package app

import "net/http"

func handleTransportInterfaces(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		http.Error(w, "method not allowed", http.StatusMethodNotAllowed)
		return
	}

	transportMu.Lock()
	clientsState := loadTransportClientsState()
	ifacesState := loadTransportInterfacesState()
	snapshot := captureTransportInterfacesStateSnapshot(clientsState, ifacesState)
	transportMu.Unlock()

	normIfaces, changed := normalizeTransportInterfacesState(ifacesState, clientsState.Items)
	if changed {
		if err := saveTransportInterfacesIfSnapshotCurrent(snapshot, normIfaces); err != nil {
			writeJSON(w, http.StatusOK, TransportInterfacesResponse{
				OK:      false,
				Code:    "TRANSPORT_INTERFACES_SAVE_FAILED",
				Message: "interfaces state save failed: " + err.Error(),
			})
			return
		}
	}

	items := buildTransportInterfaceItems(normIfaces.Items, clientsState.Items)
	if adguardTarget, ok := buildTransportPolicyAdGuardTarget(); ok {
		items = appendTransportVirtualInterfaceItems(items, []TransportClient{adguardTarget})
	}

	writeJSON(w, http.StatusOK, TransportInterfacesResponse{
		OK:      true,
		Message: "ok",
		Count:   len(items),
		Items:   items,
	})
}