package checker

import "strings"

// ProbeMode selects how strictly we validate after MTProxy init.
type ProbeMode int

const (
	// ProbeFast: handshake + init, then any inbound data within a short window (legacy behavior; fast).
	ProbeFast ProbeMode = iota
	// ProbeDeep: MTProto req_pq and expect resPQ from Telegram DC through the tunnel (stricter; slower).
	ProbeDeep
)

// Options configures Check. Nil or zero value uses ProbeFast.
type Options struct {
	Probe ProbeMode
}

// ParseProbe maps env/flag strings: "", "fast" -> ProbeFast; "deep" -> ProbeDeep.
func ParseProbe(s string) ProbeMode {
	switch strings.ToLower(strings.TrimSpace(s)) {
	case "deep", "respq", "dc":
		return ProbeDeep
	default:
		return ProbeFast
	}
}

func effectiveOpts(opts *Options) *Options {
	if opts == nil {
		return &Options{Probe: ProbeFast}
	}
	return opts
}