import type { Plugin } from 'vite'

/**
 * Dev-only: reject requests with malformed URIs before Vite's static/transform
 * middleware runs decodeURI(), which would throw and crash the server.
 * See: https://github.com/vitejs/vite/issues/6482
 */
export function viteUriGuard(): Plugin {
  return {
    name: 'vite-uri-guard',
    apply: 'serve',
    configureServer(server) {
      const guard = (req: any, res: any, next: () => void) => {
        const raw = req.url ?? req.originalUrl ?? ''
        try {
          decodeURI(raw)
          const path = raw.includes('?') ? raw.slice(0, raw.indexOf('?')) : raw
          if (path) decodeURI(path)
        } catch {
          res.statusCode = 400
          res.setHeader('Content-Type', 'text/plain')
          res.end('Bad Request: malformed URI')
          return
        }
        next()
      }
      // Prepend so we run before Vite's static/transform middleware (which calls decodeURI)
      server.middlewares.stack.unshift({ route: '', handle: guard })
    },
  }
}