<?php

declare(strict_types=1);

namespace Drupal\canvas\Entity;

use Drupal\canvas\AutoSave\AutoSaveManager;
use Drupal\canvas\CanvasUriDefinitions;
use Drupal\canvas\ComponentSource\ComponentSourceManager;
use Drupal\canvas\Plugin\Canvas\ComponentSource\JsComponent;
use Drupal\canvas\PropExpressions\StructuredData\EvaluationResult;
use Drupal\canvas\Resource\CanvasResourceLink;
use Drupal\canvas\Resource\CanvasResourceLinkCollection;
use Drupal\Core\Access\AccessResult;
use Drupal\Core\Cache\Cache;
use Drupal\Core\Cache\RefinableCacheableDependencyInterface;
use Drupal\Core\Config\Entity\ConfigEntityBase;
use Drupal\Core\Config\Entity\ConfigEntityTypeInterface;
use Drupal\Core\Entity\Attribute\ConfigEntityType;
use Drupal\Core\Entity\EntityStorageInterface;
use Drupal\Core\Entity\Query\QueryInterface;
use Drupal\Core\File\FileUrlGeneratorInterface;
use Drupal\Core\StringTranslation\TranslatableMarkup;
use Drupal\Core\Url;
use Drupal\canvas\AutoSaveEntity;
use Drupal\canvas\ClientSideRepresentation;
use Drupal\canvas\EntityHandlers\JavascriptComponentStorage;
use Drupal\canvas\EntityHandlers\VisibleWhenDisabledCanvasConfigEntityAccessControlHandler;
use Drupal\canvas\Exception\ConstraintViolationException;
use Symfony\Component\Validator\ConstraintViolation;

#[ConfigEntityType(
  id: self::ENTITY_TYPE_ID,
  label: new TranslatableMarkup('Code component'),
  label_singular: new TranslatableMarkup('code component'),
  label_plural: new TranslatableMarkup('code components'),
  label_collection: new TranslatableMarkup('Code components'),
  admin_permission: self::ADMIN_PERMISSION,
  handlers: [
    'storage' => JavascriptComponentStorage::class,
    'access' => VisibleWhenDisabledCanvasConfigEntityAccessControlHandler::class,
  ],
  entity_keys: [
    'id' => 'machineName',
    'label' => 'name',
    'status' => 'status',
  ],
  config_export: [
    'machineName',
    'name',
    'props',
    'required',
    'slots',
    'js',
    'css',
    'dataDependencies',
  ],
  constraints: [
    'JsComponentHasValidAndSupportedSdcMetadata' => NULL,
  ],
)]
final class JavaScriptComponent extends ConfigEntityBase implements CanvasAssetInterface, FolderItemInterface {

  use CanvasAssetLibraryTrait;
  use ConfigUpdaterAwareEntityTrait;

  public const string ENTITY_TYPE_ID = 'js_component';
  public const string ADMIN_PERMISSION = 'administer code components';
  private const string ASSETS_DIRECTORY = 'assets://astro-island/';

  /**
   * The component machine name.
   */
  protected string $machineName;

  /**
   * The human-readable label of the component.
   */
  protected ?string $name;

  /**
   * The props of the component.
   */
  protected ?array $props = [];

  /**
   * The required props of the component.
   *
   * @var string[]
   */
  protected ?array $required = [];

  /**
   * The slots of the component.
   */
  protected ?array $slots = [];

  /**
   * Data dependencies.
   */
  protected ?array $dataDependencies;

  /**
   * Shared instance of the ComponentSource plugin manager, for previews.
   *
   * @see ::buildPreview()
   */
  private static ComponentSourceManager $componentSourceManagerForPreviews;

  /**
   * Shared instance of the AutoSaveManager, for previews.
   *
   * @see ::buildPreview()
   */
  private static AutoSaveManager $autoSaveManagerForPreviews;

  /**
   * {@inheritdoc}
   */
  public function id(): string {
    return $this->machineName;
  }

  private function getEntityOperations(): CanvasResourceLinkCollection {
    $links = new CanvasResourceLinkCollection([]);
    // Link relation type => route name.
    $possible_operations = [
      CanvasUriDefinitions::LINK_REL_DELETE => ['route_name' => 'canvas.api.config.delete', 'op' => 'delete'],
      // @todo Add a URL template using the CanvasUriDefinitions::LINK_REL_USAGE_DETAILS link relation type
    ];
    foreach ($possible_operations as $link_rel => ['route_name' => $route_name, 'op' => $entity_operation]) {
      $access = $this->access(operation: $entity_operation, return_as_object: TRUE);
      assert($access instanceof AccessResult);
      if ($access->isAllowed()) {
        $route_params = [
          'canvas_config_entity_type_id' => self::ENTITY_TYPE_ID,
          'canvas_config_entity' => $this->id(),
        ];
        $links = $links->withLink(
          $link_rel,
          new CanvasResourceLink($access, Url::fromRoute($route_name, $route_params), $link_rel)
        );
      }
      else {
        $links->addCacheableDependency($access);
      }
    }
    return $links;
  }

  /**
   * {@inheritdoc}
   *
   * This corresponds to `CodeComponent` in openapi.yml.
   *
   * @see docs/adr/0005-Keep-the-front-end-simple.md
   */
  public function normalizeForClientSide(): ClientSideRepresentation {
    // TRICKY: config entity properties may allow NULL, but only valid, saved
    // config entities are ever normalized: those that have passed validation
    // against config schema.
    assert(is_array($this->js));
    assert(is_array($this->css));
    $linkCollection = $this->getEntityOperations();
    return ClientSideRepresentation::create(
      values: [
        'machineName' => $this->id(),
        'name' => (string) $this->label(),
        'status' => $this->status(),
        'props' => $this->props,
        'required' => $this->required,
        'slots' => $this->slots,
        'sourceCodeJs' => $this->js['original'] ?? '',
        'sourceCodeCss' => $this->css['original'] ?? '',
        'compiledJs' => $this->js['compiled'] ?? '',
        'compiledCss' => $this->css['compiled'] ?? '',
        'dataDependencies' => $this->dataDependencies,
        // @see https://jsonapi.org/format/#document-links
        'links' => $linkCollection->asArray(),
      ],
      preview: $this->buildPreview(),
    )->addCacheableDependency($this)
      ->addCacheableDependency($linkCollection);
  }

  /**
   * Renders a preview of a (saved) code component, regardless of `status`.
   *
   * Reuses the render infrastructure of the JsComponent ComponentSource plugin.
   *
   * @return array
   *   A render array.
   *
   * @see \Drupal\canvas\Plugin\Canvas\ComponentSource\JsComponent::renderComponent()
   */
  private function buildPreview(): array {
    // TRICKY: config entity properties may allow NULL, but only valid, saved
    // config entities are ever normalized: those that have passed validation
    // against config schema.
    assert(is_array($this->props));
    assert(is_array($this->slots));
    assert(is_string($this->uuid));

    // If there's an auto-saved version of this code component, load that
    // instead to generate the preview. JsComponent::renderComponent() *already*
    // does this for the auto-saved JS + CSS; this ensures the auto-saved props
    // and slots are used, too.
    self::$autoSaveManagerForPreviews ??= \Drupal::service(AutoSaveManager::class);
    $autoSavedIfAny = self::$autoSaveManagerForPreviews->getAutoSaveEntity($this)->entity;
    \assert($autoSavedIfAny === NULL || $autoSavedIfAny instanceof JavaScriptComponent);

    // Instantiate a minimally viable JsComponent source plugin instance subset.
    self::$componentSourceManagerForPreviews ??= \Drupal::service(ComponentSourceManager::class);
    $js_component_source = self::$componentSourceManagerForPreviews->createInstance(JsComponent::SOURCE_PLUGIN_ID, [
      'local_source_id' => $this->id(),
      // 💡This is left empty because this code is instantiating the JS
      // ComponentSource plugin to be able to call its `::renderComponent()`
      // method, to provide an accurate preview of the code component, even if
      // it's never been exposed (and hence has no `Component` config entity).
      // IOW: the sole purpose here is to render a preview of a code component,
      // so not specifying the field definitions to generate StaticPropSources
      // is fine.
      'prop_field_definitions' => [],
    ]);
    \assert($js_component_source instanceof JsComponent);

    // Retrieve all props' example values, prefer auto-saved ones.
    $example_inputs = array_filter(array_map(
      // Note that an example is optional!
      // @see `type: canvas.json_schema.prop.*`
      fn (array $prop_definition) : null|bool|int|float|string|\Stringable|array => $prop_definition['examples'][0] ?? NULL,
      $autoSavedIfAny->props ?? $this->props,
    ));

    // TRICKY: unlike \Drupal\canvas\Entity\Component::normalizeForClientSide(),
    // this is not getting wrapped in a render-safe container, because the only
    // failure modes for code components at the server-side rendering stage are:
    // 1. the code component's config entity does not exist. But this is a
    //    method on that config entity type, so that cannot happen.
    // 2. the code props' example values may violate the JSON schema for props:
    //    core's `ComponentValidator` would then trigger an exception … except
    //    that JsComponent::renderComponent() does not perform validation.
    // So, no render-safe container is necessary here: the only crash that can
    // happen is on the client side, or if there's a logic bug.
    $build = $js_component_source->renderComponent(
      inputs: [
        JsComponent::EXPLICIT_INPUT_NAME => array_map(
          fn (bool|int|float|string|\Stringable|array $v) => new EvaluationResult($v),
          $example_inputs,
        ),
      ],
      slot_definitions: $autoSavedIfAny->slots ?? $this->slots,
      componentUuid: $this->uuid,
      isPreview: TRUE,
    );
    return $build;
  }

  /**
   * {@inheritdoc}
   *
   * This corresponds to `CodeComponent` in openapi.yml.
   *
   * @see docs/adr/0005-Keep-the-front-end-simple.md
   */
  public static function createFromClientSide(array $data): static {
    $entity = static::create(['machineName' => $data['machineName']]);
    $entity->updateFromClientSide($data);
    return $entity;
  }

  /**
   * {@inheritdoc}
   *
   * This corresponds to `CodeComponent` in openapi.yml.
   *
   * @see docs/adr/0005-Keep-the-front-end-simple.md
   */
  public function updateFromClientSide(array $data): void {
    foreach (array_intersect_key($data, array_flip([
      'machineName',
      'name',
      'status',
      'required',
      'props',
      'slots',
      'dataDependencies',
    ])) as $key => $value) {
      $this->set($key, $value);
    }

    if (array_key_exists('sourceCodeCss', $data) || array_key_exists('compiledCss', $data)) {
      $this->set('css', [
        'original' => $data['sourceCodeCss'] ?? '',
        'compiled' => $data['compiledCss'] ?? '',
      ]);
    }

    $violation_list = new EntityConstraintViolationList($this);
    if (array_key_exists('sourceCodeJs', $data) || array_key_exists('compiledJs', $data)) {
      if (!array_key_exists('importedJsComponents', $data)) {
        $violation_list->add(new ConstraintViolation(
          "The 'importedJsComponents' field is required when 'sourceCodeJs' or 'compiledJs' is provided",
          "The 'importedJsComponents' field is required when 'sourceCodeJs' or 'compiledJs' is provided",
          [],
          NULL,
          "importedJsComponents",
          NULL
        ));
        throw new ConstraintViolationException($violation_list);
      }
      foreach ($data['importedJsComponents'] as $key => $js_component_name) {
        // Test that the importedJsComponents are valid names.
        if (!preg_match('/^[a-z0-9_-]+$/', $js_component_name)) {
          $violation_list->add(new ConstraintViolation(
            "The 'importedJsComponents' contains an invalid component name.",
            "The 'importedJsComponents' contains an invalid component name.",
            [],
            NULL,
            "importedJsComponents",
            NULL
          ));
        }
      }
      if ($violation_list->count() > 0) {
        throw new ConstraintViolationException($violation_list);
      }
      // The client calculates imported JavaScript components dependencies. This
      // value is never returned to the client as it will always recalculate it
      // based off sourceCodeJs.
      $this->addJavaScriptComponentsDependencies($data['importedJsComponents']);
      $this->set('js', [
        'original' => $data['sourceCodeJs'] ?? '',
        'compiled' => $data['compiledJs'] ?? '',
      ]);
    }
  }

  /**
   * {@inheritdoc}
   */
  public static function refineListQuery(QueryInterface &$query, RefinableCacheableDependencyInterface $cacheability): void {
    // Nothing to do.
  }

  /**
   * Code components are not Twig-defined but still aim to match SDC closely.
   *
   * TRICKY: while `props` and `slots` are already individually validated
   * against the JSON schema, the overall structure must also be valid in a way
   * that the SDC's JSON schema does not actually validate: crucial parts are
   * validated only in PHP!
   *
   * @return array{machineName: string, extension_type: string, id: string, provider: string, name: string, props: array, slots?: array, library: array, path: string, template: string}
   *
   * @see core/assets/schemas/v1/metadata-full.schema.json
   * @see \Drupal\Core\Theme\Component\ComponentValidator::validateDefinition()
   * @see \Drupal\Tests\Core\Theme\Component\ComponentValidatorTest::loadComponentDefinitionFromFs()
   */
  public function toSdcDefinition(): array {
    $definition = [
      'machineName' => (string) $this->id(),
      'extension_type' => 'module',
      'id' => 'canvas:' . $this->id(),
      'provider' => 'canvas',
      'name' => (string) $this->label(),
      'props' => [
        'type' => 'object',
        'properties' => $this->props ?? [],
      ],
      // No equivalents exist nor can be generated; specify hard-coded values
      // that allow this to be considered a valid SDC definition.
      'library' => [],
      'path' => '',
      // This needs to be non empty.
      'template' => 'phony',
    ];
    // Slots are optional. Setting the `slots` key to an empty array is invalid.
    // @see \Drupal\canvas\Plugin\Validation\Constraint\JsComponentHasValidAndSupportedSdcMetadataConstraintValidator
    if ($this->slots) {
      foreach ($this->slots as $slot_name => $slot) {
        // Force empty slots to be an object; ComponentValidator casts non-
        // empty arrays to objects, but empty arrays trigger a false positive
        // validation error: "Array value found, but an object is required".
        // @todo Remove this after https://www.drupal.org/project/drupal/issues/3524163 is fixed in core.
        if ($slot === []) {
          $slot = new \stdClass();
        }
        $definition['slots'][$slot_name] = $slot;
      }
    }
    // Required properties are optional. Setting the `props.required` key to an
    // empty array is invalid.
    // @see \Drupal\canvas\Plugin\Validation\Constraint\JsComponentHasValidAndSupportedSdcMetadataConstraintValidator
    if ($this->required) {
      $definition['props']['required'] = $this->required;
    }
    return $definition;
  }

  /**
   * Sets value for props.
   *
   * @param array<string, array{type: string, format?: string, examples?: string|array<string>, title: string}> $props
   *   Value for Props.
   */
  public function setProps(array $props): self {
    $this->props = $props;
    return $this;
  }

  /**
   * Gets required props.
   *
   * @return array
   *   Required props.
   */
  public function getRequiredProps(): array {
    return $this->required ?? [];
  }

  /**
   * Gets component props.
   *
   * @return array|null
   *   Component props.
   */
  public function getProps(): ?array {
    return $this->props;
  }

  /**
   * {@inheritdoc}
   */
  public function preSave(EntityStorageInterface $storage): void {
    parent::preSave($storage);
    static::getConfigUpdater()->updateJavaScriptComponent($this);
  }

  /**
   * {@inheritdoc}
   */
  public function postSave(EntityStorageInterface $storage, $update = TRUE): void {
    parent::postSave($storage, $update);
    // The files generated in CanvasAssetStorage::doSave() have a
    // content-dependent hash in their name. This has 2 consequences:
    // 1. Cached responses that referred to an older version, continue to work.
    // 2. New responses must use the newly generated files, which requires the
    //    asset library to point to those new files. Hence the library info must
    //    be recalculated.
    // @see \canvas_library_info_build()
    Cache::invalidateTags(['library_info']);
  }

  /**
   * Add the imported Javascript components as enforced dependencies.
   *
   * Enforced dependencies are not reset during dependency calculation.
   *
   * @param array<string> $imported_js_components
   *   The names of the JavaScript components to add as dependencies.
   *
   * @throws \Drupal\canvas\Exception\ConstraintViolationException
   *   Thrown if any of the JavaScript components do not exist.
   *
   * @see \Drupal\Core\Config\Entity\ConfigEntityBase::calculateDependencies
   */
  protected function addJavaScriptComponentsDependencies(array $imported_js_components): void {
    $violation_list = new EntityConstraintViolationList($this);
    foreach ($imported_js_components as $key => $js_component_name) {
      $js_component = JavaScriptComponent::load($js_component_name);
      if (!$js_component) {
        $violation_list->add(new ConstraintViolation(
          "The JavaScript component with the machine name '$js_component_name' does not exist.",
          "The JavaScript component with the machine name '$js_component_name' does not exist.",
          [],
          NULL,
          "importedJsComponents.$key",
          $js_component_name
        ));
      }
    }
    if ($violation_list->count() > 0) {
      throw new ConstraintViolationException($violation_list);
    }
    $imported_js_component_dependency_names = array_values(array_map(
      fn(string $component_name) => $this->getConfigPrefix() . ".$component_name",
      $imported_js_components
    ));
    $this->dependencies['enforced']['config'] ??= [];
    // Remove all the current JavaScript component enforced dependencies.
    $this->dependencies['enforced']['config'] = array_filter(
      $this->dependencies['enforced']['config'],
      fn(string $dependency) => !str_starts_with($dependency, $this->getConfigPrefix())
    );
    $this->dependencies['enforced']['config'] = array_unique(array_merge(
      $this->dependencies['enforced']['config'],
      $imported_js_component_dependency_names
    ));
    if (empty($this->dependencies['enforced']['config'])) {
      unset($this->dependencies['enforced']['config']);
    }
    if (empty($this->dependencies['enforced'])) {
      unset($this->dependencies['enforced']);
    }
  }

  protected function getConfigPrefix(): string {
    $entity_type = $this->getEntityType();
    assert($entity_type instanceof ConfigEntityTypeInterface);
    return $entity_type->getConfigPrefix();
  }

  public function getComponentUrl(FileUrlGeneratorInterface $generator, bool $isPreview): string {
    if (!$isPreview) {
      return $generator->generateString($this->getJsPath());
    }
    return Url::fromRoute('canvas.api.config.auto-save.get.js', [
      'canvas_config_entity_type_id' => self::ENTITY_TYPE_ID,
      'canvas_config_entity' => $this->id(),
    ])->toString();
  }

  /**
   * {@inheritdoc}
   */
  public function getAssetLibrary(bool $isPreview): string {
    // Inside the Canvas UI, always load the draft even if there isn't one. Let
    // the controller logic automatically serve the non-draft assets when a
    // draft disappears. This is necessary to allow for asset library
    // dependencies, and avoids race conditions.
    // @see \Drupal\canvas\Hook\LibraryHooks::libraryInfoBuild()
    // @see \Drupal\canvas\Controller\ApiConfigAutoSaveControllers::getCss()
    // @see \Drupal\canvas\Controller\ApiConfigAutoSaveControllers::getJs()
    return 'canvas/astro_island.' . $this->id() . ($isPreview ? '.draft' : '');
  }

  private static function shouldLoadAssetFromAutoSave(AutoSaveEntity $autoSave, bool $isPreview) : bool {
    return $isPreview && !$autoSave->isEmpty();
  }

  public function getComponentDependencies(AutoSaveEntity $autoSave, bool $isPreview): array {
    $instance = $this;
    if (self::shouldLoadAssetFromAutoSave($autoSave, $isPreview)) {
      \assert($autoSave->entity instanceof self);
      $instance = $autoSave->entity;
    }

    $js_dependencies = \array_filter(
      $instance->getDependencies()['config'] ?? [],
      static fn(string $dependency) => \str_starts_with($dependency, $instance->getConfigPrefix())
    );
    $js_component_ids = array_map(fn($dependency) => mb_substr($dependency, mb_strlen($this->getConfigPrefix()) + 1), $js_dependencies);
    return self::loadMultiple($js_component_ids);
  }

  public function getCacheTags() {
    $cache_tags = parent::getCacheTags();
    if ($dependencies = $this->getDependencies()) {
      $cache_tags = array_merge($cache_tags, array_map(fn($dependency) => "config:$dependency", $dependencies['config'] ?? []));
    }
    return \array_values($cache_tags);
  }

  /**
   * {@inheritdoc}
   *
   * @see \Drupal\canvas\Hook\ComponentSourceHooks::jsSettingsAlter()
   */
  public function getAssetLibraryDependencies(): array {
    return \array_map(static fn (string $dependency): string => \sprintf('canvas/canvasData.%s', $dependency), $this->dataDependencies['drupalSettings'] ?? []);
  }

}
