package server

import (
	"context"
	"encoding/json"
	"fmt"
	"log"
	"math"
	"net/http"
	"net/url"
	"sort"
	"strconv"
	"strings"
	"sync"
	"time"

	"scm.bstein.dev/bstein/soteria/internal/api"
	"scm.bstein.dev/bstein/soteria/internal/config"
	"scm.bstein.dev/bstein/soteria/internal/k8s"
	"scm.bstein.dev/bstein/soteria/internal/longhorn"

	corev1 "k8s.io/api/core/v1"
	"k8s.io/apimachinery/pkg/api/resource"
	k8svalidation "k8s.io/apimachinery/pkg/util/validation"
)

type kubeClient interface {
	ResolvePVCVolume(ctx context.Context, namespace, pvcName string) (string, *corev1.PersistentVolumeClaim, *corev1.PersistentVolume, error)
	CreateBackupJob(ctx context.Context, cfg *config.Config, req api.BackupRequest) (string, string, error)
	CreateRestoreJob(ctx context.Context, cfg *config.Config, req api.RestoreTestRequest) (string, string, error)
	ListBackupJobsForPVC(ctx context.Context, namespace, pvc string) ([]k8s.BackupJobSummary, error)
	ListBoundPVCs(ctx context.Context) ([]k8s.PVCSummary, error)
	PersistentVolumeClaimExists(ctx context.Context, namespace, pvcName string) (bool, error)
	LoadSecretData(ctx context.Context, namespace, secretName, key string) ([]byte, error)
	SaveSecretData(ctx context.Context, namespace, secretName, key string, value []byte, labels map[string]string) error
}

type longhornClient interface {
	CreateSnapshot(ctx context.Context, volume, name string, labels map[string]string) error
	SnapshotBackup(ctx context.Context, volume, name string, labels map[string]string, backupMode string) (*longhorn.Volume, error)
	GetVolume(ctx context.Context, volume string) (*longhorn.Volume, error)
	CreateVolumeFromBackup(ctx context.Context, name, size string, replicas int, backupURL string) (*longhorn.Volume, error)
	CreatePVC(ctx context.Context, volumeName, namespace, pvcName string) error
	DeleteVolume(ctx context.Context, volumeName string) error
	FindBackup(ctx context.Context, volumeName, snapshot string) (*longhorn.Backup, error)
	ListBackups(ctx context.Context, volumeName string) ([]longhorn.Backup, error)
}

type Server struct {
	cfg      *config.Config
	client   kubeClient
	longhorn longhornClient
	metrics  *telemetry
	handler  http.Handler
	ui       *uiRenderer
	policyMu sync.RWMutex
	policies map[string]api.BackupPolicy
	runMu    sync.Mutex
	running  bool
	b2Mu     sync.RWMutex
	b2Usage  api.B2UsageResponse
}

type authIdentity struct {
	Authenticated bool
	User          string
	Email         string
	Groups        []string
}

type ctxKey string

const authContextKey ctxKey = "soteria-auth"

const (
	policySecretKey      = "policies.json"
	defaultPolicyHours   = 24.0
	maxPolicyIntervalHrs = 24 * 365
)

func New(cfg *config.Config, client *k8s.Client, lh *longhorn.Client) *Server {
	s := &Server{
		cfg:      cfg,
		client:   client,
		longhorn: lh,
		metrics:  newTelemetry(),
		ui:       newUIRenderer(),
		policies: map[string]api.BackupPolicy{},
	}
	s.handler = http.HandlerFunc(s.route)
	return s
}

func (s *Server) Start(ctx context.Context) {
	if err := s.loadPolicies(ctx); err != nil {
		log.Printf("policy load failed: %v", err)
	}

	s.refreshTelemetry(ctx)
	s.refreshB2Usage(ctx)
	s.runPolicyCycle(ctx)

	metricsTicker := time.NewTicker(s.cfg.MetricsRefreshInterval)
	policyTicker := time.NewTicker(s.cfg.PolicyEvalInterval)
	var b2Ticker *time.Ticker
	var b2Tick <-chan time.Time
	if s.cfg.B2Enabled {
		b2Ticker = time.NewTicker(s.cfg.B2ScanInterval)
		b2Tick = b2Ticker.C
	}
	go func() {
		defer metricsTicker.Stop()
		defer policyTicker.Stop()
		if b2Ticker != nil {
			defer b2Ticker.Stop()
		}
		for {
			select {
			case <-ctx.Done():
				return
			case <-metricsTicker.C:
				s.refreshTelemetry(ctx)
			case <-policyTicker.C:
				s.runPolicyCycle(ctx)
			case <-b2Tick:
				s.refreshB2Usage(ctx)
			}
		}
	}()
}

func (s *Server) Handler() http.Handler {
	return s.handler
}

func (s *Server) route(w http.ResponseWriter, r *http.Request) {
	switch r.URL.Path {
	case "/healthz":
		s.handleHealth(w, r)
		return
	case "/readyz":
		s.handleReady(w, r)
		return
	case "/metrics":
		s.metrics.Handler().ServeHTTP(w, r)
		return
	}

	identity, status, err := s.authorize(r)
	if err != nil {
		s.metrics.RecordAuthzDenied(authzReason(status, err))
		writeError(w, status, err.Error())
		return
	}

	r = r.WithContext(context.WithValue(r.Context(), authContextKey, identity))

	switch r.URL.Path {
	case "/":
		s.handleUI(w, r)
	case "/v1/b2":
		s.handleB2Usage(w, r)
	case "/v1/whoami":
		s.handleWhoAmI(w, r)
	case "/v1/inventory":
		s.handleInventory(w, r)
	case "/v1/backups":
		s.handleBackups(w, r)
	case "/v1/backup":
		s.handleBackup(w, r)
	case "/v1/backup/namespace":
		s.handleNamespaceBackup(w, r)
	case "/v1/restores", "/v1/restore-test":
		s.handleRestore(w, r)
	case "/v1/restores/namespace":
		s.handleNamespaceRestore(w, r)
	case "/v1/policies":
		s.handlePolicies(w, r)
	default:
		if s.ui != nil && s.ui.ServeAsset(w, r) {
			return
		}
		if strings.HasPrefix(r.URL.Path, "/v1/policies/") {
			s.handlePolicyByID(w, r)
			return
		}
		// Serve SPA index for deep links (for example /backup) while preserving
		// explicit API and asset 404 behavior.
		if r.Method == http.MethodGet && !strings.HasPrefix(r.URL.Path, "/v1/") && !strings.Contains(r.URL.Path, ".") {
			s.handleUI(w, r)
			return
		}
		writeError(w, http.StatusNotFound, "not found")
	}
}

func (s *Server) handleHealth(w http.ResponseWriter, _ *http.Request) {
	writeJSON(w, http.StatusOK, map[string]string{"status": "ok"})
}

func (s *Server) handleReady(w http.ResponseWriter, _ *http.Request) {
	writeJSON(w, http.StatusOK, map[string]string{"status": "ready"})
}

func (s *Server) handleUI(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}
	if s.ui == nil {
		writeError(w, http.StatusInternalServerError, "UI renderer is unavailable")
		return
	}
	if err := s.ui.ServeIndex(w, r); err != nil {
		writeError(w, http.StatusInternalServerError, err.Error())
	}
}

func (s *Server) handleWhoAmI(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}
	identity := requesterFromContext(r.Context())
	writeJSON(w, http.StatusOK, api.AuthInfoResponse{
		Authenticated: identity.Authenticated,
		User:          identity.User,
		Email:         identity.Email,
		Groups:        identity.Groups,
	})
}

func (s *Server) handleInventory(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}
	inventory, err := s.buildInventory(r.Context())
	if err != nil {
		writeError(w, http.StatusBadGateway, err.Error())
		return
	}
	writeJSON(w, http.StatusOK, inventory)
}

func (s *Server) handleBackups(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodGet {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	namespace := strings.TrimSpace(r.URL.Query().Get("namespace"))
	pvcName := strings.TrimSpace(r.URL.Query().Get("pvc"))
	if namespace == "" || pvcName == "" {
		writeError(w, http.StatusBadRequest, "namespace and pvc are required")
		return
	}

	volumeName, _, _, err := s.client.ResolvePVCVolume(r.Context(), namespace, pvcName)
	if err != nil {
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	switch s.cfg.BackupDriver {
	case "longhorn":
		backups, err := s.longhorn.ListBackups(r.Context(), volumeName)
		if err != nil {
			writeError(w, http.StatusBadGateway, err.Error())
			return
		}
		writeJSON(w, http.StatusOK, api.BackupListResponse{
			Namespace: namespace,
			PVC:       pvcName,
			Volume:    volumeName,
			Backups:   buildBackupRecords(backups),
		})
	case "restic":
		jobs, err := s.client.ListBackupJobsForPVC(r.Context(), namespace, pvcName)
		if err != nil {
			writeError(w, http.StatusBadGateway, err.Error())
			return
		}
		writeJSON(w, http.StatusOK, api.BackupListResponse{
			Namespace: namespace,
			PVC:       pvcName,
			Volume:    volumeName,
			Backups:   buildResticBackupRecords(jobs),
		})
	default:
		writeError(w, http.StatusBadRequest, "unsupported backup driver")
	}
}

func (s *Server) handleBackup(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	r.Body = http.MaxBytesReader(w, r.Body, 1<<20)
	var req api.BackupRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		s.metrics.RecordBackupRequest(s.cfg.BackupDriver, "invalid_json")
		writeError(w, http.StatusBadRequest, fmt.Sprintf("invalid JSON: %v", err))
		return
	}
	if strings.TrimSpace(req.Namespace) == "" || strings.TrimSpace(req.PVC) == "" {
		s.metrics.RecordBackupRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, "namespace and pvc are required")
		return
	}
	req.Namespace = strings.TrimSpace(req.Namespace)
	req.PVC = strings.TrimSpace(req.PVC)
	requester := currentRequester(r.Context())

	response, result, err := s.executeBackup(r.Context(), req, requester)
	s.metrics.RecordBackupRequest(s.cfg.BackupDriver, result)
	if err != nil {
		writeError(w, backupStatusCode(result), err.Error())
		return
	}
	writeJSON(w, http.StatusOK, response)
}

func (s *Server) handleRestore(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	r.Body = http.MaxBytesReader(w, r.Body, 1<<20)
	var req api.RestoreTestRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, "invalid_json")
		writeError(w, http.StatusBadRequest, fmt.Sprintf("invalid JSON: %v", err))
		return
	}
	req.Namespace = strings.TrimSpace(req.Namespace)
	req.PVC = strings.TrimSpace(req.PVC)
	req.TargetPVC = strings.TrimSpace(req.TargetPVC)
	req.TargetNamespace = strings.TrimSpace(req.TargetNamespace)

	if req.Namespace == "" {
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, "namespace is required")
		return
	}
	if req.PVC == "" {
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, "pvc is required")
		return
	}
	if req.TargetPVC == "" {
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, "target_pvc is required")
		return
	}
	if req.TargetNamespace == "" {
		req.TargetNamespace = req.Namespace
	}
	if err := validateKubernetesName("namespace", req.Namespace); err != nil {
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if err := validateKubernetesName("pvc", req.PVC); err != nil {
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if err := validateKubernetesName("target_namespace", req.TargetNamespace); err != nil {
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if err := validateKubernetesName("target_pvc", req.TargetPVC); err != nil {
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if req.Namespace == req.TargetNamespace && req.PVC == req.TargetPVC {
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, "conflict")
		writeError(w, http.StatusConflict, "target namespace/pvc must differ from source")
		return
	}

	requester := currentRequester(r.Context())
	response, result, err := s.executeRestore(r.Context(), req, requester)
	s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, result)
	if err != nil {
		writeError(w, restoreStatusCode(result), err.Error())
		return
	}
	writeJSON(w, http.StatusOK, response)
}

func (s *Server) handleNamespaceBackup(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	r.Body = http.MaxBytesReader(w, r.Body, 1<<20)
	var req api.NamespaceBackupRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		s.metrics.RecordNamespaceBackupRequest(s.cfg.BackupDriver, "invalid_json")
		writeError(w, http.StatusBadRequest, fmt.Sprintf("invalid JSON: %v", err))
		return
	}
	req.Namespace = strings.TrimSpace(req.Namespace)
	if req.Namespace == "" {
		s.metrics.RecordNamespaceBackupRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, "namespace is required")
		return
	}
	if err := validateKubernetesName("namespace", req.Namespace); err != nil {
		s.metrics.RecordNamespaceBackupRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	pvcs, err := s.listNamespaceBoundPVCs(r.Context(), req.Namespace)
	if err != nil {
		s.metrics.RecordNamespaceBackupRequest(s.cfg.BackupDriver, "backend_error")
		writeError(w, http.StatusBadGateway, err.Error())
		return
	}

	requester := currentRequester(r.Context())
	response := api.NamespaceBackupResponse{
		Namespace:   req.Namespace,
		RequestedBy: requester,
		Driver:      s.cfg.BackupDriver,
		DryRun:      req.DryRun,
		Results:     make([]api.NamespaceBackupResult, 0, len(pvcs)),
	}

	for _, pvc := range pvcs {
		backupReq := api.BackupRequest{
			Namespace: req.Namespace,
			PVC:       pvc.Name,
			DryRun:    req.DryRun,
		}
		result, status, execErr := s.executeBackup(r.Context(), backupReq, requester)
		s.metrics.RecordBackupRequest(s.cfg.BackupDriver, status)

		item := api.NamespaceBackupResult{
			Namespace: req.Namespace,
			PVC:       pvc.Name,
			Status:    status,
			Volume:    result.Volume,
			Backup:    result.Backup,
		}
		if execErr != nil {
			item.Error = execErr.Error()
			response.Failed++
		} else {
			response.Succeeded++
		}
		response.Results = append(response.Results, item)
	}

	response.Total = len(response.Results)
	s.metrics.RecordNamespaceBackupRequest(s.cfg.BackupDriver, namespaceResultStatus(req.DryRun, response.Total, response.Succeeded, response.Failed))
	writeJSON(w, http.StatusOK, response)
}

func (s *Server) handleNamespaceRestore(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodPost {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}

	r.Body = http.MaxBytesReader(w, r.Body, 1<<20)
	var req api.NamespaceRestoreRequest
	if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
		s.metrics.RecordNamespaceRestoreRequest(s.cfg.BackupDriver, "invalid_json")
		writeError(w, http.StatusBadRequest, fmt.Sprintf("invalid JSON: %v", err))
		return
	}

	req.Namespace = strings.TrimSpace(req.Namespace)
	req.TargetNamespace = strings.TrimSpace(req.TargetNamespace)
	req.TargetPrefix = strings.TrimSpace(req.TargetPrefix)
	req.Snapshot = strings.TrimSpace(req.Snapshot)

	if req.Namespace == "" {
		s.metrics.RecordNamespaceRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, "namespace is required")
		return
	}
	if req.TargetNamespace == "" {
		req.TargetNamespace = req.Namespace
	}
	if err := validateKubernetesName("namespace", req.Namespace); err != nil {
		s.metrics.RecordNamespaceRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}
	if err := validateKubernetesName("target_namespace", req.TargetNamespace); err != nil {
		s.metrics.RecordNamespaceRestoreRequest(s.cfg.BackupDriver, "validation_error")
		writeError(w, http.StatusBadRequest, err.Error())
		return
	}

	pvcs, err := s.listNamespaceBoundPVCs(r.Context(), req.Namespace)
	if err != nil {
		s.metrics.RecordNamespaceRestoreRequest(s.cfg.BackupDriver, "backend_error")
		writeError(w, http.StatusBadGateway, err.Error())
		return
	}

	requester := currentRequester(r.Context())
	response := api.NamespaceRestoreResponse{
		Namespace:       req.Namespace,
		TargetNamespace: req.TargetNamespace,
		RequestedBy:     requester,
		Driver:          s.cfg.BackupDriver,
		DryRun:          req.DryRun,
		Results:         make([]api.NamespaceRestoreResult, 0, len(pvcs)),
	}

	for _, pvc := range pvcs {
		targetPVC := targetPVCName(req.TargetPrefix, pvc.Name)
		restoreReq := api.RestoreTestRequest{
			Namespace:       req.Namespace,
			PVC:             pvc.Name,
			Snapshot:        req.Snapshot,
			TargetNamespace: req.TargetNamespace,
			TargetPVC:       targetPVC,
			DryRun:          req.DryRun,
		}
		result, status, execErr := s.executeRestore(r.Context(), restoreReq, requester)
		s.metrics.RecordRestoreRequest(s.cfg.BackupDriver, status)

		item := api.NamespaceRestoreResult{
			Namespace:       req.Namespace,
			PVC:             pvc.Name,
			TargetNamespace: req.TargetNamespace,
			TargetPVC:       targetPVC,
			Status:          status,
			Volume:          result.Volume,
			BackupURL:       result.BackupURL,
		}
		if execErr != nil {
			item.Error = execErr.Error()
			response.Failed++
		} else {
			response.Succeeded++
		}
		response.Results = append(response.Results, item)
	}

	response.Total = len(response.Results)
	s.metrics.RecordNamespaceRestoreRequest(s.cfg.BackupDriver, namespaceResultStatus(req.DryRun, response.Total, response.Succeeded, response.Failed))
	writeJSON(w, http.StatusOK, response)
}

func (s *Server) handlePolicies(w http.ResponseWriter, r *http.Request) {
	switch r.Method {
	case http.MethodGet:
		writeJSON(w, http.StatusOK, api.BackupPolicyListResponse{Policies: s.listPolicies()})
	case http.MethodPost:
		r.Body = http.MaxBytesReader(w, r.Body, 1<<20)
		var req api.BackupPolicyUpsertRequest
		if err := json.NewDecoder(r.Body).Decode(&req); err != nil {
			writeError(w, http.StatusBadRequest, fmt.Sprintf("invalid JSON: %v", err))
			return
		}
		policy, err := s.upsertPolicy(r.Context(), req)
		if err != nil {
			writeError(w, http.StatusBadRequest, err.Error())
			return
		}
		writeJSON(w, http.StatusOK, policy)
	default:
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
	}
}

func (s *Server) handlePolicyByID(w http.ResponseWriter, r *http.Request) {
	if r.Method != http.MethodDelete {
		writeError(w, http.StatusMethodNotAllowed, "method not allowed")
		return
	}
	encodedID := strings.TrimPrefix(r.URL.Path, "/v1/policies/")
	if encodedID == "" {
		writeError(w, http.StatusBadRequest, "policy id is required")
		return
	}
	id, err := url.PathUnescape(encodedID)
	if err != nil {
		writeError(w, http.StatusBadRequest, "invalid policy id")
		return
	}
	removed, err := s.deletePolicy(r.Context(), id)
	if err != nil {
		writeError(w, http.StatusBadGateway, err.Error())
		return
	}
	if !removed {
		writeError(w, http.StatusNotFound, "policy not found")
		return
	}
	writeJSON(w, http.StatusOK, map[string]string{"deleted": id})
}

func (s *Server) executeBackup(ctx context.Context, req api.BackupRequest, requester string) (api.BackupResponse, string, error) {
	req.Namespace = strings.TrimSpace(req.Namespace)
	req.PVC = strings.TrimSpace(req.PVC)
	if req.Namespace == "" || req.PVC == "" {
		return api.BackupResponse{}, "validation_error", fmt.Errorf("namespace and pvc are required")
	}

	switch s.cfg.BackupDriver {
	case "longhorn":
		volumeName, _, _, err := s.client.ResolvePVCVolume(ctx, req.Namespace, req.PVC)
		if err != nil {
			return api.BackupResponse{}, "validation_error", err
		}

		backupID := backupName("backup", req.Namespace+"-"+req.PVC)
		response := api.BackupResponse{
			Driver:      "longhorn",
			Volume:      volumeName,
			Backup:      backupID,
			Namespace:   req.Namespace,
			RequestedBy: requester,
			DryRun:      req.DryRun,
		}
		if req.DryRun {
			return response, "dry_run", nil
		}

		labels := map[string]string{
			"soteria.bstein.dev/namespace":    req.Namespace,
			"soteria.bstein.dev/pvc":          req.PVC,
			"soteria.bstein.dev/requested-by": requester,
		}
		if err := s.longhorn.CreateSnapshot(ctx, volumeName, backupID, labels); err != nil {
			return api.BackupResponse{}, "backend_error", err
		}
		if _, err := s.longhorn.SnapshotBackup(ctx, volumeName, backupID, labels, s.cfg.LonghornBackupMode); err != nil {
			return api.BackupResponse{}, "backend_error", err
		}
		return response, "success", nil
	case "restic":
		jobName, secretName, err := s.client.CreateBackupJob(ctx, s.cfg, req)
		if err != nil {
			return api.BackupResponse{}, "backend_error", err
		}
		result := "success"
		if req.DryRun {
			result = "dry_run"
		}
		return api.BackupResponse{
			Driver:      "restic",
			JobName:     jobName,
			Namespace:   req.Namespace,
			Secret:      secretName,
			RequestedBy: requester,
			DryRun:      req.DryRun,
		}, result, nil
	default:
		return api.BackupResponse{}, "unsupported_driver", fmt.Errorf("unsupported backup driver")
	}
}

func (s *Server) executeRestore(ctx context.Context, req api.RestoreTestRequest, requester string) (api.RestoreTestResponse, string, error) {
	req.Namespace = strings.TrimSpace(req.Namespace)
	req.PVC = strings.TrimSpace(req.PVC)
	req.TargetNamespace = strings.TrimSpace(req.TargetNamespace)
	req.TargetPVC = strings.TrimSpace(req.TargetPVC)
	req.BackupURL = strings.TrimSpace(req.BackupURL)
	req.Snapshot = strings.TrimSpace(req.Snapshot)

	if req.TargetNamespace == "" {
		req.TargetNamespace = req.Namespace
	}

	switch s.cfg.BackupDriver {
	case "longhorn":
		exists, err := s.client.PersistentVolumeClaimExists(ctx, req.TargetNamespace, req.TargetPVC)
		if err != nil {
			return api.RestoreTestResponse{}, "validation_error", err
		}
		if exists {
			return api.RestoreTestResponse{}, "conflict", fmt.Errorf("target pvc %s/%s already exists", req.TargetNamespace, req.TargetPVC)
		}

		volumeName, _, _, err := s.client.ResolvePVCVolume(ctx, req.Namespace, req.PVC)
		if err != nil {
			return api.RestoreTestResponse{}, "validation_error", err
		}

		backupURL := req.BackupURL
		if backupURL == "" {
			backup, err := s.longhorn.FindBackup(ctx, volumeName, req.Snapshot)
			if err != nil {
				return api.RestoreTestResponse{}, "validation_error", err
			}
			backupURL = strings.TrimSpace(backup.URL)
		}
		if backupURL == "" {
			return api.RestoreTestResponse{}, "validation_error", fmt.Errorf("backup_url is required")
		}

		restoreVolumeName := backupName("restore", req.TargetNamespace+"-"+req.TargetPVC)
		response := api.RestoreTestResponse{
			Driver:          "longhorn",
			Volume:          restoreVolumeName,
			TargetNamespace: req.TargetNamespace,
			TargetPVC:       req.TargetPVC,
			BackupURL:       backupURL,
			Namespace:       req.Namespace,
			RequestedBy:     requester,
			DryRun:          req.DryRun,
		}
		if req.DryRun {
			return response, "dry_run", nil
		}

		sourceVolume, err := s.longhorn.GetVolume(ctx, volumeName)
		if err != nil {
			return api.RestoreTestResponse{}, "backend_error", err
		}
		replicas := sourceVolume.NumberOfReplicas
		if replicas == 0 {
			replicas = 2
		}

		if _, err := s.longhorn.CreateVolumeFromBackup(ctx, restoreVolumeName, sourceVolume.Size, replicas, backupURL); err != nil {
			return api.RestoreTestResponse{}, "backend_error", err
		}
		if err := s.longhorn.CreatePVC(ctx, restoreVolumeName, req.TargetNamespace, req.TargetPVC); err != nil {
			cleanupErr := s.longhorn.DeleteVolume(ctx, restoreVolumeName)
			if cleanupErr != nil {
				log.Printf("restore cleanup failed for %s: %v", restoreVolumeName, cleanupErr)
				return api.RestoreTestResponse{}, "backend_error", fmt.Errorf("create restore pvc: %v (cleanup failed: %v)", err, cleanupErr)
			}
			return api.RestoreTestResponse{}, "backend_error", fmt.Errorf("create restore pvc: %v", err)
		}
		return response, "success", nil
	case "restic":
		jobName, secretName, err := s.client.CreateRestoreJob(ctx, s.cfg, req)
		if err != nil {
			return api.RestoreTestResponse{}, "backend_error", err
		}
		result := "success"
		if req.DryRun {
			result = "dry_run"
		}
		return api.RestoreTestResponse{
			Driver:          "restic",
			JobName:         jobName,
			Namespace:       req.Namespace,
			TargetNamespace: req.TargetNamespace,
			TargetPVC:       req.TargetPVC,
			Secret:          secretName,
			RequestedBy:     requester,
			DryRun:          req.DryRun,
		}, result, nil
	default:
		return api.RestoreTestResponse{}, "unsupported_driver", fmt.Errorf("unsupported backup driver")
	}
}

func (s *Server) listNamespaceBoundPVCs(ctx context.Context, namespace string) ([]k8s.PVCSummary, error) {
	items, err := s.client.ListBoundPVCs(ctx)
	if err != nil {
		return nil, err
	}
	filtered := make([]k8s.PVCSummary, 0, len(items))
	for _, item := range items {
		if item.Namespace == namespace {
			filtered = append(filtered, item)
		}
	}
	return filtered, nil
}

func backupStatusCode(result string) int {
	switch result {
	case "validation_error", "unsupported_driver":
		return http.StatusBadRequest
	case "backend_error":
		return http.StatusBadGateway
	default:
		return http.StatusInternalServerError
	}
}

func restoreStatusCode(result string) int {
	switch result {
	case "validation_error", "unsupported_driver":
		return http.StatusBadRequest
	case "conflict":
		return http.StatusConflict
	case "backend_error":
		return http.StatusBadGateway
	default:
		return http.StatusInternalServerError
	}
}

func namespaceResultStatus(dryRun bool, total, succeeded, failed int) string {
	if dryRun {
		return "dry_run"
	}
	if total == 0 {
		return "empty"
	}
	if failed == 0 {
		return "success"
	}
	if succeeded == 0 {
		return "failed"
	}
	return "partial"
}

func targetPVCName(prefix, sourcePVC string) string {
	prefix = sanitizeName(prefix)
	if prefix == "" {
		prefix = "restore"
	}
	if !strings.HasSuffix(prefix, "-") {
		prefix += "-"
	}
	name := sanitizeName(prefix + sourcePVC)
	if name == "" {
		name = "restore"
	}
	if len(name) > 63 {
		name = strings.Trim(name[:63], "-")
	}
	if name == "" {
		name = "restore"
	}
	return name
}

func (s *Server) buildInventory(ctx context.Context) (api.InventoryResponse, error) {
	pvcs, err := s.client.ListBoundPVCs(ctx)
	if err != nil {
		return api.InventoryResponse{}, err
	}

	groups := make(map[string][]api.PVCInventory)
	for _, summary := range pvcs {
		entry := api.PVCInventory{
			Namespace:    summary.Namespace,
			PVC:          summary.Name,
			Volume:       summary.VolumeName,
			Phase:        summary.Phase,
			StorageClass: summary.StorageClass,
			Capacity:     summary.Capacity,
			AccessModes:  summary.AccessModes,
			Driver:       s.cfg.BackupDriver,
		}
		s.enrichPVCInventory(ctx, &entry)
		groups[summary.Namespace] = append(groups[summary.Namespace], entry)
	}

	namespaceNames := make([]string, 0, len(groups))
	for namespace := range groups {
		namespaceNames = append(namespaceNames, namespace)
	}
	sort.Strings(namespaceNames)

	response := api.InventoryResponse{
		GeneratedAt: time.Now().UTC().Format(time.RFC3339),
		Namespaces:  make([]api.NamespaceInventory, 0, len(namespaceNames)),
	}
	for _, namespace := range namespaceNames {
		response.Namespaces = append(response.Namespaces, api.NamespaceInventory{
			Name: namespace,
			PVCs: groups[namespace],
		})
	}
	return response, nil
}

func (s *Server) enrichPVCInventory(ctx context.Context, entry *api.PVCInventory) {
	switch s.cfg.BackupDriver {
	case "longhorn":
		backups, err := s.longhorn.ListBackups(ctx, entry.Volume)
		if err != nil {
			entry.Healthy = false
			entry.HealthReason = "lookup_failed"
			entry.Error = err.Error()
			return
		}
		entry.BackupCount = len(backups)
		totalBackupSize := int64(0)
		completedBackups := 0
		for _, backup := range backups {
			totalBackupSize += parseSizeBytes(backup.Size)
			if strings.EqualFold(backup.State, "Completed") {
				completedBackups++
			}
		}
		entry.CompletedBackups = completedBackups
		entry.TotalBackupSizeBytes = float64(totalBackupSize)
		latest, latestTime, ok := latestCompletedBackup(backups)
		if !ok {
			entry.Healthy = false
			if len(backups) == 0 {
				entry.HealthReason = "missing"
			} else {
				entry.HealthReason = "no_completed"
			}
			return
		}
		entry.LastBackupAt = latest.Created
		entry.LastBackupSizeBytes = float64(parseSizeBytes(latest.Size))
		if latestTime.IsZero() {
			entry.Healthy = false
			entry.HealthReason = "unknown_timestamp"
			return
		}
		entry.LastBackupAgeHours = roundHours(time.Since(latestTime).Hours())
		entry.Healthy = time.Since(latestTime) <= s.cfg.BackupMaxAge
		if entry.Healthy {
			entry.HealthReason = "fresh"
		} else {
			entry.HealthReason = "stale"
		}
	case "restic":
		jobs, err := s.client.ListBackupJobsForPVC(ctx, entry.Namespace, entry.PVC)
		if err != nil {
			entry.Healthy = false
			entry.HealthReason = "lookup_failed"
			entry.Error = err.Error()
			return
		}
		entry.BackupCount = len(jobs)

		completed := make([]k8s.BackupJobSummary, 0, len(jobs))
		for _, job := range jobs {
			if strings.EqualFold(job.State, "Completed") {
				completed = append(completed, job)
			}
		}
		entry.CompletedBackups = len(completed)
		if len(completed) == 0 {
			entry.Healthy = false
			if len(jobs) == 0 {
				entry.HealthReason = "missing"
			} else {
				entry.HealthReason = "no_completed"
			}
			return
		}

		latestTime := backupJobTimestamp(completed[0])
		if latestTime.IsZero() {
			entry.Healthy = false
			entry.HealthReason = "unknown_timestamp"
			return
		}
		entry.LastBackupAt = latestTime.UTC().Format(time.RFC3339)
		entry.LastBackupAgeHours = roundHours(time.Since(latestTime).Hours())
		entry.Healthy = time.Since(latestTime) <= s.cfg.BackupMaxAge
		if entry.Healthy {
			entry.HealthReason = "fresh"
		} else {
			entry.HealthReason = "stale"
		}
	default:
		entry.Healthy = false
		entry.HealthReason = "unsupported_driver"
	}
}

func (s *Server) refreshTelemetry(ctx context.Context) {
	refreshCtx, cancel := context.WithTimeout(ctx, 2*time.Minute)
	defer cancel()

	inventory, err := s.buildInventory(refreshCtx)
	if err != nil {
		log.Printf("inventory refresh failed: %v", err)
		s.metrics.RecordInventoryFailure()
		return
	}
	s.metrics.RecordInventory(inventory)
}

func (s *Server) runPolicyCycle(ctx context.Context) {
	if !s.beginRun() {
		return
	}
	defer s.endRun()

	policies := s.activePolicies()
	if len(policies) == 0 {
		return
	}

	runCtx, cancel := context.WithTimeout(ctx, 3*time.Minute)
	defer cancel()

	inventory, err := s.buildInventory(runCtx)
	if err != nil {
		log.Printf("policy cycle inventory failed: %v", err)
		s.metrics.RecordPolicyBackup("inventory_error")
		return
	}

	pvcMap := make(map[string]api.PVCInventory)
	namespaceMap := make(map[string][]api.PVCInventory)
	for _, group := range inventory.Namespaces {
		for _, pvc := range group.PVCs {
			key := pvc.Namespace + "/" + pvc.PVC
			pvcMap[key] = pvc
			namespaceMap[pvc.Namespace] = append(namespaceMap[pvc.Namespace], pvc)
		}
	}

	effectiveIntervals := map[string]float64{}
	for _, policy := range policies {
		matches := []api.PVCInventory{}
		if policy.PVC != "" {
			if pvc, ok := pvcMap[policy.Namespace+"/"+policy.PVC]; ok {
				matches = append(matches, pvc)
			}
		} else {
			matches = append(matches, namespaceMap[policy.Namespace]...)
		}

		for _, pvc := range matches {
			key := pvc.Namespace + "/" + pvc.PVC
			current, exists := effectiveIntervals[key]
			if !exists || policy.IntervalHours < current {
				effectiveIntervals[key] = policy.IntervalHours
			}
		}
	}

	for key, intervalHours := range effectiveIntervals {
		pvc, ok := pvcMap[key]
		if !ok {
			continue
		}
		if !backupDue(pvc.LastBackupAt, intervalHours) {
			s.metrics.RecordPolicyBackup("not_due")
			continue
		}

		_, result, err := s.executeBackup(runCtx, api.BackupRequest{
			Namespace: pvc.Namespace,
			PVC:       pvc.PVC,
			DryRun:    false,
		}, "policy-scheduler")
		s.metrics.RecordBackupRequest(s.cfg.BackupDriver, result)
		if err != nil {
			s.metrics.RecordPolicyBackup(result)
			log.Printf("policy backup failed for %s/%s: %v", pvc.Namespace, pvc.PVC, err)
			continue
		}
		s.metrics.RecordPolicyBackup("success")
	}
}

func (s *Server) beginRun() bool {
	s.runMu.Lock()
	defer s.runMu.Unlock()
	if s.running {
		return false
	}
	s.running = true
	return true
}

func (s *Server) endRun() {
	s.runMu.Lock()
	defer s.runMu.Unlock()
	s.running = false
}

func (s *Server) loadPolicies(ctx context.Context) error {
	raw, err := s.client.LoadSecretData(ctx, s.cfg.Namespace, s.cfg.PolicySecretName, policySecretKey)
	if err != nil {
		return err
	}
	if len(raw) == 0 {
		return nil
	}

	var doc struct {
		Policies []api.BackupPolicy `json:"policies"`
	}
	if err := json.Unmarshal(raw, &doc); err != nil {
		return fmt.Errorf("decode policy document: %w", err)
	}

	next := map[string]api.BackupPolicy{}
	now := time.Now().UTC().Format(time.RFC3339)
	for _, policy := range doc.Policies {
		namespace := strings.TrimSpace(policy.Namespace)
		pvc := strings.TrimSpace(policy.PVC)
		if namespace == "" {
			continue
		}
		interval := policy.IntervalHours
		if interval <= 0 {
			interval = defaultPolicyHours
		}
		id := policyKey(namespace, pvc)
		createdAt := policy.CreatedAt
		if createdAt == "" {
			createdAt = now
		}
		updatedAt := policy.UpdatedAt
		if updatedAt == "" {
			updatedAt = createdAt
		}
		next[id] = api.BackupPolicy{
			ID:            id,
			Namespace:     namespace,
			PVC:           pvc,
			IntervalHours: interval,
			Enabled:       policy.Enabled,
			CreatedAt:     createdAt,
			UpdatedAt:     updatedAt,
		}
	}

	s.policyMu.Lock()
	s.policies = next
	s.policyMu.Unlock()
	return nil
}

func (s *Server) persistPolicies(ctx context.Context, policies []api.BackupPolicy) error {
	doc := struct {
		Policies []api.BackupPolicy `json:"policies"`
	}{
		Policies: policies,
	}
	payload, err := json.Marshal(doc)
	if err != nil {
		return fmt.Errorf("encode policy document: %w", err)
	}
	return s.client.SaveSecretData(ctx, s.cfg.Namespace, s.cfg.PolicySecretName, policySecretKey, payload, map[string]string{
		"app.kubernetes.io/name":      "soteria",
		"app.kubernetes.io/component": "policy-store",
	})
}

func (s *Server) listPolicies() []api.BackupPolicy {
	s.policyMu.RLock()
	defer s.policyMu.RUnlock()
	policies := make([]api.BackupPolicy, 0, len(s.policies))
	for _, policy := range s.policies {
		policies = append(policies, policy)
	}
	sort.Slice(policies, func(i, j int) bool {
		if policies[i].Namespace != policies[j].Namespace {
			return policies[i].Namespace < policies[j].Namespace
		}
		if policies[i].PVC != policies[j].PVC {
			return policies[i].PVC < policies[j].PVC
		}
		return policies[i].ID < policies[j].ID
	})
	return policies
}

func (s *Server) activePolicies() []api.BackupPolicy {
	policies := s.listPolicies()
	filtered := make([]api.BackupPolicy, 0, len(policies))
	for _, policy := range policies {
		if policy.Enabled {
			filtered = append(filtered, policy)
		}
	}
	return filtered
}

func (s *Server) upsertPolicy(ctx context.Context, req api.BackupPolicyUpsertRequest) (api.BackupPolicy, error) {
	namespace := strings.TrimSpace(req.Namespace)
	pvc := strings.TrimSpace(req.PVC)
	if namespace == "" {
		return api.BackupPolicy{}, fmt.Errorf("namespace is required")
	}
	if err := validateKubernetesName("namespace", namespace); err != nil {
		return api.BackupPolicy{}, err
	}
	if pvc != "" {
		if err := validateKubernetesName("pvc", pvc); err != nil {
			return api.BackupPolicy{}, err
		}
	}

	interval := req.IntervalHours
	if interval <= 0 {
		interval = defaultPolicyHours
	}
	if interval > maxPolicyIntervalHrs {
		return api.BackupPolicy{}, fmt.Errorf("interval_hours must be <= %d", maxPolicyIntervalHrs)
	}
	enabled := true
	if req.Enabled != nil {
		enabled = *req.Enabled
	}

	id := policyKey(namespace, pvc)
	now := time.Now().UTC().Format(time.RFC3339)

	s.policyMu.Lock()
	before := clonePolicyMap(s.policies)
	createdAt := now
	if existing, ok := s.policies[id]; ok && existing.CreatedAt != "" {
		createdAt = existing.CreatedAt
	}
	policy := api.BackupPolicy{
		ID:            id,
		Namespace:     namespace,
		PVC:           pvc,
		IntervalHours: interval,
		Enabled:       enabled,
		CreatedAt:     createdAt,
		UpdatedAt:     now,
	}
	s.policies[id] = policy
	snapshot := policySliceFromMap(s.policies)
	s.policyMu.Unlock()

	if err := s.persistPolicies(ctx, snapshot); err != nil {
		s.policyMu.Lock()
		s.policies = before
		s.policyMu.Unlock()
		return api.BackupPolicy{}, err
	}
	return policy, nil
}

func (s *Server) deletePolicy(ctx context.Context, id string) (bool, error) {
	id = strings.TrimSpace(id)
	if id == "" {
		return false, nil
	}

	s.policyMu.Lock()
	if _, ok := s.policies[id]; !ok {
		s.policyMu.Unlock()
		return false, nil
	}
	before := clonePolicyMap(s.policies)
	delete(s.policies, id)
	snapshot := policySliceFromMap(s.policies)
	s.policyMu.Unlock()

	if err := s.persistPolicies(ctx, snapshot); err != nil {
		s.policyMu.Lock()
		s.policies = before
		s.policyMu.Unlock()
		return false, err
	}
	return true, nil
}

func policyKey(namespace, pvc string) string {
	scope := strings.TrimSpace(pvc)
	if scope == "" {
		scope = "_all"
	}
	return strings.TrimSpace(namespace) + "__" + scope
}

func policySliceFromMap(source map[string]api.BackupPolicy) []api.BackupPolicy {
	out := make([]api.BackupPolicy, 0, len(source))
	for _, policy := range source {
		out = append(out, policy)
	}
	sort.Slice(out, func(i, j int) bool {
		return out[i].ID < out[j].ID
	})
	return out
}

func clonePolicyMap(source map[string]api.BackupPolicy) map[string]api.BackupPolicy {
	cloned := make(map[string]api.BackupPolicy, len(source))
	for key, value := range source {
		cloned[key] = value
	}
	return cloned
}

func backupDue(lastBackupAt string, intervalHours float64) bool {
	if intervalHours <= 0 {
		intervalHours = defaultPolicyHours
	}
	if strings.TrimSpace(lastBackupAt) == "" {
		return true
	}
	timestamp, ok := parseBackupTime(lastBackupAt)
	if !ok {
		return true
	}
	interval := time.Duration(intervalHours * float64(time.Hour))
	return time.Since(timestamp) >= interval
}

func (s *Server) authorize(r *http.Request) (authIdentity, int, error) {
	if !s.cfg.AuthRequired {
		return authIdentity{}, http.StatusOK, nil
	}

	authorization := strings.TrimSpace(r.Header.Get("Authorization"))
	if strings.HasPrefix(strings.ToLower(authorization), "bearer ") {
		token := strings.TrimSpace(authorization[7:])
		for _, expected := range s.cfg.AuthBearerTokens {
			if token != "" && token == expected {
				return authIdentity{Authenticated: true, User: "service-token", Groups: []string{"service-token"}}, http.StatusOK, nil
			}
		}
	}

	identity := authIdentity{
		Authenticated: true,
		User:          firstHeader(r, "X-Auth-Request-User", "X-Forwarded-User"),
		Email:         firstHeader(r, "X-Auth-Request-Email", "X-Forwarded-Email"),
		Groups:        normalizeGroups(splitGroups(firstHeader(r, "X-Auth-Request-Groups", "X-Forwarded-Groups"))),
	}
	if identity.User == "" && identity.Email == "" {
		return authIdentity{}, http.StatusUnauthorized, fmt.Errorf("authentication required")
	}
	if len(s.cfg.AllowedGroups) == 0 {
		return identity, http.StatusOK, nil
	}
	if hasAllowedGroup(identity.Groups, s.cfg.AllowedGroups) {
		return identity, http.StatusOK, nil
	}
	return authIdentity{}, http.StatusForbidden, fmt.Errorf("access requires one of: %s", strings.Join(s.cfg.AllowedGroups, ", "))
}

func requesterFromContext(ctx context.Context) authIdentity {
	identity, _ := ctx.Value(authContextKey).(authIdentity)
	return identity
}

func currentRequester(ctx context.Context) string {
	identity := requesterFromContext(ctx)
	if identity.User != "" {
		return identity.User
	}
	if identity.Email != "" {
		return identity.Email
	}
	if identity.Authenticated {
		return "authenticated"
	}
	return "anonymous"
}

func authzReason(status int, err error) string {
	if err == nil {
		return "unknown"
	}
	switch status {
	case http.StatusUnauthorized:
		return "unauthenticated"
	case http.StatusForbidden:
		return "forbidden_group"
	default:
		return "error"
	}
}

func hasAllowedGroup(actual, allowed []string) bool {
	allowedSet := make(map[string]struct{}, len(allowed))
	for _, group := range normalizeGroups(allowed) {
		allowedSet[group] = struct{}{}
	}
	for _, group := range normalizeGroups(actual) {
		if _, ok := allowedSet[group]; ok {
			return true
		}
	}
	return false
}

func normalizeGroups(values []string) []string {
	groups := make([]string, 0, len(values))
	for _, value := range values {
		value = strings.TrimSpace(strings.TrimPrefix(value, "/"))
		if value == "" {
			continue
		}
		groups = append(groups, value)
	}
	return groups
}

func firstHeader(r *http.Request, names ...string) string {
	for _, name := range names {
		value := strings.TrimSpace(r.Header.Get(name))
		if value != "" {
			return value
		}
	}
	return ""
}

func splitGroups(raw string) []string {
	raw = strings.TrimSpace(raw)
	if raw == "" {
		return nil
	}
	return strings.FieldsFunc(raw, func(r rune) bool {
		return r == ',' || r == ';'
	})
}

func validateKubernetesName(field, value string) error {
	if errs := k8svalidation.IsDNS1123Label(value); len(errs) > 0 {
		return fmt.Errorf("%s must be a valid Kubernetes DNS-1123 label", field)
	}
	return nil
}

func buildBackupRecords(backups []longhorn.Backup) []api.BackupRecord {
	records := make([]api.BackupRecord, 0, len(backups))
	latestName := ""
	if latest, _, ok := latestCompletedBackup(backups); ok {
		latestName = latest.Name
	}

	sort.Slice(backups, func(i, j int) bool {
		left, lok := parseBackupTime(backups[i].Created)
		right, rok := parseBackupTime(backups[j].Created)
		switch {
		case lok && rok:
			return left.After(right)
		case lok:
			return true
		case rok:
			return false
		default:
			return backups[i].Name > backups[j].Name
		}
	})

	for _, backup := range backups {
		records = append(records, api.BackupRecord{
			Name:         backup.Name,
			SnapshotName: backup.SnapshotName,
			Created:      backup.Created,
			State:        backup.State,
			URL:          backup.URL,
			Size:         backup.Size,
			Latest:       backup.Name == latestName,
		})
	}
	return records
}

func buildResticBackupRecords(jobs []k8s.BackupJobSummary) []api.BackupRecord {
	records := make([]api.BackupRecord, 0, len(jobs))
	latestName := ""
	for _, job := range jobs {
		if strings.EqualFold(job.State, "Completed") {
			latestName = job.Name
			break
		}
	}

	for _, job := range jobs {
		created := ""
		if ts := backupJobTimestamp(job); !ts.IsZero() {
			created = ts.UTC().Format(time.RFC3339)
		}
		url := ""
		latest := job.Name == latestName
		if latest && strings.EqualFold(job.State, "Completed") {
			// The restore API defaults to "latest"; expose one selectable option in the UI.
			url = "latest"
		}
		records = append(records, api.BackupRecord{
			Name:         job.Name,
			SnapshotName: job.Name,
			Created:      created,
			State:        job.State,
			URL:          url,
			Latest:       latest,
		})
	}
	return records
}

func backupJobTimestamp(job k8s.BackupJobSummary) time.Time {
	if !job.CompletionTime.IsZero() {
		return job.CompletionTime
	}
	return job.CreatedAt
}

func latestCompletedBackup(backups []longhorn.Backup) (longhorn.Backup, time.Time, bool) {
	var selected longhorn.Backup
	var selectedTime time.Time
	found := false
	for _, backup := range backups {
		if backup.State != "Completed" {
			continue
		}
		createdAt, ok := parseBackupTime(backup.Created)
		if !ok {
			if !found {
				selected = backup
				found = true
			}
			continue
		}
		if !found || createdAt.After(selectedTime) {
			selected = backup
			selectedTime = createdAt
			found = true
		}
	}
	return selected, selectedTime, found
}

func parseBackupTime(raw string) (time.Time, bool) {
	layouts := []string{time.RFC3339Nano, time.RFC3339}
	for _, layout := range layouts {
		parsed, err := time.Parse(layout, raw)
		if err == nil {
			return parsed, true
		}
	}
	return time.Time{}, false
}

func writeJSON(w http.ResponseWriter, status int, payload any) {
	w.Header().Set("Content-Type", "application/json")
	w.WriteHeader(status)
	_ = json.NewEncoder(w).Encode(payload)
}

func writeError(w http.ResponseWriter, status int, message string) {
	writeJSON(w, status, map[string]string{"error": message})
}

func backupName(prefix, value string) string {
	base := sanitizeName(fmt.Sprintf("soteria-%s-%s", prefix, value))
	timestamp := time.Now().UTC().Format("20060102-150405")
	name := fmt.Sprintf("%s-%s", base, timestamp)
	if len(name) <= 63 {
		return name
	}
	maxBase := 63 - len(timestamp) - 1
	if maxBase < 1 {
		maxBase = 1
	}
	if len(base) > maxBase {
		base = base[:maxBase]
	}
	return fmt.Sprintf("%s-%s", base, timestamp)
}

func sanitizeName(value string) string {
	value = strings.ToLower(value)
	value = strings.ReplaceAll(value, "_", "-")
	value = strings.ReplaceAll(value, ".", "-")
	value = strings.ReplaceAll(value, " ", "-")
	value = strings.Trim(value, "-")
	return value
}

func roundHours(value float64) float64 {
	return math.Round(value*100) / 100
}

func parseSizeBytes(raw string) int64 {
	raw = strings.TrimSpace(raw)
	if raw == "" {
		return 0
	}
	if value, err := strconv.ParseInt(raw, 10, 64); err == nil {
		return value
	}
	if value, err := strconv.ParseFloat(raw, 64); err == nil {
		if value < 0 {
			return 0
		}
		return int64(value)
	}
	if quantity, err := resource.ParseQuantity(raw); err == nil {
		return quantity.Value()
	}
	return 0
}