<?php
/**
 * REST endpoints for the settings screen.
 *
 * These exist so the screen never has to reload: saving and the batched comment cleanup both
 * happen in place. The form still posts normally when JavaScript is unavailable — these routes
 * are an enhancement, not the only way in.
 *
 * Local routes only. The plugin makes no outbound requests of any kind.
 *
 * @package Adminkeep
 */

namespace Adminkeep\Admin;

use Adminkeep\FeatureRegistry;
use Adminkeep\Service\CommentPurger;
use Adminkeep\Settings;

defined( 'ABSPATH' ) || exit;

/**
 * Registers and handles the plugin's admin-only REST routes.
 */
class RestController {

	/**
	 * Route namespace.
	 */
	const NAMESPACE_V1 = 'adminkeep/v1';

	/**
	 * Feature registry.
	 *
	 * @var FeatureRegistry
	 */
	private $registry;

	/**
	 * Settings page, reused for its sanitising.
	 *
	 * @var SettingsPage
	 */
	private $page;

	/**
	 * Constructor.
	 *
	 * @param FeatureRegistry $registry Feature registry.
	 * @param SettingsPage    $page     Settings page.
	 */
	public function __construct( FeatureRegistry $registry, SettingsPage $page ) {
		$this->registry = $registry;
		$this->page     = $page;
	}

	/**
	 * Register hooks.
	 *
	 * @return void
	 */
	public function boot() {
		add_action( 'rest_api_init', array( $this, 'register_routes' ) );
	}

	/**
	 * Register the routes.
	 *
	 * @return void
	 */
	public function register_routes() {
		register_rest_route(
			self::NAMESPACE_V1,
			'/settings',
			array(
				'methods'             => 'POST',
				'callback'            => array( $this, 'save_settings' ),
				'permission_callback' => array( $this, 'can_manage' ),
			)
		);

		register_rest_route(
			self::NAMESPACE_V1,
			'/comments/purge',
			array(
				'methods'             => 'POST',
				'callback'            => array( $this, 'purge_comments' ),
				'permission_callback' => array( $this, 'can_moderate' ),
				'args'                => array(
					'include_approved' => array(
						'type'    => 'boolean',
						'default' => false,
					),
					'include_woo'      => array(
						'type'    => 'boolean',
						'default' => false,
					),
				),
			)
		);
	}

	/**
	 * Whether the current user may change settings.
	 *
	 * @return bool
	 */
	public function can_manage() {
		return current_user_can( SettingsPage::CAPABILITY );
	}

	/**
	 * Whether the current user may delete comments.
	 *
	 * @return bool
	 */
	public function can_moderate() {
		return current_user_can( SettingsPage::CAPABILITY ) && current_user_can( 'moderate_comments' );
	}

	/**
	 * Save settings.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response
	 */
	public function save_settings( $request ) {
		$posted = $request->get_param( 'adminkeep' );
		$posted = is_array( $posted ) ? $posted : array();

		$this->page->save_values( $posted );

		return rest_ensure_response(
			array(
				'saved' => true,
				'state' => $this->state(),
			)
		);
	}

	/**
	 * Delete one batch of comments.
	 *
	 * Returns what remains so the caller can drive a progress bar and come back for more. The
	 * batching lives here rather than in the client so a closed tab cannot leave a half-run in a
	 * strange state — each request is complete on its own.
	 *
	 * @param \WP_REST_Request $request Request.
	 * @return \WP_REST_Response
	 */
	public function purge_comments( $request ) {
		$include_approved = (bool) $request->get_param( 'include_approved' );
		$include_woo      = (bool) $request->get_param( 'include_woo' );

		$deleted   = CommentPurger::delete_batch( CommentPurger::BATCH_SIZE, $include_approved, $include_woo );
		$remaining = CommentPurger::count( $include_approved, $include_woo );

		return rest_ensure_response(
			array(
				'deleted'   => $deleted,
				'remaining' => $remaining,
				'done'      => 0 === $remaining || 0 === $deleted,
				'state'     => $this->state(),
			)
		);
	}

	/**
	 * The bits of state the screen re-renders after an action.
	 *
	 * @return array
	 */
	private function state() {
		$features = array();

		foreach ( $this->registry->all() as $id => $feature ) {
			$features[ $id ] = array(
				'enabled' => Settings::is_enabled( $id ),
				'state'   => $this->page->state_label( $feature ),
				'link'    => $this->page->panel_link_for( $feature ),
				'notice'  => $this->page->panel_notice_for( $feature ),
			);
		}

		return array(
			'features' => $features,
			'comments' => CommentPurger::counts(),
		);
	}
}