package api

import (
	"testing"
	"time"

	"github.com/ponzischeme89/memby/server/internal/store"
)

var heroRevisionZone = time.FixedZone("NZST", 12*60*60)

func heroRevisionAt(policy store.HeroPolicy, user string, at time.Time) string {
	return heroRevision(policy, user, at, heroRevisionZone)
}

func pinnedPolicy(placement string, ids ...string) store.HeroPolicy {
	return store.HeroPolicy{Placements: map[string]store.HeroPlacementPolicy{
		placement: {PinnedItemIDs: ids},
	}}
}

func TestHeroRevisionIsStableWithinASlot(t *testing.T) {
	policy := pinnedPolicy(store.HeroPlacementHome, "film-1")
	morning := time.Date(2026, 8, 20, 8, 0, 0, 0, heroRevisionZone)
	if heroRevisionAt(policy, "user-1", morning) != heroRevisionAt(policy, "user-1", morning.Add(90*time.Minute)) {
		t.Fatal("hero revision moved without anything changing; every poll would refetch")
	}
}

func TestHeroRevisionMovesWhenAnOperatorEditsPins(t *testing.T) {
	now := time.Date(2026, 8, 20, 8, 0, 0, 0, heroRevisionZone)
	before := heroRevisionAt(pinnedPolicy(store.HeroPlacementHome, "film-1"), "user-1", now)
	for name, policy := range map[string]store.HeroPolicy{
		"added":    pinnedPolicy(store.HeroPlacementHome, "film-1", "film-2"),
		"removed":  pinnedPolicy(store.HeroPlacementHome),
		"replaced": pinnedPolicy(store.HeroPlacementHome, "film-2"),
	} {
		if heroRevisionAt(policy, "user-1", now) == before {
			t.Fatalf("hero revision did not move when a pin was %s", name)
		}
	}
	// Order is the operator's decision about which card leads, so reordering is a change
	// even though the same titles are pinned.
	reordered := pinnedPolicy(store.HeroPlacementHome, "film-2", "film-1")
	if heroRevisionAt(reordered, "user-1", now) ==
		heroRevisionAt(pinnedPolicy(store.HeroPlacementHome, "film-1", "film-2"), "user-1", now) {
		t.Fatal("hero revision did not move when pins were reordered")
	}
}

func TestHeroRevisionSeparatesPlacements(t *testing.T) {
	now := time.Date(2026, 8, 20, 8, 0, 0, 0, heroRevisionZone)
	home := heroRevisionAt(pinnedPolicy(store.HeroPlacementHome, "film-1"), "user-1", now)
	movies := heroRevisionAt(pinnedPolicy(store.HeroPlacementMovies, "film-1"), "user-1", now)
	if home == movies {
		t.Fatal("pinning a title to Movies read as the same policy as pinning it to Home")
	}
}

func TestHeroRevisionIgnoresACosmeticSave(t *testing.T) {
	now := time.Date(2026, 8, 20, 8, 0, 0, 0, heroRevisionZone)
	saved := pinnedPolicy(store.HeroPlacementHome, "film-1")
	// UpdatedAt moves on every write. Hashing the document rather than what it resolves to
	// would repaint every launcher in the house for a save that changed nothing.
	resaved := pinnedPolicy(store.HeroPlacementHome, "film-1")
	resaved.UpdatedAt = now
	if heroRevisionAt(saved, "user-1", now) != heroRevisionAt(resaved, "user-1", now) {
		t.Fatal("hero revision moved for a save that changed nothing")
	}
}

func TestHeroRevisionMovesWhenAScheduleOpensAndCloses(t *testing.T) {
	policy := store.HeroPolicy{Schedules: []store.HeroSchedule{{
		ID: "s1", ItemID: "film-9", Enabled: true,
		Frequency: "daily", StartTime: "20:00", EndTime: "22:00",
		Placements: []string{store.HeroPlacementHome},
	}}}
	before := time.Date(2026, 8, 20, 19, 0, 0, 0, heroRevisionZone)
	during := time.Date(2026, 8, 20, 21, 0, 0, 0, heroRevisionZone)
	// Two readings within one rotation slot, so only the schedule can be the difference.
	if heroRotationSlot(before, heroRevisionZone) != heroRotationSlot(during, heroRevisionZone) {
		t.Fatal("test times straddle a rotation slot; the schedule is no longer the only variable")
	}
	if heroRevisionAt(policy, "user-1", before) == heroRevisionAt(policy, "user-1", during) {
		t.Fatal("hero revision did not move when a scheduled hero came into force")
	}
	empty := store.HeroPolicy{}
	if heroRevisionAt(policy, "user-1", before) != heroRevisionAt(empty, "user-1", before) {
		t.Fatal("a schedule that is not yet in force changed the revision; the launcher would repaint for nothing")
	}
}

func TestHeroRevisionIsPerViewerForAPersonalSchedule(t *testing.T) {
	now := time.Date(2026, 8, 20, 21, 0, 0, 0, heroRevisionZone)
	policy := store.HeroPolicy{Schedules: []store.HeroSchedule{{
		ID: "s1", ItemID: "film-9", Enabled: true, UserID: "user-1",
		Frequency: "daily", StartTime: "20:00", EndTime: "22:00",
		Placements: []string{store.HeroPlacementHome},
	}}}
	if heroRevisionAt(policy, "user-1", now) == heroRevisionAt(policy, "user-2", now) {
		t.Fatal("one viewer's scheduled hero moved another viewer's revision")
	}
}

func TestHeroRevisionMovesWithTheRotationSlot(t *testing.T) {
	policy := pinnedPolicy(store.HeroPlacementHome, "film-1")
	morning := time.Date(2026, 8, 20, 8, 0, 0, 0, heroRevisionZone)
	evening := time.Date(2026, 8, 20, 20, 0, 0, 0, heroRevisionZone)
	if heroRevisionAt(policy, "user-1", morning) == heroRevisionAt(policy, "user-1", evening) {
		t.Fatal("hero revision did not move across rotation slots; the day's draw would never be refetched")
	}
}