// This file is part of the happyDomain (R) project.
// Copyright (c) 2020-2026 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"

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

// sshfpAlignmentRule compares the published SSHFP records with the
// observed host keys (match, missing, mismatch, uncovered family).
type sshfpAlignmentRule struct{}

func (r *sshfpAlignmentRule) Name() string { return "ssh.sshfp_alignment" }
func (r *sshfpAlignmentRule) Description() string {
	return "Compares published SSHFP records against the observed host keys (match, missing, mismatch)."
}

func (r *sshfpAlignmentRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState {
	data, errSt := loadSSHData(ctx, obs)
	if errSt != nil {
		return []sdk.CheckState{*errSt}
	}
	var issues []Issue
	sawKey := false
	for _, ep := range data.Endpoints {
		if len(ep.HostKeys) == 0 {
			continue
		}
		sawKey = true
		issues = append(issues, analyseSSHFPAlignment(ep.Address, ep.HostKeys, data.SSHFP)...)
	}
	if !sawKey {
		return []sdk.CheckState{notTestedState("ssh.sshfp_alignment.skipped", "No host key observed; SSHFP alignment cannot be assessed.")}
	}
	if len(issues) == 0 {
		return []sdk.CheckState{passState("ssh.sshfp_alignment.ok", "Published SSHFP records match the observed host keys.")}
	}
	return statesFromIssues(issues)
}

// sshfpHashRule flags an SSHFP set that uses only the deprecated SHA-1
// (type 1) hash variant.
type sshfpHashRule struct{}

func (r *sshfpHashRule) Name() string { return "ssh.sshfp_hash" }
func (r *sshfpHashRule) Description() string {
	return "Flags SSHFP record sets that only publish SHA-1 (type 1) fingerprints instead of SHA-256."
}

func (r *sshfpHashRule) Evaluate(ctx context.Context, obs sdk.ObservationGetter, _ sdk.CheckerOptions) []sdk.CheckState {
	data, errSt := loadSSHData(ctx, obs)
	if errSt != nil {
		return []sdk.CheckState{*errSt}
	}
	if !data.SSHFP.Present {
		return []sdk.CheckState{notTestedState("ssh.sshfp_hash.skipped", "No SSHFP records published.")}
	}
	var issues []Issue
	for _, ep := range data.Endpoints {
		issues = append(issues, analyseSSHFPHashes(ep.Address, ep.HostKeys, data.SSHFP)...)
	}
	if len(issues) == 0 {
		return []sdk.CheckState{passState("ssh.sshfp_hash.ok", "SSHFP records include a SHA-256 (type 2) fingerprint.")}
	}
	return statesFromIssues(issues)
}