import { createHash } from 'node:crypto'
import type { Configuration } from '#domain/configuration/configuration'

/**
 * Computes a 12-character hex content hash of a Configuration's desired state.
 * The hash is based on the sorted desiredParameters and firmwareTarget.
 */
export function computeContentHash(config: Configuration): string {
  const payload = JSON.stringify({
    desiredParameters: config.desiredParameters
      .slice()
      .sort((a, b) => a.name.localeCompare(b.name)),
    firmwareTarget: config.firmwareTarget || null,
  })
  return createHash('sha256').update(payload).digest('hex').substring(0, 12)
}

/**
 * Builds the ProvisioningCode string for a Configuration.
 * Format: `<identifier>(v<version>)-<hash12>`
 * Example: `BM632w-standard(v1.0.1)-a1b2c3d4e5f6`
 */
export function buildProvisioningCode(config: Configuration): string {
  const hash = computeContentHash(config)
  return `${config.identifier}(v${config.version})-${hash}`
}

/**
 * Parses an existing ProvisioningCode string.
 * Returns null if the format is invalid.
 */
export function parseProvisioningCode(
  code: string
): { identifier: string; version: string; hash: string } | null {
  const match = code.match(/^(.+)\(v(.+)\)-([a-f0-9]{12})$/)
  if (!match) return null
  return { identifier: match[1], version: match[2], hash: match[3] }
}