package api

import (
	"context"
	"net/http"
	"net/http/httptest"
	"testing"
	"time"

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

const liveCam = "22222222-3333-4444-5555-666666666666"

// The whole cost argument for this feature: a camera nobody is watching must
// cost a shop nothing at all. If Wanted were ever optimistic, every shop PC in
// an estate would upload continuously.
func TestNobodyWatchingMeansNothingIsWanted(t *testing.T) {
	h := NewLiveHub()
	if h.Wanted(liveCam) {
		t.Fatal("a camera nobody has asked for was reported as wanted")
	}
	if got := h.WantedAmong([]string{liveCam, "other"}); len(got) != 0 {
		t.Fatalf("wanted %v with no viewers", got)
	}
}

func TestAViewerMakesACameraWantedAndReleasingStopsIt(t *testing.T) {
	h := NewLiveHub()
	_, release := h.Watch(liveCam)
	if !h.Wanted(liveCam) {
		t.Fatal("a watched camera was not wanted")
	}
	release()
	if h.Wanted(liveCam) {
		t.Fatal("the camera stayed wanted after the last viewer left")
	}
}

// The opposite policy to the arrivals Hub, and deliberately so. There nothing
// may be lost; here the only frame worth having is the newest one, and a queue
// would show a viewer an ever-growing delay behind the shop instead of dropping
// back to live.
func TestASlowViewerGetsTheNewestFrameNotTheOldest(t *testing.T) {
	h := NewLiveHub()
	frames, release := h.Watch(liveCam)
	defer release()

	for _, f := range []string{"one", "two", "three"} {
		h.Publish(liveCam, []byte(f))
	}
	select {
	case got := <-frames:
		if string(got) != "three" {
			t.Fatalf("a slow viewer was served %q, want the newest frame", got)
		}
	default:
		t.Fatal("nothing was delivered")
	}
}

// Publish reporting false is what stops the shop PC uploading. If it kept
// saying true the agent would push into an empty room until the session cap.
func TestPublishReportsWhenTheLastViewerHasGone(t *testing.T) {
	h := NewLiveHub()
	_, release := h.Watch(liveCam)
	if !h.Publish(liveCam, []byte("frame")) {
		t.Fatal("publish said to stop while somebody was watching")
	}
	release()
	if h.Publish(liveCam, []byte("frame")) {
		t.Fatal("publish did not say to stop after the last viewer left")
	}
}

// A browser that vanishes without saying so - the normal way a tab closes -
// must stop the upload on its own.
func TestInterestExpiresWithoutBeingRefreshed(t *testing.T) {
	h := NewLiveHub()
	frames, release := h.Watch(liveCam)
	defer release()
	_ = frames

	h.mu.Lock()
	h.cameras[liveCam].wanted = time.Now().Add(-time.Second)
	h.mu.Unlock()

	if h.Wanted(liveCam) {
		t.Fatal("interest did not lapse")
	}
	if h.Publish(liveCam, []byte("frame")) {
		t.Fatal("publish kept the shop uploading for a viewer that had gone")
	}
}

// The relay is keyed on a camera id and a hub does not know whose camera it is
// holding, so ownership has to be proved before anything streams. Otherwise a
// camera id - which is not a secret - would be enough to watch another
// company's shop floor.
func TestAnotherTenantCannotWatchYourCamera(t *testing.T) {
	srv, fs := newServer(t)
	fs.addCameraRef(liveCam, "client-1", "site-1", "cam1")

	rr := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodGet, "/api/cameras/"+liveCam+"/live", nil)
	req = req.WithContext(context.WithValue(req.Context(), principalKey,
		auth.Principal{ClientID: "someone-else", Role: "owner"}))
	srv.handleWatchLive(rr, req)

	if rr.Code != http.StatusNotFound {
		t.Fatalf("status %d, want 404", rr.Code)
	}
}

// An agent may only push into its OWN site's camera. The agent supplies this
// id, and a camera id is not a secret.
func TestAnAgentCannotPushIntoAnotherSitesCamera(t *testing.T) {
	srv, fs := newServer(t)
	fs.addCameraRef(liveCam, "client-1", "site-1", "cam1")
	fs.addAgent("agent-token", AgentPrincipal{ClientID: "client-1", SiteID: "site-2"})

	rr := httptest.NewRecorder()
	req := httptest.NewRequest(http.MethodPost,
		"/api/agent/cameras/"+liveCam+"/live", nil)
	req.Header.Set("Authorization", "Bearer agent-token")
	srv.Routes().ServeHTTP(rr, req)

	if rr.Code != http.StatusNotFound {
		t.Fatalf("status %d, want 404", rr.Code)
	}
}