<?php

/**
 * @file
 * Install, update and uninstall functions for the Site Structure module.
 */

declare(strict_types=1);

use Drupal\taxonomy\Entity\Term;

/**
 * Implements hook_install().
 */
function site_structure_install(): void {
  // Create default terms for site_section vocabulary.
  _site_structure_create_default_terms();

  // Display success message.
  \Drupal::messenger()->addStatus(t('Site Structure module installed successfully. Configure Pathauto patterns at /admin/config/search/path/patterns'));
}

/**
 * Creates default terms for the site_section vocabulary.
 */
function _site_structure_create_default_terms(): void {
  $vocabulary = 'site_section';

  // Check if terms already exist (avoid duplication on reinstall).
  $existing = \Drupal::entityQuery('taxonomy_term')
    ->accessCheck(FALSE)
    ->condition('vid', $vocabulary)
    ->count()
    ->execute();

  if ($existing > 0) {
    return;
  }

  // Structure: name => children.
  $terms_structure = [
    'News' => [],
    'Events' => [],
    'People' => [],
    'Institutional' => [
      'About',
      'Communication',
      'Information and Services',
      'Team',
      'Management',
      'Inclusion and Belonging',
    ],
    'Undergraduate' => [
      'Statistics',
      'Mathematics',
      'Applied Mathematics',
      'Mathematics Teaching',
    ],
    'Graduate' => [
      'Statistics Program',
      'Mathematics Program',
      'Applied Mathematics Program',
    ],
    'Research' => [],
    'Extension' => [],
    'Administration' => [],
    'Departments' => [
      'Statistics Department',
      'Mathematics Department',
      'Applied Mathematics Department',
    ],
    'Library' => [],
    'IT Services' => [],
  ];

  $weight = 0;
  foreach ($terms_structure as $parent_name => $children) {
    // Create parent term.
    $parent_term = Term::create([
      'vid' => $vocabulary,
      'name' => $parent_name,
      'weight' => $weight++,
    ]);
    $parent_term->save();

    // Create child terms.
    $child_weight = 0;
    foreach ($children as $child_name) {
      $child_term = Term::create([
        'vid' => $vocabulary,
        'name' => $child_name,
        'parent' => $parent_term->id(),
        'weight' => $child_weight++,
      ]);
      $child_term->save();
    }
  }
}

/**
 * Implements hook_uninstall().
 */
function site_structure_uninstall(): void {
  $entity_type_manager = \Drupal::entityTypeManager();

  // Remove nodes from module's content types.
  foreach (['section_page', 'content_page'] as $bundle) {
    $nids = \Drupal::entityQuery('node')
      ->accessCheck(FALSE)
      ->condition('type', $bundle)
      ->execute();
    if ($nids) {
      $nodes = $entity_type_manager->getStorage('node')->loadMultiple($nids);
      $entity_type_manager->getStorage('node')->delete($nodes);
      \Drupal::messenger()->addWarning(t('Deleted @count @bundle nodes.', [
        '@count' => count($nids),
        '@bundle' => $bundle,
      ]));
    }
  }

  // Remove terms from site_section vocabulary.
  $tids = \Drupal::entityQuery('taxonomy_term')
    ->accessCheck(FALSE)
    ->condition('vid', 'site_section')
    ->execute();
  if ($tids) {
    $terms = $entity_type_manager->getStorage('taxonomy_term')->loadMultiple($tids);
    $entity_type_manager->getStorage('taxonomy_term')->delete($terms);
  }

  // Remove configurations in correct order (dependencies first).
  $configs_to_delete = [
    // Views.
    'views.view.child_pages',
    // Pathauto patterns.
    'pathauto.pattern.section_page',
    'pathauto.pattern.content_page',
    'pathauto.pattern.site_section_term',
    // Entity displays.
    'core.entity_form_display.node.section_page.default',
    'core.entity_view_display.node.section_page.default',
    'core.entity_form_display.node.content_page.default',
    'core.entity_view_display.node.content_page.default',
    // Field instances.
    'field.field.node.section_page.field_site_section',
    'field.field.node.section_page.body',
    'field.field.node.content_page.field_parent_page',
    'field.field.node.content_page.field_site_section',
    'field.field.node.content_page.body',
    // Field storages (only if not used by other bundles).
    'field.storage.node.field_site_section',
    'field.storage.node.field_parent_page',
    // Node types.
    'node.type.section_page',
    'node.type.content_page',
    // Vocabulary.
    'taxonomy.vocabulary.site_section',
  ];

  $config_factory = \Drupal::configFactory();
  foreach ($configs_to_delete as $config_name) {
    $config = $config_factory->getEditable($config_name);
    if (!$config->isNew()) {
      $config->delete();
    }
  }

  \Drupal::messenger()->addStatus(t('Site Structure module uninstalled successfully.'));
}

/**
 * Implements hook_requirements().
 */
function site_structure_requirements(string $phase): array {
  $requirements = [];

  if ($phase === 'runtime') {
    // Check if site_section vocabulary has terms.
    $term_count = \Drupal::entityQuery('taxonomy_term')
      ->accessCheck(FALSE)
      ->condition('vid', 'site_section')
      ->count()
      ->execute();

    if ($term_count === 0) {
      $requirements['site_structure_terms'] = [
        'title' => t('Site Structure'),
        'value' => t('No terms in site_section vocabulary'),
        'description' => t('The Site Structure module requires terms in the "Site Section" vocabulary. <a href=":url">Add terms</a>.', [
          ':url' => '/admin/structure/taxonomy/manage/site_section/add',
        ]),
        'severity' => REQUIREMENT_WARNING,
      ];
    }
    else {
      $requirements['site_structure_terms'] = [
        'title' => t('Site Structure'),
        'value' => t('@count terms configured', ['@count' => $term_count]),
        'severity' => REQUIREMENT_OK,
      ];
    }
  }

  return $requirements;
}