<?php
declare(strict_types=1);

namespace Unsupervised\Schedular\Policy;

use Unsupervised\Schedular\Auth\RoleManager;
use Unsupervised\Schedular\Val;

class PolicyController {

	public function __construct(
		private PolicyRepository $policies,
		private PolicyVersionRepository $versions,
		private PolicyService $service,
	) {}

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

		$notice        = '';
		$viewVersionId = 0;

		if ( isset( $_POST['usc_action'] ) && check_admin_referer( 'usc_policy_action' ) ) {
			[ $notice, $viewVersionId ] = $this->handleFormAction();
		}

		// phpcs:disable WordPress.Security.NonceVerification.Recommended -- read-only policy/version selectors.
		$policyId = absint( Val::int( $_GET['policy_id'] ?? 0 ) );
		if ( 0 === $viewVersionId ) {
			$viewVersionId = absint( Val::int( $_GET['version_id'] ?? 0 ) );
		}
		// phpcs:enable WordPress.Security.NonceVerification.Recommended

		$policyList     = $this->policies->findAll();
		$selectedPolicy = $policyId > 0 ? $this->policies->findById( $policyId ) : null;
		$policyVersions = null !== $selectedPolicy ? $this->versions->findByPolicy( (int) $selectedPolicy->id ) : null;
		$viewedVersion  = null !== $selectedPolicy ? $this->loadVersionForPolicy( (int) $selectedPolicy->id, $viewVersionId ) : null;

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

	/**
	 * Process the posted action.
	 *
	 * @return array{string, int} Status notice, and the version to open in the
	 *                            viewer (0 to leave the current selection alone).
	 */
	private function handleFormAction(): array {
		// Nonce is verified by the caller (renderPage) before this method runs.
		// phpcs:disable WordPress.Security.NonceVerification.Missing
		$action = sanitize_key( Val::string( wp_unslash( $_POST['usc_action'] ?? '' ) ) );

		if ( 'create_policy' === $action ) {
			$title   = sanitize_text_field( Val::string( wp_unslash( $_POST['title'] ?? '' ) ) );
			$slugRaw = sanitize_text_field( Val::string( wp_unslash( $_POST['slug'] ?? '' ) ) );
			$slug    = sanitize_title( '' !== $slugRaw ? $slugRaw : $title );
			$scope   = sanitize_key( Val::string( wp_unslash( $_POST['acceptance_scope'] ?? Policy::SCOPE_BOOKING ) ) );

			if ( ! in_array( $scope, Policy::VALID_SCOPES, true ) ) {
				$scope = Policy::SCOPE_BOOKING;
			}

			$withinLimits = mb_strlen( $title ) <= Policy::MAX_TITLE_LENGTH && mb_strlen( $slug ) <= Policy::MAX_SLUG_LENGTH;

			if ( '' !== $title && '' !== $slug && $withinLimits && null === $this->policies->findBySlug( $slug ) ) {
				$this->service->createPolicy( $title, $slug, $scope );
			}

			return [ '', 0 ];
		}

		$policyId = absint( Val::int( $_POST['policy_id'] ?? 0 ) );
		if ( $policyId <= 0 || null === $this->policies->findById( $policyId ) ) {
			return [ '', 0 ];
		}

		if ( 'add_version' === $action ) {
			$body = wp_kses_post( Val::string( wp_unslash( $_POST['body'] ?? '' ) ) );
			$this->service->addDraftVersion( $policyId, $body );
		}

		if ( 'edit_version' === $action ) {
			$source = $this->loadVersionForPolicy( $policyId, absint( Val::int( $_POST['version_id'] ?? 0 ) ) );
			if ( null === $source ) {
				return [ '', 0 ];
			}

			$body = wp_kses_post( Val::string( wp_unslash( $_POST['body'] ?? '' ) ) );

			// A draft has never been shown to a student, so it is edited in place.
			// A published (or archived) version is what students accepted, so an
			// edit branches a new draft and leaves the original untouched.
			if ( PolicyVersion::STATUS_DRAFT === $source->status ) {
				$this->versions->updateBody( (int) $source->id, $body );

				return [
					sprintf(
						/* translators: %d: the edited version number. */
						__( 'Draft version %d was updated.', 'unsupervised-schedular' ),
						$source->versionNumber
					),
					(int) $source->id,
				];
			}

			return [
				sprintf(
					/* translators: %d: the version number the edit was based on. */
					__( 'Your changes to version %d were saved as a new draft version.', 'unsupervised-schedular' ),
					$source->versionNumber
				),
				$this->service->addDraftVersion( $policyId, $body ),
			];
		}

		if ( 'publish_version' === $action ) {
			$versionId = absint( Val::int( $_POST['version_id'] ?? 0 ) );
			if ( $versionId > 0 ) {
				$this->service->publishVersion( $policyId, $versionId );
			}
		}
		// phpcs:enable WordPress.Security.NonceVerification.Missing

		return [ '', 0 ];
	}

	/**
	 * Load a version by id, confirming it belongs to the given policy.
	 */
	private function loadVersionForPolicy( int $policyId, int $versionId ): ?PolicyVersion {
		if ( $versionId <= 0 ) {
			return null;
		}

		$version = $this->versions->findById( $versionId );

		return null !== $version && $version->policyId === $policyId ? $version : null;
	}
}