<?php

namespace Drupal\views;

use Drupal\Core\Entity\EntityFieldManagerInterface;
use Drupal\Core\Entity\EntityStorageInterface;
use Drupal\Core\Entity\EntityTypeManagerInterface;
use Drupal\Core\Entity\Sql\SqlContentEntityStorage;
use Drupal\Core\Field\FieldTypePluginManagerInterface;
use Drupal\Core\Render\Markup;
use Drupal\Core\StringTranslation\StringTranslationTrait;
use Drupal\field\Entity\FieldConfig;
use Drupal\field\FieldStorageConfigInterface;

/**
 * Provide default views data for fields.
 */
class FieldViewsDataProvider {

  use StringTranslationTrait;

  public function __construct(
    protected readonly EntityTypeManagerInterface $entityTypeManager,
    protected readonly FieldTypePluginManagerInterface $fieldTypePluginManager,
    protected readonly EntityFieldManagerInterface $entityFieldManager,
  ) {}

  /**
   * Default views data implementation for a field.
   *
   * @param \Drupal\field\FieldStorageConfigInterface $field_storage
   *   The field definition.
   *
   * @return array
   *   The default views data for the field.
   */
  public function defaultFieldImplementation(FieldStorageConfigInterface $field_storage): array {
    $data = [];

    // Check the field type is available.
    if (!$this->fieldTypePluginManager->hasDefinition($field_storage->getType())) {
      return $data;
    }
    // Check the field storage has fields.
    if (!$field_storage->getBundles()) {
      return $data;
    }

    // Ignore custom storage too.
    if ($field_storage->hasCustomStorage()) {
      return $data;
    }

    // Check whether the entity type storage is supported.
    $storage = $this->getSqlStorageForField($field_storage);
    if (!$storage) {
      return $data;
    }

    $field_name = $field_storage->getName();
    $field_columns = $field_storage->getColumns();

    // Grab information about the entity type tables.
    // We need to join to both the base table and the data table, if available.
    $entity_type_id = $field_storage->getTargetEntityTypeId();
    $entity_type = $this->entityTypeManager->getDefinition($entity_type_id);
    if (!$base_table = $entity_type->getBaseTable()) {
      // We cannot do anything if for some reason there is no base table.
      return $data;
    }
    $entity_tables = [$base_table => $entity_type_id];
    // Some entities may not have a data table.
    $data_table = $entity_type->getDataTable();
    if ($data_table) {
      $entity_tables[$data_table] = $entity_type_id;
    }
    $entity_revision_table = $entity_type->getRevisionTable();
    $supports_revisions = $entity_type->hasKey('revision') && $entity_revision_table;
    if ($supports_revisions) {
      $entity_tables[$entity_revision_table] = $entity_type_id;
      $entity_revision_data_table = $entity_type->getRevisionDataTable();
      if ($entity_revision_data_table) {
        $entity_tables[$entity_revision_data_table] = $entity_type_id;
      }
    }

    // Description of the field tables.
    // @todo Generalize this code to make it work with any table layout. See
    //   https://www.drupal.org/node/2079019.
    $table_mapping = $storage->getTableMapping();
    $field_tables = [
      EntityStorageInterface::FIELD_LOAD_CURRENT => [
        'table' => $table_mapping->getDedicatedDataTableName($field_storage),
        'alias' => "{$entity_type_id}__{$field_name}",
      ],
    ];
    if ($supports_revisions) {
      $field_tables[EntityStorageInterface::FIELD_LOAD_REVISION] = [
        'table' => $table_mapping->getDedicatedRevisionTableName($field_storage),
        'alias' => "{$entity_type_id}_revision__{$field_name}",
      ];
    }

    // Determine if the fields are translatable.
    $bundles_names = $field_storage->getBundles();
    $translation_join_type = FALSE;
    $fields = [];
    $translatable_configs = [];
    $untranslatable_configs = [];
    $untranslatable_config_bundles = [];

    foreach ($bundles_names as $bundle) {
      $fields[$bundle] = FieldConfig::loadByName($entity_type->id(), $bundle, $field_name);
    }
    foreach ($fields as $bundle => $config_entity) {
      if (!empty($config_entity)) {
        if ($config_entity->isTranslatable()) {
          $translatable_configs[$bundle] = $config_entity;
        }
        else {
          $untranslatable_configs[$bundle] = $config_entity;
        }
      }
      else {
        // https://www.drupal.org/node/2451657#comment-11462881
        \Drupal::logger('views')->error(
          'A non-existent config entity name returned by FieldStorageConfigInterface::getBundles(): entity type: %entity_type, bundle: %bundle, field name: %field',
          [
            '%entity_type' => $entity_type->id(),
            '%bundle' => $bundle,
            '%field' => $field_name,
          ]
        );
      }
    }

    // If the field is translatable on all the bundles, there will be a join on
    // the langcode.
    if (!empty($translatable_configs) && empty($untranslatable_configs)) {
      $translation_join_type = 'language';
    }
    // If the field is translatable only on certain bundles, there will be a
    // join on langcode OR bundle name.
    elseif (!empty($translatable_configs) && !empty($untranslatable_configs)) {
      foreach ($untranslatable_configs as $config) {
        $untranslatable_config_bundles[] = $config->getTargetBundle();
      }
      $translation_join_type = 'language_bundle';
    }

    // Build the relationships between the field table and the entity tables.
    $table_alias = $field_tables[EntityStorageInterface::FIELD_LOAD_CURRENT]['alias'];
    if ($data_table) {
      // Tell Views how to join to the base table, via the data table.
      $data[$table_alias]['table']['join'][$data_table] = [
        'table' => $table_mapping->getDedicatedDataTableName($field_storage),
        'left_field' => $entity_type->getKey('id'),
        'field' => 'entity_id',
        'extra' => [
          ['field' => 'deleted', 'value' => 0, 'numeric' => TRUE],
        ],
      ];
    }
    else {
      // If there is no data table, just join directly.
      $data[$table_alias]['table']['join'][$base_table] = [
        'table' => $table_mapping->getDedicatedDataTableName($field_storage),
        'left_field' => $entity_type->getKey('id'),
        'field' => 'entity_id',
        'extra' => [
          ['field' => 'deleted', 'value' => 0, 'numeric' => TRUE],
        ],
      ];
    }

    if ($data_table) {
      if ($translation_join_type === 'language_bundle') {
        $data[$table_alias]['table']['join'][$data_table]['join_id'] = 'field_or_language_join';
        $data[$table_alias]['table']['join'][$data_table]['extra'][] = [
          'left_field' => 'langcode',
          'field' => 'langcode',
        ];
        $data[$table_alias]['table']['join'][$data_table]['extra'][] = [
          'field' => 'bundle',
          'value' => $untranslatable_config_bundles,
        ];
      }
      elseif ($translation_join_type === 'language') {
        $data[$table_alias]['table']['join'][$data_table]['extra'][] = [
          'left_field' => 'langcode',
          'field' => 'langcode',
        ];
      }
    }

    if ($supports_revisions) {
      $table_alias = $field_tables[EntityStorageInterface::FIELD_LOAD_REVISION]['alias'];
      if ($entity_revision_data_table) {
        // Tell Views how to join to the revision table, via the data table.
        $data[$table_alias]['table']['join'][$entity_revision_data_table] = [
          'table' => $table_mapping->getDedicatedRevisionTableName($field_storage),
          'left_field' => $entity_type->getKey('revision'),
          'field' => 'revision_id',
          'extra' => [
            ['field' => 'deleted', 'value' => 0, 'numeric' => TRUE],
          ],
        ];
      }
      else {
        // If there is no data table, just join directly.
        $data[$table_alias]['table']['join'][$entity_revision_table] = [
          'table' => $table_mapping->getDedicatedRevisionTableName($field_storage),
          'left_field' => $entity_type->getKey('revision'),
          'field' => 'revision_id',
          'extra' => [
            ['field' => 'deleted', 'value' => 0, 'numeric' => TRUE],
          ],
        ];
      }
      if ($translation_join_type === 'language_bundle') {
        $data[$table_alias]['table']['join'][$entity_revision_data_table]['join_id'] = 'field_or_language_join';
        $data[$table_alias]['table']['join'][$entity_revision_data_table]['extra'][] = [
          'left_field' => 'langcode',
          'field' => 'langcode',
        ];
        $data[$table_alias]['table']['join'][$entity_revision_data_table]['extra'][] = [
          'value' => $untranslatable_config_bundles,
          'field' => 'bundle',
        ];
      }
      elseif ($translation_join_type === 'language' && $entity_revision_data_table) {
        $data[$table_alias]['table']['join'][$entity_revision_data_table]['extra'][] = [
          'left_field' => 'langcode',
          'field' => 'langcode',
        ];
      }
    }

    $group_name = $entity_type->getLabel();
    // Get the list of bundles the field appears in.
    $bundles_names = $field_storage->getBundles();
    // Build the list of additional fields to add to queries.
    $add_fields = ['delta', 'langcode', 'bundle'];
    foreach (array_keys($field_columns) as $column) {
      $add_fields[] = $table_mapping->getFieldColumnName($field_storage, $column);
    }
    // Determine the label to use for the field. We don't have a label available
    // at the field level, so we just go through all fields and take the one
    // which is used the most frequently.
    [$label, $all_labels] = $this->entityFieldManager->getFieldLabels($entity_type_id, $field_name);

    // Expose data for the field as a whole.
    foreach ($field_tables as $type => $table_info) {
      $table = $table_info['table'];
      $table_alias = $table_info['alias'];

      if ($type == EntityStorageInterface::FIELD_LOAD_CURRENT) {
        $group = $group_name;
        $field_alias = $field_name;
      }
      else {
        $group = $this->t('@group (historical data)', ['@group' => $group_name]);
        $field_alias = $field_name . '__revision_id';
      }

      $data[$table_alias][$field_alias] = [
        'group' => $group,
        'title' => $label,
        'title short' => $label,
        'help' => $this->t('Appears in: @bundles.', ['@bundles' => implode(', ', $bundles_names)]),
      ];

      // Go through and create a list of aliases for all possible combinations
      // of entity type + name.
      $aliases = [];
      $also_known = [];
      foreach ($all_labels as $label_name => $true) {
        if ($type == EntityStorageInterface::FIELD_LOAD_CURRENT) {
          if ($label != $label_name) {
            $aliases[] = [
              'base' => $base_table,
              'group' => $group_name,
              'title' => $label_name,
              'help' => $this->t('This is an alias of @group: @field.', ['@group' => $group_name, '@field' => $label]),
            ];
            $also_known[] = $this->t('@group: @field', ['@group' => $group_name, '@field' => $label_name]);
          }
        }
        elseif ($supports_revisions && $label != $label_name) {
          $aliases[] = [
            'base' => $table,
            'group' => $this->t('@group (historical data)', ['@group' => $group_name]),
            'title' => $label_name,
            'help' => $this->t('This is an alias of @group: @field.', ['@group' => $group_name, '@field' => $label]),
          ];
          $also_known[] = $this->t('@group (historical data): @field', ['@group' => $group_name, '@field' => $label_name]);
        }
      }
      if ($aliases) {
        $data[$table_alias][$field_alias]['aliases'] = $aliases;
        // The $also_known variable contains markup that is HTML escaped and
        // that loses safeness when imploded. The help text is used in
        // #description and therefore XSS admin filtered by default. Escaped
        // HTML is not altered by XSS filtering, therefore it is safe to just
        // concatenate the strings. Afterwards we mark the entire string as
        // safe, so it won't be escaped, no matter where it is used.
        // Considering the dual use of this help data (both as metadata and as
        // help text), other patterns such as use of #markup would not be
        // correct here.
        $data[$table_alias][$field_alias]['help'] = Markup::create($data[$table_alias][$field_alias]['help'] . ' ' . $this->t('Also known as:') . ' ' . implode(', ', $also_known));
      }

      $keys = array_keys($field_columns);
      $real_field = reset($keys);
      $data[$table_alias][$field_alias]['field'] = [
        'table' => $table,
        'id' => 'field',
        'field_name' => $field_name,
        'entity_type' => $entity_type_id,
        // Provide a real field for group by.
        'real field' => $field_name . '_' . $real_field,
        'additional fields' => $add_fields,
        // Default the element type to div, let the UI change it if necessary.
        'element type' => 'div',
        'is revision' => $type == EntityStorageInterface::FIELD_LOAD_REVISION,
      ];
    }

    // Expose data for each field property individually.
    foreach ($field_columns as $column => $attributes) {
      $allow_sort = TRUE;

      // Identify likely filters and arguments for each column based on field
      // type.
      switch ($attributes['type']) {
        case 'int':
        case 'mediumint':
        case 'tinyint':
        case 'bigint':
        case 'serial':
        case 'numeric':
        case 'float':
          $filter = 'numeric';
          $argument = 'numeric';
          $sort = 'standard';
          if ($field_storage->getType() == 'boolean') {
            $filter = 'boolean';
          }
          break;

        case 'blob':
          // It does not make sense to sort by blob.
          $allow_sort = FALSE;
        default:
          $filter = 'string';
          $argument = 'string';
          $sort = 'standard';
          break;
      }

      if (count($field_columns) == 1 || $column == 'value') {
        $title = $this->t('@label (@name)', ['@label' => $label, '@name' => $field_name]);
        $title_short = $label;
      }
      else {
        $title = $this->t('@label (@name:@column)', ['@label' => $label, '@name' => $field_name, '@column' => $column]);
        $title_short = $this->t('@label:@column', ['@label' => $label, '@column' => $column]);
      }

      // Expose data for the property.
      foreach ($field_tables as $type => $table_info) {
        $table = $table_info['table'];
        $table_alias = $table_info['alias'];

        if ($type == EntityStorageInterface::FIELD_LOAD_CURRENT) {
          $group = $group_name;
        }
        else {
          $group = $this->t('@group (historical data)', ['@group' => $group_name]);
        }
        $column_real_name = $table_mapping->getFieldColumnName($field_storage, $column);

        // Load all the fields from the table by default.
        $additional_fields = $table_mapping->getAllColumns($table);

        $data[$table_alias][$column_real_name] = [
          'group' => $group,
          'title' => $title,
          'title short' => $title_short,
          'help' => $this->t('Appears in: @bundles.', ['@bundles' => implode(', ', $bundles_names)]),
        ];

        // Go through and create a list of aliases for all possible combinations
        // of entity type + name.
        $aliases = [];
        $also_known = [];
        foreach ($all_labels as $label_name => $true) {
          if ($label != $label_name) {
            if (count($field_columns) == 1 || $column == 'value') {
              $alias_title = $this->t('@label (@name)', ['@label' => $label_name, '@name' => $field_name]);
            }
            else {
              $alias_title = $this->t('@label (@name:@column)', ['@label' => $label_name, '@name' => $field_name, '@column' => $column]);
            }
            $aliases[] = [
              'group' => $group_name,
              'title' => $alias_title,
              'help' => $this->t('This is an alias of @group: @field.', ['@group' => $group_name, '@field' => $title]),
            ];
            $also_known[] = $this->t('@group: @field', ['@group' => $group_name, '@field' => $title]);
          }
        }
        if ($aliases) {
          $data[$table_alias][$column_real_name]['aliases'] = $aliases;
          // The $also_known variable contains markup that is HTML escaped and
          // that loses safeness when imploded. The help text is used in
          // #description and therefore XSS admin filtered by default. Escaped
          // HTML is not altered by XSS filtering, therefore it is safe to just
          // concatenate the strings. Afterwards we mark the entire string as
          // safe, so it won't be escaped, no matter where it is used.
          // Considering the dual use of this help data (both as metadata and as
          // help text), other patterns such as use of #markup would not be
          // correct here.
          $data[$table_alias][$column_real_name]['help'] = Markup::create($data[$table_alias][$column_real_name]['help'] . ' ' . $this->t('Also known as:') . ' ' . implode(', ', $also_known));
        }

        $data[$table_alias][$column_real_name]['argument'] = [
          'field' => $column_real_name,
          'table' => $table,
          'id' => $argument,
          'additional fields' => $additional_fields,
          'field_name' => $field_name,
          'entity_type' => $entity_type_id,
          'empty field name' => $this->t('- No value -'),
        ];
        $data[$table_alias][$column_real_name]['filter'] = [
          'field' => $column_real_name,
          'table' => $table,
          'id' => $filter,
          'additional fields' => $additional_fields,
          'field_name' => $field_name,
          'entity_type' => $entity_type_id,
          'allow empty' => TRUE,
        ];
        if (!empty($allow_sort)) {
          $data[$table_alias][$column_real_name]['sort'] = [
            'field' => $column_real_name,
            'table' => $table,
            'id' => $sort,
            'additional fields' => $additional_fields,
            'field_name' => $field_name,
            'entity_type' => $entity_type_id,
          ];
        }

        // Set click sortable if there is a field definition.
        if (isset($data[$table_alias][$field_name]['field'])) {
          $data[$table_alias][$field_name]['field']['click sortable'] = $allow_sort;
        }

        // Expose additional delta column for multiple value fields.
        if ($field_storage->isMultiple()) {
          $title_delta = $this->t('@label (@name:delta)', ['@label' => $label, '@name' => $field_name]);
          $title_short_delta = $this->t('@label:delta', ['@label' => $label]);

          $data[$table_alias]['delta'] = [
            'group' => $group,
            'title' => $title_delta,
            'title short' => $title_short_delta,
            'help' => $this->t('Delta - Appears in: @bundles.', ['@bundles' => implode(', ', $bundles_names)]),
          ];
          $data[$table_alias]['delta']['field'] = [
            'id' => 'numeric',
          ];
          $data[$table_alias]['delta']['argument'] = [
            'field' => 'delta',
            'table' => $table,
            'id' => 'numeric',
            'additional fields' => $additional_fields,
            'empty field name' => $this->t('- No value -'),
            'field_name' => $field_name,
            'entity_type' => $entity_type_id,
          ];
          $data[$table_alias]['delta']['filter'] = [
            'field' => 'delta',
            'table' => $table,
            'id' => 'numeric',
            'additional fields' => $additional_fields,
            'field_name' => $field_name,
            'entity_type' => $entity_type_id,
            'allow empty' => TRUE,
          ];
          $data[$table_alias]['delta']['sort'] = [
            'field' => 'delta',
            'table' => $table,
            'id' => 'standard',
            'additional fields' => $additional_fields,
            'field_name' => $field_name,
            'entity_type' => $entity_type_id,
          ];
        }
      }
    }

    return $data;
  }

  /**
   * Determines whether the entity type the field appears in is SQL based.
   *
   * @param \Drupal\field\FieldStorageConfigInterface $field_storage
   *   The field storage definition.
   *
   * @return \Drupal\Core\Entity\Sql\SqlContentEntityStorage|false
   *   Returns the entity type storage if supported and FALSE otherwise.
   */
  public function getSqlStorageForField(FieldStorageConfigInterface $field_storage): SqlContentEntityStorage|bool {
    $result = FALSE;
    if ($this->entityTypeManager->hasDefinition($field_storage->getTargetEntityTypeId())) {
      $storage = $this->entityTypeManager->getStorage($field_storage->getTargetEntityTypeId());
      $result = $storage instanceof SqlContentEntityStorage ? $storage : FALSE;
    }
    return $result;
  }

}
