<?php
/**
 * Schema validation for AI Domain Data.
 *
 * @package AIDD
 */

// If this file is called directly, abort.
if ( ! defined( 'WPINC' ) ) {
	die;
}

/**
 * Validates AI Domain Data payloads against the v0.1.1 schema.
 */
class AIDD_Validator {

	/**
	 * Valid entity types according to schema.org.
	 *
	 * @var array
	 */
	private static $valid_entity_types = array(
		'Organization',
		'Person',
		'Blog',
		'NGO',
		'Community',
		'Project',
		'CreativeWork',
		'SoftwareApplication',
		'Thing',
	);

	/**
	 * Validate a domain profile against the schema.
	 *
	 * @param array $profile The profile data to validate.
	 * @return array Validation result with 'valid' boolean and 'errors' array.
	 */
	public static function validate( $profile ) {
		$errors = array();

		// Check required fields.
		$required = array( 'spec', 'name', 'description', 'website', 'contact' );
		foreach ( $required as $field ) {
			if ( ! isset( $profile[ $field ] ) || empty( $profile[ $field ] ) ) {
				$errors[] = sprintf(
					/* translators: %s: Field name */
					__( 'Missing required field: %s', 'ai-domain-data' ),
					$field
				);
			}
		}

		// Validate spec field.
		if ( isset( $profile['spec'] ) && $profile['spec'] !== 'https://ai-domain-data.org/spec/v0.1' ) {
			$errors[] = __( 'Invalid spec URL. Must be "https://ai-domain-data.org/spec/v0.1"', 'ai-domain-data' );
		}

		// Validate name.
		if ( isset( $profile['name'] ) && strlen( trim( $profile['name'] ) ) < 1 ) {
			$errors[] = __( 'Name must not be empty', 'ai-domain-data' );
		}

		// Validate description.
		if ( isset( $profile['description'] ) && strlen( trim( $profile['description'] ) ) < 1 ) {
			$errors[] = __( 'Description must not be empty', 'ai-domain-data' );
		}

		// Validate website URL.
		if ( isset( $profile['website'] ) && ! filter_var( $profile['website'], FILTER_VALIDATE_URL ) ) {
			$errors[] = __( 'Website must be a valid URL', 'ai-domain-data' );
		}

		// Validate contact.
		if ( isset( $profile['contact'] ) && strlen( trim( $profile['contact'] ) ) < 1 ) {
			$errors[] = __( 'Contact must not be empty', 'ai-domain-data' );
		}

		// Validate logo URL if provided.
		if ( isset( $profile['logo'] ) && ! empty( $profile['logo'] ) ) {
			if ( ! filter_var( $profile['logo'], FILTER_VALIDATE_URL ) ) {
				$errors[] = __( 'Logo must be a valid URL', 'ai-domain-data' );
			}
		}

		// Validate entity_type if provided.
		if ( isset( $profile['entity_type'] ) && ! empty( $profile['entity_type'] ) ) {
			if ( ! in_array( $profile['entity_type'], self::$valid_entity_types, true ) ) {
				$errors[] = sprintf(
					/* translators: %s: Valid entity types */
					__( 'Invalid entity_type. Must be one of: %s', 'ai-domain-data' ),
					implode( ', ', self::$valid_entity_types )
				);
			}
		}

		// Validate jsonld if provided.
		if ( isset( $profile['jsonld'] ) && ! empty( $profile['jsonld'] ) ) {
			if ( ! is_array( $profile['jsonld'] ) ) {
				$errors[] = __( 'jsonld must be an object', 'ai-domain-data' );
			} else {
				if ( ! isset( $profile['jsonld']['@context'] ) || $profile['jsonld']['@context'] !== 'https://schema.org' ) {
					$errors[] = __( 'jsonld must include @context: "https://schema.org"', 'ai-domain-data' );
				}
				if ( ! isset( $profile['jsonld']['@type'] ) || empty( $profile['jsonld']['@type'] ) ) {
					$errors[] = __( 'jsonld must include a non-empty @type', 'ai-domain-data' );
				}
			}
		}

		return array(
			'valid'  => empty( $errors ),
			'errors' => $errors,
		);
	}
}