<?php

/**
 * @file
 * EBSCO Drupal integration module.
 *
 * Copyright [2017] [EBSCO Information Services]
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *     http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

require_once 'lib/EBSCODocument.php';

// Global variable.
$_ebsco_document = NULL;


/******************************************
 * Hooks
 ******************************************/

/**
 * Implements hook_user_login().
 */
function ebsco_user_login(&$edit, $account) {

  // Redirect after login.
  if (isset($_SESSION['EBSCO']['redirect'])) {
    $_GET['destination'] = urldecode($_SESSION['EBSCO']['redirect']['destination']);
    unset($_SESSION['EBSCO']['redirect']);
  }
}

/**
 * Implements hook_help().
 */
function ebsco_help($path, $arg) {
  $output = "";
  switch ($path) {
    case "admin/help#ebsco":
      $output .= '<h2>' . t("Full-text articles and eBooks from EBSCOhost Discovery Services") . '</h2>';
      $output .= '<p>' . t("EBSCO Discovery Service provides users with an easy, yet powerful means of accessing all of an institution's information resources through a single search.") . '</p>';
      $output .= '<p>' . t("This is achieved by harvesting metadata from both internal (library) and external (database vendors) sources, and creating a pre-indexed service of unprecedented size and speed.") . '</p>';
      $output .= '<p>' . t("Although the resulting collection can be massive in size and scope, the fact that it is indexed locally (on the EBSCOhost&reg; servers) allows for exceptionally fast search response times.") . '</p>';
      $output .= '<p>' . t("As no two institutions are the same, EBSCO Discovery Service offers a vast array of customization options with regard to both the underlying collection of metadata as well as the front-end delivery of search results. All of this functionality is based upon the powerful EBSCOhost search experience familiar to researchers worldwide.") . '</p>';
      break;
  }
  return $output;
}

/**
 * Implements hook_theme().
 */
function ebsco_theme() {
  $themes = array(
    'ebsco_result' => array(
      'template' => 'templates/ebsco-result',
    ),
    'ebsco_results' => array(
      'template' => 'templates/ebsco-results',
    ),
    'ebsco_side_facets' => array(
      'template' => 'templates/ebsco-side-facets',
    ),
    'ebsco_basic_search' => array(
      'template' => 'templates/ebsco-basic-search',
    ),
    'ebsco_advanced_search' => array(
      'template' => 'templates/ebsco-advanced-search',
    ),
  );
  return $themes;
}

/**
 * Implements hook_permission().
 *
 * Since the access to our new custom pages will be granted based on
 * special permissions, we need to define what those permissions are here.
 * This ensures that they are available to enable on the user role
 * administration pages.
 */
function ebsco_permission() {
  return array(
    'administer ebsco' => array(
      'title' => t('Administer EBSCO'),
    ),
    'use ebsco' => array(
      'title' => t('Use EBSCO'),
    ),
  );
}

/**
 * Implements hook_admin().
 */
function ebsco_admin() {
  $form = array();

  $form['ebsco_credentials'] = array(
    '#type' => 'fieldset',
    '#title' => t('EDS API credentials'),
  );

  $form['ebsco_credentials']['ebsco_profile'] = array(
    '#type' => 'textfield',
    '#title' => t('Profile Id'),
    '#default_value' => variable_get('ebsco_profile'),
    '#size' => 50,
    '#description' => t("The API Profile Id."),
    '#required' => TRUE,
  );

  $form['ebsco_credentials']['ebsco_user'] = array(
    '#type' => 'textfield',
    '#title' => t('User Id'),
    '#default_value' => variable_get('ebsco_user'),
    '#size' => 50,
    '#description' => t("The API User Id."),
    '#required' => TRUE,
  );

  $form['ebsco_credentials']['ebsco_password'] = array(
    '#type' => 'textfield',
    '#title' => t('Password'),
    '#default_value' => variable_get('ebsco_password'),
    '#size' => 50,
    '#description' => t("The API password."),
    '#required' => TRUE,
  );

  $form['ebsco_credentials']['ebsco_interface'] = array(
    '#type' => 'textfield',
    '#title' => t('Interface Id'),
    '#default_value' => variable_get('ebsco_interface'),
    '#size' => 50,
    '#description' => t("The API Interface Id."),
    '#required' => FALSE,
  );

  $form['ebsco_credentials']['ebsco_organization'] = array(
    '#type' => 'textfield',
    '#title' => t('Organization Id'),
    '#default_value' => variable_get('ebsco_organization'),
    '#size' => 50,
    '#description' => t("The API Organization Id."),
    '#required' => FALSE,
  );

  $form['ebsco_credentials']['ebsco_local_ips'] = array(
    '#type' => 'textfield',
    '#title' => t('Local IP addresses'),
    '#default_value' => variable_get('ebsco_local_ips'),
    '#size' => 100,
    '#description' => t("Local IP address list for guest detection (ex: 127.0.0.1, 192.168.10.1, 172.18.12)"),
    '#required' => FALSE,
  );

  $form['ebsco_credentials']['ebsco_guest'] = array(
    '#type' => 'radios',
    '#title' => t('Guest ?'),
    '#default_value' => variable_get('ebsco_guest', 0),
    '#description' => t("The Guest session."),
    '#options' => array(t('No'), t('Yes')),
    '#required' => TRUE,
  );

  $form['ebsco_general'] = array(
    '#type' => 'fieldset',
    '#title' => t('General Settings'),
  );

  $form['ebsco_general']['ebsco_default_limit'] = array(
    '#type' => 'select',
    '#title' => t('Default limit'),
    '#default_value' => variable_get('ebsco_default_limit', 10),
    '#description' => t("Default number of results per page."),
    '#options' => EBSCODocument::limit_options(),
    '#required' => TRUE,
  );

  $form['ebsco_general']['ebsco_default_sort'] = array(
    '#type' => 'select',
    '#title' => t('Default sort'),
    '#default_value' => variable_get('ebsco_default_sort', 'relevance'),
    '#description' => t("Default sorting option."),
    '#options' => EBSCODocument::sort_options(),
    '#required' => TRUE,
  );

  $form['ebsco_general']['ebsco_default_amount'] = array(
    '#type' => 'select',
    '#title' => t('Default detail level'),
    '#default_value' => variable_get('ebsco_default_amount', 'brief'),
    '#description' => t("Default level of data detail."),
    '#options' => EBSCODocument::amount_options(),
    '#required' => TRUE,
  );

  $form['ebsco_general']['ebsco_default_mode'] = array(
    '#type' => 'select',
    '#title' => t('Default search mode'),
    '#default_value' => variable_get('ebsco_default_mode', 'all'),
    '#description' => t("Default search mode."),
    '#options' => EBSCODocument::mode_options(),
    '#required' => TRUE,
  );

  return system_settings_form($form);
}

/**
 * Implements hook_menu().
 */
function ebsco_menu() {
  // Ths is a route.
  $items['ebsco/results'] = array(
    'title' => 'EBSCO Results',
    'page callback' => 'ebsco_results_page',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );

  $items['ebsco/result'] = array(
    'title' => 'EBSCO Record',
    'page callback' => 'ebsco_result_page',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );

  $items['ebsco/pdf'] = array(
    'title' => 'EBSCO Record',
    'page callback' => 'ebsco_pdf_page',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );

  $items['ebsco/fulltext'] = array(
    'title' => 'EBSCO Record',
    'page callback' => 'ebsco_fulltext_page',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );

  $items['ebsco/advanced'] = array(
    'title' => 'EBSCO advanced search',
    'page callback' => 'ebsco_advanced_search_page',
    'access callback' => TRUE,
    'type' => MENU_CALLBACK,
  );

  $items['admin/config/search/ebsco'] = array(
    'title' => 'EBSCO settings',
    'description' => 'Configure EBSCO Service.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('ebsco_admin'),
    'access arguments' => array('administer ebsco'),
    'type' => MENU_NORMAL_ITEM,
  );

  return $items;
}

/**
 * Implements hook_block_info().
 */
function ebsco_block_info() {
  $blocks['ebsco_main'] = array(
    'info'  => t('EBSCO Search Form'),
    'cache' => DRUPAL_CACHE_PER_PAGE,
  );

  $blocks['ebsco_facets'] = array(
    'info'  => t('EBSCO Narrow Search'),
    'cache' => DRUPAL_CACHE_PER_PAGE,
  );

  return $blocks;
}

/**
 * Implements hook_block_view().
 *
 * Prepares the content of the block.
 */
function ebsco_block_view($delta = '') {
  $params = $_GET;
  $block = array();
  switch ($delta) {
    case 'ebsco_main':
      $reject = isset($params['q']) && strpos('ebsco/advanced', $params['q']) !== FALSE;
      $block['content'] = $reject ? '' : ebsco_basic_search_block();
      break;

    case 'ebsco_facets':
      $reject = isset($params['q']) && strpos('ebsco/advanced', $params['q']) !== FALSE;
      $reject = $reject || (isset($params['edit']) && strpos('ebsco/results', $params['q']) !== FALSE);
      $reject = $reject || (isset($params['q']) && strpos('ebsco/result', $params['q']) !== FALSE);
      $block['content'] = $reject ? '' : ebsco_side_facets_block();
      break;
  }
  return $block;
}

/**
 * EBSCO search results page callback.
 */
function ebsco_results_page() {
  return theme('ebsco_results');
}

/**
 * EBSCO search result page callback.
 */
function ebsco_result_page() {
  $is_xhr = !empty($_SERVER['HTTP_X_REQUESTED_WITH']) && $_SERVER['HTTP_X_REQUESTED_WITH'] == 'XMLHttpRequest';
  if ($is_xhr) {
    print theme('ebsco_result');
    return TRUE;
  }
  else {
    return theme('ebsco_result');
  }
}

/**
 * EBSCO fulltext page callback.
 */
function ebsco_fulltext_page() {
  $is_xhr = !empty($_SERVER['HTTP_X_REQUESTED_WITH']) && $_SERVER['HTTP_X_REQUESTED_WITH'] == 'XMLHttpRequest';
  if (user_is_logged_in()) {
    if ($is_xhr) {
      print theme('ebsco_result');
      return TRUE;
    }
    else {
      return theme('ebsco_result');
    }
  }
  else {
    $_SESSION['EBSCO']['redirect'] = drupal_get_destination();
    if ($is_xhr) {
      echo "<script type=\"text/javascript\">window.location.href = '" . url('user') . "';</script>";
      return;
    }
    else {
      drupal_goto('user');
    }
  }
}

/**
 * EBSCO pdf page callback.
 */
function ebsco_pdf_page() {
  global $_ebsco_document;
  $params = $_REQUEST;

  if (user_is_logged_in()) {
    if (empty($_ebsco_document)) {
      $_ebsco_document = new EBSCODocument();
    }
    $_ebsco_document->retrieve();
    $record = $_ebsco_document->record();
    drupal_goto($record->pdf_link);
  }
  else {
    $_SESSION['EBSCO']['redirect'] = drupal_get_destination();
    drupal_goto('user');
  }
}

/**
 * EBSCO advanced search page callback.
 */
function ebsco_advanced_search_page() {
  return theme('ebsco_advanced_search');
}

/**
 * EBSCO basic search page callback.
 */
function ebsco_basic_search_block() {
  return theme('ebsco_basic_search');
}

/**
 * EBSCO side facets block callback.
 */
function ebsco_side_facets_block() {
  return theme('ebsco_side_facets');
}

/******************************************************
 * Form builders, form handlers and templates handlers
 ******************************************************/

/**
 * Form builder; Output a sort form for the search results.
 *
 * @ingroup forms
 */
function ebsco_sort_form() {
  $params = $_REQUEST;

  $form = array(
    '#attributes' => array('class' => 'sort-form'),
    '#method'     => 'get',
  );

  $options = EBSCODocument::amount_options();
  $values = array_values($options);
  $default_value = isset($params['amount']) ? $params['amount'] : variable_get('ebsco_default_amount', 'brief');
  $form['mode'] = array(
    '#id'            => 'ebsco-amount',
    '#type'          => 'select',
    '#title'         => t('Page options'),
    '#default_value' => $default_value,
    '#options'       => $options,
    '#attributes'    => array('class' => array('form-select', '_jump_menu')),
  );

  $options = EBSCODocument::sort_options();
  $values = array_values($options);
  $default_value = isset($params['sort']) ? $params['sort'] : $values[0];
  $form['sort'] = array(
    '#id'            => 'ebsco-sort',
    '#type'          => 'select',
    '#title'         => t('Sort'),
    '#default_value' => $default_value,
    '#options'       => $options,
    '#attributes'    => array('class' => array('form-select', '_jump_menu')),
  );

  return $form;
}

/**
 * Form builder; Output a search form for the search block's search box.
 *
 * @ingroup forms
 */
function ebsco_basic_search_form() {
  $params = $_REQUEST;

  $form = array(
    '#attributes' => array('class' => 'search-form'),
    '#action'     => url('ebsco/results'),
    '#method'     => 'get',
  );

  $form['basic']['q'] = array(
    '#type'          => 'hidden',
    '#default_value' => 'ebsco/results',
  );

  $default_value = isset($params['lookfor']) ? $params['lookfor'] : '';
  $form['basic']['lookfor'] = array(
    '#id'            => 'ebsco-basic-search-lookfor',
    '#type'          => 'textfield',
    '#size'          => 40,
    '#default_value' => $default_value,
    '#attributes'    => array('title' => t('Enter the terms you wish to search for.')),
  );

  $default_value = isset($params['type']) ? $params['type'] : '';
  $form['basic']['type'] = array(
    '#id'            => 'ebsco-basic-search-type',
    '#type'          => 'select',
    '#options'       => EBSCODocument::basic_search_type_options(),
    '#default_value' => $default_value,
  );

  $form['basic']['submit'] = array(
    '#id'    => 'ebsco-basic-search-submit',
    '#type'  => 'submit',
    '#value' => t('Search'),
  );

  $link = url('ebsco/advanced');
  $form['basic']['links'] = array(
    '#type'  => 'fieldset',
    '#value' => "<a href=\"$link\">" . t('Advanced search') . "</a>",
  );

  $form['basic']['offscreen'] = array(
    '#type'  => 'container',
  );

  if (isset($params['filter'])) {
    foreach ($params['filter'] as $key => $value) {
      $form['basic']['offscreen']['group' . $key]['filter[]'] = array(
        '#id'            => 'ebsco-basic-search-filter' . $key,
        '#type'          => 'checkbox',
      // doesn't work.
        '#default_value' => $value,
        '#attributes'    => array('checked' => 'checked', 'value' => $value),

      );
    }

    $form['basic']['remember'] = array(
      '#type'          => 'checkbox',
      '#title'         => t('Retain my current filters'),
      '#prefix'        => '<br />',
      '#default_value' => TRUE,
    );
  }

  return $form;
}

/**
 * Form builder; Output a search form for the search block's search box.
 *
 * @ingroup forms
 */
function ebsco_advanced_search_form() {
  global $_ebsco_document;
  $params = $_REQUEST;

  if (isset($params['edit']) && !empty($params['edit'])) {
    $query = $_SESSION['EBSCO']['last-search']['query'];
    parse_str($query, $new_params);
    $params = $_REQUEST = array_merge($_REQUEST, $new_params);
  }
  $counter = isset($params['group']) ? count($params['group']) : 3;

  $form = array(
    '#attributes' => array('class' => 'search-form'),
    '#action'     => url('ebsco/advanced'),
  );

  $form['advanced'] = array(
    '#type'        => 'fieldset',
    '#title'       => t('Advanced Search'),
    '#collapsible' => FALSE,
    '#collapsed'   => FALSE,
  );

  $form['advanced']['rows'] = array(
    '#type'        => 'fieldset',
    '#title'       => '',
  );

  for ($i = 0; $i < $counter; $i++) {
    $form['advanced']['rows']['group' . $i] = array(
      '#type'       => 'fieldset',
      '#tree'       => TRUE,
      '#attributes' => array('class' => array('_advanced-row')),
    );

    $default_value = isset($params['group'][$i]['bool']) ? $params['group'][$i]['bool'] : '';
    if ($i > 0) {
      $form['advanced']['rows']['group' . $i]['bool'] = array(
        '#id'            => 'ebsco-advanced-search-bool' . $i,
        '#type'          => 'select',
        '#default_value' => $default_value,
        '#options'       => EBSCODocument::bool_options(),
      );
    }
    else {
      $form['advanced']['rows']['group' . $i]['bool'] = array(
        '#id'            => 'ebsco-advanced-search-bool' . $i,
        '#type'          => 'hidden',
        '#default_value' => 'AND',
      );
    }

    $title = $i == 0 ? t('Search for :') : '';
    $default_value = isset($params['group'][$i]['lookfor']) ? $params['group'][$i]['lookfor'] : '';
    $form['advanced']['rows']['group' . $i]['lookfor'] = array(
      '#id'            => 'ebsco-advanced-search-lookfor' . $i,
      '#type'          => 'textfield',
      '#size'          => 30,
      '#default_value' => $default_value,
      '#title'         => $title,
      '#attributes'    => array('title' => t('Enter the terms you wish to search for.')),
    );

    $default_value = isset($params['group'][$i]['type']) ? $params['group'][$i]['type'] : '';
    $form['advanced']['rows']['group' . $i]['type'] = array(
      '#id'            => 'ebsco-advanced-search-type' . $i,
      '#type'          => 'select',
      '#default_value' => $default_value,
      '#title'         => t('in'),
      '#options'       => EBSCODocument::advanced_search_type_options(),
    );

    if ($i > 2) {
      $form['advanced']['rows']['group' . $i]['remove'] = array(
        '#markup' => '<div class="delete-search"><a href="#" class="delete _delete_row" id="delete_search_link_' . $i . '">' . t('Remove Search Field') . '</a></div>',
      );
    }
  }

  $form['advanced']['rows']['add_row'] = array(
    '#type'  => 'fieldset',
    '#value' => "<a class=\"add _add_row\" href=\"#\">" . t('Add Search Field') . "</a>",
  );

  $items = array(
        array(
          'url'   => url('ebsco/results'),
          'title' => t('Basic search'),
        ),
        array(
          'url'   => url('ebsco/advanced'),
          'title' => t('Advanced search'),
        ),
  );
  $links = array();
  foreach ($items as $item) {
    $links[] = "<a href=\"{$item['url']}\">{$item['title']}</a>";
  }
  $form['advanced']['links'] = array(
    '#type'  => 'fieldset',
    '#value' => implode(' | ', $links),
  );

  $form['advanced']['modes'] = array(
    '#type'  => 'fieldset',
    '#title' => t('Search modes'),
  );

  $form['advanced']['modes']['mode'] = array(
    '#type'          => 'radios',
    '#default_value' => 'all',
    '#options'       => EBSCODocument::mode_options(),
  );

  $expanders = $_ebsco_document->expanders();
  $limiters = $_ebsco_document->limiters();
  $options = array('' => TRUE);
  foreach ($expanders as $key => $expander) {
    $options[$expander['Action']] = TRUE;
  }
  foreach ($limiters as $key => $limiter) {
    if (!empty($limiter['Values'])) {
      $options[$limiter['Id']] = TRUE;
      foreach ($limiter['Values'] as $value) {
        $options[str_replace('value', $value['Value'], $value['Action'])] = TRUE;
      }
    }
    else {
      $options[str_replace('value', 'y', $limiter['Action'])] = TRUE;
    }
  }

  $form['advanced']['expanders'] = array(
    '#type'  => 'fieldset',
    '#title' => t('Expand results'),
  );

  $form['advanced']['limiters'] = array(
    '#type'  => 'fieldset',
    '#title' => t('Limit results'),
  );

  $children = array();
  foreach ($expanders as $key => $expander) {
    $element = array(
      '#type'          => 'checkbox',
      '#id'            => 'ebsco-advanced-search-expander' . $key,
      '#title'         => $expander['Label'],
      '#title_display' => 'after',
      '#name'          => 'filter[]',
      '#attributes'    => array('value' => $expander['Action']),
      '#checked'       => $expander['selected'],
    );
    $element['#children'] = ($key != 0) ? '<br />' : '';
    $element['#children'] .= theme('checkbox', array('element' => $element));

    $children[] = theme('form_element', array('element' => $element));

  }

  $form['advanced']['expanders']['filter'] = array(
    '#type'      => 'checkboxes',
    '#validated' => TRUE,
    '#options'   => $options,
    '#children'  => implode('', $children),
  );

  $checkboxes = $selects = $dates = array();
  foreach ($limiters as $key => $limiter) {
    if ($limiter['Type'] == 'text' || $limiter['Type'] == 'select') {
      $element = array(
        '#type'          => 'checkbox',
        '#id'            => 'ebsco-advanced-search-limiter' . $limiter['Id'],
        '#title'         => $limiter['Label'],
        '#title_display' => 'after',
        '#name'          => 'filter[]',
        '#attributes'    => array(
          'value' => str_replace('value', 'y', $limiter['Action']),
        ),
        '#checked'       => $limiter['selected'],

      );
      $element['#children'] = ($key != 0) ? '<br />' : '';
      if (!isset($element['#children'])) {
        $element['#children'] = "";
      }
      $element['#children'] .= theme('checkbox', array('element' => $element));
      $checkboxes[] = theme('form_element', array('element' => $element));
    }
    elseif ($limiter['Type'] == 'multiselectvalue') {
      $opts = array('' => t('All'));
      foreach ($limiter['Values'] as $value) {
        $opts[$value['Action']] = $value['Value'];
      }
      $element = array(
        '#type'          => 'select',
        '#multiple'      => TRUE,
        '#size'          => 4,
        '#id'            => 'ebsco-advanced-search-limiter' . $limiter['Id'],
        '#title'         => $limiter['Label'],
        '#name'          => 'filter[]',
        '#options'       => $opts,
      // Empty value means "All".
        '#default_value' => $limiter['selected'],
        '#value'         => $limiter['selected'],
        '#attributes'    => array('class' => array('multiselectvalue'), 'multiple' => 'multiple'),
      );
      $element['#children'] = theme('select', array('element' => $element));
      $selects[] = theme('form_element', array('element' => $element));
    }
    elseif ($limiter['Type'] == 'ymrange') {
      $value = $limiter['selected'] ? $limiter['selected'] : '';
      $displayValue = str_replace(array('addlimiter(DT1:', '-1/2013-1)'), array('', ''), $value);
      $element = array(
        '#type'              => 'textfield',
        '#id'                => $limiter['Id'],
        '#title'             => $limiter['Label'],
        '#value'             => $displayValue,
        '#name'              => $limiter['Id'],
        '#autocomplete_path' => NULL,
        '#attributes'        => array(
          'size'          => 4,
          'maxlength'     => 4,
          'class'         => array('yearbox'),
        ),
      );
      $element['#children'] = theme('textfield', array('element' => $element));
      $element['#children'] .= '<input id="ebsco-advanced-search-limiter' . $limiter['Id'] . '" type="hidden" name="filter[]" value="' . $value . '"/>';
      $element['#children'] .= '<div id="ebsco-advanced-search-slider' . $limiter['Id'] . '" class="dateSlider"></div>';
      $dates[] = theme('form_element', array('element' => $element));
    }
  }

  $form['advanced']['limiters']['checkboxes'] = array(
    '#type'      => 'checkboxes',
    '#validated' => TRUE,
    '#options'   => $options,
    '#children'  => implode('', $checkboxes),
  );

  $form['advanced']['limiters']['dates'] = array(
    '#type'      => 'container',
    '#validated' => TRUE,
    '#prefix'    => '<hr />',
    '#children'  => implode('', $dates),
  );

  $form['advanced']['limiters']['selects'] = array(
    '#type'      => 'container',
    '#prefix'    => '<hr />',
    '#validated' => TRUE,
    '#children'  => implode('', $selects),
  );

  $form['advanced']['submit'] = array(
    '#id'    => 'ebsco-advanced-search-submit',
    '#type'  => 'submit',
    '#value' => t('Search'),
  );

  $reset_button_text = t('Clear');
  $form['advanced']['clear'] = array(
    '#markup'  => '<input id="ebsco-advanced-search-clear" class="form-submit" type="reset" value="' . $reset_button_text . '" name="reset">',
  );

  return $form;
}

/**
 * Form validation handler for ebsco_basic_search_form().
 *
 * @see ebsco_basic_search_form_submit()
 */
function ebsco_basic_search_form_validate($form, &$form_state) {
  $params = $form_state['values'];
  if (empty($params['lookfor'])) {
    form_set_error('lookfor', t('Please enter some keywords.'));
  }
}

/**
 * Form validation handler for ebsco_advanced_search_form().
 *
 * @see ebsco_advanced_search_form_submit()
 */
function ebsco_advanced_search_form_validate($form, &$form_state) {
  $params = $form_state['values'];
  if (empty($params['group0']['lookfor']) &&
        empty($params['group1']['lookfor']) &&
        empty($params['group2']['lookfor'])) {
    form_set_error('group0][lookfor', t('Please enter some keywords.'));
  }
}

/**
 * Form submission handler for ebsco_basic_search_form().
 *
 * @see ebsco_basic_search_form_validate()
 */
function ebsco_basic_search_form_submit($form, &$form_state) {
  $params = $form_state['values'];
  $allowed_keys = array('lookfor', 'type');
  foreach ($params as $key => $value) {
    if (!in_array($key, $allowed_keys)) {
      unset($params[$key]);
    }
  }
  $form_state['rebuild'] = FALSE;
  $form_state['redirect'] = array('ebsco/results', array('query' => $params));
}

/**
 * Form submission handler for ebsco_advanced_search_form().
 *
 * @see ebsco_advanced_search_form_validate()
 */
function ebsco_advanced_search_form_submit($form, &$form_state) {
  $params = $_REQUEST;
  $new_params = array();
  $allowed_keys = array('filter', 'mode');

  foreach ($params as $key => $value) {
    if (!(in_array($key, $allowed_keys) || strpos($key, 'group') !== FALSE)) {
      unset($params[$key]);
    }
    else {
      if ($key == 'filter') {
        foreach ($value as $k => $v) {
          if (empty($v)) {
            unset($params[$key][$k]);
          }
        }
      }
      elseif (empty($value)) {
        unset($params[$key]);
      }
    }
  }

  foreach ($params as $key => $value) {
    if (strpos($key, 'group') !== FALSE) {
      $new_params['group'][] = $value;
      unset($params[$key]);
    }
  }
  $params = array_merge($params, $new_params);

  $form_state['rebuild'] = FALSE;
  $form_state['redirect'] = array('ebsco/results', array('query' => $params));
}

/**
 * Process variables for ebsco-results.tpl.php.
 *
 * @see ebsco-results.tpl.php
 */
function template_preprocess_ebsco_results(&$variables) {
  global $_ebsco_document;
  $params = $_REQUEST;

  $_SESSION['EBSCO']['redirect'] = drupal_get_destination();
  if (empty($_ebsco_document)) {
    $_ebsco_document = new EBSCODocument();
  }

  $title = !empty($params['lookfor']) ? ' - ' . $params['lookfor'] : '';
  drupal_set_title('Search results' . $title);

  $_ebsco_document->search();

  $variables['records'] = $_ebsco_document->records();
  $variables['record_start'] = $_ebsco_document->record_start();
  $variables['record_end'] = $_ebsco_document->record_end();
  $variables['record_count'] = $_ebsco_document->record_count();
  $variables['search_view'] = $_ebsco_document->search_view();
  $variables['search_time'] = $_ebsco_document->search_time();
  $variables['relatedContent'] = $_ebsco_document->relatedContent();
  $variables['autoSuggestTerms'] = $_ebsco_document->autoSuggestTerms();
  $variables['lookfor'] = '';
  if (isset($params['lookfor'])) {
    $variables['lookfor'] = $params['lookfor'];
  }
  elseif (isset($params['group'])) {
    $types = EBSCODocument::basic_search_type_options();
    foreach ($params['group'] as $key => $group) {
      if (!empty($group['lookfor'])) {
        $pre = $key == 0 ? '' : " {$group['bool']} ";
        $variables['lookfor'] .= $pre . $types[$group['type']] . ':' . $group['lookfor'];
      }
    }
  }
  $variables['pager'] = $_ebsco_document->pager();

  $v1 = drupal_get_form('ebsco_sort_form');
  $variables['sort_form'] = drupal_render($v1);

  // Save data needed by scroller in Detailed view page
  // $_ebsco_document->search_write();
}

/**
 * Process variables for ebsco-basic-search.tpl.php.
 *
 * @see ebsco-basic-search.tpl.php
 */
function template_preprocess_ebsco_basic_search(&$variables) {
  global $_ebsco_document;
  $params = $_REQUEST;

  if (empty($_ebsco_document)) {
    $_ebsco_document = new EBSCODocument();
  }

  $variables['search_view'] = $_ebsco_document->search_view();
  $variables['lookfor'] = '';
  if (isset($params['lookfor'])) {
    $variables['lookfor'] = $params['lookfor'];
  }
  elseif (isset($params['group'])) {
    $types = EBSCODocument::basic_search_type_options();
    foreach ($params['group'] as $key => $group) {
      if (!empty($group['lookfor'])) {
        $pre = $key == 0 ? '' : " {$group['bool']} ";
        $variables['lookfor'] .= $pre . $types[$group['type']] . ':' . $group['lookfor'];
      }
    }
  }
  $v1 = drupal_get_form('ebsco_basic_search_form');
  $variables['search_form'] = drupal_render($v1);
}

/**
 * Process variables for ebsco-advanced-search.tpl.php.
 *
 * @see ebsco-advanced-search.tpl.php
 */
function template_preprocess_ebsco_advanced_search(&$variables) {
  drupal_add_library('system', 'ui.slider');
  global $_ebsco_document;
  $params = $_REQUEST;

  if (empty($_ebsco_document)) {
    $_ebsco_document = new EBSCODocument();
  }
  $_ebsco_document->info();

  $v1 = drupal_get_form('ebsco_advanced_search_form');
  $variables['search_form'] = drupal_render($v1);
}

/**
 * Process variables for ebsco-result.tpl.php.
 *
 * @see ebsco-result.tpl.php
 */
function template_preprocess_ebsco_result(&$variables) {
  $params = $_REQUEST;
  $params['op'] = isset($params['op']) ? $params['op'] : 'Next';

  $_SESSION['EBSCO']['redirect'] = drupal_get_destination();
  if (empty($_ebsco_document)) {
    $_ebsco_document = new EBSCODocument();
  }
  $_ebsco_document->retrieve();
  $record = $_ebsco_document->record();

  $variables['record'] = $record;
  $lastSearch = isset($params['id']) ? $_ebsco_document->search_read($params['id'], $params['op']) : '';
  $variables['last_search'] = $lastSearch;

  drupal_set_title($record->title);
}

/**
 * Process variables for ebsco-side-facets.tpl.php.
 *
 * @see ebsco-side-facets.tpl.php
 */
function template_preprocess_ebsco_side_facets(&$variables) {
  global $_ebsco_document;

  if (empty($_ebsco_document)) {
    $_ebsco_document = new EBSCODocument();
  }
  $_ebsco_document->info();

  $variables['record_count'] = $_ebsco_document->record_count();
  $variables['expanders'] = $_ebsco_document->expanders();
  $variables['limiters'] = $_ebsco_document->limiters();
  $variables['facets'] = $_ebsco_document->facets();
  // Applied facets, limiters or expanders.
  $variables['filters'] = $_ebsco_document->filters();
  // Hidden parameters.
  $variables['search_params'] = $_ebsco_document->search_params();
  // Hidden parameters.
  $variables['link_search_params'] = $_ebsco_document->link_search_params();
}

/******************************************
 * View Helpers
 ******************************************/

/**
 * Returns the current request's URL without the specified filter parameter.
 *
 * @return string
 *   the filtered request URL
 */
function remove_filter_link($filter) {
  $params = $_REQUEST;
  if (isset($params['filter'])) {
    foreach ($params['filter'] as $key => $value) {
      if ($value == $filter['action']) {
        unset($params['filter'][$key]);
      }
    }
  }
  return url('ebsco/results', array('query' => $params));
}

/**
 * Convert URLs in the given string into HTML link tags.
 *
 * Performs a regex and replaces any URLs with links containing themselves
 * as the text.
 *
 * @return string
 *   the filtered request URL
 */
function auto_link($string) {
  $linkedString = preg_replace_callback(
    "/\b(https?):\/\/([-A-Z0-9+&@#\/%?=~_|!:,.;]*[-A-Z0-9+&@#\/%=~_|]*)\b/i",
    create_function(
      '$matches',
      'return "<a href=\'".($matches[0])."\'>".($matches[0])."</a>";'
    ),
    $string
  );
  return $linkedString;
}