// SPDX-FileCopyrightText: 2026 Echolot contributors
// SPDX-License-Identifier: GPL-3.0-or-later

//go:build !linux

package dataplane

import (
	"fmt"

	"echo-lot.app/server/internal/session"
)

// Crafting IP fragments needs a raw socket and Linux's IP_HDRINCL semantics. Off Linux the
// capability is simply not advertised, so a client never asks for it — better than answering
// with a measurement we cannot actually make.

type FragMode string

const (
	FragInOrder   FragMode = "in_order"
	FragReversed  FragMode = "reversed"
	FragFirstLast FragMode = "first_last"
)

type FragResult struct {
	Mode      FragMode `json:"mode"`
	SizeBytes int      `json:"size_bytes"`
	Fragments int      `json:"fragments"`
	Sent      bool     `json:"sent"`
	Err       string   `json:"err,omitempty"`
}

func RawFragSupported() bool { return false }

func (s *Server) FragSend(
	sess *session.Session, g *session.Grant, sizeBytes int, mode FragMode, fragSize int,
) (FragResult, error) {
	return FragResult{Mode: mode, SizeBytes: sizeBytes},
		fmt.Errorf("crafted fragmentation is only implemented on Linux")
}