// This file is part of the happyDomain (R) project.
// Copyright (c) 2026 happyDomain
// Authors: Pierre-Olivier Mercier, et al.
//
// This program is offered under a commercial and under the AGPL license.
// For commercial licensing, contact us at <contact@happydomain.org>.
//
// For AGPL licensing:
// This program is free software: you can redistribute it and/or modify
// it under the terms of the GNU Affero General Public License as published by
// the Free Software Foundation, either version 3 of the License, or
// (at your option) any later version.
//
// This program is distributed in the hope that it will be useful,
// but WITHOUT ANY WARRANTY; without even the implied warranty of
// MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU Affero General Public License for more details.
//
// You should have received a copy of the GNU Affero General Public License
// along with this program.  If not, see <https://www.gnu.org/licenses/>.

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)
}