<?php
/**
* @file
*   Provisioning Framework
*
* This module provides a framework for a Drupal site to manage and install new Drupal sites, using the command line
* Drush utility. 
*
* It allows for pluggable 'provisioning modules' that can extend and modify the actions that are taken during installation.
*
* Each site has the following commands that can be run on it.
*
* Implemented : 
*   install - Install a new Drupal site. The install command uses 3 separate hooks to do it's job, 
*              namely hook_provision_pre_install(), hook_provision_install() and hook_provision_post_install()
*   synch   - Recreate all configuration files, to be in synch with changes in the front end.
*   stats   - Return an associated array of site statistics. (implemented in provision_stats module, is thus optional)
*   import  - Import the details of an already existing site into the provisioning framework.
*             This command inspects the settings.php and generates the site.php file that the framework uses for configuration.
*
* Not implemented yet :
*   disable - Disable an installed Drupal site. This is done by removing the virtual host file, so that Apache no longer serves it.
*   enable  - Re-enable a site that has already been disabled. Recreates the virtual host file.
*   upgrade - Accepts a site package (backup) as argument, and redeploys it, running the upgrade processes on it.
*             Uses hook_provision_pre_upgrade(), hook_provision_upgrade() and hook_provision_post_upgrade() hooks,
*             and allows clean roll back if any errors occur. Will include stringent checking of module versions,
*             and allow unit tests to be run.
*   backup  - Generates a tarball containing the sites directory, the site data configuration and the database dump.
*             This allows the tarball to act as a 'site package', which can be redeployed on other installations,
*             or used for an upgrade.
*   rollback - Revert to a previous backup of the site.
*   rename  - Change the url of a site. This requires moving of files, and numerous other issues.
*   delete -  Generates a back up of the site, and then removes all references to it.
*/


/** Include the provisioning API. */
include_once('provision.inc');

/**
 * Implementation of hook_perm().
 */
function hook_perm() {
  return array("administer provisioning");
}


/**
 * @defgroup provisionui Configure provisioning framework.
 * @{
 */

/**
 * Implementation of hook_menu().
 */
function provision_menu($items, $may_cache = true) {
  if ($may_cache) {
    $items[] = array(
      'path' => 'admin/settings/provision',
      'title' => t('Provisioning'),
      'description' => t("Configure how new Drupal sites will be provisioned."),
      'callback' => 'drupal_get_form',
      'callback arguments' => array('provision_configure'),
      'access' => user_access('administer provisioning'),
    );
  }
  return $items;
}

/**
 * Menu callback.
 * 
 * Configuration screen for the provisioning framework.
 */
function provision_configure() {
  
  $form['provision_root'] = array(
    '#type' => 'textfield',
    '#title' => t('Provision root'),
    '#description' => t('The path where the provision platform is based.'),
    '#default_value' => variable_get('provision_root', ereg_replace("/webroot$", "", $_SERVER['DOCUMENT_ROOT'])),
    '#size' => 40,
    '#maxlength' => 255,
  );

  $form['provision_tempurl_base'] = array(
    '#type' => 'textfield',
    '#required' => TRUE,
    '#title' => t('Temporary URL base'),
    '#description' => t('Each new domain that gets created gets created with a temporary url base that allows it to be immediately accessible.'),
    '#default_value' => variable_get('provision_tempurl_base', $_SERVER['HTTP_HOST']),
    '#size' => 40,
    '#maxlength' => 255,
  );
  
  $form['provision_user'] = array(
    '#type' => 'textfield',
    '#title' => t('Provision user'),
    '#description' => t('The owner of the files. must not be the web server user.'),
    '#default_value' => variable_get('provision_user', 'hosting'),
    '#size' => 40,
    '#maxlength' => 255,
  );
  
  $form['provision_group'] = array(
    '#type' => 'textfield',
    '#title' => t('Provision group'),
    '#description' => t('The group owner of the files. should be the group the web server is running as.'),
    '#default_value' => variable_get('provision_group', 'apache'),
    '#size' => 40,
    '#maxlength' => 255,
  );

  foreach (module_implements('provision_configure') as $module) {
    $form[$module] = array(
      '#type' => 'fieldset',
      '#title' => module_invoke($module, 'provision_service'),
      '#collapsible' => TRUE,
      '#collapsed' => FALSE,
      '#access' => user_access('administer provisioning'),
    );
    $form[$module] = array_merge($form[$module], module_invoke($module, "provision_configure"));
  }
  return system_settings_form($form);
}

/**
 * @} End of "defgroup provisionui"
 */


/**
 * @defgroup provisiondrush Command line interface for Provision.
 * @{
 */
/**
 * Implementation of hook_drush_command().
 */
function provision_drush_command() {
  $items['provision install'] = array(
    'callback' => 'provision_install_cmd',
    'description' => 'Provision a new site using the provided data.'
  );

  $items['provision synch'] = array(
    'callback' => '_provision_synch',
    'description' => 'Regenerate all the config files for a site.'
  );  
  $items['provision import'] = array(
    'callback' => '_provision_import',
    'description' => 'Turn an already running site into a provisioned site.'
  );  
  /*
  $items['provision enable'] = array(
    'callback' => '_provision_enable',
    'description' => 'Enable a disabled site.'
  );
  $items['provision disable'] = array(
    'callback' => '_provision_disable',
    'description' => 'Disable a site.'
  );  
  // Not implemented yet.
  $items['provision delete'] = array(
    'callback' => '_provision_delete',
    'description' => 'Delete a site.'
  );

  $items['provision backup'] = array(
    'callback' => '_provision_backup',
    'description' => 'Generate a back up for the site.'
  );
  $items['provision rollback'] = array(
    'callback' => '_provision_rollback',
    'description' => 'Roll back the site to a previous backup.'
  );
  $items['provision deploy'] = array(
    'callback' => '_provision_deploy',
    'description' => 'Deploy a backup made on another provisioning platform on this one.'
  );
  $items['provision rename'] = array(
    'callback' => '_provision_rename',
    'description' => 'Change the url of an existing site.'
  );

  */
  return $items;
}

/**
 * Drush callback function
 *
 * Installs a new site at $url.
 * It does so by calling hook_provision_pre_install(), hook_provision_install() and hook_provision_post_install().
 *
 * @param url
 *    The url of the site being installed.
 * @return
 *    Returns provision_output on success or error. 
 *    Will exit with a PROVISION_SITE_INSTALLED error if the site already exists.
 *    Will exit with a PROVISION_FRAMEWORK_ERROR if the command is incorrectly used.
 */
function provision_install_cmd($url) {
  global $args;
  $data = provision_get_site_data($url);

  if (!$args['commands'][2]) {
    print "Usage: drush.php provision install DOMAIN [OPTIONS]\n";
    print "Install a new site for the domain DOMAIN.\n";
    print "Example: drush.php provision install mydomain.com --site-db-host=localhost\n";
    provision_set_log("error", "Incorrect usage of the provisioning framework");
    drupal_set_error(PROVISION_FRAMEWORK_ERROR);
    provision_output($url, $data);
  }
  $ops = array('pre_install', 'install', 'post_install'); # these are the provision hooks that will get triggered.

  if ($data['site-installed'] == TRUE) {
    print "The site $url is already installed.\nIf you want to re-install it, you will need to delete it first.";
    drupal_set_error(PROVISION_SITE_INSTALLED);
    provision_output($url, $data);
  }

  foreach ($ops as $op ) {
    $func = "_provision_$op";
    $func($url, $data);
  }

  provision_save_site_data($url, $data);
  provision_output($url, $data);
}

/**
 * Drush action. 
 *
 * Calls hook_provision_pre_install().
 * Also responsible for calling creating site directory layout, and the drupal settings file.
 *
 * @param url
 *   The url of the site being invoked.
 * @param data
 *   A reference to the associated array containing the data for the site. This needs to be a reference, 
 *   because the modules might provide additional information about the site.
 * @return
 *   Boolean denoting whether the provision_invoke rolled back changes made. 
 */
function _provision_pre_install($url, &$data) {  
  $rolled_back = provision_invoke("pre_install", $url, $data);

  if (!provision_get_error()) {
    // This is the actual drupal provisioning requirements. 
    _provision_drupal_create_directories($url, $data['profile']);
    // Requires at least the database settings to complete.
    _provision_drupal_create_settings_file($url, $data);
  }
  return $rolled_back;
}

/**
 * Install drupal site
 *
 * The magic here is that we need to drive the install api through this code. 
 * At this point, we no longer have access to the central database, and we need to be able
 * to drive this code blind, without causing bad stuff to happen.
 *
 * Install profile gets triggered at the end of this code.
 *
 * @param url
 *   The url of the site being invoked.
 * @param data
 *   A reference to the associated array containing the data for the site. This needs to be a reference, 
 *   because the modules might provide additional information about the site.
 * @return
 *   Boolean denoting whether the provision_invoke rolled back changes made. 
 */
function _provision_install($url, &$data) {
  $rolled_back = provision_invoke("install", $url, $data);

  if (!$rolled_back) {
    _provision_drupal_switch_active_site($url); # Change headers and db info, also backs up
    _provision_drupal_force_load_modules($url);
    _provision_drupal_install_schema($data['site-profile']);
    _provision_drupal_force_load_modules();
    _provision_drupal_switch_active_site(); # This *should* bring the site back to where we were before installing
  }
  return $rolled_back;
}

/** 
 * Clean up after installation.
 *
 * Most notably give the web server the opportunity to recheck it's configuration files.
 *
 * @param url
 *   The url of the site being installed.
 * @param data
 *   A reference to the associated array containing the data for the site. This needs to be a reference, 
 *   because the modules might provide additional information about the site.
 * @return
 *   Boolean denoting whether the provision_invoke rolled back changes made. 
 */
function _provision_post_install($url, &$data) {
  $rolled_back = provision_invoke("post_install", $url, $data);
  if (!$rolled_back) {
    $data['site-installed'] = true;  
  }
  return $rolled_back;
}

/**
 * Regenerate the config files of an already running site.
 *
 * @param url
 *   The url of the site being synched.
 * @return
 *   Output of drupal_output() function.
 *   Will exit with a PROVISION_SITE_NOT_FOUND error if the site does not exist.
 */
function _provision_synch($url) {
  if (!_provision_drupal_site_exists($url)) {
    provision_log("Error", "Site has not been installed yet.");
    drupal_set_error(PROVISION_SITE_NOT_FOUND);
    drupal_output($url, $data);
  }
  $data = provision_get_site_data($url);
  // This is the actual drupal provisioning requirements. 
  _provision_drupal_create_directories($url, $data['profile']);
  $rolled_back = provision_invoke("synch", $url, $data);
   // Requires at least the database settings to complete.
   _provision_drupal_create_settings_file($url, $data);
   provision_save_site_data($url, $data);
   drupal_output($url, $data);
}

/**
 * Import a running Drupal site into a provisioned site.
 *
 * This is accomplished by inspecting the settings.php file and generating a site.php file.
 *
 * @param url
 *   The url of the site being synched.
 * @return
 *   Output of drupal_output() function.
 *   Will exit with a PROVISION_SITE_NOT_FOUND error if the site does not exist.
 */
function _provision_import($url) {
  if (!_provision_drupal_site_exists($url)) {
    provision_log("Error", "Site directory is not present, and can not be imported.");
    drupal_set_error(PROVISION_SITE_NOT_FOUND);
    drupal_output($url, $data);
  }
  $data = provision_get_site_data($url);
  
  include_once("sites/$url/settings.php");
  
  $parts = parse_url($db_url);
  $data['site-db-type'] = $parts['scheme'];
  $data['site-db-user'] = $parts['user'];
  $data['site-db-host'] = $parts['host'];
  $data['site-db-passwd'] = $parts['pass'];
  $data['site-db-name'] = substr($parts['path'], 1);
  $data['site-profile'] = $installed_profile;
  
  provision_save_site_data($url, $data);
  provision_output($url, $data);
}