package surf

import (
	"fmt"
	"net/http"
	"strconv"
	"strings"
)

func bodyLimit(n int64) func(http.Handler) http.Handler {
	return func(next http.Handler) http.Handler {
		return http.HandlerFunc(func(w http.ResponseWriter, r *http.Request) {
			if n > 0 && r.Body != nil {
				r.Body = http.MaxBytesReader(w, r.Body, n)
			}
			next.ServeHTTP(w, r)
		})
	}
}

func parseBodyLimit(param string) (int64, error) {
	n, err := strconv.ParseInt(param, 10, 64)
	if err != nil || n <= 0 {
		return 0, fmt.Errorf("invalid body.limit %q", param)
	}
	return n, nil
}

func routeBodyLimit(rt route, defaultBytes int64) (int64, error) {
	if rt.raw {
		return 0, nil
	}
	limit := defaultBytes
	for _, name := range rt.middleware {
		base, param, ok := strings.Cut(name, ":")
		if !ok || base != "body.limit" {
			continue
		}
		n, err := parseBodyLimit(param)
		if err != nil {
			return 0, err
		}
		limit = n
	}
	return limit, nil
}