<?php
/**
 * @file FrxRepoMan.inc
 * Enter description here ...
 * @author davidmetzler
 *
 */
class FrxRepoMan {

  public $repositories;
  private $repository;


  //Determine data sources.
  public function __construct() {
    global $_forena_repositories;
    // Empty repository so we need to initialize
    // Build the default sample one
    $repos = array();

    // Load the repository list from the global settings.php file.
    if ($_forena_repositories) {
      $repos = $_forena_repositories;
    }

    // Overide difinitions of the sample and drupal repositories.
    $path = drupal_get_path('module', 'forena');
    $repos['forena_help'] = array(
      'path' => $path . '/repos/forena_help',
      'title' => 'Forena Help Reports',
    );

    $repos['drupal'] = array(
      'path' => $path . '/repos/drupal',
      'title' => 'Drupal Reports',
    );

    $repos['sampledb'] = array(
      'path' => $path . '/repos/sample',
      'title' => 'Sample DB Repository'
      );


      drupal_alter('forena_repos',  $repos);

      // Retrieve the repositories defined in the database;
      $results = db_query('SELECT * FROM {forena_repositories}');
      foreach ($results as $r) {
        if ($r->config) {
          $new_r = unserialize($r->config);
        }
        else {
          $new_r = array();
        }
        $r_name = $r->repository;
        if (is_array(@$repos[$r_name])) {
          $new_r = array_merge($new_r, $repos[$r_name]);
        }
        else {
          $new_r['source'] = 'user';
        }
        $new_r ['title'] = $r->title;
        $new_r ['enabled'] = $r->enabled;

        $repos[$r_name] = $new_r;
      }

      if ($_forena_repositories) {
        array_merge($repos, $_forena_repositories);
      }

      $this->repositories = $repos;

  }

  /**
   * Load repository
   * @param $name Name of the repository
   * @return FrxDataSource
   */
  public function repository($name) {
    // Now determine if the object exists
    if (isset($this->repositories[$name])) {
      if (@!is_object($this->repositories[$name]['data'])) {
        $this->load_repository($this->repositories[$name], $name);
      }
      return $this->repositories[$name]['data'];
    }
    else {
      Frx::error('Undefined repository' . $name, "Undefined Repository: $name ");
    }
  }

  // Putting this in a function to sandbox the repository settings
  public function load_repository(&$repo, $name) {
    // First determine if the class file exisits
    $path = @$repo['path'];
    $conf = array();

    if (file_exists($path . '/settings.php')) {
      // Override with repository specific data
      include($path . '/settings.php');
    }

    $repo = array_merge($conf, $repo);
    if (!isset($repos['data'])||!is_object($repo['data'])) $repo['data'] = $this->load_provider($repo, $path, $name);

  }

  /**
   * Load the data provider class based on the class name.
   *
   * @param string $name
   * @return object The data provider object
   */
  public function load_provider($conf, $repo_path, $repos_name) {
    @$name = isset($conf['data provider'])? $conf['data provider'] : $conf['data_engine'];
    Frx::plugins('FrxDataSource');
    // Instantiate the path
    if (class_exists($name)) {
      $o = new $name($conf, $repo_path, $repos_name);
      return $o;
    }
    else {
      Frx::error('Data provider not found for ' . $conf['title']);
    }
  }


  /**
   * Load Block
   * Enter description here ...
   * @param $data_block string name of data block.
   */
  public function loadBlock($data_block) {
    $block = array();
    list($provider, $block_name) = explode('/', $data_block, 2);
    $repos = @$this->repositories[$provider];
    if (isset($repos['enabled']) && !$repos['enabled']) {
      return array();
    }

    $o = $this->repository($provider);
    if ($o) {
      $access = TRUE;
      $block = $o->loadBlock($block_name);
    }
    return $block;
  }

  /**
   * Save a data block ...
   * @param unknown_type $data_block
   * @param unknown_type $data
   */
  public function saveBlock($data_block, $data) {
    $block = array();
    list($provider, $block_name) = explode('/', $data_block, 2);
      $modified = time();
    $builder = @$data['builder'];
    if (is_array($builder)) {
      $builder = serialize($builder);
    }
    $file = isset($data['access']) ?  "--ACCESS=" . $data['access'] . "\n" . $data['file'] : $data['file'];
    Frx::DataFile()->save($data_block .'.sql', $file);

  }

  /**
   * Save a data block ...
   * @param unknown_type $data_block
   * @param unknown_type $data
   */
  public function deleteBlock($data_block) {
    $block = array();
    list($provider, $block_name) = explode('/', $data_block, 2);
    Frx::DataFile()->delete($data_block . '.sql');
    Frx::DataFile()->validateAllCache();

  }


  /**
   * Extract the data by running a block
   *
   * @param $data_block String name ob block to load
   * @return unknown
   */
  function data($data_block, $raw_mode=FALSE) {
    list($provider, $block_name) = explode('/', $data_block, 2);
    //Intstantiate the provider
    $o = $this->repository($provider);
    $repos = @$this->repositories[$provider];
    if (isset($repos['enabled']) && !$repos['enabled']) {
      return '';
    }
    //Populate user callback.
    if (isset($repos['user callback'])) {
      $user_fn = $repos['user callback'];
      if (is_callable($user_fn)) {
        $current_user =   $user_fn();
        Frx::Data()->setValue('current_user', $current_user);
      }
    }


    $xml = '';
    if ($o) {
      $access = TRUE;
      $block = $this->loadBlock($data_block);
      $right = @$block['access'];
      if ($block && $o->access($right)) {
        if ($raw_mode) $block['options']['return_type'] = 'raw';
        switch ($block['type'])  {
          case 'sql':
            $xml = $o->sqlData($block['source'], @$block['options']);
            break;
          case 'xml':
            $xml = $o->xmlData($block['source']);
            break;
          case 'php':
            $data = Frx::Data()->currentContextArray();
            $xml = $o->phpData($block['object'], $data );
            break;
        }

      }
      return $xml;
    }
    else {
      return '';
    }
  }

  /**
   * Execute sql on a provider
   * @param $provider String Data provider index to reference
   * @param $sql String sql command to execute
   */
  public function sqlData($provider, $sql, $parms = array()) {
    $xml = '';

    //Intstantiate the provider
    $o = $this->repository($provider);

    $repos = @$this->repositories[$provider];
    if (isset($repos['enabled']) && !$repos['enabled']) {
      return '';
    }
    //Populate user callback.
    if (isset($repos['user callback'])) {
      $user_fn = $repos['user callback'];
      if (is_callable($user_fn)) {
        $current_user =   $user_fn();
        $parms['current_user'] = $current_user;
      }
    }


    if ($o && $sql) {
      Frx::Data()->push($parms, 'parm');

      // Parse the sql file
      $data = $o->parseSQLFile($sql);
      //now get the built SQL back
      $sql = $data['source'];
      $xml = $o->sqlData($sql, @$data['options']);
      Frx::Data()->pop();
    }
    return $xml;
  }

  /**
   * Parse a block into its data
   * @param $source Text data of the SQL block definition
   * @return array block definition.
   */
  public function sqlBlock($provider, $source) {      //Intstantiate the provider
    $o = $this->repository($provider);

    $repos = @$this->repositories[$provider];
    if (isset($repos['enabled']) && !$repos['enabled']) {
      return '';
    }
    if ($o)
    return $o->parseSQLFile($source);
  }

  /**
   * Build an SQL statement from the data provider
   * @param $provider string data provider name
   * @param $builder Array containing build information.
   */
  public function buildSQL($provider, $builder) {
    $repos = @$this->repositories[$provider];
    if (isset($repos['enabled']) && !$repos['enabled']) {
      return '';
    }
    $o = $this->repository($provider);
    $sql = "SELECT * FROM (\n";
    $sql .= '--INCLUDE=' . $builder['block_name'] . "\n";
    $sql .= ") t\n";
    if (@$builder['where']) {
      $sql .= "WHERE " . $o->buildFilterSQL($builder['where']);
    }
    return $sql;

  }


  /**
   * Check access control using the block in a data block.  In this case
   * public assess returns true.
   * @param $block  Repository block used to test access
   * @param $path   xpath to user right within xml data.
   * @param $access Access to test
   * @return boolean
   */
  function blockAccess($block, $path, $access, $cache=TRUE) {
    // PUBLIC always returns true.
    if ($access=='PUBLIC') return TRUE;
    if (!isset($_SESSION['forena_access'])) $_SESSION['forena_access'] = array();
    if ($cache && isset($_SESSION['forena_access'][$block])) {
      $rights = $_SESSION['forena_access'][$block];
    }
    else {
      $rights = array();
      // Get the block from the repository
      $frxData = Frx::Data();
      $frxData->push(array(), 'frx-block-access');
      $data = Frx::RepoMan()->data($block);
      $frxData->pop();
      if ($data) {
        if (!$path) {
          $path ='*/*';
        }
        $nodes = $data->xpath($path);
        if ($nodes) foreach ($nodes as $node) {
          $rights[] = (string)$node;
        }
        $_SESSION['forena_access'][$block]=$rights;
      }
    }
    foreach ($rights as $right) {
      if ($access == $right) return TRUE;
    }
    return FALSE;
  }


  /*
   * Recieves a datablock and returns an array of values from the data block.
   * @data_block: name of the data block to be invoked for values
   * @field: Specific field name within the data block. The values returned will only
   * come from this field.
   * @params: filtering for the data block
   * @where_clause: Where clause for data block to be filtered against.
   *
   */
  function dataBlockParams($data_block, $field, $label) {
    $xml = Frx::RepoMan()->data($data_block);

    $list = array();
    if ($xml) {
      $path = ($field) ? $field : '*[1]';
      $label_path = ($label) ? $label : '*[2]';


      //walk through the $xml.
      //$rows = $xml->xpath('*');
      if ($xml) foreach ($xml as $row) {
        $value = $row->xpath($path);
        $label_field = $row->xpath($label_path);
        $label_value =  $label_field ? (string)$label_field[0] : (string)$value[0];
        $list[(string)$value[0]] = (string)$label_value;

      }
    }
    return $list;
  }

  public function listRepos() {
    $r = array();

    foreach ($this->repositories as $k=>$repos) {
      if (user_access("access $k data")) {
        $r[$k] = $repos['title'];
      }
    }
    asort($r);
    return $r;
  }

}