package app

import (
	"net/http"
	"syscall"
)

func handleTrafficAdvancedReset(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}
	lock, lockMsg := acquireTrafficApplyLock()
	if lockMsg != nil {
		writeJSON(w, http.StatusOK, *lockMsg)
		return
	}
	defer func() {
		_ = syscall.Flock(int(lock.Fd()), syscall.LOCK_UN)
		_ = lock.Close()
	}()

	prev := normalizeTrafficModeState(loadTrafficModeState())
	next := prev
	next.AutoLocalBypass = false
	next.IngressReplyBypass = false

	nextIface, _ := resolveTrafficIface(next.PreferredIface)
	if err := applyTrafficMode(next, nextIface); err != nil {
		prevIface, _ := resolveTrafficIface(prev.PreferredIface)
		_ = applyTrafficMode(prev, prevIface)
		msg := evaluateTrafficMode(prev)
		msg.Message = "advanced reset failed, rolled back: " + err.Error()
		writeJSON(w, http.StatusOK, msg)
		return
	}

	if err := saveTrafficModeState(next); err != nil {
		prevIface, _ := resolveTrafficIface(prev.PreferredIface)
		_ = applyTrafficMode(prev, prevIface)
		_ = saveTrafficModeState(prev)
		msg := evaluateTrafficMode(prev)
		msg.Message = "advanced reset save failed, rolled back: " + err.Error()
		writeJSON(w, http.StatusOK, msg)
		return
	}

	res := evaluateTrafficMode(next)
	if !res.Healthy {
		prevIface, _ := resolveTrafficIface(prev.PreferredIface)
		_ = applyTrafficMode(prev, prevIface)
		_ = saveTrafficModeState(prev)
		rolled := evaluateTrafficMode(prev)
		rolled.Message = "advanced reset verification failed, rolled back: " + res.Message
		writeJSON(w, http.StatusOK, rolled)
		return
	}

	events.push("traffic_advanced_reset", map[string]any{
		"mode":            res.Mode,
		"applied":         res.AppliedMode,
		"active_iface":    res.ActiveIface,
		"healthy":         res.Healthy,
		"auto_local":      res.AutoLocalBypass,
		"ingress_reply":   res.IngressReplyBypass,
		"advanced_active": res.AdvancedActive,
	})
	res.Message = "advanced bypass reset"
	writeJSON(w, http.StatusOK, res)
}