import type { Request, Response, NextFunction } from 'express'

export function requireBody(...fields: string[]) {
  return (req: Request, res: Response, next: NextFunction): void => {
    const missing = fields.filter((f) => req.body[f] === undefined || req.body[f] === null)
    if (missing.length > 0) { res.status(400).json({ error: { code: 'MISSING_FIELDS', message: `Missing required fields: ${missing.join(', ')}` } }); return }
    next()
  }
}

export function sanitizeString(val: unknown): string {
  if (typeof val !== 'string') return ''
  return val.trim().slice(0, 10_000)
}

export function sanitizeInt(val: unknown): number | null {
  const n = Number(val)
  if (!Number.isInteger(n) || n < 0) return null
  return n
}