package config

import "fmt"

type ZoneType string

const (
	ZoneIP       ZoneType = "ip"
	ZoneIPSec    ZoneType = "ipsec"
	ZoneFirewall ZoneType = "firewall"
	ZoneLoopback ZoneType = "loopback"
)

type Zone struct {
	Type    ZoneType `yaml:"type"`
	Parent  string   `yaml:"parent,omitempty"`
	Options []string `yaml:"options,omitempty"`
}

func (c *Config) validateZones() error {
	if len(c.Zones) == 0 {
		return fmt.Errorf("no zones defined")
	}

	firewallCount := 0
	for name, z := range c.Zones {
		switch z.Type {
		case ZoneIP, ZoneIPSec, ZoneFirewall, ZoneLoopback:
		default:
			return fmt.Errorf("zone %q: unknown type %q", name, z.Type)
		}
		if z.Type == ZoneFirewall {
			firewallCount++
		}
		if z.Parent != "" {
			if _, ok := c.Zones[z.Parent]; !ok {
				return fmt.Errorf("zone %q: parent zone %q not defined", name, z.Parent)
			}
		}
	}

	if firewallCount != 1 {
		return fmt.Errorf("exactly one firewall zone required, found %d", firewallCount)
	}

	return nil
}