<?php
/**
 * CSV export of findings (F-MONITOR-04).
 *
 * @package ForensixDigital
 */

declare(strict_types=1);

namespace ForensixDigital\Apps\Monitor;

defined( 'ABSPATH' ) || exit;

use ForensixDigital\Services\Findings\FindingStore;

/**
 * One line per finding. Cells that start with =, +, - or @ get a leading apostrophe, so a
 * spreadsheet cannot run text from a page as a formula.
 */
final class CsvExport {

	/**
	 * The header line.
	 *
	 * @return array<int, string>
	 */
	public static function header(): array {
		return array(
			__( 'Status', 'forensix-digital' ),
			__( 'Severity', 'forensix-digital' ),
			__( 'Type', 'forensix-digital' ),
			__( 'Check', 'forensix-digital' ),
			__( 'Problem', 'forensix-digital' ),
			__( 'Address', 'forensix-digital' ),
			__( 'Location', 'forensix-digital' ),
			__( 'Pages affected', 'forensix-digital' ),
			__( 'First seen', 'forensix-digital' ),
			__( 'Last seen', 'forensix-digital' ),
		);
	}

	/**
	 * The cells of one finding.
	 *
	 * @param array<string, mixed> $finding Finding row from FindingStore.
	 * @return array<int, string>
	 */
	public static function cells( array $finding ): array {
		return array(
			(string) $finding['status'],
			(string) $finding['severity'],
			(string) $finding['type'],
			(string) $finding['check_id'],
			(string) $finding['title'],
			(string) $finding['target'],
			(string) $finding['source_label'],
			(string) $finding['affected'],
			(string) $finding['first_seen'],
			(string) $finding['last_seen'],
		);
	}

	/**
	 * One CSV line, with quotes where needed and a line break at the end.
	 *
	 * @param array<int, string> $cells Cells.
	 */
	public static function line( array $cells ): string {
		$out = array();
		foreach ( $cells as $cell ) {
			$cell = str_replace( array( "\r\n", "\r", "\n" ), ' ', $cell );
			if ( '' !== $cell && str_contains( "=+-@\t", $cell[0] ) ) {
				$cell = "'" . $cell;
			}
			$out[] = '"' . str_replace( '"', '""', $cell ) . '"';
		}
		return implode( ',', $out ) . "\r\n";
	}

	/**
	 * Every open finding as CSV lines, header first. Reads 100 findings at a time.
	 *
	 * @param FindingStore $store Findings.
	 * @param string       $app   App id.
	 * @return \Generator<int, string>
	 */
	public static function lines( FindingStore $store, string $app ): \Generator {
		yield self::line( self::header() );
		$page = 1;
		do {
			$result = $store->query( array( 'app' => $app ), $page, 100 );
			$count  = count( $result['items'] );
			foreach ( $result['items'] as $finding ) {
				yield self::line( self::cells( $finding ) );
			}
			++$page;
		} while ( 100 === $count );
	}
}