<?php
// $Id: apachesolr_mlt.module,v 1.1.2.5 2009-09-28 22:45:52 damienvancouver Exp $

/**
 * Implementation of hook_menu()
 */
function apachesolr_mlt_menu($may_cache) {
  $items = array();
  if (!$may_cache) {
    $items[] = array(
      'path' => 'admin/settings/apachesolr_mlt',
      'title' => t('Apache Solr More Like This'),
      'description' => t('Configure content recommendation blocks using the ApacheSolr "More Like This" handler.'),
      'callback' => 'apachesolr_mlt_settings',
      'access' => user_access('administer search'),
    );
    $items[] = array(
      'path' => 'admin/settings/apachesolr_mlt/configure_block',
      'type' => MENU_CALLBACK,
      'callback' => 'drupal_get_form',
      'callback arguments' => array('apachesolr_mlt_block_form', arg(4)),
      'access' => user_access('administer search'),
      );
    $items[] = array(
      'path' => 'admin/settings/apachesolr_mlt/delete_block',
      'type' => MENU_CALLBACK,
      'callback' => 'drupal_get_form',
      'callback arguments' => array('apachesolr_mlt_delete_block_form', arg(4)),
      'access' => user_access('administer search'),
      );
    
  }
  return $items;
}

/**
 * Implementation of hook_block
 */
function apachesolr_mlt_block ($op = 'list', $delta = 0, $edit = array()) {
  if ($op == 'list') {
    //return all of the moreLikeThis blocks that the user has created
    $blocks = apachesolr_mlt_list_blocks();
    return $blocks;
  }
  else if ($op == 'view' && !empty($delta)) {
    //return the content of the block, based on the delta
    return apachesolr_mlt_suggestions($delta);
  }
}

/**
 * function apachesolr_mlt_suggestions()
 * This function loads a the parameters for each moreLikeThis query, performs
 * the query, and returns a list of linked node titles.
 * 
 * @param int $block_id A block ID for loading the suggestions
 *
 * @return array An array to be returned to hook_block
 */
function apachesolr_mlt_suggestions($block_id) {
  if (arg(0) == 'node' && is_numeric(arg(1))) {
    $nid = check_plain(arg(1));
    $solr = & apachesolr_get_solr ( variable_get ( 'apachesolr_host', 'localhost' ), variable_get ( 'apachesolr_port', 8983 ), variable_get ( 'apachesolr_path', '/solr' ) );
    
    try {
      $fields = array('mlt.mintf', 'mlt.mindf', 'mlt.minwl', 'mlt.maxwl', 'mlt.maxqt', 'mlt.boost', 'mlt.qf');
      $block = apachesolr_mlt_load_block($block_id);
      $params = array(
          'mlt' => 'true',
          'fl' => 'nid,title',
          'mlt.fl' => check_plain(implode(',', $block['mlt_fl'])),
      );
      unset($block['mlt_fl']);
      foreach ($fields as $field) {
        $drupal_fieldname = str_replace('.', '_', $field);
        if (!empty($block[$drupal_fieldname])) {
          $params[$field] = check_plain($block[$drupal_fieldname]);
        }
      }
      $response = $solr->search('nid:' . $nid, 0, 10, $params);
      
      $r =  (array) end($response->moreLikeThis);
      //TODO: Figure out why this works
      $links = array();
      
      if (is_array($r['docs'])) {
        foreach ($r['docs'] as $doc) {
          $links[] = l($doc->title, 'node/' . $doc->nid);
        }
       }

      $suggestions = array();
      if (count($links) > 0) {
        $suggestions['subject'] = $block['name'];
        $suggestions['content'] = theme('apachesolr_mlt_recommendation_block', $links);
      }
      return $suggestions;
    } catch ( Exception $e ) {
        watchdog ( 'Apache Solr', $e->getMessage (), WATCHDOG_ERROR );
    }
  }
}

function theme_apachesolr_mlt_recommendation_block($links) {
  return theme('item_list', $links);
}

/**
 * function apachesolr_mlt_settings()
 * returns the settings page.
 */
function apachesolr_mlt_settings() {
  $query = "SELECT * FROM {apachesolr_mlt}";
  $results = db_query($query);
  $rows = array();
  while ($block = db_fetch_object($results)) {
    $block->data = unserialize($block->data);
    $rows[] = array(
      $block->id,
      $block->data['name'],
      l('Edit', 'admin/settings/apachesolr_mlt/configure_block/' . check_plain($block->id)) .' | ' . l('Delete', 'admin/settings/apachesolr_mlt/delete_block/'.check_plain($block->id)),
    );
  }
  $header = array(t('Id'), t('name'), t('options'));
  $output = l(t('Add block'), 'admin/settings/apachesolr_mlt/configure_block');
  $output .= theme('table', $header, $rows);
  return $output;
}

/**
 * function apachesolr_mlt_block_form()
 * Allows users to create and edit moreLikeThis Blocks.
 * @param int $block_id If editing, the id of the block to edit.
 *
 * @return array The form used for editing.
 * TODO:
 *   Add term boost settings
 *   Enable the user to specify a query, rather then forcing suggestions based
 *     on the node id.
 *
 */
function apachesolr_mlt_block_form($block_id = NULL) {
  //if editing, load the current settings for the block.
  if($block_id && is_numeric($block_id)) {
    $block = apachesolr_mlt_load_block($block_id);
    $form['block_id'] = array(
      '#type' => 'hidden',
      '#value' => $block_id,
    );
  }

  $form['name'] = array(
    '#type' => 'textfield',
    '#title' => t('Block Name'),
    '#description' => t('Please enter the block name.  This will only be seen by the administratior'),
    '#default_value' => check_plain($block['name']),
    '#weight' => '-2',
  );
  $form['mlt.count'] = array(
    '#type' => 'textfield',
    '#title' => t('Maximum number of results'),
    '#default_value' => $block['mlt_count'] ? $block['mlt_count'] : 5,
    '#weight' => -1,
    );
 
  $form['comparison'] = array(
    '#type' => 'fieldset',
    '#title' => t('Comparison settings'),
    '#weight' => 0,
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
    );
  $form['comparison']['mlt_fl'] = array(
    '#type' => 'checkboxes',
    '#title' => t('Fields for comparison'),
    '#description' => t('The fields to be used in caclulating similarity.'),
    '#options' => apachesolr_mlt_get_fields(),
    '#default_value' => isset($block['mlt_fl']) ? $block['mlt_fl'] : array('title', 'taxonomy_name'),
  );

  $form['advanced'] = array(
    '#type' => 'fieldset',
    '#title' => t('Advanced Configuration'),
    '#weight' => '1',
    '#collapsible' => TRUE,
    '#collapsed' => FALSE,
  );
  $form['advanced']['mlt_mintf'] = array(
    '#type' => 'textfield',
    '#title' => t('Minimum Term Frequency'),
    '#description' => t('The frequency below which terms will be ignored in the source document.'),
    '#default_value' => $block['mlt_mintf'] ? (int) $block['mlt_mintf'] : 1,
  );
  $form['advanced']['mlt_mindf'] = array(
    '#type' => 'textfield',
    '#title' => t('Minimum Document Frequency'),
    '#description' => t('The frequency at which words will be ignored which do not occur in at least this many documents.'),
    '#default_value' => $block['mlt_mindf'] ? (int) $block['mlt_mindf'] : 1,
  );
  $form['advanced']['mlt_minwl'] = array(
    '#type' => 'textfield',
    '#title' => t('Minimum Word Length'),
    '#description' => 'Words must be at least this long or they will be ignored.',
    '#default_value' => $block['mlt_minwl'] ? (int) $block['mlt_minwl'] : 3,
  );
  $form['advanced']['mlt_maxwl'] = array(
    '#type' => 'textfield',
    '#title' => t('Maximum World Length'),
    '#description' => t('Words above this length will be ignored.'),
    '#default_value' => $block['mlt_maxwl'] ? (int) $block['mlt_maxwl'] : 15,
  );
  $form['advanced']['mlt_maxqt'] = array(
    '#type' => 'textfield',
    '#title' => t('Maximum number of query terms'),
    '#description' => t('The maximum number of query terms that will be included in any generated query. Lower numbers will result in fewer recommendations but perform better.'),
    '#default_value' => $block['mlt_maxqt'] ? (int) $block['mlt_maxqt'] : 30,
  );

  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Save'),
    '#weight' => '5',
  );

  $form['#redirect'] = 'admin/settings/apachesolr_mlt';

  return $form;
}

/**
 * function apachesolr_mlt_block_validate()
 *
 * Perform basic form field validation on the morelikethis fields
 * 
 * @param string $form_id the form ID
 * @param array $form_values an array of from values
 */
function apachesolr_mlt_block_form_validate($form_id, $form_values) {
  if ($form_id == 'apachesolr_mlt_block_form') {
    foreach ($form_values as $key => $value) {
      //make sure the user inputed a number, accept for the field list
      if (strpos($key, 'mlt_') === 0 && $key != 'mlt_fl') {
        if (!empty($value) && !is_numeric($value)) {
          form_set_error($key, t("This field must contain a whole number."));
        }
      }
    }
  }
}

/**
 * function apachesolr_mlt_block_submit()
 * @param string $form_id the form ID
 * @param array $form_values an array of from values
 */
function apachesolr_mlt_block_form_submit($form_id, $form_values) {
  if ($form_id == 'apachesolr_mlt_block_form') {
    $form_values['mlt_fl'] = array_diff($form_values['mlt_fl'], array(0));
    apachesolr_mlt_save_block($form_values, $form_values['block_id']);
  }
}


/**
 * function apachesolr_mlt_get_fields()
 * A list of field names used on the settings form.
 * @return array An array containing a the fields in the solr instance.
 */
function apachesolr_mlt_get_fields() {
  include_once drupal_get_path('module', 'apachesolr') .'/Solr_Base_Query.php';
  $fields = Solr_Base_Query::get_fields_in_index();
  $rows = array();
  foreach ($fields as $field_name => $field) {
    if ($field->schema{4} == 'V')
    $rows[$field_name] = $field_name;
  }

  return $rows;
}


/**
 * function apachesolr_mlt_load_block()
 * A loader function for the apachesolr more like this module.  If the function
 * is passed a proper block id, the function will return the settings for the
 * moreLikeThis request.  If the block id is invalid the function returns an
 * empty array.
 *
 * @param int $block_id the id of the block you wish to load
 *
 * @return array Either the array of settings to perform the moreLikeThis request
 * or an empty array if the block id is invalid.
 */
function apachesolr_mlt_load_block($block_id = 0) {
  if (is_numeric($block_id)) {
    $query_results = db_result(db_query('SELECT data FROM {apachesolr_mlt} WHERE id = %d', $block_id));
    if (strlen($query_results)) {
      return unserialize($query_results);
    }
  }
  else {
    return array();
  }
}

/**
 * function apachesolr_mlt_save_block()
 * A helper function save the block data to the database.  If passed a valid
 * block id, the function will update block settings in the database.  If it is
 * not passed a block id, the function will create a new block.
 *
 * @param array $block_settings An array containing the settings required to form
 * a moreLikeThis request.
 *
 * @param int $block_id The id of the block you wish to update.
 */
function apachesolr_mlt_save_block($block_settings = array(), $block_id = 0) {
  if (is_numeric($block_id) && $block_id > 0) {
    db_query("UPDATE {apachesolr_mlt} SET data = '%s' WHERE id = %d", serialize($block_settings), $block_id);
  }
  else {
    db_query("INSERT INTO {apachesolr_mlt} (data) VALUES ('%s')", serialize($block_settings));
  }
}

/**
 * function apachesolr_mlt_list_blocks()
 * returns a list of blocks.  used by hook_block
 */
function apachesolr_mlt_list_blocks() {
  $block_results = db_query("SELECT * FROM {apachesolr_mlt}");
  $blocks = array();
  while ($block = db_fetch_object($block_results)) {
    $block->data = unserialize($block->data);
    $blocks[$block->id] = array('info' => t('ApacheSolr recommendations: ') . $block->data['name']);
  }
  return $blocks;
}

function apachesolr_mlt_delete_block_form($block_id = NULL) {
  if (is_numeric($block_id)) {
    $block = apachesolr_mlt_load_block($block_id);
    $form['block_id'] = array(
      '#type' => 'value',
      '#value' => $block_id
    );
    $form['#redirect'] = 'admin/settings/apachesolr_mlt';
    return confirm_form($form,
      t('Are you sure you want to delete the ApacheSolr content recommendation block %name?', array('%name' => $block['name'])),
      'admin/settings/apachesolr_mlt',
      t('The block will be deleted. This action cannot be undone.'),
      t('Delete'), t('Cancel'));
  }
}

function apachesolr_mlt_delete_block_form_submit($form_id, $form_values) {
  db_query('DELETE FROM {apachesolr_mlt} WHERE id = %d', $form_values['block_id']['#value']);
}