<?php

/**
 * Observium
 *
 *   This file is part of Observium.
 *
 * @package    observium
 * @subpackage influx
 * @author     Bill Fenner <fenner@gmail.com>
 * @copyright  (C) 2017 Observium Limited
 *
 */

/* This is very much a feature in testing. Please monitor servers closely after enabling.

/**
 * Escapes a string for the InfluxDB Line Protocol.
 * https://docs.influxdata.com/influxdb/v1.2/write_protocols/line_protocol_tutorial/
 *
 * @param string str
**/
function influxdb_escape($str)
{
  $str = str_replace( ',', '\,', $str );
  $str = str_replace( '=', '\=', $str );
  $str = str_replace( ' ', '\ ', $str );
  return $str;
}

/**
 * Quotes an array for the InfluxDB Line Protocol.
 * https://docs.influxdata.com/influxdb/v1.2/write_protocols/line_protocol_tutorial/
 *
 * @param array data
**/
function influxdb_format_data($data)
{
  $values = array();
  foreach ($data as $key=>$value) {
    $values[] = influxdb_escape($key) . "=" . influxdb_escape($value);
  }
  return implode( ",", $values );
}

/**
 * Posts an update to InfluxDB.
 *
 * @param string database
 * @param array  tags
 * @param array  data
**/
function influxdb_update_data($database, $tags, $data)
{
  global $config;

  if ( !$config['influxdb']['enabled'] ) {
    return;
  }

  $influx_update = $database;
  if ( $tags ) {
    $influx_update = $influx_update . "," . influxdb_format_data( $tags );
  }
  $influx_update = $influx_update . " " . influxdb_format_data( $data );

  // This code posts each update to influx individually.
  // Influx can accept multiple updates in one post, but
  // is very equivocal about how many -- the documentation
  // says you "may" have to split up your request if you
  // have more than 5,000 updates.  We should be able to
  // build up a queue of updates, and flush them to the
  // server if the queue gets too long, or at the end of the
  // poll, but until it becomes a real problem, we post the
  // udpates one by one.
  if ( $config['influxdb']['debug'] ) {
    $f = fopen( '/tmp/influx-updates.txt', 'a' );
    fwrite( $f, $influx_update . "\n" );
    fclose( $f );
    return;
  }
  $url = 'http://' . $config['influxdb']['server'] . '/write?db=' . $config['influxdb']['db'];
  $c = curl_init();
  curl_setopt_array( $c, array(
    CURLOPT_URL => $url,
    CURLOPT_CUSTOMREQUEST => 'POST',
    CURLOPT_POSTFIELDS => $influx_update,
    ) );
  $response = curl_exec( $c );
  $httpcode = curl_getinfo($c, CURLINFO_HTTP_CODE);
  $error = 'cURL error num: '.curl_errno($c).' => '.curl_error($c);
  print_debug('INFLUXDB POST: ' . $httpcode . ' ' . $error);
  if (OBS_DEBUG > 1)
  {
    print_message('INFLUXDB REQUEST ' . print_r(curl_getinfo($c), TRUE), 'console');
    print_message('INFLUXDB RESPONSE ' . print_r($response, TRUE), 'console');
  }
  curl_close( $c );
}

/**
 * Pushes a set of data points that we want to add to an rrd file
 * to influxdb too.
 *
 * @param array  device
 * @param string filename
 * @param array  ds
 * @param array  definition
**/
function influxdb_update($device, $filename, $ds, $definition = NULL, $index = NULL)
{
  global $config;

  $start = microtime(TRUE);

  // This happens when called from obsolete rrdtool_update
  // This code can go away when rrdtool_update is deleted.
  if (!is_array($ds))
  {
    $tmpds = explode( ':', $ds );
    // get rid of the timestamp (it's always "N")
    array_shift( $tmpds );
    $ds = array();
    if ( count( $tmpds) == 1 ) {
      $ds[ 'value' ] = $tmpds[ 0 ];
    } else {
      foreach ($tmpds as $idx => $value) {
        $ds[ 'value' . (string)($idx + 1) ] = $value;
      }
    }
  }
  $influx_tags = array();
  if ( !is_null( $device ) ) {
    $influx_tags[ 'host' ] = $device[ 'hostname' ];
  }
  if ( !is_null( $index ) ) {
    // If we have an index, then we have a definition too.
    $filename = $definition[ 'file' ];
    $filename = str_replace( '-%index%', '', $filename );
    $influx_tags[ 'index' ] = $index;
  }
  $filename = str_replace( '.rrd', '', $filename );
  $filename = influxdb_escape( $filename );

  // Disable debugging for now
  //print_vars(array($filename, $ds, $definition, $index, $influx_tags, $ds));


  influxdb_update_data($filename, $influx_tags, $ds);

  $runtime = microtime(TRUE) - $start;
  $GLOBALS['influxdb_stats']['time'] += $runtime;
  $GLOBALS['influxdb_stats']['count']++;
}

// EOF