<?php
/**
 * Admin integration: menus, assets, notices, CSV export, test-data endpoint.
 *
 * @package Enrollment_Verifier_Logger
 */

defined( 'ABSPATH' ) || exit;

/**
 * Admin controller.
 */
class EVLFL_Admin {

	const PAGE_SLUG     = EVLFL_Plugin::LOGS_PAGE;
	const SETTINGS_SLUG = EVLFL_Plugin::SETTINGS_PAGE;

	/**
	 * Repository.
	 *
	 * @var EVLFL_Logger
	 */
	private $logger;

	/**
	 * Hook suffixes of our two screens.
	 *
	 * @var string[]
	 */
	private $hook_suffixes = array();

	/**
	 * Settings screen controller.
	 *
	 * @var EVLFL_Settings_Page
	 */
	private $settings_page;

	/**
	 * Whether the dependency notice was printed.
	 *
	 * @var bool
	 */
	private static $notice_printed = false;

	/**
	 * Constructor.
	 *
	 * @param EVLFL_Logger        $logger        Repository.
	 * @param EVLFL_Settings_Page $settings_page Settings screen.
	 */
	public function __construct( EVLFL_Logger $logger, EVLFL_Settings_Page $settings_page ) {
		$this->logger        = $logger;
		$this->settings_page = $settings_page;
	}

	/**
	 * Hooks.
	 *
	 * @return void
	 */
	public function init() {
		$this->settings_page->init();
		add_action( 'admin_menu', array( $this, 'register_menu' ) );
		add_action( 'admin_enqueue_scripts', array( $this, 'enqueue_assets' ) );
		add_action( 'admin_notices', array( $this, 'dependency_notice' ) );
		add_action( 'admin_post_evlfl_generate_test_data', array( $this, 'handle_generate_test_data' ) );
		add_action( 'admin_post_evlfl_export_csv', array( $this, 'handle_export_csv' ) );
	}

	/**
	 * Menu: top-level "Enrollment Logs" with "View Logs" and "Logs Settings".
	 *
	 * @return void
	 */
	public function register_menu() {
		$cap   = EVLFL_Plugin::capability();
		$title = __( 'Enrollment Logs', 'accesstrace-for-learndash' );

		$this->hook_suffixes[] = (string) add_menu_page( $title, $title, $cap, self::PAGE_SLUG, array( $this, 'render_page' ), 'dashicons-list-view', 81 );
		// Same slug as the parent: renames the first submenu entry from "Enrollment Logs" to "View Logs".
		add_submenu_page( self::PAGE_SLUG, __( 'View Logs', 'accesstrace-for-learndash' ), __( 'View Logs', 'accesstrace-for-learndash' ), $cap, self::PAGE_SLUG, array( $this, 'render_page' ) );
		$this->hook_suffixes[] = (string) add_submenu_page( self::PAGE_SLUG, __( 'Logs Settings', 'accesstrace-for-learndash' ), __( 'Logs Settings', 'accesstrace-for-learndash' ), $cap, self::SETTINGS_SLUG, array( $this->settings_page, 'render' ) );
	}

	/**
	 * Enqueue CSS on our screen only.
	 *
	 * @param string $hook Hook suffix.
	 * @return void
	 */
	public function enqueue_assets( $hook ) {
		if ( in_array( $hook, $this->hook_suffixes, true ) ) {
			$file = EVLFL_PLUGIN_DIR . 'assets/css/admin.css';
			// filemtime, not the plugin version, so every edit to the stylesheet busts the
			// browser cache on its own; a visitor never has to hard-refresh after an update.
			$ver = file_exists( $file ) ? (string) filemtime( $file ) : EVLFL_VERSION;
			wp_enqueue_style( 'evl-admin', EVLFL_PLUGIN_URL . 'assets/css/admin.css', array( 'dashicons' ), $ver );
		}
	}

	/**
	 * Notice when LearnDash is missing (once per request; limited to relevant screens).
	 *
	 * @return void
	 */
	public function dependency_notice() {
		if ( self::$notice_printed || EVLFL_LearnDash::is_available() || ! current_user_can( EVLFL_Plugin::capability() ) ) {
			return;
		}
		$screen = function_exists( 'get_current_screen' ) ? get_current_screen() : null;
		$id     = $screen ? $screen->id : '';
		if ( ! in_array( $id, array( 'dashboard', 'plugins' ), true ) && false === strpos( $id, self::PAGE_SLUG ) && false === strpos( $id, self::SETTINGS_SLUG ) ) {
			return;
		}
		self::$notice_printed = true;
		printf(
			'<div class="notice notice-warning"><p>%s</p></div>',
			esc_html__( 'AccessTrace for LearnDash requires LearnDash to be active. No enrollment events will be logged until LearnDash is available.', 'accesstrace-for-learndash' )
		);
	}

	/**
	 * Page router.
	 *
	 * @return void
	 */
	public function render_page() {
		if ( ! current_user_can( EVLFL_Plugin::capability() ) ) {
			wp_die( esc_html__( 'You do not have permission to access this page.', 'accesstrace-for-learndash' ), '', array( 'response' => 403 ) );
		}

		$event_id = isset( $_GET['evlfl_event'] ) ? absint( wp_unslash( $_GET['evlfl_event'] ) ) : 0; // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- read-only view.
		if ( $event_id > 0 ) {
			$row      = $this->logger->get( $event_id );
			$list_url = add_query_arg( 'page', self::PAGE_SLUG, admin_url( 'admin.php' ) );
			$view     = $row ? EVLFL_Log_Details::build( $row ) : null;
			include EVLFL_PLUGIN_DIR . 'admin/views/log-details.php';
			return;
		}

		self::load_list_table();
		$stats = $this->logger->status_counts();
		$table = new EVLFL_Log_List_Table( $this->logger );
		$table->set_overall_total( $stats['total'] );
		$table->prepare_items();
		$test_data_enabled = EVLFL_Test_Data::is_enabled();
		$notice            = $this->read_notice();
		$refresh_url       = $this->refresh_url();
		$export_url        = $this->export_url();
		include EVLFL_PLUGIN_DIR . 'admin/views/logs.php';
	}

	/**
	 * The list table class (and its parent, WP_List_Table) are not loaded by WordPress on
	 * every admin request - admin-post.php, for one, does not load them. Everything that
	 * uses EVLFL_Log_List_Table goes through here first.
	 *
	 * @return void
	 */
	public static function load_list_table() {
		require_once EVLFL_PLUGIN_DIR . 'admin/class-log-list-table.php';
	}

	/**
	 * "Refresh": this screen with the current filters, sort and page, so it re-runs the same view.
	 *
	 * @return string Raw URL (escape on output).
	 */
	public function refresh_url() {
		self::load_list_table();
		// phpcs:disable WordPress.Security.NonceVerification.Recommended -- read-only view state, every value validated.
		$args  = array_merge( EVLFL_Log_List_Table::url_args( EVLFL_Log_List_Table::parse_filters( $_GET ) ), EVLFL_Log_List_Table::sort_args( $_GET ) );
		$paged = isset( $_GET['paged'] ) && is_scalar( $_GET['paged'] ) ? absint( $_GET['paged'] ) : 0;
		// phpcs:enable
		if ( $paged > 1 ) {
			$args['paged'] = $paged;
		}
		return EVLFL_Log_List_Table::list_url( $args );
	}

	/**
	 * "Export CSV": admin-post endpoint with the current filters and a nonce.
	 *
	 * @return string Raw URL (escape on output).
	 */
	public function export_url() {
		self::load_list_table();
		$args = EVLFL_Log_List_Table::url_args( EVLFL_Log_List_Table::parse_filters( $_GET ) ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- validated.
		$url  = add_query_arg( rawurlencode_deep( array_merge( array( 'action' => 'evlfl_export_csv' ), $args ) ), admin_url( 'admin-post.php' ) );
		return add_query_arg( '_wpnonce', wp_create_nonce( 'evlfl_export_csv' ), $url );
	}

	/**
	 * Download the currently filtered events as CSV. Read-only: nothing is changed.
	 *
	 * @return void
	 */
	public function handle_export_csv() {
		if ( ! current_user_can( EVLFL_Plugin::capability() ) ) {
			wp_die( esc_html__( 'You do not have permission to do that.', 'accesstrace-for-learndash' ), '', array( 'response' => 403 ) );
		}
		check_admin_referer( 'evlfl_export_csv' );
		self::load_list_table();

		$filters                 = EVLFL_Log_List_Table::parse_filters( $_GET ); // phpcs:ignore WordPress.Security.NonceVerification.Recommended -- nonce checked above; values validated by parse_filters().
		$filters['search_email'] = EVLFL_Log_List_Table::can_search_email();
		$filename                = 'enrollment-logs-' . wp_date( 'Y-m-d-His' ) . '.csv';
		if ( ! $this->send_download_headers( $filename ) ) {
			wp_die( esc_html__( 'The export could not start because another plugin already sent output. Please try again.', 'accesstrace-for-learndash' ), '', array( 'response' => 500 ) );
		}

		self::allow_long_request();
		$out = fopen( 'php://output', 'w' );
		$this->write_csv( $out, $filters );
		fclose( $out ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fclose -- closing the php://output stream, not a file.
		$this->end_request();
	}

	/**
	 * A big log takes a while to stream: use WordPress's (higher) admin memory limit.
	 * Rows are streamed in keyset batches with names looked up once per batch, so the
	 * export stays fast without changing the PHP time limit.
	 *
	 * @return void
	 */
	private static function allow_long_request() {
		if ( function_exists( 'wp_raise_memory_limit' ) ) {
			wp_raise_memory_limit( 'admin' );
		}
	}

	/**
	 * CSV download headers.
	 *
	 * @param string $filename File name offered to the browser.
	 * @return bool False when output has already started (headers can no longer be sent).
	 */
	protected function send_download_headers( $filename ) {
		if ( headers_sent() ) {
			return false;
		}
		nocache_headers();
		header( 'Content-Type: text/csv; charset=utf-8' );
		header( 'Content-Disposition: attachment; filename="' . sanitize_file_name( $filename ) . '"' );
		header( 'X-Content-Type-Options: nosniff' );
		return true;
	}

	/**
	 * Ends the download request. A separate method so tests can run the handler without exiting.
	 *
	 * @return void
	 */
	protected function end_request() {
		exit;
	}

	/**
	 * Write the CSV: UTF-8 BOM (so Excel shows accented names correctly), a header row, then one
	 * row per matching event, newest first.
	 *
	 * @param resource $handle  Writable stream.
	 * @param array    $filters Output of EVLFL_Log_List_Table::parse_filters().
	 * @return int Number of event rows written.
	 */
	public function write_csv( $handle, array $filters ) {
		fwrite( $handle, "\xEF\xBB\xBF" ); // phpcs:ignore WordPress.WP.AlternativeFunctions.file_system_operations_fwrite -- streaming to php://output.
		self::put_csv(
			$handle,
			array(
				__( 'Event ID', 'accesstrace-for-learndash' ),
				__( 'Date (site time)', 'accesstrace-for-learndash' ),
				__( 'Date (UTC)', 'accesstrace-for-learndash' ),
				__( 'User', 'accesstrace-for-learndash' ),
				__( 'User ID', 'accesstrace-for-learndash' ),
				__( 'Course', 'accesstrace-for-learndash' ),
				__( 'Course ID', 'accesstrace-for-learndash' ),
				__( 'Action', 'accesstrace-for-learndash' ),
				__( 'Source', 'accesstrace-for-learndash' ),
				__( 'Trigger', 'accesstrace-for-learndash' ),
				__( 'Status', 'accesstrace-for-learndash' ),
				__( 'Confidence', 'accesstrace-for-learndash' ),
				__( 'Reason', 'accesstrace-for-learndash' ),
			)
		);

		// Names are looked up once per batch (not once per row), and only the current batch's
		// names are kept, so memory stays flat however long the log is.
		$users    = array();
		$on_batch = static function ( array $rows ) use ( &$users ) {
			$users = array();
			$ids   = array_values( array_unique( array_map( 'intval', wp_list_pluck( $rows, 'user_id' ) ) ) );
			$found = get_users(
				array(
					'include'     => $ids,
					'fields'      => array( 'ID', 'display_name' ),
					'blog_id'     => 0,
					'count_total' => false,
				)
			);
			foreach ( $found as $u ) {
				$users[ (int) $u->ID ] = (string) $u->display_name;
			}
			if ( function_exists( '_prime_post_caches' ) ) {
				_prime_post_caches( array_values( array_unique( array_map( 'intval', wp_list_pluck( $rows, 'course_id' ) ) ) ), false, false );
			}
		};

		return $this->logger->each(
			$filters,
			static function ( array $row ) use ( $handle, &$users ) {
				$name   = isset( $users[ $row['user_id'] ] ) ? $users[ $row['user_id'] ] : null;
				$course = get_post( $row['course_id'] );
				self::put_csv(
					$handle,
					array(
						(int) $row['id'],
						EVLFL_Log_Details::format_time( $row['event_time'] ),
						(string) $row['event_time'],
						/* translators: %d: user ID */
						null !== $name ? $name : sprintf( __( '[Deleted User #%d]', 'accesstrace-for-learndash' ), $row['user_id'] ),
						(int) $row['user_id'],
						/* translators: %d: course ID */
						$course ? $course->post_title : sprintf( __( '[Deleted Course #%d]', 'accesstrace-for-learndash' ), $row['course_id'] ),
						(int) $row['course_id'],
						EVLFL_Event::label( 'action', $row['action'] ),
						EVLFL_Event::label( 'source', $row['source'] ),
						EVLFL_Event::label( 'trigger', $row['event_trigger'] ),
						EVLFL_Event::label( 'status', $row['status'] ),
						EVLFL_Event::label( 'confidence', $row['confidence'] ),
						(string) $row['verification_reason'],
					)
				);
			},
			500,
			$on_batch
		);
	}

	/**
	 * One RFC 4180 CSV line. Text cells that a spreadsheet would run as a formula (they start
	 * with = + - @, tab or CR - e.g. a course titled "=HYPERLINK(...)") get a leading
	 * apostrophe, so opening the export can never execute anything.
	 *
	 * @param resource $handle Writable stream.
	 * @param array    $cells  Cell values.
	 * @return void
	 */
	public static function put_csv( $handle, array $cells ) {
		foreach ( $cells as $i => $cell ) {
			if ( is_int( $cell ) ) {
				continue;
			}
			$cell = (string) $cell;
			if ( '' !== $cell && false !== strpos( "=+-@\t\r", $cell[0] ) ) {
				$cell = "'" . $cell;
			}
			$cells[ $i ] = $cell;
		}
		fputcsv( $handle, $cells, ',', '"', '' );
	}

	/**
	 * Allowlisted notice key from the query string.
	 *
	 * @return string
	 */
	private function read_notice() {
		$key = isset( $_GET['evlfl_notice'] ) ? sanitize_key( wp_unslash( $_GET['evlfl_notice'] ) ) : ''; // phpcs:ignore WordPress.Security.NonceVerification.Recommended
		return in_array( $key, array( 'generated' ), true ) ? $key : '';
	}

	/**
	 * Generate sample events (constant-gated, capability + nonce protected).
	 *
	 * @return void
	 */
	public function handle_generate_test_data() {
		if ( ! current_user_can( EVLFL_Plugin::capability() ) || ! EVLFL_Test_Data::is_enabled() ) {
			wp_die( esc_html__( 'You do not have permission to do that.', 'accesstrace-for-learndash' ), '', array( 'response' => 403 ) );
		}
		check_admin_referer( 'evlfl_generate_test_data' );
		EVLFL_Test_Data::generate( $this->logger, get_current_user_id() );
		wp_safe_redirect(
			add_query_arg(
				array(
					'page'         => self::PAGE_SLUG,
					'evlfl_notice' => 'generated',
				),
				admin_url( 'admin.php' )
			)
		);
		exit;
	}
}