package app

import (
	"fmt"
	"os"
)

// ---------------------------------------------------------------------
// основной routesUpdate
// ---------------------------------------------------------------------

// EN: Core selective-routes orchestration pipeline.
// EN: This unit prepares policy routing, nftables objects, domain expansion,
// EN: resolver execution, status artifacts, and GUI-facing progress events.
// RU: Основной orchestration-пайплайн selective-routes.
// RU: Модуль готовит policy routing, nftables-объекты, расширение доменов,
// RU: запуск резолвера, статусные артефакты и события прогресса для GUI.

// ---------------------------------------------------------------------
// EN: `routesUpdate` contains core logic for routes update.
// RU: `routesUpdate` - содержит основную логику для routes update.
// ---------------------------------------------------------------------
func routesUpdate(iface string) cmdResult {
	logp := func(format string, args ...any) {
		appendTraceLine("routes", fmt.Sprintf(format, args...))
	}
	heartbeat := func() {
		_ = os.WriteFile(heartbeatFile, []byte{}, 0o644)
	}

	res := cmdResult{OK: false}

	iface = normalizePreferredIface(iface)
	if iface == "" {
		iface, _ = resolveTrafficIface(loadTrafficModeState().PreferredIface)
	}
	if iface == "" {
		logp("no active vpn iface, exit 0")
		res.OK = true
		res.Message = "interface not found, skipped"
		return res
	}

	skip, message, err := routesUpdateStagePreflight(iface, logp, heartbeat)
	if err != nil {
		res.Message = message
		return res
	}
	if skip {
		res.OK = true
		res.Message = message
		return res
	}

	if err := routesUpdateStagePolicy(iface, logp); err != nil {
		res.Message = err.Error()
		return res
	}
	heartbeat()

	routesUpdateStageNftBase(iface)
	heartbeat()

	resolveStage, err := routesUpdateStageResolve(logp, heartbeat)
	if err != nil {
		res.Message = err.Error()
		return res
	}
	defer resolveStage.cleanup()

	if err := routesUpdateStagePopulateNFT(resolveStage, logp, heartbeat); err != nil {
		res.Message = err.Error()
		return res
	}

	if err := routesUpdateStageArtifacts(iface, resolveStage, heartbeat); err != nil {
		res.Message = err.Error()
		return res
	}

	res.OK = true
	res.Message = fmt.Sprintf(
		"update done: domains=%d unique_ips=%d direct_ips=%d wildcard_ips=%d",
		len(resolveStage.domains),
		resolveStage.ipCount,
		resolveStage.directIPCount,
		resolveStage.wildcardIPCount,
	)
	res.ExitCode = resolveStage.ipCount
	return res
}