package proxmox

import (
	"net/netip"

	"gitea.home.hrajfrisbee.cz/kacerr/egress-proxies-operator/internal/provider"
)

// mapState turns status/current's status and qmpstatus plus the discovered
// address into the contract's state (spec entry 9). A VM is Running only
// with an address; prelaunch is still starting; any other qmpstatus of a
// running VM (paused, suspended, io-error, …) and any status not recognised
// is Stopped, which the reconciler answers by replacing the VM. An empty
// qmpstatus is taken as running: the field is missing, not a state.
func mapState(status, qmpStatus, ip string) provider.InstanceState {
	switch {
	case guestRunning(status, qmpStatus):
		if ip == "" {
			return provider.StateProvisioning
		}
		return provider.StateRunning
	case status == "running" && qmpStatus == "prelaunch":
		return provider.StateProvisioning
	default:
		return provider.StateStopped
	}
}

// guestRunning reports a VM whose guest runs, the only state in which its
// agent can answer and mapState can call it Running.
func guestRunning(status, qmpStatus string) bool {
	return status == "running" && (qmpStatus == "running" || qmpStatus == "")
}

// firstIPv4 picks the first usable IPv4 from the guest agent's interfaces,
// in the agent's order: not on the loopback interface, not loopback,
// link-local or unspecified. Empty means no address yet.
func firstIPv4(ifaces []agentInterface) string {
	for _, iface := range ifaces {
		if iface.Name == "lo" {
			continue
		}
		for _, a := range iface.IPAddresses {
			if a.Type != "ipv4" {
				continue
			}
			addr, err := netip.ParseAddr(a.Address)
			if err != nil || !addr.Is4() || addr.IsLoopback() || addr.IsLinkLocalUnicast() || addr.IsUnspecified() {
				continue
			}
			return addr.String()
		}
	}
	return ""
}