<?php
/**
 * Sanitizes and masks sensitive data in validated workflow arrays.
 *
 * @package BreznFlow
 * @since   1.0.0
 */

namespace BreznFlow\Security;

if ( ! defined( 'ABSPATH' ) ) {
	exit;
}

/**
 * Sanitizes and masks sensitive data in validated n8n workflow arrays.
 */
class WorkflowSanitizer {
	/**
	 * Log of masked items accumulated during processing.
	 *
	 * @var array<int, array<string, string>>
	 */
	private array $mask_log = array();

	/**
	 * Processes (sanitizes + masks) a validated workflow data array.
	 *
	 * @param array $data Validated workflow data from WorkflowValidator.
	 * @return array{ data: array, mask_log: array } Processed data and mask log.
	 */
	public function process( array $data ): array {
		$this->mask_log = array();

		// Pass 1: Sanitize all strings.
		$sanitized = $this->sanitize_recursive( $data );

		// Pass 2: Mask secrets in nodes.
		if ( isset( $sanitized['nodes'] ) && is_array( $sanitized['nodes'] ) ) {
			foreach ( $sanitized['nodes'] as &$node ) {
				$node = $this->mask_node( $node );
			}
			unset( $node );
		}

		return array(
			'data'     => $sanitized,
			'mask_log' => $this->mask_log,
		);
	}

	/**
	 * Recursively sanitizes all string values in the data.
	 * jsCode is preserved as-is (displayed with esc_html(), never executed).
	 *
	 * @since 1.0.0
	 * @param mixed  $value      Value to sanitize.
	 * @param string $parent_key Parent array key for context.
	 * @return mixed Sanitized value.
	 */
	private function sanitize_recursive( $value, string $parent_key = '' ): mixed {
		if ( is_array( $value ) ) {
			$result = array();
			foreach ( $value as $key => $item ) {
				$result[ $key ] = $this->sanitize_recursive( $item, (string) $key );
			}
			return $result;
		}

		if ( is_string( $value ) ) {
			// Preserve jsCode as-is; it will be displayed with esc_html().
			if ( 'jsCode' === $parent_key ) {
				return $value;
			}
			return sanitize_text_field( $value );
		}

		if ( is_int( $value ) || is_float( $value ) ) {
			return $value;
		}

		if ( is_bool( $value ) ) {
			return $value;
		}

		return null;
	}

	/**
	 * Applies masking rules to a single node's parameters.
	 *
	 * @since 1.0.0
	 * @param array $node Single workflow node array.
	 * @return array Node with masked parameter values.
	 */
	private function mask_node( array $node ): array {
		if ( ! isset( $node['parameters'] ) || ! is_array( $node['parameters'] ) ) {
			return $node;
		}

		$node['parameters'] = $this->mask_parameters_recursive( $node['parameters'] );
		return $node;
	}

	/**
	 * Recursively applies masking rules to parameter values.
	 *
	 * @since 1.0.0
	 * @param array $params Parameters array to process.
	 * @return array Parameters with sensitive values masked.
	 */
	private function mask_parameters_recursive( array $params ): array {
		foreach ( $params as $key => &$value ) {
			if ( is_string( $value ) && 'jsCode' !== $key ) {
				$value = MaskingRules::apply( $value, (string) $key, $this->mask_log );

				// Condition rightValue heuristic.
				if ( 'rightValue' === $key && '[REDACTED]' !== $value ) {
					$value = MaskingRules::apply_condition_heuristic( $value, $this->mask_log );
				}
			} elseif ( is_array( $value ) ) {
				// {name, value} pair pattern — e.g. HTTP header/body parameters.
				// If the 'name' field indicates a sensitive header, mask its 'value'.
				if ( isset( $value['name'], $value['value'] ) && is_string( $value['value'] ) ) {
					$this->mask_name_value_pair( $value );
				}
				$value = $this->mask_parameters_recursive( $value );
			}
		}
		unset( $value );
		return $params;
	}

	/**
	 * Masks the 'value' of a {name, value} pair when the name implies sensitive data.
	 * Covers HTTP headers like Authorization, API-Key, X-Auth-Token, etc.
	 *
	 * @param array $item Passed by reference — modifies $item['value'] in place.
	 */
	private function mask_name_value_pair( array &$item ): void {
		if ( '[REDACTED]' === $item['value'] ) {
			return;
		}

		$name_lower = strtolower( (string) $item['name'] );
		$sensitive  = array( 'authorization', 'token', 'api-key', 'apikey', 'x-api-key', 'x-auth', 'secret', 'password', 'bearer' );

		foreach ( $sensitive as $keyword ) {
			if ( str_contains( $name_lower, $keyword ) ) {
				$this->mask_log[] = array(
					'reason' => 'sensitive_header_name',
					'key'    => 'value',
					'note'   => 'Parameter name "' . esc_html( $item['name'] ) . '" indicates sensitive data.',
				);
				$item['value']    = '[REDACTED]';
				return;
			}
		}
	}
}