package checker

import (
	"context"
	"fmt"

	sdk "git.happydns.org/checker-sdk-go/checker"
)

// Rule returns the delegation check rule.
func Rule() sdk.CheckRule {
	return &delegationRule{}
}

type delegationRule struct{}

func (r *delegationRule) Name() string { return "delegation_check" }

func (r *delegationRule) Description() string {
	return "Verifies a DNS delegation against its parent zone and the delegated name servers"
}

func (r *delegationRule) ValidateOptions(opts sdk.CheckerOptions) error {
	if v, ok := opts["minNameServers"]; ok {
		f, ok := v.(float64)
		if !ok {
			return fmt.Errorf("minNameServers must be a number")
		}
		if f < 1 {
			return fmt.Errorf("minNameServers must be >= 1")
		}
	}
	return nil
}

func (r *delegationRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, opts sdk.CheckerOptions) []sdk.CheckState {
	var data DelegationData
	if err := obs.Get(ctx, ObservationKeyDelegation, &data); err != nil {
		return []sdk.CheckState{{
			Status:  sdk.StatusError,
			Message: fmt.Sprintf("Failed to get delegation data: %v", err),
			Code:    "delegation_error",
		}}
	}
	return Evaluate(&data)
}