONE      = 126;
  const CODE_HUNG      = 127;
  const CODE_DONE      = 128;

  static function code2string(int $code) : string
  {
    switch($code)
    {
      case self::CODE_MESSAGE:
        return "message";
      case self::CODE_EXCEPTION:
        return "exception";
      case self::CODE_WARN:
        return "warning";
      case self::CODE_STUCK:
        return "stuck";
      case self::CODE_NSTART:
        return "nstart";
      case self::CODE_GONE:
        return "gone";
      case self::CODE_HUNG:
        return "hung";
      case self::CODE_DONE:
        return "done";
    }
    return "???";
  }

  public ?Plan $plan = null;

  //async execution id
  public int $run_id = 0;
  //'true' if async coroutine is resolved
  public bool $run_status = false;  
  //async execution exception if any
  public ?object $run_error = null;   

  //attached device
  public ?string $device = null;     

  public int $attempts = 1;
  //signal to dispatcher to re-start execution of the task
  public bool $need_reschedule = false;

  public Cmd $cmd;
  public array $args = array();

  public string $title = '';

  public float $start_time = 0;
  public float $reset_time = 0;

  public float $last_progress = 0;
  public int $last_done_arg_idx = -1;
  public float $last_alive_check_time = 0;
  public float $last_stuck_check_time = 1;
  public float $last_ext_status_item_time = 0;
  //array of tuples [code, msg]
  public array $status_codes = array();

  function __construct(Cmd $cmd, array $args, $title = '')
  {
    $this->cmd = $cmd;
    $this->args = $args;
    $this->title = $title;
  }

  function getCmd() : Cmd
  {
    return $this->cmd;
  }

  function getCmdArgs() : array
  {
    return $this->args;
  }

  function getProgress() : float
  {
    if($this->last_progress == 0 && $this->isDone())
      return 1;
    return $this->last_progress;
  }

  static function isProblemCode($code) : bool
  {
    return $code > self::CODE_MESSAGE && $code < self::CODE_DONE;
  }

  static function isFatalCode($code) : bool
  {
    return 
      $code == Task::CODE_STUCK || 
      $code == Task::CODE_NSTART || 
      $code == Task::CODE_GONE || 
      $code == Task::CODE_HUNG || 
      $code == Task::CODE_EXCEPTION;
  }

  function hasFatalProblem() : bool
  {
    return $this->getLastFatalProblem() != 0;
  }

  function getLastFatalProblem() : int
  {
    for($i=sizeof($this->status_codes);$i-- > 0;)
    {
      $item = $this->status_codes[$i];
      if(self::isFatalCode($item[0]))
        return $item[0];
    }
    return 0;
  }

  function hasStatusCode($code)
  {
    foreach($this->status_codes as $item)
    {
      if($item[0] === $code)
        return true;
    }
    return false;
  }

  function isDone()
  {
    return $this->hasStatusCode(Task::CODE_DONE);
  }
  
  function addStatusCode($code, $msg = '')
  {
    //plan stores history of all status codes
    $this->plan->addStatusCode($code, $msg);

    $this->status_codes[] = array($code, $msg);
  }

  function onFatalProblem() 
  {
    if($this->attempts < 3)
      $this->reschedule();
  }

  function onProgress($jzon)
  {
    try
    {
      $data = jzon_parse(trim(str_replace('\"', '"', $jzon)));
      if(isset($data['p']))
        $this->last_progress = floatval(str_replace(',', '.', $data['p']));
      if(isset($data['arg_idx']))
        $this->last_done_arg_idx = (int)$data['arg_idx'];
    }
    catch(Exception $e)
    {
      echo $e->getMessage() . "\n";
    }
  }

  function _resetCheckTimes()
  {
    $this->reset_time = microtime(true);
    $this->last_alive_check_time = $this->reset_time;
    $this->last_stuck_check_time = $this->reset_time;
    $this->last_ext_status_item_time = 0;
  }

  function reschedule()
  {
    ++$this->attempts;
    $this->device = null;
    $this->need_reschedule = true;
  }

  function start()
  {
    $this->_resetCheckTimes();
    $this->status_codes = array();
    $this->start_time = time();
  }

  function getDuration()
  {
    return time() - $this->start_time;
  }
}

class TestLevelsTask extends Task
{
  public $arg_offset = 0;

  private $rseeds = array();
  private $seed = null;
  private $timescale = null;

  function __construct(Cmd $cmd, array $args, $with_rseeds = false, $seed = null, $timescale = null, $title = '')
  {
    $level_ids = array();
    //TODO: should not really be here
    if($with_rseeds)
    {
      foreach($args as $item)
      {
        $level_ids[] = $item[0];
        $this->rseeds[] = $item[1];
      }
    }
    else
      $level_ids = $args;

    $this->seed = $seed;
    $this->timescale = $timescale;

    parent::__construct($cmd, $level_ids, $title);
  }

  function getCmdArgs() : array
  {
    $args = array();

    if($this->rseeds)
    {
      foreach($this->args as $idx => $arg)
      {
        $args[] = $arg;
        $args[] = $this->rseeds[$idx];
      } 
    }
    else
      $args = $this->args;

    //appending arg. offset as a first argument
    array_unshift($args, ''.$this->arg_offset);
    array_unshift($args, '--offset');

    if($this->rseeds)
    {
      array_unshift($args, 'true');
      array_unshift($args, '--levels-with-rseed');
    }

    if($this->seed !== null)
    {
      array_unshift($args, ''.$this->seed);
      array_unshift($args, '--seed');
    }

    if($this->timescale !== null)
    {
      array_unshift($args, ''.$this->timescale);
      array_unshift($args, '--timescale');
    }

    return $args;
  }

  function onFatalProblem()
  {
    $start_arg = isset($this->args[$this->arg_offset]) ? $this->args[$this->arg_offset] : '?';
    $done_arg = isset($this->args[$this->last_done_arg_idx]) ? $this->args[$this->last_done_arg_idx] : '?';

    $this->plan->post("Handling error, progress:".round($this->getProgress(),2).", last done arg:{$done_arg}, start arg:{$start_arg}, arg offset:{$this->arg_offset}, args:".sizeof($this->args)." *$this->device*"); 

    //we're allowed to skip only in case of exceptions
    if($this->getLastFatalProblem() == Task::CODE_EXCEPTION)
    {
      if($this->last_done_arg_idx > $this->arg_offset)
        $this->arg_offset = $this->last_done_arg_idx;
      ++$this->arg_offset;
    }

    //let's reschedule the task if it still makes sense
    if($this->arg_offset < sizeof($this->args))
      $this->reschedule();
  }
}