import { DEFAULTED_FIELDS } from './policy-defaults'
import type { DefaultedField } from './policy-defaults'

const OPTIONAL_FIELDS = ['processingPurposes', 'legalBasis', 'legitimateInterests',
  'storageDuration', 'dataSource', 'dataCategories'] as const
const REQUIRED_FIELDS = ['title', 'processingDescription', 'recipients'] as const
export type PolicyInput = Record<typeof REQUIRED_FIELDS[number], string> &
  Partial<Record<DefaultedField | typeof OPTIONAL_FIELDS[number], string | null>> & { isPublic?: boolean }

/** Validate untrusted request values before callers use string operations. */
export function parsePolicyInput(value: unknown): PolicyInput | null {
  if (!value || typeof value !== 'object' || Array.isArray(value)) return null
  const input = value as Record<string, unknown>
  if (input.isPublic !== undefined && typeof input.isPublic !== 'boolean') return null
  const fields = [...REQUIRED_FIELDS, ...OPTIONAL_FIELDS, ...DEFAULTED_FIELDS]
  for (const field of fields) {
    const text = input[field]
    if (text !== undefined && text !== null && (typeof text !== 'string' || text.length > 100000)) return null
  }
  const text = (key: string) => typeof input[key] === 'string' ? input[key].trim() : ''
  return {
    ...Object.fromEntries([...OPTIONAL_FIELDS, ...DEFAULTED_FIELDS].map(key => [key, text(key) || null])),
    title: text('title'), processingDescription: text('processingDescription'), recipients: text('recipients'),
    ...(input.isPublic === undefined ? {} : { isPublic: input.isPublic as boolean }),
  }
}