extract-instance-variant-props.ts

import { sanitizePropertyName } from '../props/selector'

/**
 * Reserved variant keys that should not be passed as props.
 * These are used internally for responsive and effect handling.
 */
const RESERVED_VARIANT_KEYS = ['effect', 'viewport']

/**
 * Check if a key is a reserved variant key (case-insensitive).
 */
export function isReservedVariantKey(key: string): boolean {
  const lowerKey = key.toLowerCase()
  return RESERVED_VARIANT_KEYS.some(
    (reserved) => lowerKey === reserved || lowerKey.startsWith(`${reserved}#`),
  )
}

/**
 * Extract variant props from an Instance node's componentProperties.
 * Returns an object with sanitized property names as keys and variant values as string values.
 * Filters out reserved variant keys (effect, viewport) which are used internally.
 *
 * @example
 * // Instance with componentProperties: { "status#123": { type: "VARIANT", value: "scroll" } }
 * // Returns: { status: "scroll" }
 */
export function extractInstanceVariantProps(
  node: InstanceNode,
): Record<string, unknown> {
  const variantProps: Record<string, unknown> = {}

  let componentProperties: InstanceNode['componentProperties']
  try {
    componentProperties = node.componentProperties
  } catch {
    // Figma throws when the component set has validation errors
    // (e.g. duplicate variant names, missing properties).
    return variantProps
  }

  if (!componentProperties) {
    return variantProps
  }

  for (const [key, prop] of Object.entries(componentProperties)) {
    if (isReservedVariantKey(key)) continue
    const sanitizedKey = sanitizePropertyName(key)
    if (prop.type === 'VARIANT') {
      variantProps[sanitizedKey] = String(prop.value)
    } else if (prop.type === 'BOOLEAN' && prop.value === true) {
      variantProps[sanitizedKey] = true
    }
  }

  return variantProps
}