package config

import (
	"fmt"
	"strings"

	"gopkg.in/yaml.v3"
)

type HostKeyPolicy string

const (
	HostKeyPolicyStrict    HostKeyPolicy = "strict"
	HostKeyPolicyAcceptNew HostKeyPolicy = "accept-new"
	HostKeyPolicyOff       HostKeyPolicy = "off"
)

func (p *HostKeyPolicy) UnmarshalYAML(value *yaml.Node) error {
	switch value.Kind {
	case yaml.ScalarNode:
	default:
		return fmt.Errorf("host_key_policy must be a boolean or string")
	}

	switch value.Tag {
	case "!!bool":
		var enabled bool
		if err := value.Decode(&enabled); err != nil {
			return err
		}
		if enabled {
			*p = HostKeyPolicyStrict
		} else {
			*p = HostKeyPolicyOff
		}
		return nil
	case "!!str":
		var raw string
		if err := value.Decode(&raw); err != nil {
			return err
		}
		normalized, ok := NormalizeHostKeyPolicy(raw)
		if !ok {
			return fmt.Errorf("host_key_policy must be strict, true, accept-new, off, or false")
		}
		*p = normalized
		return nil
	default:
		return fmt.Errorf("host_key_policy must be a boolean or string")
	}
}

func NormalizeHostKeyPolicy(value string) (HostKeyPolicy, bool) {
	switch strings.ToLower(value) {
	case "", string(HostKeyPolicyAcceptNew):
		return HostKeyPolicyAcceptNew, true
	case string(HostKeyPolicyStrict), "true":
		return HostKeyPolicyStrict, true
	case string(HostKeyPolicyOff), "false":
		return HostKeyPolicyOff, true
	default:
		return "", false
	}
}