<?php
namespace Activitypub\Integration;

use DateTime;
use Activitypub\Webfinger as Webfinger_Util;
use Activitypub\Http;
use Activitypub\Collection\Users;
use Activitypub\Collection\Followers;
use Activitypub\Integration\Nodeinfo;
use Enable_Mastodon_Apps\Mastodon_API;
use Enable_Mastodon_Apps\Entity\Account;
use Enable_Mastodon_Apps\Entity\Status;
use Enable_Mastodon_Apps\Entity\Media_Attachment;

use function Activitypub\get_remote_metadata_by_actor;

/**
 * Class Enable_Mastodon_Apps
 *
 * This class is used to enable Mastodon Apps to work with ActivityPub
 *
 * @see https://github.com/akirk/enable-mastodon-apps
 */
class Enable_Mastodon_Apps {
	/**
	 * Initialize the class, registering WordPress hooks
	 */
	public static function init() {
		\add_filter( 'mastodon_api_account_followers', array( self::class, 'api_account_followers' ), 10, 2 );
		\add_filter( 'mastodon_api_account', array( self::class, 'api_account_add_followers' ), 20, 2 );
		\add_filter( 'mastodon_api_account', array( self::class, 'api_account_external' ), 10, 2 );
		\add_filter( 'mastodon_api_search', array( self::class, 'api_search' ), 40, 2 );
		\add_filter( 'mastodon_api_get_posts_query_args', array( self::class, 'api_get_posts_query_args' ) );
		\add_filter( 'mastodon_api_statuses', array( self::class, 'api_statuses_external' ), 10, 2 );
	}

	/**
	 * Add followers to Mastodon API
	 *
	 * @param array           $followers An array of followers
	 * @param string          $user_id   The user id
	 * @param WP_REST_Request $request   The request object
	 *
	 * @return array The filtered followers
	 */
	public static function api_account_followers( $followers, $user_id ) {
		$activitypub_followers = Followers::get_followers( $user_id, 40 );
		$mastodon_followers    = array_map(
			function ( $item ) {
				$acct = Webfinger_Util::uri_to_acct( $item->get_id() );

				if ( $acct && ! is_wp_error( $acct ) ) {
					$acct = \str_replace( 'acct:', '', $acct );
				} else {
					$acct = $item->get_url();
				}

				$account = new Account();
				$account->id = \strval( $item->get__id() );
				$account->username = $item->get_preferred_username();
				$account->acct = $acct;
				$account->display_name = $item->get_name();
				$account->url = $item->get_url();
				$account->uri = $item->get_id();
				$account->avatar = $item->get_icon_url();
				$account->avatar_static = $item->get_icon_url();
				$account->created_at = new DateTime( $item->get_published() );
				$account->last_status_at = new DateTime( $item->get_published() );
				$account->note = $item->get_summary();
				$account->header = $item->get_image_url();
				$account->header_static = $item->get_image_url();
				$account->followers_count = 0;
				$account->following_count = 0;
				$account->statuses_count = 0;
				$account->bot = false;
				$account->locked = false;
				$account->group = false;
				$account->discoversable = false;
				$account->indexable = false;
				$account->hide_collections = false;
				$account->noindex = false;
				$account->fields = array();
				$account->emojis = array();
				$account->roles = array();

				return $account;
			},
			$activitypub_followers
		);

		$followers = array_merge( $mastodon_followers, $followers );

		return $followers;
	}

	/**
	 * Add followers count to Mastodon API
	 *
	 * @param Enable_Mastodon_Apps\Entity\Account $account The account
	 * @param int                                 $user_id The user id
	 *
	 * @return Enable_Mastodon_Apps\Entity\Account The filtered Account
	 */
	public static function api_account_add_followers( $account, $user_id ) {
		if ( ! $account instanceof Account || ! is_numeric( $user_id ) ) {
			return $account;
		}

		$user = Users::get_by_id( $user_id );

		if ( ! $user || is_wp_error( $user ) ) {
			return $account;
		}

		$header = $user->get_image();
		if ( $header ) {
			$account->header = $header['url'];
			$account->header_static = $header['url'];
		}

		foreach ( $user->get_attachment() as $attachment ) {
			if ( 'PropertyValue' === $attachment['type'] ) {
				$account->fields[] = array(
					'name' => $attachment['name'],
					'value' => $attachment['value'],
				);
			}
		}

		$account->acct = $user->get_preferred_username();
		$account->note = $user->get_summary();

		$account->followers_count = Followers::count_followers( $user_id );
		return $account;
	}

	/**
	 * Resolve external accounts for Mastodon API
	 *
	 * @param Enable_Mastodon_Apps\Entity\Account $user_data The user data
	 * @param string                              $user_id   The user id
	 *
	 * @return Enable_Mastodon_Apps\Entity\Account The filtered Account
	 */
	public static function api_account_external( $user_data, $user_id ) {
		if ( $user_data || is_numeric( $user_id ) ) {
			// Only augment.
			return $user_data;
		}

		$uri = Webfinger_Util::resolve( $user_id );

		if ( ! $uri || is_wp_error( $uri ) ) {
			return $user_data;
		}

		$account = self::get_account_for_actor( $uri );
		if ( $account ) {
			return $account;
		}

		return $user_data;
	}

	private static function get_account_for_actor( $uri ) {
		if ( ! is_string( $uri ) ) {
			return null;
		}
		$data = get_remote_metadata_by_actor( $uri );

		if ( ! $data || is_wp_error( $data ) ) {
			return null;
		}
		$account = new Account();

		$acct = Webfinger_Util::uri_to_acct( $uri );
		if ( str_starts_with( $acct, 'acct:' ) ) {
			$acct = substr( $acct, 5 );
		}

		$account->id             = $acct;
		$account->username       = $acct;
		$account->acct           = $acct;
		$account->display_name   = $data['name'];
		$account->url            = $uri;

		if ( ! empty( $data['summary'] ) ) {
			$account->note = $data['summary'];
		}

		if (
			isset( $data['icon']['type'] ) &&
			isset( $data['icon']['url'] ) &&
			'Image' === $data['icon']['type']
		) {
			$account->avatar        = $data['icon']['url'];
			$account->avatar_static = $data['icon']['url'];
		}

		if ( isset( $data['image'] ) ) {
			$account->header        = $data['image']['url'];
			$account->header_static = $data['image']['url'];
		}

		$account->created_at = new DateTime( $data['published'] );

		return $account;
	}

	public static function api_search( $search_data, $request ) {
		$user_id = \get_current_user_id();
		if ( ! $user_id ) {
			return $search_data;
		}

		$q = $request->get_param( 'q' );
		if ( ! $q ) {
			return $search_data;
		}
		$q = sanitize_text_field( wp_unslash( $q ) );

		$followers = Followers::get_followers( $user_id, 40, null, array( 's' => $q ) );
		if ( ! $followers ) {
			return $search_data;
		}

		foreach ( $followers as $follower ) {
			$acct = Webfinger_Util::uri_to_acct( $follower->get_id() );

			if ( $acct && ! is_wp_error( $acct ) ) {
				$acct = \str_replace( 'acct:', '', $acct );
			} else {
				$acct = $follower->get_url();
			}

			$account = new Account();
			$account->id = \strval( $follower->get__id() );
			$account->username = $follower->get_preferred_username();
			$account->acct = $acct;
			$account->display_name = $follower->get_name();
			$account->url = $follower->get_url();
			$account->uri = $follower->get_id();
			$account->avatar = $follower->get_icon_url();
			$account->avatar_static = $follower->get_icon_url();
			$account->created_at = new DateTime( $follower->get_published() );
			$account->last_status_at = new DateTime( $follower->get_published() );
			$account->note = $follower->get_summary();
			$account->header = $follower->get_image_url();
			$account->header_static = $follower->get_image_url();

			$search_data['accounts'][] = $account;
		}

		return $search_data;
	}

	public function api_get_posts_query_args( $args ) {
		if ( isset( $args['author'] ) && is_string( $args['author'] ) ) {
			$uri = Webfinger_Util::resolve( $args['author'] );
			if ( $uri && ! is_wp_error( $uri ) ) {
				$args['activitypub'] = $uri;
				unset( $args['author'] );
			}
		}

		return $args;
	}

	public static function api_statuses_external( $statuses, $args ) {
		if ( ! isset( $args['activitypub'] ) ) {
			return $statuses;
		}

		$data = get_remote_metadata_by_actor( $args['activitypub'] );

		if ( ! $data || is_wp_error( $data ) || ! isset( $data['outbox'] ) ) {
			return $statuses;
		}

		$response = Http::get( $data['outbox'], true );
		if ( is_wp_error( $response ) || wp_remote_retrieve_response_code( $response ) !== 200 ) {
			return $statuses;
		}

		$outbox = json_decode( wp_remote_retrieve_body( $response ), true );
		if ( ! $outbox || is_wp_error( $outbox ) || ! isset( $outbox['first'] ) ) {
			return $statuses;
		}

		$account = self::get_account_for_actor( $args['activitypub'] );
		if ( ! $account ) {
			return $statuses;
		}

		$response = Http::get( $outbox['first'], true );
		if ( is_wp_error( $response ) || wp_remote_retrieve_response_code( $response ) !== 200 ) {
			return $statuses;
		}
		$posts = json_decode( wp_remote_retrieve_body( $response ), true );

		$activitypub_statuses = array_map(
			function ( $item ) use ( $account ) {
				$object = $item['object'];
				if ( ! isset( $object['type'] ) || 'Note' !== $object['type'] ) {
					return null;
				}

				$status = new Status();
				$status->id         = Mastodon_API::remap_url( $object['id'] );
				$status->created_at = new DateTime( $object['published'] );
				$status->content    = $object['content'];
				$status->account    = $account;

				if ( ! empty( $object['inReplyTo'] ) ) {
					$status->in_reply_to_id = $object['inReplyTo'];
				}

				if ( ! empty( $object['visibility'] ) ) {
					$status->visibility = $object['visibility'];
				}

				$status->uri = $object['url'];

				if ( ! empty( $object['attachment'] ) ) {
					$status->media_attachments = array_map(
						function ( $attachment ) {
							$default_attachment = array(
								'url' => null,
								'mediaType' => null,
								'name' => null,
								'width' => 0,
								'height' => 0,
								'blurhash' => null,
							);

							$attachment = array_merge( $default_attachment, $attachment );

							$media_attachment = new Media_Attachment();
							$media_attachment->id = Mastodon_API::remap_url( $attachment['url'], $attachment );
							$media_attachment->type = strtok( $attachment['mediaType'], '/' );
							$media_attachment->url = $attachment['url'];
							$media_attachment->preview_url = $attachment['url'];
							$media_attachment->description = $attachment['name'];
							$media_attachment->blurhash = $attachment['blurhash'];
							$media_attachment->meta = array(
								'original' => array(
									'width'  => $attachment['width'],
									'height' => $attachment['height'],
									'size'   => $attachment['width'] . 'x' . $attachment['height'],
									'aspect' => $attachment['width'] / $attachment['height'],
								),
							);
							return $media_attachment;
						},
						$object['attachment']
					);
				}

				return $status;
			},
			$posts['orderedItems']
		);

		return $activitypub_statuses;
	}
}