<?php
/**
 * @file
 * This is the primary module file for the lassie module.
*/


/**
 * Converts the string into a compatible "machine name" for Lassie to use.
 */
function lassie_get_machine_name($str) {
  $str = fp_get_machine_readable($str);
  $str = trim(substr($str, 0, 200));  // make sure the name isn't more than 200 chars, which might cause problems.
  return $str;
}


 
/**
 * Set a new job for Lassie to watch.
 * 
 * @param $job_machine_name - The machine name of this job. Must be alphanumeric + underscore.  Ex:  job_123
 * @param $hours  - must be integer or a warning will be logged and displayed via fpm().
 * @param $emails - comma separated listed of email addresses to notify if the job fails to finish.
 */
function lassie_start($job_machine_name, $hours = 2, $emails = "") {
  global $user;

  if (!is_int($hours)) {
    fpm("WARNING: hours ($hours) supplied to lassie_start() function is not an integer.  Casting to int.");
    fpm(debug_backtrace());
    watchdog('lassie', "WARNING: hours ($hours) supplied to lassie_start() function is not integer.  Casting to int. Backtrace: <pre>" . print_r(debug_backtrace(), TRUE) . "</pre>", array(), WATCHDOG_ERROR);
    $hours = intval($hours);
  }

  $job_machine_name = lassie_get_machine_name($job_machine_name);
    
  $data = array( 
    'start' => time(),
    'hours' => $hours,
    'expires' => strtotime("NOW + $hours HOURS"),
    'emails' => $emails,
    'user_uid' => $user->uid,
  );
  
  
  variable_set('lassie_job__' . $job_machine_name, $data);
  
  watchdog('lassie', t("Beginning new job: ") . $job_machine_name . ". " . print_r($data, TRUE));
  
}

/**
 * Tell Lassie that we have finished the job.
 */
function lassie_finish($job_machine_name) {
    
  $job_machine_name = lassie_get_machine_name($job_machine_name);
  
  $data = variable_get('lassie_job__' . $job_machine_name, array());
  $start = $data['start'];
  $elapsed = round((time() - $start) / 60, 3);
    
  watchdog('lassie', t("Finished job: ") . $job_machine_name . ". " . $elapsed . " minutes elapsed.");
  
  // TODO:  Implement a hook?
  
  db_query("DELETE FROM variables WHERE name = ?", array("lassie_job__$job_machine_name"));
  
    
}


/**
 * Check to see if an email needs to be sent regarding this job.
 */
function lassie_check($job_machine_name) {
  $job_machine_name = lassie_get_machine_name($job_machine_name);
  
  $data = variable_get('lassie_job__' . $job_machine_name, array());
  $start = $data['start'];
  $elapsed = round((time() - $start) / 60, 3);
  $expires = $data['expires'];
  if (time() > $expires) {
    // YES!  We need to trigger the email, this job has expired.
    $emails = $data['emails'];
    // TODO: also include any default emails from settings.
    
    
    $hours = $data['hours'];
    $user_uid = $data['user_uid'];
    
    // TODO:  Implement a hook so other modules can act?
    
    
    // Implement the warning email.
    $msg = "";
    $msg .= "FlightPath Lassie module reports that a job has failed to complete in the expected time.\n\n";
    $msg .= "Current Time: " . format_date(convert_time(time())) . "\n-------------------------\n";
    $msg .= "Site: " . $GLOBALS['fp_system_settings']["base_url"] . "\n";
    $msg .= "Job Name: $job_machine_name \n";
    $msg .= "Started: " . format_date(convert_time($start)) . "\n";
    $msg .= "Hours  : $hours \n";
    $msg .= "Expires: " . format_date(convert_time($expires)) . "\n";
    $msg .= "Elapsed: $elapsed min.";
        
    if ($emails != "") {    
      fp_mail($emails, "FlightPath job failed to end: $job_machine_name", $msg);    
    }
        
    // Delete from variables table.
    db_query("DELETE FROM variables WHERE name = ?", array("lassie_job__$job_machine_name"));
    watchdog('lassie', t("Expired job: ") . $job_machine_name . ". " . $elapsed . " minutes elapsed.", array(), WATCHDOG_ERROR);
    
  }
  
}


/**
 * Check all of the jobs we are currently waiting on.
 */
function lassie_check_all() {
  
  $res = db_query("SELECT * FROM variables WHERE name LIKE 'lassie_job__%' ");
  while ($cur = db_fetch_array($res)) {
    $name = $cur['name'];
    $job_name = str_replace("lassie_job__", "", $name);
    lassie_check($job_name);
  }
}



/**
 * Implements hook_cron
 */
function lassie_cron() {
      
  // If its been less than 45 minutes since last check, then skip.  Saves checks if our cron is running very frequently.  
  $last_check = variable_get("lassie_last_check", 0);
  if (time() < ($last_check + (45 * 60))) return; 
  
  watchdog("lassie", "Lassie checking for any long-running jobs....", array(), WATCHDOG_DEBUG);
  
  lassie_check_all();
  
  variable_set("lassie_last_check", time());
  
}