memby/server/internal/store/viewers_test.go

package store

import (
	"testing"
	"time"
)

// A shadow id must never be mistaken for an Emby user id: the two are substituted for one
// another in twenty tables that cannot tell the difference, so telling them apart by
// inspection is the safety property the whole scheme rests on.
func TestShadowViewerIDIsDistinguishableFromEmbyUserID(t *testing.T) {
	id, err := NewShadowViewerID()
	if err != nil {
		t.Fatalf("mint shadow id: %v", err)
	}
	if !IsShadowViewerID(id) {
		t.Fatalf("minted id %q not recognised as a shadow id", id)
	}
	// Emby's are 32 hex characters with no prefix.
	if IsShadowViewerID("8f14e45fceea167a5a36dedd4bea2543") {
		t.Fatal("an Emby user id was read as a shadow viewer")
	}
	if IsShadowViewerID("") || IsShadowViewerID("v") || IsShadowViewerID("viewer") {
		t.Fatal("a short string was read as a shadow viewer")
	}
	other, err := NewShadowViewerID()
	if err != nil {
		t.Fatalf("mint second shadow id: %v", err)
	}
	if other == id {
		t.Fatal("two minted ids collided")
	}
}

func TestPlayedFromPosition(t *testing.T) {
	const hour = int64(36_000_000_000) // one hour in Emby ticks

	for _, tc := range []struct {
		name     string
		position int64
		runtime  int64
		want     bool
	}{
		{"finished", hour, hour, true},
		{"at the threshold", hour * 9 / 10, hour, true},
		{"just short of it", hour*9/10 - 1, hour, false},
		{"barely started", hour / 100, hour, false},
		// A runtime of zero means the length was not known, not that the title is zero
		// long. Reading it the other way marks everything watched at the first second.
		{"unknown runtime", hour, 0, false},
		{"nothing watched", 0, hour, false},
		{"negative position", -hour, hour, false},
		// Playing past the stated runtime is ordinary — a container whose duration is a
		// little short of its own last frame.
		{"past the end", hour * 2, hour, true},
	} {
		t.Run(tc.name, func(t *testing.T) {
			if got := PlayedFromPosition(tc.position, tc.runtime); got != tc.want {
				t.Fatalf("PlayedFromPosition(%d, %d) = %v, want %v",
					tc.position, tc.runtime, got, tc.want)
			}
		})
	}
}

// The rollup a series card's tick and count are built from. It is done in Go rather than in
// SQL — the query groups by the season/series pair and this folds it twice — so it is worth
// pinning that both directions add up and that the date is the latest of them.
func TestViewerAggregateRollup(t *testing.T) {
	earlier := time.Date(2026, 8, 1, 20, 0, 0, 0, time.UTC)
	later := time.Date(2026, 8, 18, 21, 30, 0, 0, time.UTC)
	aggregates := map[string]ViewerAggregate{}

	// Two seasons of one show, folded into the series and kept apart per season.
	addViewerAggregate(aggregates, "show-1", 10, 10, &earlier)
	addViewerAggregate(aggregates, "season-1", 10, 10, &earlier)
	addViewerAggregate(aggregates, "show-1", 8, 3, &later)
	addViewerAggregate(aggregates, "season-2", 8, 3, &later)

	series := aggregates["show-1"]
	if series.Total != 18 || series.Played != 13 {
		t.Errorf("series rollup = %d of %d, want 13 of 18", series.Played, series.Total)
	}
	if series.LastPlayedAt == nil || !series.LastPlayedAt.Equal(later) {
		t.Errorf("series last played = %v, want the later of the two", series.LastPlayedAt)
	}
	if got := aggregates["season-1"]; got.Total != 10 || got.Played != 10 {
		t.Errorf("season one = %d of %d, want 10 of 10", got.Played, got.Total)
	}
	if got := aggregates["season-2"]; got.Total != 8 || got.Played != 3 {
		t.Errorf("season two = %d of %d, want 3 of 8", got.Played, got.Total)
	}

	// An episode filed under no series or no season contributes to neither, rather than to
	// a row keyed on the empty string — which would be an aggregate about nothing.
	addViewerAggregate(aggregates, "", 5, 5, &later)
	if _, ok := aggregates[""]; ok {
		t.Error("an unfiled episode produced an aggregate")
	}
}