package config

import "fmt"

// RoutingRule directs traffic matching source/dest criteria to a specific
// provider's routing table. Requires providers to be configured.
type RoutingRule struct {
	// Source address, interface, or interface:address. Use "&interface" for interface's
	// primary IP. "lo" matches firewall-originated traffic.
	Source string `yaml:"source,omitempty"`

	// Destination address or network in CIDR format.
	Dest string `yaml:"dest,omitempty"`

	// Provider name, provider number, or "main" (254) for the main routing table.
	Provider string `yaml:"provider"`

	// Numeric priority determining rule evaluation order.
	// 1000-1999: before mark rules, 11000-11999: after mark rules,
	// 26000-26999: after ISP interface rules.
	Priority int `yaml:"priority"`

	// Persist rule even if the provider's interface is disabled.
	Persistent bool `yaml:"persistent,omitempty"`

	// Packet mark match. Format: mark[/mask].
	Mark string `yaml:"mark,omitempty"`

	Comment string `yaml:"comment,omitempty"`
}

func (c *Config) validateRoutingRules() error {
	if len(c.RoutingRules) > 0 && len(c.Providers) == 0 {
		return fmt.Errorf("rtrules require providers to be configured")
	}

	providerNames := make(map[string]bool)
	providerNames["main"] = true
	for _, p := range c.Providers {
		providerNames[p.Name] = true
		providerNames[fmt.Sprintf("%d", p.Number)] = true
	}
	providerNames["254"] = true

	for i, r := range c.RoutingRules {
		if r.Source == "" && r.Dest == "" {
			return fmt.Errorf("rtrules[%d]: source or dest required", i)
		}

		if r.Provider == "" {
			return fmt.Errorf("rtrules[%d]: provider required", i)
		}
		if !providerNames[r.Provider] {
			return fmt.Errorf("rtrules[%d]: provider %q not defined", i, r.Provider)
		}

		if r.Priority < 1000 || r.Priority > 26999 {
			return fmt.Errorf("rtrules[%d]: priority must be 1000-26999", i)
		}
	}
	return nil
}