<?php

function random_record (){

  // Generate a random number for sorting by random
  $random = rand();

  // Assemble a query string to send to Solr. This uses the Solr hostname from config.env. Solr's query syntax can be found at many sites including https://lucene.apache.org/solr/guide/6_6/the-standard-query-parser.html
  // This query retrieves only the bib identifier field for records which satisfy the search query
  #$solrurl = 'http://host.docker.internal:8983/solr/epo_data/select?q.op=OR&q=*%3A*&wt=json&sort=random_' . $random . '%20asc';
  $solrurl = 'http://' . $_ENV["SOLR_HOSTNAME"] . ':' . $_ENV["SOLR_PORT"] . '/solr/' . $_ENV["SOLR_CORE"] . '/select?q.op=OR&q=*%3A*&wt=json&sort=random_' . $random . '%20asc';

  // Perform Curl request on the Solr API
  $ch = curl_init();
  curl_setopt($ch, CURLOPT_URL, $solrurl);
  curl_setopt($ch, CURLOPT_RETURNTRANSFER, TRUE);
  curl_setopt($ch, CURLOPT_HEADER, FALSE);
  curl_setopt($ch, CURLOPT_CUSTOMREQUEST, 'GET');
  $response = curl_exec($ch);
  curl_close($ch);

  // Turn the API response into useful Json
  $json = json_decode($response);

  // Pick a random key out of the docs array
  $random = array_rand($json->response->docs);

  // Search for the application ID in the content element and display it
  $content = $json->response->docs[$random]->content;
  preg_match('/Application.*\n(.*)\n/', $content, $application_id);
  $output['application_id'] = $application_id[1];

  // Search for the publication URL in the content element and display it
  $content = $json->response->docs[$random]->content;
  preg_match('/Publication.*\n(.*)\n/', $content, $publication);
  $output['publication_url'] = $publication[1];

  // Search for the title in the content element and display it
  $content = $json->response->docs[$random]->content;
  preg_match('/Title.*\n(.*)\n/', $content, $title);
  $output['title'] = $title[1];

  // Search for the abstract in the content element and display it
  $content = $json->response->docs[$random]->content;
  preg_match('/Abstract.*\n(.*)\n/', $content, $abstract);
  $output['abstract'] = $abstract[1];

  return $output;

}

?>