package resolver

import (
	"context"
	"fmt"
	"net/url"

	"git.zb-server.de/Sebi/ssh-netbox-wrapper/internal/netbox"
)

// InterfaceNameStrategy finds the first IP assigned to a named interface (e.g. "mgmt0", "eth0").
type InterfaceNameStrategy struct {
	name string
}

func (s *InterfaceNameStrategy) Name() string { return "interface_name" }

func (s *InterfaceNameStrategy) Resolve(ctx context.Context, entry *netbox.HostEntry, client *netbox.Client) (string, error) {
	// NetBox filters IP addresses by interface name with interface= (devices)
	// and vminterface= (VMs); unknown parameters would be ignored silently and
	// return every address of the host. A missing interface is an HTTP 400,
	// which lets the chain try the next strategy.
	var filterParam string
	switch entry.Kind {
	case "device":
		filterParam = fmt.Sprintf("device_id=%d&interface=%s", entry.ID, url.QueryEscape(s.name))
	case "vm":
		filterParam = fmt.Sprintf("virtual_machine_id=%d&vminterface=%s", entry.ID, url.QueryEscape(s.name))
	default:
		return "", fmt.Errorf("unknown kind %q", entry.Kind)
	}

	ips, err := client.GetIPsWithFilterForHost(ctx, *entry, filterParam)
	if err != nil {
		return "", fmt.Errorf("fetching IPs for interface %q: %w", s.name, err)
	}
	if len(ips) == 0 {
		return "", ErrNoIP
	}
	return ips[0], nil
}