EvoBGP/internal/store/memory_crud.go

package store

import (
	"fmt"
	"strconv"
	"strings"
	"time"

	"github.com/google/uuid"
)

var _ Backend = (*Memory)(nil)

func (m *Memory) CreateModule(tenantID string, in *Module) (*Module, error) {
	if in == nil || strings.TrimSpace(in.Type) == "" || strings.TrimSpace(in.Name) == "" {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, ok := m.tenants[tenantID]; !ok {
		return nil, ErrTenantScope
	}
	id := uuid.NewString()
	mod := &Module{
		ID:                 id,
		TenantID:           tenantID,
		Type:               in.Type,
		Name:               strings.TrimSpace(in.Name),
		Enabled:            in.Enabled,
		Priority:           in.Priority,
		RefreshIntervalSec: in.RefreshIntervalSec,
		CronExpr:           in.CronExpr,
		DefaultCommunityID: in.DefaultCommunityID,
		DohProfileID:       in.DohProfileID,
		LastRefreshedAt:    in.LastRefreshedAt,
	}
	m.modules[id] = mod
	return mod, nil
}

func (m *Memory) UpdateModule(tenantID, moduleID string, patch *ModulePatch) (*Module, error) {
	if patch == nil {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	mod, ok := m.modules[moduleID]
	if !ok || mod.DeletedAt != nil || mod.TenantID != tenantID {
		return nil, ErrNotFound
	}
	if patch.Name != nil {
		mod.Name = strings.TrimSpace(*patch.Name)
	}
	if patch.Enabled != nil {
		mod.Enabled = *patch.Enabled
	}
	if patch.Priority != nil {
		mod.Priority = *patch.Priority
	}
	if patch.RefreshIntervalSec != nil {
		mod.RefreshIntervalSec = *patch.RefreshIntervalSec
	}
	if patch.CronExpr != nil {
		mod.CronExpr = *patch.CronExpr
	}
	if patch.DefaultCommunityID != nil {
		v := strings.TrimSpace(*patch.DefaultCommunityID)
		if v == "" {
			mod.DefaultCommunityID = nil
		} else {
			mod.DefaultCommunityID = &v
		}
	}
	if patch.DohProfileID != nil {
		v := strings.TrimSpace(*patch.DohProfileID)
		if v == "" {
			mod.DohProfileID = nil
		} else {
			mod.DohProfileID = &v
		}
	}
	if patch.LastRefreshedAt != nil {
		t := patch.LastRefreshedAt.UTC()
		mod.LastRefreshedAt = &t
	}
	return mod, nil
}

func (m *Memory) SoftDeleteModule(tenantID, moduleID string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if m.moduleSnapshots != nil {
		delete(m.moduleSnapshots, moduleSnapshotKey(tenantID, moduleID))
	}
	mod, ok := m.modules[moduleID]
	if !ok || mod.TenantID != tenantID {
		return ErrNotFound
	}
	now := time.Now().UTC()
	mod.DeletedAt = &now
	return nil
}

func (m *Memory) moduleWriteOK(tenantID, moduleID string) (*Module, error) {
	mod, ok := m.modules[moduleID]
	if !ok || mod.DeletedAt != nil || mod.TenantID != tenantID {
		return nil, ErrNotFound
	}
	return mod, nil
}

func (m *Memory) ListCDNSources(tenantID, moduleID string) ([]*CDNSource, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	mod, err := m.moduleWriteOK(tenantID, moduleID)
	if err != nil {
		return nil, err
	}
	if mod.Type != "CDN_CIDRS" {
		return nil, ErrInvalidInput
	}
	var out []*CDNSource
	for _, s := range m.cdnSources {
		if s.ModuleID == moduleID {
			out = append(out, s)
		}
	}
	return out, nil
}

func (m *Memory) CreateCDNSource(tenantID, moduleID string, in *CDNSource) (*CDNSource, error) {
	if in == nil || strings.TrimSpace(in.URL) == "" {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	mod, err := m.moduleWriteOK(tenantID, moduleID)
	if err != nil {
		return nil, err
	}
	if mod.Type != "CDN_CIDRS" {
		return nil, ErrInvalidInput
	}
	id := uuid.NewString()
	s := &CDNSource{
		ID:                 id,
		ModuleID:           moduleID,
		SourceKind:         in.SourceKind,
		URL:                strings.TrimSpace(in.URL),
		PrefixPath:         strings.TrimSpace(in.PrefixPath),
		Etag:               in.Etag,
		RefreshIntervalSec: in.RefreshIntervalSec,
		CommunityID:        in.CommunityID,
		LastRefreshedAt:    in.LastRefreshedAt,
	}
	m.cdnSources[id] = s
	return s, nil
}

func (m *Memory) UpdateCDNSource(tenantID, moduleID, sourceID string, patch *CDNSourcePatch) (*CDNSource, error) {
	if patch == nil {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, err := m.moduleWriteOK(tenantID, moduleID); err != nil {
		return nil, err
	}
	s, ok := m.cdnSources[sourceID]
	if !ok || s.ModuleID != moduleID {
		return nil, ErrNotFound
	}
	if patch.SourceKind != nil {
		s.SourceKind = *patch.SourceKind
	}
	if patch.URL != nil {
		s.URL = strings.TrimSpace(*patch.URL)
	}
	if patch.PrefixPath != nil {
		s.PrefixPath = strings.TrimSpace(*patch.PrefixPath)
	}
	if patch.Etag != nil {
		s.Etag = *patch.Etag
	}
	if patch.RefreshIntervalSec != nil {
		s.RefreshIntervalSec = patch.RefreshIntervalSec
	}
	if patch.CommunityID != nil {
		v := strings.TrimSpace(*patch.CommunityID)
		if v == "" {
			s.CommunityID = nil
		} else {
			s.CommunityID = &v
		}
	}
	if patch.LastRefreshedAt != nil {
		t := patch.LastRefreshedAt.UTC()
		s.LastRefreshedAt = &t
	}
	return s, nil
}

func (m *Memory) DeleteCDNSource(tenantID, moduleID, sourceID string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, err := m.moduleWriteOK(tenantID, moduleID); err != nil {
		return err
	}
	s, ok := m.cdnSources[sourceID]
	if !ok || s.ModuleID != moduleID {
		return ErrNotFound
	}
	delete(m.cdnSources, sourceID)
	return nil
}

func (m *Memory) ListASEntries(tenantID, moduleID string) ([]*ASEntry, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	mod, err := m.moduleWriteOK(tenantID, moduleID)
	if err != nil {
		return nil, err
	}
	if mod.Type != "AS_PREFIXES" {
		return nil, ErrInvalidInput
	}
	var out []*ASEntry
	for _, e := range m.asEntries {
		if e.ModuleID == moduleID {
			out = append(out, e)
		}
	}
	return out, nil
}

func (m *Memory) CreateASEntry(tenantID, moduleID string, in *ASEntry) (*ASEntry, error) {
	if in == nil || !ValidASN(in.ASN) {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	mod, err := m.moduleWriteOK(tenantID, moduleID)
	if err != nil {
		return nil, err
	}
	if mod.Type != "AS_PREFIXES" {
		return nil, ErrInvalidInput
	}
	id := uuid.NewString()
	e := &ASEntry{ID: id, ModuleID: moduleID, ASN: in.ASN, CommunityID: in.CommunityID}
	m.asEntries[id] = e
	return e, nil
}

func (m *Memory) UpdateASEntry(tenantID, moduleID, entryID string, patch *ASEntryPatch) (*ASEntry, error) {
	if patch == nil {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, err := m.moduleWriteOK(tenantID, moduleID); err != nil {
		return nil, err
	}
	e, ok := m.asEntries[entryID]
	if !ok || e.ModuleID != moduleID {
		return nil, ErrNotFound
	}
	prevASN := e.ASN
	if patch.ASN != nil {
		e.ASN = *patch.ASN
	}
	if patch.CommunityID != nil {
		v := strings.TrimSpace(*patch.CommunityID)
		if v == "" {
			e.CommunityID = nil
		} else {
			e.CommunityID = &v
		}
	}
	if !ValidASN(e.ASN) {
		return nil, ErrInvalidInput
	}
	if patch.ASN != nil && e.ASN != prevASN {
		e.ASNName = ""
		e.PrefixCount = nil
		e.ASNResolvedAt = nil
	}
	return e, nil
}

func (m *Memory) UpdateASEntryResolveMeta(tenantID, moduleID, entryID string, asnName string, prefixCount int64, resolvedAt time.Time) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, err := m.moduleWriteOK(tenantID, moduleID); err != nil {
		return err
	}
	e, ok := m.asEntries[entryID]
	if !ok || e.ModuleID != moduleID {
		return ErrNotFound
	}
	e.ASNName = strings.TrimSpace(asnName)
	pc := prefixCount
	e.PrefixCount = &pc
	t := resolvedAt.UTC()
	e.ASNResolvedAt = &t
	return nil
}

func (m *Memory) DeleteASEntry(tenantID, moduleID, entryID string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, err := m.moduleWriteOK(tenantID, moduleID); err != nil {
		return err
	}
	e, ok := m.asEntries[entryID]
	if !ok || e.ModuleID != moduleID {
		return ErrNotFound
	}
	delete(m.asEntries, entryID)
	return nil
}

func (m *Memory) ListDomainEntries(tenantID, moduleID string) ([]*DomainEntry, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	mod, err := m.moduleWriteOK(tenantID, moduleID)
	if err != nil {
		return nil, err
	}
	if mod.Type != "DOMAINS" {
		return nil, ErrInvalidInput
	}
	var out []*DomainEntry
	for _, e := range m.domainEnt {
		if e.ModuleID == moduleID {
			out = append(out, e)
		}
	}
	return out, nil
}

func (m *Memory) CreateDomainEntry(tenantID, moduleID string, in *DomainEntry) (*DomainEntry, error) {
	if in == nil || strings.TrimSpace(in.FQDN) == "" {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	mod, err := m.moduleWriteOK(tenantID, moduleID)
	if err != nil {
		return nil, err
	}
	if mod.Type != "DOMAINS" {
		return nil, ErrInvalidInput
	}
	id := uuid.NewString()
	e := &DomainEntry{ID: id, ModuleID: moduleID, FQDN: strings.TrimSpace(in.FQDN), CommunityID: in.CommunityID}
	m.domainEnt[id] = e
	return e, nil
}

func (m *Memory) UpdateDomainEntry(tenantID, moduleID, entryID string, patch *DomainEntryPatch) (*DomainEntry, error) {
	if patch == nil {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, err := m.moduleWriteOK(tenantID, moduleID); err != nil {
		return nil, err
	}
	e, ok := m.domainEnt[entryID]
	if !ok || e.ModuleID != moduleID {
		return nil, ErrNotFound
	}
	if patch.FQDN != nil {
		e.FQDN = strings.TrimSpace(*patch.FQDN)
	}
	if patch.CommunityID != nil {
		v := strings.TrimSpace(*patch.CommunityID)
		if v == "" {
			e.CommunityID = nil
		} else {
			e.CommunityID = &v
		}
	}
	return e, nil
}

func (m *Memory) DeleteDomainEntry(tenantID, moduleID, entryID string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, err := m.moduleWriteOK(tenantID, moduleID); err != nil {
		return err
	}
	e, ok := m.domainEnt[entryID]
	if !ok || e.ModuleID != moduleID {
		return ErrNotFound
	}
	delete(m.domainEnt, entryID)
	return nil
}

func (m *Memory) ListIPRangeEntries(tenantID, moduleID string) ([]*IPRangeEntry, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	mod, err := m.moduleWriteOK(tenantID, moduleID)
	if err != nil {
		return nil, err
	}
	if mod.Type != "IP_RANGES" {
		return nil, ErrInvalidInput
	}
	var out []*IPRangeEntry
	for _, e := range m.ipRanges {
		if e.ModuleID == moduleID {
			out = append(out, e)
		}
	}
	return out, nil
}

func (m *Memory) CreateIPRangeEntry(tenantID, moduleID string, in *IPRangeEntry) (*IPRangeEntry, error) {
	if in == nil || strings.TrimSpace(in.Prefix) == "" {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	mod, err := m.moduleWriteOK(tenantID, moduleID)
	if err != nil {
		return nil, err
	}
	if mod.Type != "IP_RANGES" {
		return nil, ErrInvalidInput
	}
	id := uuid.NewString()
	e := &IPRangeEntry{ID: id, ModuleID: moduleID, Prefix: strings.TrimSpace(in.Prefix), CommunityID: in.CommunityID}
	m.ipRanges[id] = e
	return e, nil
}

func (m *Memory) UpdateIPRangeEntry(tenantID, moduleID, entryID string, patch *IPRangePatch) (*IPRangeEntry, error) {
	if patch == nil {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, err := m.moduleWriteOK(tenantID, moduleID); err != nil {
		return nil, err
	}
	e, ok := m.ipRanges[entryID]
	if !ok || e.ModuleID != moduleID {
		return nil, ErrNotFound
	}
	if patch.Prefix != nil {
		e.Prefix = strings.TrimSpace(*patch.Prefix)
	}
	if patch.CommunityID != nil {
		v := strings.TrimSpace(*patch.CommunityID)
		if v == "" {
			e.CommunityID = nil
		} else {
			e.CommunityID = &v
		}
	}
	return e, nil
}

func (m *Memory) DeleteIPRangeEntry(tenantID, moduleID, entryID string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, err := m.moduleWriteOK(tenantID, moduleID); err != nil {
		return err
	}
	e, ok := m.ipRanges[entryID]
	if !ok || e.ModuleID != moduleID {
		return ErrNotFound
	}
	delete(m.ipRanges, entryID)
	return nil
}

func (m *Memory) ListDohProfiles(tenantID string) ([]*DohProfile, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	var out []*DohProfile
	for _, p := range m.dohProfiles {
		if p.TenantID == tenantID {
			out = append(out, p)
		}
	}
	return out, nil
}

func (m *Memory) GetDohProfile(tenantID, id string) (*DohProfile, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	p, ok := m.dohProfiles[id]
	if !ok || p.TenantID != tenantID {
		return nil, ErrNotFound
	}
	return p, nil
}

func (m *Memory) CreateDohProfile(tenantID string, in *DohProfile) (*DohProfile, error) {
	if in == nil || strings.TrimSpace(in.URL) == "" {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, ok := m.tenants[tenantID]; !ok {
		return nil, ErrTenantScope
	}
	id := uuid.NewString()
	p := &DohProfile{
		ID:        id,
		TenantID:  tenantID,
		Name:      in.Name,
		URL:       strings.TrimSpace(in.URL),
		TimeoutMs: in.TimeoutMs,
		SecretRef: in.SecretRef,
	}
	m.dohProfiles[id] = p
	return p, nil
}

func (m *Memory) UpdateDohProfile(tenantID, id string, patch *DohProfilePatch) (*DohProfile, error) {
	if patch == nil {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	p, ok := m.dohProfiles[id]
	if !ok || p.TenantID != tenantID {
		return nil, ErrNotFound
	}
	if patch.Name != nil {
		p.Name = *patch.Name
	}
	if patch.URL != nil {
		p.URL = strings.TrimSpace(*patch.URL)
	}
	if patch.TimeoutMs != nil {
		p.TimeoutMs = patch.TimeoutMs
	}
	if patch.SecretRef != nil {
		p.SecretRef = patch.SecretRef
	}
	return p, nil
}

func (m *Memory) DeleteDohProfile(tenantID, id string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	p, ok := m.dohProfiles[id]
	if !ok || p.TenantID != tenantID {
		return ErrNotFound
	}
	for _, mod := range m.modules {
		if mod.DohProfileID != nil && *mod.DohProfileID == id {
			return ErrInvalidInput
		}
	}
	delete(m.dohProfiles, id)
	return nil
}

func (m *Memory) ListCommunities(tenantID string) ([]*Community, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	var out []*Community
	for _, c := range m.communities {
		if c.TenantID == tenantID {
			out = append(out, c)
		}
	}
	return out, nil
}

func (m *Memory) GetCommunity(tenantID, id string) (*Community, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	c, ok := m.communities[id]
	if !ok || c.TenantID != tenantID {
		return nil, ErrNotFound
	}
	return c, nil
}

func (m *Memory) CreateCommunity(tenantID string, in *Community) (*Community, error) {
	if in == nil || strings.TrimSpace(in.Community) == "" {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, ok := m.tenants[tenantID]; !ok {
		return nil, ErrTenantScope
	}
	id := uuid.NewString()
	vj := in.ValueJSON
	if strings.TrimSpace(vj) == "" {
		vj = "{}"
	}
	c := &Community{ID: id, TenantID: tenantID, Community: strings.TrimSpace(in.Community), Title: strings.TrimSpace(in.Title), ValueJSON: vj}
	m.communities[id] = c
	return c, nil
}

func (m *Memory) UpdateCommunity(tenantID, id string, patch *CommunityPatch) (*Community, error) {
	if patch == nil {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	c, ok := m.communities[id]
	if !ok || c.TenantID != tenantID {
		return nil, ErrNotFound
	}
	if patch.Community != nil {
		c.Community = strings.TrimSpace(*patch.Community)
	}
	if patch.Title != nil {
		c.Title = strings.TrimSpace(*patch.Title)
	}
	if patch.ValueJSON != nil {
		c.ValueJSON = *patch.ValueJSON
	}
	return c, nil
}

func (m *Memory) DeleteCommunity(tenantID, id string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	c, ok := m.communities[id]
	if !ok || c.TenantID != tenantID {
		return ErrNotFound
	}
	_ = c
	// weak check: modules default_community
	for _, mod := range m.modules {
		if mod.DefaultCommunityID != nil && *mod.DefaultCommunityID == id {
			return ErrInvalidInput
		}
	}
	delete(m.communities, id)
	return nil
}

func (m *Memory) GetPeer(tenantID, id string) (*BGPPeer, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	p, ok := m.peers[id]
	if !ok || p.TenantID != tenantID {
		return nil, ErrNotFound
	}
	return p, nil
}

func (m *Memory) CreatePeer(tenantID string, in *BGPPeer) (*BGPPeer, error) {
	if in == nil || in.RemoteASN == 0 {
		return nil, ErrInvalidInput
	}
	neighbor, ok := NormalizePeerNeighborString(in.Neighbor)
	if !ok {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, ok := m.tenants[tenantID]; !ok {
		return nil, ErrTenantScope
	}
	id := uuid.NewString()
	p := &BGPPeer{
		ID: id, TenantID: tenantID, SpeakerID: in.SpeakerID, Name: in.Name,
		Neighbor: neighbor, RemoteASN: in.RemoteASN,
		Enabled:      EffectivePeerEnabledOnCreate(in.Enabled, in.SessionState),
		SessionState: in.SessionState, PoliciesJSON: in.PoliciesJSON,
	}
	m.peers[id] = p
	return p, nil
}

func (m *Memory) UpdatePeer(tenantID, id string, patch *PeerPatch) (*BGPPeer, error) {
	if patch == nil {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	p, ok := m.peers[id]
	if !ok || p.TenantID != tenantID {
		return nil, ErrNotFound
	}
	if patch.Neighbor != nil {
		n, ok := NormalizePeerNeighborString(*patch.Neighbor)
		if !ok {
			return nil, ErrInvalidInput
		}
		p.Neighbor = n
	}
	if patch.RemoteASN != nil {
		p.RemoteASN = *patch.RemoteASN
	}
	if patch.SpeakerID != nil {
		v := strings.TrimSpace(*patch.SpeakerID)
		if v == "" {
			p.SpeakerID = nil
		} else {
			p.SpeakerID = &v
		}
	}
	if patch.Enabled != nil {
		p.Enabled = *patch.Enabled
	}
	if patch.Name != nil {
		p.Name = *patch.Name
	}
	if patch.SessionState != nil {
		p.SessionState = *patch.SessionState
	}
	if patch.PoliciesJSON != nil {
		p.PoliciesJSON = *patch.PoliciesJSON
	}
	return p, nil
}

func (m *Memory) DeletePeer(tenantID, id string) error {
	m.mu.Lock()
	defer m.mu.Unlock()
	p, ok := m.peers[id]
	if !ok || p.TenantID != tenantID {
		return ErrNotFound
	}
	delete(m.peers, id)
	_ = p
	return nil
}

func (m *Memory) CreateSpeaker(tenantID string, in *Speaker) (*Speaker, error) {
	if in == nil || strings.TrimSpace(in.Role) == "" {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, ok := m.tenants[tenantID]; !ok {
		return nil, ErrTenantScope
	}
	id := uuid.NewString()
	sp := &Speaker{ID: id, TenantID: tenantID, Role: strings.TrimSpace(in.Role), Endpoint: in.Endpoint, MetaJSON: in.MetaJSON}
	m.speakers[id] = sp
	return sp, nil
}

func (m *Memory) UpdateSpeaker(tenantID, id string, patch *SpeakerPatch) (*Speaker, error) {
	if patch == nil {
		return nil, ErrInvalidInput
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	sp, ok := m.speakers[id]
	if !ok || sp.TenantID != tenantID {
		return nil, ErrNotFound
	}
	if patch.Role != nil {
		sp.Role = strings.TrimSpace(*patch.Role)
	}
	if patch.Endpoint != nil {
		sp.Endpoint = *patch.Endpoint
	}
	if patch.MetaJSON != nil {
		sp.MetaJSON = *patch.MetaJSON
	}
	return sp, nil
}

func (m *Memory) ListRevisionPrefixes(tenantID, revisionID string, cursor string, limit int) ([]PrefixRow, string, bool) {
	if limit <= 0 {
		limit = 50
	}
	m.mu.RLock()
	defer m.mu.RUnlock()
	if _, err := m.getRevisionLocked(tenantID, revisionID); err != nil {
		return nil, "", false
	}
	all := m.revPrefixes[revisionID]
	off := 0
	if cursor != "" {
		if n, err := strconv.Atoi(cursor); err == nil && n >= 0 {
			off = n
		}
	}
	end := off + limit
	next := ""
	more := false
	if end > len(all) {
		end = len(all)
	} else {
		more = true
		next = fmt.Sprintf("%d", end)
	}
	if off >= len(all) {
		return nil, "", false
	}
	return all[off:end], next, more
}

func (m *Memory) ListGlobalSettings(tenantID string) (map[string]any, error) {
	m.mu.RLock()
	defer m.mu.RUnlock()
	if m.settings[tenantID] == nil {
		return map[string]any{}, nil
	}
	out := make(map[string]any, len(m.settings[tenantID]))
	for k, v := range m.settings[tenantID] {
		out[k] = v
	}
	return out, nil
}

func (m *Memory) PatchGlobalSettings(tenantID string, patch map[string]any) error {
	if patch == nil {
		return nil
	}
	m.mu.Lock()
	defer m.mu.Unlock()
	if _, ok := m.tenants[tenantID]; !ok {
		return ErrTenantScope
	}
	if m.settings[tenantID] == nil {
		m.settings[tenantID] = make(map[string]any)
	}
	for key, val := range patch {
		if strings.TrimSpace(key) == "" {
			continue
		}
		if val == nil {
			delete(m.settings[tenantID], key)
			continue
		}
		m.settings[tenantID][key] = val
	}
	return nil
}