<?php

/**
 *  @file
 *  UI-related improvements to the Workflow module and tokens for Rules.
 *
 *  1a) Replaces the traditional workflow radio-buttons by either a drop-down or
 *  single-action buttons featuring context-sensitive labels (using replacement
 *  tokens) for a more intuitive user experience.
 *  See also the discussion on intelligent buttons at drupal.org/node/282122.
 *  All three UI styles (radio, dropw-down or single-action) are available as a
 *  block.
 *  1b) Suppresses the workflow schedule transition form if not selected by the
 *  user.
 *  2) The module also defines tokens which when used with Rules allow you to
 *  more easily invoke actions when something did NOT happen for some time.
 *
 *  Re 1a)
 *  Let's say we have a basic workflow with states "draft", "review" and "live".
 *  Traditionally authors and moderators must select the next state by pressing
 *  the correct radio-button and clicking submit. Experience from the field
 *  suggests that not everybody finds this intuitive. Rather than having to
 *  think in terms of state transitions, users prefer to press a button with a
 *  an explanatory label that clearly expresses what is going to happen.
 *  Using this module authors will find on the edit form a couple of clearly
 *  labeled buttons: "Save as draft, don't submit" and "Submit for publication".
 *  In old workflow-speak the latter action is represented by radio buttons plus
 *  a submit button and read less intuitively as: transition workflow state
 *  from "draft" to "review".
 *  Similarly, with this module a moderator will see on their edit form buttons
 *  like "Reject and return to author John" (i.e. "review -> draft") and
 *  "Publish this" ("review -> live").
 *  The alternative buttons appear on:
 *  a) the node edit form (node/%/edit)
 *  b) the comment edit form, if enabled
 *  c) the workflow tab, if enabled (node/%/workflow)
 *
 *  Re 2)
 *  This module defines a replacement token [node:workflow-state-age], which
 *  when used in a scheduled rule set, make it easier to invoke actions when
 *  a workflow state was NOT changed after a specified elapsed time.
 *  See drupal.org/project/workflow_extensions for full instructions on
 *  how to do this using Rules.
 */

define('WORKFLOW_EXTENSIONS_UI_RADIOS',   1); // the original Workflow style
define('WORKFLOW_EXTENSIONS_UI_BUTTONS',  2); // single-action buttons
define('WORKFLOW_EXTENSIONS_UI_DROPDOWN', 3); // dropdown selector + update

/**
 * Implementation of hook_perm().
 */
function workflow_extensions_perm() {
  return array(
    'change workflow state via node edit form',
    'edit workflow log',
    'view workflow state change block even when state cannot be changed');
}

/**
 * Implementation of hook_menu().
 */
function workflow_extensions_menu() {
  $items = array();
  $items['workflow-log/%workflow_state_transition_record'] = array( // maps to function workflow_state_transition_record_load()
    'title' => 'Edit workflow log comment',
    'description' => 'Edit workflow state transition comment.',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('workflow_extensions_workflow_comment_edit_form', 1),
    'access arguments' => array('edit workflow log')
  );
  $items['admin/settings/workflow_extensions'] = array(
    'title' => 'Workflow extensions',
    'description' => 'Configure workflow form style (buttons and labels).',
    'page callback' => 'drupal_get_form',
    'page arguments' => array('workflow_extensions_admin_configure'),
    'access arguments' => array('administer site configuration'),
    'file' => 'workflow_extensions.admin.inc'
  );
  return $items;
}

/**
 * Load function belonging to the above menu option 'workflow-log/%workflow-state-transition-record'.
 * Maps to this function just like 'node/%node' maps to node_load().
 *
 * @param $hid
 *   The ID of the workflow state transition record to load.
 * @return
 *   object representing one row from the {workflow_node_history} table
 */
function workflow_state_transition_record_load($hid) {
  $workflow_state_transition_record = db_fetch_object(db_query('SELECT * FROM {workflow_node_history} WHERE hid = %d', $hid));
  return $workflow_state_transition_record;
}

/**
 * Display a text area populated with the selected workflow log comment and
 * allow the user to modify and save it.
 */
function workflow_extensions_workflow_comment_edit_form($form_state, $workflow_state_transition_record) {
  $form = array();
  $form['hid'] = array('#type' => 'value', '#value' => $workflow_state_transition_record->hid);
  $form['nid'] = array('#type' => 'value', '#value' => $workflow_state_transition_record->nid);
  $form['workflow']['workflow_comment'] = array(
    '#type' => 'textarea',
    '#title' => t('Comment'),
    '#description' => t('Modify this workflow state transition comment and press submit.'),
    '#default_value' => $workflow_state_transition_record->comment,
    '#rows' => 2,
  );
  $form['submit'] = array(
    '#type' => 'submit',
    '#value' => t('Submit')
  );
  return $form;
}

/**
 * Submit handler for the workflow transition comment edit form.
 *
 * @see workflow_extensions_workflow_comment_edit_form()
 */
function workflow_extensions_workflow_comment_edit_form_submit($form, &$form_state) {
  $hid = $form_state['values']['hid'];
  $comment = $form_state['values']['workflow_comment'];

  db_query("UPDATE {workflow_node_history} SET comment = '%s' WHERE hid = %d", $comment, $hid);

  $nid = $form_state['values']['nid'];

  // Whatever is set here, is overriden by the "?destination=..." parameter, if present
  $form_state['redirect'] = module_exists('views') && views_get_view('workflow_history')
    ? "workflow-history/$nid"
    : (workflow_node_tab_access(node_load($nid)) ? "node/$nid/workflow" : "node/$nid");
}

/**
 * Implementation of hook_form_alter().
 *
 * 1) Remove the Workflow radio buttons and replace each state transition by a
 * submit button with a configurable, explanatory label.
 * To allow saving of edits to the node without a state transition, display
 * an additional button "Save, don't submit" (or similar).
 * 2) If on the create/edit form suppress the workflow fieldset if the user
 * does not have the relevant permission
 * 3) If the schedule state transition form is enabled, suppress it until the
 * user clicks the radio button to reveal it.
 * 4) Add an (extra) form validator
 */
function workflow_extensions_form_alter(&$form, &$form_state, $form_id) {

  // If there's no Workflow fieldset, then we have nothing further to do.
  if (!isset($form['#wf'])) { // was $form['workflow'] but need to exclude content type edit form
    return;
  }

  // 4) Add form validator
  if (empty($form['#validate'])) {
    $form['#validate'] = array();
  }
  elseif (!is_array($form['#validate'])) {
    $form['#validate'] = array($form['#validate']);
  }
  $form['#validate'][] = 'workflow_extensions_workflow_form_validate';

  // 2) Suppress Workflow fieldset on the create/edit form if not permitted.
  if (isset($form['#id']) && $form['#id'] == 'node-form' && !user_access('change workflow state via node edit form')) {
    unset($form['workflow']);
    return;
  }

  // The next if-statement implements point 3) above
  if (variable_get('workflow_extensions_display_schedule_toggle', TRUE)) {
    $path = drupal_get_path('module', 'workflow_extensions');
    drupal_add_js($path . '/workflow_schedule.js', 'module');
  }

  // The rest of this function implements point 1)
  $workflow_name = workflow_extensions_extract_workflow_name($form);
  $workflow_radios = $form['workflow'][$workflow_name];

  if (is_array($workflow_radios) && isset($workflow_radios['#options'])) {
    // Use the form to work out the potential state transitions for this user.
    $states = $workflow_radios['#options'];
    // $states will be empty when creating node
    if (!empty($states)) {

      $title = variable_get('workflow_extensions_change_state_form_title', '');
      if (!empty($title)) {
        if (trim($title) == '<none>') {
          unset($form['workflow'][$workflow_name]['#title']);
        }
        else {
          $form['workflow'][$workflow_name]['#title'] = workflow_extensions_replace_tokens_raw($title);
        }
      }

      if (empty($form['#submit'])) {
        // This seems to happen as a side-effect of using hook_forms(), i.e
        // the case where workflow_extensions_change_state_form() is called,
        // for instance when the state change form appears in a block or View.
        // In the latter case, we also create ourselves an option to redirect
        // to page different from the default (which is node/%), as set in
        // workflow_tab_form_submit().
        $form['#submit'] = array('workflow_tab_form_submit', 'workflow_extensions_form_redirect');
      }

      switch (variable_get('workflow_extensions_ui_style', WORKFLOW_EXTENSIONS_UI_BUTTONS)) {

        case WORKFLOW_EXTENSIONS_UI_BUTTONS:
          if (count($states) > 1) {
            _workflow_extensions_replace_with_buttons($form, $workflow_name);
          }
          break;

        case WORKFLOW_EXTENSIONS_UI_DROPDOWN:
          _workflow_extensions_replace_with_dropdown($form, $workflow_name);
          // no break;

        default: // radios
          if (isset($form['submit'])) {
            $submit_label = variable_get('workflow_extensions_change_state_button_label', '');
            if (!empty($submit_label)) {
              $form['submit']['#value'] = workflow_extensions_replace_tokens_raw($submit_label);
            }
          }
          break;
      }
    }
  }
}

/**
 * Implementation of hook_forms();
 *
 * Called as a result of the fact that there are no form handlers for the
 * unique form_id's generated in workflow_extensions_change_state_form().
 * Here we map these form_id's back to the same 'workflow_tab_form'. This
 * allows us to have multiple copies of the same form on the same page.
 * Note: first of the args is typically the node object.
 */
function workflow_extensions_forms($form_id, $args) {
  if (strpos($form_id, 'workflow_tab_form_nid') === 0) {
    $form = array(
      $form_id => array(
        'callback' => 'workflow_tab_form',
        'callback arguments' => array()
      )
    );
    return $form;
  }
}

/**
 * Validate the workflow form, in particular the state transition comment and
 * the scheduled state transition time (the date is a drop-down so requires no
 * validation).
 */
function workflow_extensions_workflow_form_validate($form, &$form_state) {
  $nid = substr($form['#id'], strrpos($form['#id'], '-') + 1);
  $title = isset($form_state['values']['title']) ? $form_state['values']['title'] : $form_state['values']['node']->title;

  if (!empty($form_state['values']['workflow_scheduled_hour'])) {
    if (!strtotime($form_state['values']['workflow_scheduled_hour'])) {
      form_set_error(is_numeric($nid) ? "workflow_scheduled_hour_$nid" : 'workflow_scheduled_hour', t('%title: scheduled time is not in the correct format.', array('%title' => $title)));
    }
  }
  if (!variable_get('workflow_extensions_allow_blank_comments', TRUE)) {
    if (!isset($form_state['values']['nid']) && !isset($form_state['values']['node'])) {
      // Bypass node creation
      return;
    }
    $comment = $form_state['values']['workflow_comment'];
    if (!trim($comment)) {
      form_set_error(is_numeric($nid) ? "workflow_comment_$nid" : 'workflow_comment', t('%title: please enter a non-blank comment for the workflow log.', array('%title' => $title)));
    }
  }
}

/**
 * Handler for the single-action submit buttons on the edit form.
 * Does NOT get called when radio buttons or drop-down are used.
 */
function workflow_extensions_form_submit($form, &$form_state) {
  // In the original form_submit handler that we pass control to next, the
  // selected workflow state is taken from form_state['values']['workflow']. So
  // that's the entry we need to set here in accordance with the clicked button.
  // See node_form_submit() -> node_submit() for the edit form.
  // See workflow_tab_form_submit() for the Workflow tab.
  $form_state['values']['workflow'] = $form_state['clicked_button']['#to_state'];
  // ... now proceed to next handler, e.g. node_form_submit for a normal save
}

/**
 * If the workflow state was not transitioned via either the node edit form or
 * the Workflow tab, then redirect to a configurable page, e.g. some View.
 */
function workflow_extensions_form_redirect($form, &$form_state) {
  if (arg(0) != 'node') {
    $path = variable_get('workflow_extensions_redirect_page', ''); // @todo: make this a UI config option
    $form_state['redirect'] = empty($path) ? $_GET['q'] : $path;   // @todo: save query-string too (Views pager)
  }
}

function _workflow_extensions_replace_with_buttons(&$form, $workflow_name) {
  $current_sid = $form['workflow'][$workflow_name]['#default_value'];
  if (function_exists('workflow_get_state_name')) {
    $current_state_name = workflow_get_state_name($current_sid);
  }
  else {
    $current_state = workflow_get_state($current_sid);
    $current_state_name = $current_state['state'];
  }
  // We need a node-context for token replacement. When on the Workflow tab
  // form, the node object will already have been loaded on the form.
  // When creating content (node/add/<type>) we only have limited data. In
  // the remaining cases we load the node from the cache based on the nid
  // found on the form.
  $form_id = $form['form_id']['#value'];
  if (strpos($form_id, 'workflow_tab_form') === 0) {
    $node = $form['node']['#value'];
  }
  elseif (is_numeric($nid = $form['nid']['#value'])) {
    $node = node_load($nid);
  }
  else { // Creating new content, nid not yet known
    $node = $form['#node'];
  }
  $states = $form['workflow'][$workflow_name]['#options'];
  $submit_handlers = _workflow_extensions_assign_handlers($form);
  foreach ($states as $sid => $to_state_name) {
    if ($sid != $current_sid) {
      // Create button for transition from current_sid to destination state.
      $button = array();
      $button['#value'] = workflow_extensions_get_transition_label($form['#wf']->wid, $current_state_name, workflow_get_state_name($sid), $node);
      $button['#type'] = 'submit';
      $button['#to_state'] = $sid;
      if (isset($form['buttons']['submit']['#weight'])) { // node form
        $button['#weight'] = $form['buttons']['submit']['#weight'] + 1;
      }
      elseif (isset($form['submit']['#weight'])) { // comment form
        $button['#weight'] = $form['submit']['#weight'];
      }
      $button['#submit'] = $submit_handlers;
      $form['buttons']["submit_to_$to_state_name"] = $button;
    }
  }
  // Get rid of workflow radio buttons that live inside the fieldset
  unset($form['workflow'][$workflow_name]);
  // If after this the fieldset is empty, remove it altogher
  if (!isset($form['workflow']['workflow_scheduled']) &&
    (!isset($form['workflow']['workflow_comment']) || $form['workflow']['workflow_comment']['#type'] == 'hidden')) {
    unset($form['workflow']);
  }
  // With the existing Save button now impotent to submit a workflow
  // transition, we can re-purpose it for saving all other edits to the
  // node without changing the workflow state.
  // This does not make sense for the Workflow tab form though, as there is
  // nothing to save but a state change. In this case we simply remove the
  // Save button.
  if ($form_id == 'comment_form') {
    $form['buttons']['submit'] = $form['submit'];
    $form['buttons']['submit']['#submit'] = $form['#submit'];
    $form['buttons']['submit']['#weight']--; // left-most
  }
  if (strpos($form_id, 'workflow_tab_form') !== 0 && ($label = variable_get('workflow_extensions_default_save_button_label', ''))) {
    $form['buttons']['submit']['#value'] = workflow_extensions_replace_state_name_tokens($label, $current_state_name);
  }
  unset($form['submit']);  // the button
//unset($form['#submit']); // don't remove handler, [#1097328]
}

function _workflow_extensions_replace_with_dropdown(&$form, $workflow_name) {
  $form['workflow'][$workflow_name]['#type'] = 'select';
  $form['workflow'][$workflow_name]['#name'] = 'workflow';
}

/**
 * Implementation of hook_block().
 */
function workflow_extensions_block($op = 'list', $delta = 0) {
  if (!module_exists('workflow')) {
    return;
  }
  if ($op == 'list') {
    $block[0]['info'] = t('Workflow state change form');
    return $block;
  }
  elseif ($op == 'view' && arg(0) == 'node') {
    $node = node_load(arg(1));
    $block['content'] = workflow_extensions_change_state_form($node);
    $block['subject'] = '';
    return $block;
  }
}

/**
 * Use this function in a code-snippet to output a workflow state change form
 * on any page. May be used multiple times on the same page (for different
 * nodes), e.g. using the 'Views PHP' module, as a unique form_id is generated
 * for each occurrence of the form.
 *
 * @param $node
 */
function workflow_extensions_change_state_form($node) {

  if (!$node || !($wid = workflow_get_workflow_for_type($node->type))) {
    return '';
  }

  $choices = workflow_field_choices($node);
  if (count($choices) == 1) {
    if (user_access('view workflow state change block even when state cannot be changed')) {
      // Generate single-option form without Submit button
      return drupal_get_form('workflow_extensions_single_state_form', workflow_get_name($wid), $choices);
    }
    return ''; // not allowed to view state
  }

  $result = db_query("SELECT sid, state FROM {workflow_states} WHERE status = 1 ORDER BY sid");
  while ($row = db_fetch_object($result)) {
    $workflow_states[$row->sid] = check_plain(t($row->state));
  }
  $sid_current = workflow_node_current_state($node);
  require_once drupal_get_path('module', 'workflow') . '/workflow.pages.inc';
  $output = drupal_get_form('workflow_tab_form_nid_'. $node->nid, $node, $wid, $workflow_states, $sid_current);
  return $output;
}

/**
 * Form used to display the current state, without a submit button to change it.
 * @param $form_state
 * @param $workflow_name
 * @param $current_state, an array of one element, indexed by its sid
 */
function workflow_extensions_single_state_form($form_state, $workflow_name, $current_state) {
  $sids = array_keys($current_state);
  $form['workflow']['#title'] = $workflow_name;
  $form['workflow'][$workflow_name] = array(
    '#type' => 'radios', // may be overridden by workflow_extensions_form_alter()
    '#options' => $current_state,
    '#default_value' => $sids[0]
  );
  return $form;
}

function workflow_extensions_extract_workflow_name($form) {
  // Current and allowed next states for this user and node live in
  // $form['workflow'][$workflow_name]['#options].
  // At the time of writing, the workflow.module (6.x.1-4) contained a bug that
  // resulted in the $workflow_name being passed as blank. Luckily we can work
  // around this and also be compatible with later versions that don't have the
  // bug.
  if (isset($form['workflow'][''])) {
    return '';
  }
  return isset($form['#wf']->name) ? $form['#wf']->name : $form['workflow']['#title'];
}

function _workflow_extensions_assign_handlers($form) {
  $original_handlers = $form['#submit']; // e.g. 'workflow_tab_form_submit' or 'menu_node_form_submit'
  return ($form['#id'] == 'node-form') // 'menu_node_form_submit', 'upload_node_form_submit'
    ? array('workflow_extensions_form_submit', 'node_form_submit') // node_form_submit() will add original handlers
    : array_merge(array('workflow_extensions_form_submit'), $original_handlers);

  // [#1346078] ?
  //$original_handlers = array_merge($original_handlers, $form['buttons']['submit']['#submit']);
  //  return array_merge(array('workflow_extensions_form_submit'), $original_handlers);
}

/**
 * Implementation of hook_token_list().
 *
 * Note: [workflow-new-state-name] is in fact a pseudo-token, but the user
 * doesn't have to know that!
 */
function workflow_extensions_token_list($context = 'all') {
  if (module_exists('workflow') && in_array($context, array('workflow', 'node', 'all'))) {
    $tokens['workflow']['workflow-new-state-name'] = 'New state of content';
    $tokens['workflow']['workflow-state-age'] = 'Seconds elapsed since last state change';
  }
  if ($context == 'node'|| $context == 'all') {
    $tokens['node']['mod-since-seconds'] = 'Seconds elapsed since last modification';
  }
  return $tokens;
}

/**
 * Implementation of hook_token_values().
 *
 * Returning [workflow-state-age] for both node and workflow contexts as there
 * seems to be an issue with using Workflow state as the data type argument in
 * a Rule set. Such a Rule set won't show as available in a scheduled triggered
 * rule. The Content (ie node) data type must be used instead.
 */
function workflow_extensions_token_values($context, $object = NULL) {
  $values = array();
  switch ($context) {
    case 'node':
    case 'workflow':
      if (isset($object)) {
        $node = (object)$object;
        if (module_exists('workflow')) {
          $stamp = db_result(db_query_range("SELECT stamp FROM {workflow_node_history} WHERE nid = %d ORDER BY stamp DESC", $node->nid, 0, 1));
          $values['workflow-state-age'] = $stamp ? (time() - $stamp) : 0;
        }
        $values['mod-since-seconds'] = $node->changed ? (time() - $node->changed) : 0;
      }
      break;
  }
  return $values;
}

/**
 * Return the name for the workflow transition identified by the supplied
 * from-state and to-state names.
 *
 * @param int $wid, workflow identifier, maybe NULL (but then the combination
 *  of $from_state_name and $to_state_name must be unique across all workflows)
 * @param string $from_state_name
 * @param string $to_state_name
 * @param object $node, context for token replacement; if omitted an attempt
 *   will be made to load the node based on the nid in the URL. This will fail
 *   when creating new content, in which case a partial node must be supplied.
 */
function workflow_extensions_get_transition_label($wid, $from_state_name, $to_state_name, $node = NULL) {
  if (module_exists('workflow_named_transitions')) {
    $transitions = workflow_named_transitions_get_transitions($wid);
    foreach ($transitions as $transition) {
      if ($transition['from_state'] == $from_state_name && $transition['to_state'] == $to_state_name) {
        return workflow_extensions_replace_state_name_tokens($transition['label'], $to_state_name, $node);
      }
    }
    // No label defined, fall through as if module 'workflow_named_transitions'
    // wasn't installed
  }
  $tokenized_label = variable_get('workflow_extensions_change_state_button_label', '');
  // Don't think we need to check_markup(). Only users with 'administer site
  // configuration' permission can set the label pattern, so it's up to them to
  // use or not use HTML and/or javascript.
  return workflow_extensions_replace_state_name_tokens($tokenized_label, $to_state_name, $node);
}

function workflow_extensions_replace_state_name_tokens($tokenized_label, $to_state_name = NULL, $node = NULL) {
  if (empty($tokenized_label)) {
    return t('Move to "@state_name"', array('@state_name' => $to_state_name));
  }
  $label = workflow_extensions_replace_tokens_raw($tokenized_label, $node);
  if (!empty($to_state_name)) {
    // Once the real tokens have been replaced, replace the pseudo-token
    // [workflow-new-state-name]
    $label = str_replace('[workflow-new-state-name]', $to_state_name, $label);
  }
  return $label;
}

function workflow_extensions_replace_tokens_raw($tokenized_label, $node = NULL) {
  if (module_exists('token')) {
    global $user;
    $objects['global'] = NULL;
    $objects['user'] = $user;
    if ($node == NULL && arg(0) == 'node' && is_numeric(arg(1))) {
      $node = node_load(arg(1)); // node/%
    }
    $objects['node'] = $objects['workflow'] = $node;
    return token_replace_multiple($tokenized_label, $objects);
  }
  return $tokenized_label;
}

/**
 * Implementation of hook_views_api().
 */
function workflow_extensions_views_api() {
  return array(
    'api' => views_api_version(),
    'path' => drupal_get_path('module', 'workflow_extensions') .'/views'
  );
}