Read-Only Import Dry Run

Code

<?php

/*
 * Copyright (c) 2026 Jeffery L. Paris <jparis@phpog.com>.
 * Free for personal and internal use. Paid project use requires visible credit
 * to Jeffery L. Paris. Corporate use requires a paid license fee unless a
 * separate written license states otherwise.
 */

/**
 * Read-Only Import Dry Run.
 *
 * Purpose:
 * Reviews incoming rows before an import writes anything to storage.
 *
 * @param array $incoming_rows Rows prepared for import.
 * @param array $required_fields Field names required on every row.
 * @param array $existing_slugs Existing slugs already present in storage.
 * @return array Dry-run report with counts, row errors, and planned actions.
 */
function ogSnippetReadOnlyImportDryRun(array $incoming_rows, array $required_fields, array $existing_slugs): array {
	$existing_slug_map = array();
	$row_errors = array();
	$planned_actions = array();
	$insert_count = 0;
	$update_count = 0;
	$duplicate_count = 0;

	foreach ($existing_slugs as $existing_slug) {
		$existing_slug = strtolower(trim((string) $existing_slug));

		if ($existing_slug !== '') {
			$existing_slug_map[$existing_slug] = true;
		}
	}

	$row_number = 0;

	foreach ($incoming_rows as $row) {
		$row_number++;
		$errors = array();

		if (is_array($row) === false) {
			$row_errors[] = array(
				'row' => $row_number,
				'errors' => array('Row is not an array.')
			);
			continue;
		}

		foreach ($required_fields as $field_name) {
			$field_name = trim((string) $field_name);

			if ($field_name === '') {
				continue;
			}

			if (isset($row[$field_name]) === false || trim((string) $row[$field_name]) === '') {
				$errors[] = 'Missing required field: '.$field_name;
			}
		}

		$slug = '';

		if (isset($row['slug']) === true) {
			$slug = strtolower(trim((string) $row['slug']));
		}

		if ($slug === '') {
			$errors[] = 'Missing slug.';
		}

		if (count($errors) > 0) {
			$row_errors[] = array(
				'row' => $row_number,
				'errors' => $errors
			);
			continue;
		}

		if (isset($existing_slug_map[$slug]) === true) {
			$update_count++;
			$duplicate_count++;
			$planned_actions[] = array(
				'row' => $row_number,
				'slug' => $slug,
				'action' => 'review-update'
			);
		} else {
			$insert_count++;
			$existing_slug_map[$slug] = true;
			$planned_actions[] = array(
				'row' => $row_number,
				'slug' => $slug,
				'action' => 'insert'
			);
		}
	}

	return array(
		'row_count' => count($incoming_rows),
		'insert_count' => $insert_count,
		'update_review_count' => $update_count,
		'duplicate_slug_count' => $duplicate_count,
		'error_count' => count($row_errors),
		'row_errors' => $row_errors,
		'planned_actions' => $planned_actions
	);
}

$incoming_manifest = array(
	array('title' => 'Stargate Dialing Library', 'slug' => 'stargate-dialing-library'),
	array('title' => 'Rocinante Flight Log', 'slug' => 'rocinante-flight-log'),
	array('title' => '', 'slug' => 'broken-import-row')
);

$dry_run = ogSnippetReadOnlyImportDryRun($incoming_manifest, array('title', 'slug'), array('rocinante-flight-log'));
echo 'Import dry-run errors: '.$dry_run['error_count'];