package api

import (
	"context"
	"crypto/sha256"
	"encoding/hex"
	"errors"
	"fmt"
	"github.com/jackc/pgx/v5/pgconn"
	"net/http"
	"strings"
	"sync"
	"time"

	"github.com/jackc/pgx/v5"

	"github.com/loyaly/behavision-server/internal/auth"
)

// fakeStore is an in-memory Store. Handlers are where the security decisions
// live - which tenant, which message on failure, what is echoed back - and
// those are exactly what a real database would make slow and awkward to test.
type fakeStore struct {
	// Which tenant and site each camera belongs to. The live relay is keyed on
	// a camera id and a hub does not know whose camera it holds, so ownership
	// is proved before anything streams - and that is what these tests check.
	cameraRefs map[string]cameraRef

	// Camera pictures held by the server, for a deployment with no bucket.
	// Keyed as written by PutCameraSnapshot (by camera_id) and as read by
	// CameraSnapshot ("client/camera"), so a test has to say which it means.
	snapshots          map[string][]byte
	snapshotRejects    bool
	lastSnapshotClient string
	lastSnapshotSite   string

	mu sync.Mutex

	users     map[string]UserRecord // by lower-cased email
	sessions  map[string]*fakeSession
	byAccess  map[string]string // access hash hex -> session id
	byRefresh map[string]string

	visitors  []Customer
	history   []VisitRow
	footfall  []FootfallPoint
	totals    Totals
	sales     SalesReport
	sites     []SiteHealth
	enrolment map[string]Enrolment

	// Recorded calls, so a test can assert what the handler asked for rather
	// than only what it returned.
	lastReport        ReportQuery
	lastProfile       Profile
	lastProfileClient string
	lastPurchase      PurchaseInput
	audits            []AuditEntry

	// arrivals is the whole table; arrivalQ records what the handler asked for
	// so a test can assert on the keyset window rather than only its output.
	arrivals     []Arrival
	arrivalQ     ArrivalQuery
	arrivalsErr  error
	arrivalCalls int

	pendingChecks    []AgentCheckJob
	checkResults     []AgentCheckResult
	releasedStale    int
	lastCodeActor    string
	lastCodeTTL      time.Duration
	lastCheckKind    string
	lastCheckSeconds int

	// Invitations, and the faces this server holds itself.
	invites        map[string]*fakeInvite // by code hash hex
	faces          map[string][]byte      // "client/id"
	lastFaceClient string
	lastFaceSite   string
	deletedFaces   []string
	faceDeleteErr  error

	cameras          []Camera
	agentCameras     []AgentCamera
	lastCameraReport AgentCameraReport
	lastReportClient string
	lastReportSite   string
	saveCameraErr    error
	lastSaved        CameraInput

	clients       []ClientRow
	lastNewClient NewClientInput
	newClientErr  error
	loginTouched  []string

	profileErr  error
	purchaseErr error
	forgetErr   error
	nextID      int

	agentTokens map[string]AgentPrincipal
	imageKeys   map[string]string
	forgotten   []string
}

type fakeSession struct {
	id                    string
	p                     auth.Principal
	accessExp, refreshExp time.Time
	device                string
	revoked               bool
}

func newFakeStore() *fakeStore {
	return &fakeStore{
		users:       map[string]UserRecord{},
		sessions:    map[string]*fakeSession{},
		byAccess:    map[string]string{},
		byRefresh:   map[string]string{},
		enrolment:   map[string]Enrolment{},
		agentTokens: map[string]AgentPrincipal{},
		imageKeys:   map[string]string{},
	}
}

func (f *fakeStore) addUser(email, password string, rec UserRecord) {
	hash, err := auth.HashPassword(password)
	if err != nil {
		panic(err)
	}
	rec.Email = email
	rec.PasswordHash = hash
	rec.Found = true
	if rec.ID == "" {
		rec.ID = "user-" + email
	}
	if rec.Role == "" {
		rec.Role = "manager"
	}
	f.users[auth.NormalizeEmail(email)] = rec
}

func (f *fakeStore) UserByEmail(_ context.Context, email string) (UserRecord, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	u, ok := f.users[email]
	if !ok {
		return UserRecord{Found: false}, nil
	}
	return u, nil
}

func (f *fakeStore) TouchUserLogin(_ context.Context, id string) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.loginTouched = append(f.loginTouched, id)
	return nil
}

func (f *fakeStore) CreateSession(_ context.Context, n NewSession) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.nextID++
	// uuid-SHAPED, because the handlers validate the shape of an id before
	// spending a database round trip on it. A fake that mints "sess-1" would
	// make every id-addressed session route 404 in tests and pass in
	// production, which is the wrong way round.
	id := fmt.Sprintf("00000000-0000-4000-8000-%012d", f.nextID)
	var rec UserRecord
	for _, u := range f.users {
		if u.ID == n.UserID {
			rec = u
		}
	}
	s := &fakeSession{
		id: id,
		p: auth.Principal{
			UserID: n.UserID, SessionID: id, ClientID: n.ClientID,
			ClientName: rec.ClientName, Email: rec.Email,
			FullName: rec.FullName, Role: rec.Role,
		},
		accessExp: n.AccessExpiry, refreshExp: n.RefreshExp,
		device: n.Device,
	}
	f.sessions[id] = s
	f.byAccess[hex.EncodeToString(n.AccessHash)] = id
	f.byRefresh[hex.EncodeToString(n.RefreshHash)] = id
	return nil
}

func (f *fakeStore) lookup(index map[string]string, hash []byte, refresh bool) (
	auth.Principal, time.Time, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	id, ok := index[hex.EncodeToString(hash)]
	if !ok {
		return auth.Principal{}, time.Time{}, auth.ErrNoSession
	}
	s := f.sessions[id]
	if s == nil || s.revoked {
		return auth.Principal{}, time.Time{}, auth.ErrNoSession
	}
	if refresh {
		return s.p, s.refreshExp, nil
	}
	return s.p, s.accessExp, nil
}

func (f *fakeStore) SessionByAccess(_ context.Context, h []byte) (auth.Principal, time.Time, error) {
	return f.lookup(f.byAccess, h, false)
}

func (f *fakeStore) SessionByRefresh(_ context.Context, h []byte) (auth.Principal, time.Time, error) {
	return f.lookup(f.byRefresh, h, true)
}

func (f *fakeStore) RotateSession(_ context.Context, id string, n NewSession) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	s := f.sessions[id]
	if s == nil || s.revoked {
		return auth.ErrNoSession
	}
	// Mirrors the real store: the old hashes stop resolving the moment the new
	// ones are written.
	for k, v := range f.byAccess {
		if v == id {
			delete(f.byAccess, k)
		}
	}
	for k, v := range f.byRefresh {
		if v == id {
			delete(f.byRefresh, k)
		}
	}
	f.byAccess[hex.EncodeToString(n.AccessHash)] = id
	f.byRefresh[hex.EncodeToString(n.RefreshHash)] = id
	s.accessExp, s.refreshExp = n.AccessExpiry, n.RefreshExp
	return nil
}

func (f *fakeStore) RevokeSession(_ context.Context, id string) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	if s := f.sessions[id]; s != nil {
		s.revoked = true
	}
	return nil
}

func (f *fakeStore) Footfall(_ context.Context, q ReportQuery) ([]FootfallPoint, Totals, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.lastReport = q
	return f.footfall, f.totals, nil
}

func (f *fakeStore) Conversion(_ context.Context, q ReportQuery) (SalesReport, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.lastReport = q
	return f.sales, nil
}

func (f *fakeStore) CreateSite(_ context.Context, clientID, slug, name, tz string) (NewSite, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	for _, s := range f.sites {
		if s.Slug == slug {
			return NewSite{}, &pgconn.PgError{Code: "23505"}
		}
	}
	id := "site-" + slug
	f.sites = append(f.sites, SiteHealth{SiteID: id, Slug: slug, Name: name, Timezone: tz})
	return NewSite{SiteID: id, Slug: slug, Name: name, Timezone: tz, Username: "acme." + slug, Password: "pw-" + slug}, nil
}

func (f *fakeStore) DeleteNewSite(_ context.Context, _ string, siteID string) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	kept := f.sites[:0]
	for _, s := range f.sites {
		if s.SiteID != siteID {
			kept = append(kept, s)
		}
	}
	f.sites = kept
	return nil
}

func (f *fakeStore) SiteHealth(_ context.Context, _ string) ([]SiteHealth, error) {
	return f.sites, nil
}

func (f *fakeStore) SearchVisitors(_ context.Context, clientID, q string, limit int) (
	[]Customer, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.lastReport = ReportQuery{ClientID: clientID}
	if limit < len(f.visitors) {
		return f.visitors[:limit], nil
	}
	return f.visitors, nil
}

func (f *fakeStore) VisitorHistory(_ context.Context, _, _ string, _ int) ([]VisitRow, error) {
	return f.history, nil
}

// Arrivals fakes the keyset window in memory: rows are held oldest-first, a
// cursor slices past it, and no cursor returns the newest Limit - the same
// contract the SQL implements, so a handler test that passes here is testing
// the handler and not a stub that is easier than the real thing.
func (f *fakeStore) Arrivals(_ context.Context, q ArrivalQuery) ([]Arrival, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.arrivalQ = q
	f.arrivalCalls++
	if f.arrivalsErr != nil {
		return nil, f.arrivalsErr
	}
	rows := make([]Arrival, 0, len(f.arrivals))
	for _, a := range f.arrivals {
		if q.SiteID != "" && a.SiteID != q.SiteID {
			continue
		}
		if q.AfterSeq != nil && a.Seq <= *q.AfterSeq {
			continue
		}
		rows = append(rows, a)
	}
	if q.AfterSeq == nil && len(rows) > q.Limit {
		// No cursor: the newest window, matching the real query.
		rows = rows[len(rows)-q.Limit:]
	} else if len(rows) > q.Limit {
		rows = rows[:q.Limit]
	}
	return rows, nil
}

func (f *fakeStore) SaveProfile(_ context.Context, clientID string, p Profile, _ string) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.lastProfile, f.lastProfileClient = p, clientID
	return f.profileErr
}

func (f *fakeStore) RecordPurchase(_ context.Context, _ string, p PurchaseInput, _ string) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.lastPurchase = p
	return f.purchaseErr
}

func (f *fakeStore) RedeemEnrolment(_ context.Context, hash []byte) (Enrolment, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	en, ok := f.enrolment[hex.EncodeToString(hash)]
	if !ok {
		return Enrolment{}, errors.New("unknown token")
	}
	// Single use, like the real UPDATE.
	delete(f.enrolment, hex.EncodeToString(hash))
	return en, nil
}

func (f *fakeStore) Cameras(_ context.Context, _, siteID string) ([]Camera, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	var out []Camera
	for _, c := range f.cameras {
		if siteID == "" || c.SiteID == siteID {
			out = append(out, c)
		}
	}
	return out, nil
}

func (f *fakeStore) CameraByID(_ context.Context, _, id string) (Camera, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	for _, c := range f.cameras {
		if c.ID == id {
			return c, nil
		}
	}
	return Camera{}, errors.New("no rows in result set")
}

func (f *fakeStore) SaveCamera(_ context.Context, _, siteID, cameraID string,
	in CameraInput) (Camera, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.lastSaved = in
	if f.saveCameraErr != nil {
		return Camera{}, f.saveCameraErr
	}
	// A real-shaped uuid: the handlers check the shape before touching SQL, so
	// a placeholder id would exercise the 404 path instead of the one under
	// test.
	cam := Camera{ID: fakeCameraUUID(cameraID), SiteID: siteID, CameraID: cameraID,
		Port: 554, Path: "/", MaxWidth: 1280, Enabled: true, Revision: 1}
	if in.Label != nil {
		cam.Label = *in.Label
	}
	if in.Host != nil {
		cam.Host = *in.Host
	}
	if in.Username != nil {
		cam.Username = *in.Username
	}
	cam.HasPassword = in.Password != nil && *in.Password != ""
	f.cameras = append(f.cameras, cam)
	return cam, nil
}

// fakeCameraUUID derives a stable uuid-shaped id from a camera name so tests
// can address a camera they just created without reading the response.
func fakeCameraUUID(cameraID string) string {
	sum := sha256.Sum256([]byte(cameraID))
	h := hex.EncodeToString(sum[:16])
	return h[0:8] + "-" + h[8:12] + "-" + h[12:16] + "-" + h[16:20] + "-" + h[20:32]
}

func (f *fakeStore) DeleteCamera(_ context.Context, _, id string) (Camera, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	for i, c := range f.cameras {
		if c.ID == id {
			f.cameras = append(f.cameras[:i], f.cameras[i+1:]...)
			return c, nil
		}
	}
	return Camera{}, errors.New("no rows in result set")
}

func (f *fakeStore) AgentCameras(_ context.Context, _ string) ([]AgentCamera, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	return f.agentCameras, nil
}

func (f *fakeStore) ApplyAgentReport(_ context.Context, clientID, siteID string,
	rep AgentCameraReport) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.lastCameraReport = rep
	f.lastReportClient, f.lastReportSite = clientID, siteID
	return nil
}

func (f *fakeStore) IssueEnrolmentCode(_ context.Context, clientID, siteID,
	actorID, label string, ttl time.Duration) (EnrolmentCode, error) {

	f.mu.Lock()
	defer f.mu.Unlock()
	for _, si := range f.sites {
		if si.SiteID == siteID {
			f.lastCodeActor, f.lastCodeTTL = actorID, ttl
			return EnrolmentCode{
				Code: "ABCDEF-123456-GHIJKL-789012", SiteID: siteID,
				SiteName: si.Name, Label: label,
				ExpiresAt: time.Now().Add(ttl).UTC(),
			}, nil
		}
	}
	return EnrolmentCode{}, pgx.ErrNoRows
}

func (f *fakeStore) RequestCheck(_ context.Context, _, id, kind string, seconds int) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	for i := range f.cameras {
		if f.cameras[i].ID == id {
			f.cameras[i].Check = CameraCheck{Kind: kind, Seconds: seconds, State: "requested"}
			f.lastCheckKind, f.lastCheckSeconds = kind, seconds
			return nil
		}
	}
	return errors.New("no rows in result set")
}

func (f *fakeStore) ClaimChecks(_ context.Context, _ string) ([]AgentCheckJob, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	out := f.pendingChecks
	f.pendingChecks = nil // claimed once, like the real UPDATE ... RETURNING
	return out, nil
}

func (f *fakeStore) RecordCheckResult(_ context.Context, _ string, res AgentCheckResult) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.checkResults = append(f.checkResults, res)
	return nil
}

func (f *fakeStore) ReleaseStaleChecks(_ context.Context, _ time.Duration) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.releasedStale++
	return nil
}

func (f *fakeStore) SetClientActive(_ context.Context, clientID string, active bool) (ClientRow, int, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	for i := range f.clients {
		if f.clients[i].ID != clientID {
			continue
		}
		f.clients[i].Active = active
		revoked := 0
		if !active {
			for _, sess := range f.sessions {
				if sess.p.ClientID == clientID && !sess.revoked {
					sess.revoked = true
					revoked++
				}
			}
		}
		return f.clients[i], revoked, nil
	}
	return ClientRow{}, 0, pgx.ErrNoRows
}

func (f *fakeStore) ClientOwners(_ context.Context, clientID string) ([]TeamMember, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	var out []TeamMember
	for _, u := range f.users {
		if u.ClientID == clientID && u.Role == "owner" && u.Active {
			out = append(out, TeamMember{ID: u.ID, Email: u.Email, FullName: u.FullName, Role: u.Role, Active: u.Active})
		}
	}
	return out, nil
}

func (f *fakeStore) ClientImageKeys(_ context.Context, _ string) ([]string, error) { return nil, nil }

func (f *fakeStore) DeleteClient(_ context.Context, clientID string) (ClientRow, []string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	for i, c := range f.clients {
		if c.ID != clientID {
			continue
		}
		if c.Active {
			return c, nil, errors.New("client is active")
		}
		f.clients = append(f.clients[:i], f.clients[i+1:]...)
		return c, []string{c.Slug + ".shop1"}, nil
	}
	return ClientRow{}, nil, pgx.ErrNoRows
}

func (f *fakeStore) UpdateSite(_ context.Context, _ string, siteID string, in SiteUpdate) (SiteHealth, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	for i := range f.sites {
		if f.sites[i].SiteID == siteID {
			if in.Name != nil {
				f.sites[i].Name = *in.Name
			}
			if in.Timezone != nil {
				f.sites[i].Timezone = *in.Timezone
			}
			return f.sites[i], nil
		}
	}
	return SiteHealth{}, pgx.ErrNoRows
}

func (f *fakeStore) DeleteEmptySite(_ context.Context, _ string, siteID string) (string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	for _, c := range f.cameras {
		if c.SiteID == siteID {
			return "", ErrSiteInUse
		}
	}
	for i, s := range f.sites {
		if s.SiteID == siteID {
			f.sites = append(f.sites[:i], f.sites[i+1:]...)
			return "acme." + s.Slug, nil
		}
	}
	return "", pgx.ErrNoRows
}

func (f *fakeStore) ListClients(_ context.Context) ([]ClientRow, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	return f.clients, nil
}

func (f *fakeStore) CreateClientWithOwner(_ context.Context, in NewClientInput) (
	NewClientResult, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.lastNewClient = in
	if f.newClientErr != nil {
		return NewClientResult{}, f.newClientErr
	}
	pw := in.Password
	if pw == "" {
		pw = "generated-password"
	}
	return NewClientResult{ClientID: "new-client-id", Slug: in.Slug,
		OwnerEmail: in.OwnerEmail, Password: pw}, nil
}

func (f *fakeStore) Audit(_ context.Context, e AuditEntry) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.audits = append(f.audits, e)
}

func itoa(n int) string {
	if n == 0 {
		return "0"
	}
	var b []byte
	for n > 0 {
		b = append([]byte{byte('0' + n%10)}, b...)
		n /= 10
	}
	return string(b)
}

// -- images and agents ------------------------------------------------------

func (f *fakeStore) SetAgentAPIToken(_ context.Context, agentID string, hash []byte) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	if f.agentTokens == nil {
		f.agentTokens = map[string]AgentPrincipal{}
	}
	f.agentTokens[hex.EncodeToString(hash)] = AgentPrincipal{
		AgentID: agentID, ClientID: "client-acme", SiteID: "site-1",
		Slug: "acme.store1", Client: "acme", Site: "store1",
	}
	return nil
}

// addAgent registers a plaintext agent token, hashed the way the middleware
// will look it up.
func (f *fakeStore) addAgent(token string, ap AgentPrincipal) {
	f.mu.Lock()
	defer f.mu.Unlock()
	f.agentTokens[hex.EncodeToString(auth.HashToken(token))] = ap
}

func (f *fakeStore) AgentByToken(_ context.Context, hash []byte) (AgentPrincipal, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	ap, ok := f.agentTokens[hex.EncodeToString(hash)]
	if !ok {
		return AgentPrincipal{}, errors.New("no such agent")
	}
	return ap, nil
}

func (f *fakeStore) VisitorImageKey(_ context.Context, _, visitorID string) (string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	return f.imageKeys[visitorID], nil
}

func (f *fakeStore) VisitorImageKeys(_ context.Context, _, visitorID string) ([]string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	if k := f.imageKeys[visitorID]; k != "" {
		return []string{k}, nil
	}
	return nil, nil
}

func (f *fakeStore) ForgetVisitor(_ context.Context, _, visitorID string) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	if f.forgetErr != nil {
		return f.forgetErr
	}
	f.forgotten = append(f.forgotten, visitorID)
	delete(f.imageKeys, visitorID)
	return nil
}

// fakeBlob records what the handlers asked storage to do. Deleting is the part
// worth recording: an erasure that reports success without removing the object
// is the failure this whole path exists to prevent.
type fakeBlob struct {
	mu       sync.Mutex
	deleted  []string
	presigns []string
	failNext error
}

func (b *fakeBlob) Key(client, site, objectID string, at time.Time) string {
	return fmt.Sprintf("behavision/%s/%s/%04d/%02d/%02d/%s.jpg",
		client, site, at.Year(), int(at.Month()), at.Day(), objectID)
}

func (b *fakeBlob) PresignPut(key string, _ time.Duration) (string, http.Header, error) {
	h := http.Header{}
	h.Set("x-amz-acl", "private")
	h.Set("Content-Type", "image/jpeg")
	return "https://bucket.example.com/" + key + "?X-Amz-Signature=fake", h, nil
}

func (b *fakeBlob) PresignGet(key string, _ time.Duration) (string, error) {
	b.mu.Lock()
	defer b.mu.Unlock()
	b.presigns = append(b.presigns, key)
	return "https://bucket.example.com/" + key + "?X-Amz-Signature=fake", nil
}

func (b *fakeBlob) Delete(_ context.Context, key string) error {
	b.mu.Lock()
	defer b.mu.Unlock()
	if b.failNext != nil {
		err := b.failNext
		b.failNext = nil
		return err
	}
	b.deleted = append(b.deleted, key)
	return nil
}

// ------------------------------------------------------- camera snapshots --

func (f *fakeStore) PutCameraSnapshot(_ context.Context,
	clientID, siteID, cameraID string, jpeg []byte) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	if f.snapshots == nil {
		f.snapshots = map[string][]byte{}
	}
	if f.snapshotRejects {
		return ErrNoSnapshot
	}
	f.lastSnapshotClient, f.lastSnapshotSite = clientID, siteID
	f.snapshots[cameraID] = append([]byte(nil), jpeg...)
	return nil
}

func (f *fakeStore) CameraSnapshot(_ context.Context, clientID, cameraID string) (
	[]byte, time.Time, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	img, ok := f.snapshots[clientID+"/"+cameraID]
	if !ok {
		return nil, time.Time{}, ErrNoSnapshot
	}
	return img, time.Unix(1756900000, 0).UTC(), nil
}

// ------------------------------------------------------------ live relay --

func (f *fakeStore) CameraRef(_ context.Context, clientID, cameraID string) (string, string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	ref, ok := f.cameraRefs[cameraID]
	if !ok || ref.client != clientID {
		return "", "", ErrNoSnapshot
	}
	return ref.site, ref.engineID, nil
}

func (f *fakeStore) CameraRefBySite(_ context.Context, siteID, cameraID string) (string, string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	ref, ok := f.cameraRefs[cameraID]
	if !ok || ref.site != siteID {
		return "", "", ErrNoSnapshot
	}
	return ref.site, ref.engineID, nil
}

func (f *fakeStore) SiteCameraIDs(_ context.Context, siteID string) ([]string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	var out []string
	for id, ref := range f.cameraRefs {
		if ref.site == siteID {
			out = append(out, id)
		}
	}
	return out, nil
}

// addCameraRef registers a camera so ownership checks have something to check.
func (f *fakeStore) addCameraRef(id, client, site, engineID string) {
	f.mu.Lock()
	defer f.mu.Unlock()
	if f.cameraRefs == nil {
		f.cameraRefs = map[string]cameraRef{}
	}
	f.cameraRefs[id] = cameraRef{client: client, site: site, engineID: engineID}
}

type cameraRef struct{ client, site, engineID string }

// ==================================== team, invitations, sessions, faces ====
//
// These behave rather than merely satisfy the interface: single use, tenant
// scoping and "the role comes from the invitation" are the properties the
// handlers are trusted for, so a fake that always says yes would make the tests
// that check them meaningless.

type fakeInvite struct {
	id, clientID, email, fullName, role string
	expires                             time.Time
	used, revoked                       bool
}

func (f *fakeStore) CreateInvitation(_ context.Context, in NewInvitation) (Invitation, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	if f.invites == nil {
		f.invites = map[string]*fakeInvite{}
	}
	f.nextID++
	id := fmt.Sprintf("00000000-0000-4000-9000-%012d", f.nextID)
	f.invites[hex.EncodeToString(in.CodeHash)] = &fakeInvite{
		id: id, clientID: in.ClientID, email: in.Email,
		fullName: in.FullName, role: in.Role, expires: in.ExpiresAt,
	}
	return Invitation{
		ID: id, Email: in.Email, FullName: in.FullName, Role: in.Role,
		ExpiresAt: in.ExpiresAt.UTC().Format(time.RFC3339),
		CreatedAt: time.Now().UTC().Format(time.RFC3339),
	}, nil
}

func (f *fakeStore) PendingInvitations(_ context.Context, clientID string) ([]Invitation, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	var out []Invitation
	for _, v := range f.invites {
		if v.clientID != clientID || v.used || v.revoked {
			continue
		}
		out = append(out, Invitation{ID: v.id, Email: v.email,
			FullName: v.fullName, Role: v.role,
			ExpiresAt: v.expires.UTC().Format(time.RFC3339)})
	}
	return out, nil
}

func (f *fakeStore) RevokeInvitation(_ context.Context, clientID, id string) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	for _, v := range f.invites {
		if v.id == id && v.clientID == clientID && !v.used && !v.revoked {
			v.revoked = true
			return nil
		}
	}
	return errors.New("no such pending invitation")
}

func (f *fakeStore) InvitationByCode(_ context.Context, hash []byte) (InvitationPreview, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	v, ok := f.invites[hex.EncodeToString(hash)]
	if !ok || v.used || v.revoked || time.Now().After(v.expires) {
		return InvitationPreview{}, errors.New("that invitation is not valid")
	}
	return InvitationPreview{Client: "Fake Co", Email: v.email,
		FullName: v.fullName, Role: v.role}, nil
}

func (f *fakeStore) RedeemInvitation(_ context.Context, hash []byte,
	fullName, passwordHash string) (UserRecord, error) {

	f.mu.Lock()
	defer f.mu.Unlock()
	v, ok := f.invites[hex.EncodeToString(hash)]
	if !ok || v.used || v.revoked || time.Now().After(v.expires) {
		return UserRecord{}, errors.New("that invitation is not valid")
	}
	if _, taken := f.users[v.email]; taken {
		return UserRecord{}, errors.New("app_users_email_idx")
	}
	// Marked spent BEFORE the account exists, mirroring the real store's one
	// transaction: a test that redeems the same code twice must get one user.
	v.used = true
	f.nextID++
	rec := UserRecord{
		ID: fmt.Sprintf("00000000-0000-4000-a000-%012d", f.nextID),
		// From the INVITATION, never from the request - which is the property
		// worth having a fake at all for.
		ClientID: v.clientID, ClientName: "Fake Co", Email: v.email,
		FullName: fullName, Role: v.role, Active: true, Found: true,
		PasswordHash: passwordHash,
	}
	if rec.FullName == "" {
		rec.FullName = v.fullName
	}
	f.users[v.email] = rec
	return rec, nil
}

func (f *fakeStore) Team(_ context.Context, clientID string) ([]TeamMember, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	var out []TeamMember
	for _, u := range f.users {
		if u.ClientID != clientID {
			continue
		}
		out = append(out, TeamMember{ID: u.ID, Email: u.Email,
			FullName: u.FullName, Role: u.Role, Active: u.Active})
	}
	return out, nil
}

func (f *fakeStore) UpdateTeamMember(_ context.Context, clientID, userID string,
	up TeamUpdate) (TeamMember, error) {

	f.mu.Lock()
	defer f.mu.Unlock()
	for email, u := range f.users {
		if u.ID != userID || u.ClientID != clientID {
			continue
		}
		if up.Role != nil {
			u.Role = *up.Role
		}
		if up.Active != nil {
			u.Active = *up.Active
			if !u.Active {
				// The real store revokes in the same transaction; the fake
				// does it here so a test can prove "they have left" actually
				// signs them out rather than waiting twelve hours.
				for _, s := range f.sessions {
					if s.p.UserID == userID {
						s.revoked = true
					}
				}
			}
		}
		f.users[email] = u
		return TeamMember{ID: u.ID, Email: u.Email, FullName: u.FullName,
			Role: u.Role, Active: u.Active}, nil
	}
	return TeamMember{}, errors.New("no such team member")
}

func (f *fakeStore) UserSessions(_ context.Context, userID string) ([]DeviceSession, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	var out []DeviceSession
	for _, s := range f.sessions {
		if s.p.UserID != userID || s.revoked {
			continue
		}
		out = append(out, DeviceSession{ID: s.id, Device: s.device,
			ExpiresAt: s.refreshExp.UTC().Format(time.RFC3339)})
	}
	return out, nil
}

func (f *fakeStore) RevokeUserSession(_ context.Context, userID, sessionID string) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	s, ok := f.sessions[sessionID]
	// Scoped by user id, exactly as the real UPDATE is: a session id travels in
	// a list and is not a secret, so it must not sign anybody else out.
	if !ok || s.p.UserID != userID || s.revoked {
		return errors.New("no such session")
	}
	s.revoked = true
	return nil
}

func (f *fakeStore) RevokeOtherSessions(_ context.Context, userID, keep string) (int, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	n := 0
	for _, s := range f.sessions {
		if s.p.UserID == userID && s.id != keep && !s.revoked {
			s.revoked = true
			n++
		}
	}
	return n, nil
}

func (f *fakeStore) PutVisitFace(_ context.Context, clientID, siteID string,
	jpeg []byte) (string, error) {

	f.mu.Lock()
	defer f.mu.Unlock()
	if f.faces == nil {
		f.faces = map[string][]byte{}
	}
	f.nextID++
	id := fmt.Sprintf("00000000-0000-4000-b000-%012d", f.nextID)
	f.faces[clientID+"/"+id] = jpeg
	f.lastFaceClient, f.lastFaceSite = clientID, siteID
	return "db:" + id, nil
}

func (f *fakeStore) VisitFace(_ context.Context, clientID, key string) ([]byte, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	img, ok := f.faces[clientID+"/"+strings.TrimPrefix(key, "db:")]
	if !ok {
		return nil, errors.New("no such face image")
	}
	return img, nil
}

func (f *fakeStore) DeleteVisitFaces(_ context.Context, clientID string, keys []string) error {
	f.mu.Lock()
	defer f.mu.Unlock()
	if f.faceDeleteErr != nil {
		return f.faceDeleteErr
	}
	for _, k := range keys {
		delete(f.faces, clientID+"/"+strings.TrimPrefix(k, "db:"))
		f.deletedFaces = append(f.deletedFaces, k)
	}
	return nil
}

// ============================================ public reference resolution ===
//
// These behave rather than merely satisfy the interface. The properties the
// handlers are trusted for - a reference resolves only within the caller's own
// tenant, and an ambiguous camera name resolves to nothing rather than to
// whichever row came first - are exactly what a fake that always said yes would
// stop any test from checking.

func (f *fakeStore) SiteIDBySlug(_ context.Context, clientID, slug string) (string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	for _, s := range f.sites {
		// An owner of "" is a site the fake was not told about, which is the
		// ordinary case: SiteHealth carries no client id, and most tests seed
		// one tenant. Tests that assert cross-tenant resolution seed a camera,
		// which is what gives a site an owner here.
		if owner := f.siteClient(s.Slug, s.SiteID); s.Slug == slug &&
			(owner == "" || owner == clientID) {
			return s.SiteID, nil
		}
	}
	return "", nil
}

// siteClient answers which tenant a site belongs to. SiteHealth carries no
// client id of its own - it is already scoped by the query that returns it - so
// the fake reads ownership from the cameras it was seeded with.
func (f *fakeStore) siteClient(_, siteID string) string {
	for _, ref := range f.cameraRefs {
		if ref.site == siteID {
			return ref.client
		}
	}
	for _, c := range f.cameras {
		if c.SiteID == siteID {
			return f.cameraOwner(c.ID)
		}
	}
	return ""
}

func (f *fakeStore) cameraOwner(id string) string {
	if ref, ok := f.cameraRefs[id]; ok {
		return ref.client
	}
	return ""
}

func (f *fakeStore) CameraIDByRef(_ context.Context, clientID, ref string) (string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	var found []string
	for _, c := range f.cameras {
		if c.CameraID != ref {
			continue
		}
		if owner := f.cameraOwner(c.ID); owner != "" && owner != clientID {
			continue
		}
		found = append(found, c.ID)
	}
	// A camera id is unique per site, not per tenant. Two shops may each have
	// an "Office1", and acting on whichever sorted first would edit the wrong
	// shop's camera, so ambiguity is no match.
	if len(found) != 1 {
		return "", nil
	}
	return found[0], nil
}

func (f *fakeStore) VisitorIDByNumber(_ context.Context, clientID string, number int64) (string, error) {
	f.mu.Lock()
	defer f.mu.Unlock()
	want := VisitorRef(number)
	for _, v := range f.visitors {
		if v.Ref == want {
			return v.ID, nil
		}
	}
	return "", nil
}

// CreateMember behaves like the real store on the two things the handler
// branches on: the account lands in the caller's tenant and nowhere else, and
// an address that already exists anywhere is a conflict named the way Postgres
// names it, so conflictMessage recognises it.
func (f *fakeStore) CreateMember(_ context.Context, clientID string,
	in NewMemberInput, hash string) (TeamMember, error) {

	f.mu.Lock()
	defer f.mu.Unlock()
	if _, taken := f.users[in.Email]; taken {
		return TeamMember{}, errors.New(`duplicate key value violates unique constraint "app_users_email_idx"`)
	}
	// The real UserByEmail joins clients for the name; this fake reads it off
	// the record, so copy it from a tenant-mate or a login as the new member
	// comes back with no company name and looks like it landed nowhere.
	clientName := ""
	for _, u := range f.users {
		if u.ClientID == clientID && u.ClientName != "" {
			clientName = u.ClientName
			break
		}
	}
	id := "member-" + itoa(len(f.users)+1)
	f.users[in.Email] = UserRecord{
		ID: id, ClientID: clientID, ClientName: clientName,
		Email: in.Email, FullName: in.FullName,
		Role: in.Role, Active: true, PasswordHash: hash, Found: true,
	}
	return TeamMember{ID: id, Email: in.Email, FullName: in.FullName,
		Role: in.Role, Active: true}, nil
}

// ResetMemberPassword mirrors the real one: tenant-scoped, and every session
// the member holds is revoked with it.
func (f *fakeStore) ResetMemberPassword(_ context.Context, clientID, userID,
	hash string) (TeamMember, error) {

	f.mu.Lock()
	defer f.mu.Unlock()
	for email, u := range f.users {
		if u.ID != userID || u.ClientID != clientID {
			continue
		}
		u.PasswordHash = hash
		f.users[email] = u
		for _, s := range f.sessions {
			if s.p.UserID == userID {
				s.revoked = true
			}
		}
		return TeamMember{ID: u.ID, Email: u.Email, FullName: u.FullName,
			Role: u.Role, Active: u.Active}, nil
	}
	return TeamMember{}, errors.New("no such team member")
}