package config

import "fmt"

type PolicyAction string

const (
	PolicyAccept   PolicyAction = "accept"
	PolicyDrop     PolicyAction = "drop"
	PolicyReject   PolicyAction = "reject"
	PolicyContinue PolicyAction = "continue"
	PolicyNone     PolicyAction = "none"
)

type Policy struct {
	Source    string       `yaml:"source"`
	Dest     string       `yaml:"dest"`
	Action   PolicyAction `yaml:"action"`
	Log      string       `yaml:"log,omitempty"`
	RateLimit string      `yaml:"rate_limit,omitempty"`
	ConnLimit int         `yaml:"conn_limit,omitempty"`
}

func (c *Config) validatePolicy() error {
	if len(c.Policy) == 0 {
		return fmt.Errorf("no policies defined")
	}

	for i, p := range c.Policy {
		if p.Source == "" {
			return fmt.Errorf("policy[%d]: source required", i)
		}
		if p.Dest == "" {
			return fmt.Errorf("policy[%d]: dest required", i)
		}
		if p.Source != "all" {
			if _, ok := c.Zones[p.Source]; !ok {
				return fmt.Errorf("policy[%d]: source zone %q not defined", i, p.Source)
			}
		}
		if p.Dest != "all" {
			if _, ok := c.Zones[p.Dest]; !ok {
				return fmt.Errorf("policy[%d]: dest zone %q not defined", i, p.Dest)
			}
		}
		switch p.Action {
		case PolicyAccept, PolicyDrop, PolicyReject, PolicyContinue, PolicyNone:
		default:
			return fmt.Errorf("policy[%d]: unknown action %q", i, p.Action)
		}
	}
	return nil
}