<?php
declare(strict_types=1);

namespace Unsupervised\Schedular\Auth;

use Unsupervised\Schedular\Uninstaller;
use Unsupervised\Schedular\Val;

/**
 * The site owner's page: whether WordPress administrators automatically receive
 * the studio-admin and/or instructor capabilities, and what deleting the plugin
 * takes with it.
 *
 * Both capability grants default on, preserving the out-of-the-box experience
 * where a single administrator runs the studio and teaches from one account. The
 * settings page is gated on `manage_options` (the core WordPress administrator
 * capability, which the plugin never grants or revokes) so an administrator can
 * always reach it to re-enable a grant — disabling one can never lock them out.
 *
 * The data-removal choice lives here for the same reason: `manage_options` is
 * held by exactly the people who can delete a plugin, so the switch and the act
 * it governs are in the same pair of hands. {@see Uninstaller} explains what the
 * two answers mean.
 */
class AccessSettings {

	public const OPT_GRANT_STUDIO     = 'us_admin_grant_studio';
	public const OPT_GRANT_INSTRUCTOR = 'us_admin_grant_instructor';

	/**
	 * Whether WordPress administrators implicitly hold the studio-admin
	 * capabilities (offerings, policies, billing, reports, …).
	 */
	public function adminsAreStudioAdmins(): bool {
		return $this->flag( self::OPT_GRANT_STUDIO );
	}

	/**
	 * Whether WordPress administrators implicitly hold the instructor
	 * capabilities (manage their own availability and lessons).
	 */
	public function adminsAreInstructors(): bool {
		return $this->flag( self::OPT_GRANT_INSTRUCTOR );
	}

	/**
	 * Read a stored toggle, defaulting to on so a fresh install keeps the
	 * single-account behaviour.
	 */
	private function flag( string $option ): bool {
		return '0' !== Val::string( get_option( $option, '1' ) );
	}

	public function renderPage(): void {
		if ( ! current_user_can( 'manage_options' ) ) {
			wp_die( esc_html__( 'You do not have permission to manage access settings.', 'unsupervised-schedular' ) );
		}

		$error = '';
		if ( isset( $_POST['usc_action'] ) && check_admin_referer( 'usc_access_action' ) ) {
			$error = $this->save();
		}

		$adminsAreStudioAdmins = $this->adminsAreStudioAdmins();
		$adminsAreInstructors  = $this->adminsAreInstructors();
		$deleteDataOnUninstall = Uninstaller::deletesDataOnUninstall();

		include USC_PLUGIN_DIR . 'templates/admin/access.php';
	}

	/**
	 * Persist the submitted settings, reporting why the data-removal choice was
	 * refused when it was. Everything else on the page saves either way: a
	 * mistyped confirmation must not also swallow a capability change.
	 */
	private function save(): string {
		// Nonce is verified by the caller (renderPage) before this method runs.
		// phpcs:disable WordPress.Security.NonceVerification.Missing
		update_option( self::OPT_GRANT_STUDIO, isset( $_POST['grant_studio'] ) ? '1' : '0' );
		update_option( self::OPT_GRANT_INSTRUCTOR, isset( $_POST['grant_instructor'] ) ? '1' : '0' );

		$wanted = isset( $_POST['delete_data'] );

		// Switching it off is not the dangerous direction, and needs no ceremony.
		if ( ! $wanted ) {
			Uninstaller::setDeletesDataOnUninstall( false );

			return '';
		}

		// Already on and left on: this save is about something else on the page,
		// so do not make them retype the word to keep a setting they already made.
		if ( Uninstaller::deletesDataOnUninstall() ) {
			return '';
		}

		// Turning it on erases records that cannot be got back, so the tick alone
		// is not enough — it is one stray click, and this is the only place in the
		// plugin where a stray click is unrecoverable.
		$confirmed = 'delete' === sanitize_key( Val::string( wp_unslash( $_POST['delete_data_confirm'] ?? '' ) ) );
		// phpcs:enable WordPress.Security.NonceVerification.Missing

		if ( ! $confirmed ) {
			return __( 'Data removal was not enabled: type DELETE in the confirmation box to turn it on. Everything else on this page was saved.', 'unsupervised-schedular' );
		}

		Uninstaller::setDeletesDataOnUninstall( true );

		return '';
	}
}