<?php
/**
 * @file
 *   Provides node access permissions based on workflow states.
 */

/**
 * Implements hook_menu().
 */
function workflow_access_menu() {
  $items = array();

  $items["admin/config/workflow/access/%workflow"] = array(
    'title' => 'Access',
    'access arguments' => array('administer workflow'),
    'page callback' => 'drupal_get_form',
    'page arguments' => array('workflow_access_form', 4),
    'type' => MENU_CALLBACK,
    );

  return $items;
}

/**
 * Implements hook_node_grants().
 *
 * Supply the workflow access grants. We are simply using
 * roles as access lists, so rids translate directly to gids.
 */
function workflow_access_node_grants($account, $op) {
  return array(
    'workflow_access' => array_keys($account->roles),
    'workflow_access_owner' => array($account->uid),
  );
}

/**
 * Implements hook_node_access_records().
 *
 * Returns a list of grant records for the passed in node object.
 */
function workflow_access_node_access_records($node) {
  $grants = array();
  if ($state = workflow_get_workflow_node_by_nid($node->nid)) {
    $state = workflow_get_workflow_states_by_sid($state->sid);
    foreach (workflow_access_get_workflow_access_by_sid($state->sid) as $grant) {
      $grants[] = array(
        'realm' => ($grant->rid == -1) ? 'workflow_access_owner' : 'workflow_access',
        'gid' => ($grant->rid == -1) ? $node->uid : $grant->rid,
        'grant_view' => $grant->grant_view,
        'grant_update' => $grant->grant_update,
        'grant_delete' => $grant->grant_delete,
        'priority' => 0,
      );
    }
  }
  return $grants;
}

/**
 * Implements hook_node_access_explain().
 * This is a Devel Node Access hook.
 */
function workflow_access_node_access_explain($row) {
  static $interpretations = array();
  switch ($row->realm) {
    case 'workflow_access_owner':
      $interpretations[$row->gid] = t('Workflow access: author of the content may access');
      break;
    case 'workflow_access':
      $roles = user_roles();
      $interpretations[$row->gid] = t('Workflow access: %role may access', array('%role' => $roles[$row->gid]));
      break;
  }
  return (!empty($interpretations[$row->gid]) ? $interpretations[$row->gid] : NULL);
}

/**
 * Implements hook_workflow_operations().
 * Create action link for access form.
 */
function workflow_access_workflow_operations($op, $workflow = NULL, $state = NULL) {
  switch ($op) {
    case 'workflow':
      $alt = t('Control content access for @wf', array('@wf' => $workflow->name));
      $actions = array(
        'workflow_access_form' => array(
          'title' => t('Access'),
          'href' => "admin/config/workflow/access/$workflow->wid",
          'attributes' => array('alt' => $alt, 'title' => $alt),
          ),
        );

      return $actions;
  }
}

/**
 * Implements hook_form().
 *
 * Add a "three dimensional" (state, role, permission type) configuration
 * interface to the workflow edit form.
 */
function workflow_access_form($form, $form_state, $workflow) {
  if ($workflow) {
    drupal_set_title(t('@name Access', array('@name' => $workflow->name)));
  }
  else {
    drupal_set_message(t('Unknown workflow'));
    drupal_goto('admin/config/workflow/workflow');
  }

  $bc = array(l(t('Home'), '<front>'));
  $bc[] = l(t('Configuration'), 'admin/config');
  $bc[] = l(t('Workflow'), 'admin/config/workflow');
  $bc[] = l(t('Workflow'), 'admin/config/workflow/workflow');
  $bc[] = l(t($workflow->name), "admin/config/workflow/workflow/$workflow->wid");
//  $bc[] = l(t('Access'), "admin/config/workflow/access/$workflow->wid");
  drupal_set_breadcrumb($bc);

  $form = array('#tree' => TRUE);

  $form['#wid'] = $workflow->wid;

  // A list of roles available on the site and our
  // special -1 role used to represent the node author.
  $rids = user_roles(FALSE, 'participate in workflow');

  $rids['-1'] = t('author');

  // Add a table for every workflow state.
  $options = array('status' => 1);
  foreach (workflow_get_workflow_states_by_wid($workflow->wid, $options) as $state) {
    if ($state->state == t('(creation)')) {
      // No need to set perms on creation.
      continue;
    }
    $view = $update = $delete = array();
    $count = 0;
    foreach (workflow_access_get_workflow_access_by_sid($state->sid) as $access) {
      $count++;
      if ($access->grant_view) {
        $view[] = $access->rid;
      }
      if ($access->grant_update) {
        $update[] = $access->rid;
      }
      if ($access->grant_delete) {
        $delete[] = $access->rid;
      }
    }
    // Allow view grants by default for anonymous and authenticated users,
    // if no grants were set up earlier.
    if (!$count) {
      $view = array(DRUPAL_ANONYMOUS_RID, DRUPAL_AUTHENTICATED_RID);
    }
    // TODO better tables using a #theme function instead of direct #prefixing
    $form[$state->sid] = array(
      '#type' => 'fieldset',
      '#title' => t('@state', array('@state' => $state->state)),
      '#collapsible' => TRUE,
      '#collapsed' => FALSE,
      '#tree' => TRUE,
      );

    $form[$state->sid]['view'] = array(
      '#type' => 'checkboxes',
      '#options' => $rids,
      '#default_value' => $view,
      '#title' => t('Roles who can view posts in this state'),
      '#prefix' => '<table width="100%" style="border: 0;"><tbody style="border: 0;"><tr><td>',
      );

    $form[$state->sid]['update'] = array(
      '#type' => 'checkboxes',
      '#options' => $rids,
      '#default_value' => $update,
      '#title' => t('Roles who can edit posts in this state'),
      '#prefix' => "</td><td>",
      );

    $form[$state->sid]['delete'] = array(
      '#type' => 'checkboxes',
      '#options' => $rids,
      '#default_value' => $delete,
      '#title' => t('Roles who can delete posts in this state'),
      '#prefix' => "</td><td>",
      '#suffix' => "</td></tr></tbody></table>",
    );
  }
  
  $form['warning'] = array(
    '#type' => 'markup',
    '#markup' => '<p><strong>'
      . t('WARNING:')
      . '</strong> '
      . t('Use of the "Edit any" and/or "Edit own" permissions for the content type may override these access settings.')
      . '</p>',
      );

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

  return $form;
  // Place our block comfortably down the page.
  $form['submit']['#weight'] = 10;
  $form['#submit'][] = 'workflow_access_form_submit';
}

/**
 * Store permission settings for workflow states.
 */
function workflow_access_form_submit($form, &$form_state) {
  foreach ($form_state['values'] as $sid => $access) {
    // Ignore irrelevant keys.
    if (!is_numeric($sid)) {
      continue;
    }
    $grants = array();
    foreach ($access['view'] as $rid => $checked) {
      $data = array(
        'sid' => $sid,
        'rid' => $rid,
        'grant_view' => (!empty($checked)) ? (bool) $checked : 0,
        'grant_update' => (!empty($access['update'][$rid])) ? (bool) $access['update'][$rid] : 0,
        'grant_delete' => (!empty($access['delete'][$rid])) ? (bool) $access['delete'][$rid] : 0,
      );
      $id = workflow_access_insert_workflow_access_by_sid($data);
    }

    // Update all nodes having same workflow state to reflect new settings.
    foreach (workflow_get_workflow_node_by_sid($sid) as $data) {
      // Instead of trying to construct what the grants should be per node as we save.
      // Let's fall back on existing node grant systems that will find it for us.
      $node = node_load($data->nid);
      node_access_acquire_grants($node);
    }
  }

  drupal_set_message(t('Workflow access permissions updated.'));
  $form_state['redirect'] = 'admin/config/workflow/workflow/' . $form['#wid'];
}

/**
 * Implements hook_workflow().
 *
 * Update grants when a node changes workflow state.
 * This is already called when node_save is called.
 */
function workflow_access_workflow($op, $old_sid, $sid, $node) {
  // ALERT:
  // This is a tricky spot when called on node_insert as part of the transition from create to state1.
  // node_save invokes this function as a hook before calling node_access_acquire_grants.
  // But when it calls node_access_acquire_grants later, it does so without deleting the access
  // set when calling workflow_node_insert because it is an insert and no prior grants are expected.
  // This leads to a SQL error of duplicate grants which causes a rollback of all changes.
  // Unfortunately, setting access rights isn't the only thing we're doing on node_insert so we
  // can't skip the whole thing. So we need to fix it further downstream in order to get this to work.
  // Here we don't want to run this in the case of (and ONLY in the case of) a brand new node.
  // Node access grants will be run as part of node_save's own granting after this.
  //
  // NOTE: Any module that sets node access rights on insert will hit this situation.
  //
  if ($old_state = workflow_get_workflow_states_by_sid($old_sid)) {
    if ($op == 'transition post' && $old_sid != $sid && (empty($node->is_new) || !$node->is_new)) {
      node_access_acquire_grants($node);
    }
  }
}

/**
 * DB functions - all DB interactions are isolated here to make for easy updating should our schema change.
 */

/**
 * Given a sid, retrieve the access information and return the row(s).
 */
function workflow_access_get_workflow_access_by_sid($sid) {
  $results = db_query('SELECT * from {workflow_access} where sid = :sid', array(':sid' => $sid));
  return $results->fetchAll();
}

/**
 * Given a sid and a rid (the  unique key), delete all access data for this state.
 */
function workflow_access_delete_workflow_access_by_sid_rid($sid, $rid) {
  db_delete('workflow_access')->condition('sid', $sid)->condition('rid', $rid)->execute();
}

/**
 * Given a sid, delete all access data for this state.
 */
function workflow_access_delete_workflow_access_by_sid($sid) {
  db_delete('workflow_access')->condition('sid', $sid)->execute();
}

/**
 * Given data, insert into workflow access - we never update.
 */
function workflow_access_insert_workflow_access_by_sid(&$data) {
  $data = (object) $data;
  workflow_access_delete_workflow_access_by_sid_rid($data->sid, $data->rid);
  drupal_write_record('workflow_access', $data);
}

/**
 * Implements hook_features_api().
 *
 * Tell the Features module that we intend to provide one exportable component.
 */
function workflow_access_features_api() {
  return array(
    'workflow_access' => array(
      'name' => t('Workflow access'),
      'file' => drupal_get_path('module', 'workflow_access') . '/workflow_access.features.inc',
      'default_hook' => 'workflow_access_features_default_settings',
      'default_file' => FEATURES_DEFAULTS_INCLUDED,
      'feature_source' => TRUE,
    ),
  );
}
