import crypto from 'node:crypto'

function stableStringify(value: unknown): string {
  if (value === null || value === undefined) return 'null'
  if (typeof value === 'string') return JSON.stringify(value)
  if (typeof value === 'number' || typeof value === 'boolean') return JSON.stringify(value)
  if (Array.isArray(value)) return `[${value.map((item) => stableStringify(item)).join(',')}]`
  if (typeof value === 'object') {
    const entries = Object.entries(value as Record<string, unknown>).sort(([a], [b]) => a.localeCompare(b))
    return `{${entries.map(([key, val]) => `${JSON.stringify(key)}:${stableStringify(val)}`).join(',')}}`
  }
  return JSON.stringify(value)
}

export function computeChecksum(source: unknown): string {
  const serialized = stableStringify(source)
  return crypto.createHash('sha256').update(serialized).digest('hex')
}