package db

import (
	"context"
	"database/sql"
	"errors"
	"fmt"
	"path/filepath"
	"testing"
	"time"

	"tangled.org/core/spindle/quota"
)

func testCacheEntry(id, hash, state string, createdAt time.Time) CacheEntry {
	return CacheEntry{
		ID:         id,
		StorageKey: "objects/" + id,
		OwnerDID:   "did:plc:owner",
		RepoDID:    "did:plc:repo",
		Engine:     "microvm",
		CacheKey:   "dependencies",
		CacheHash:  hash,
		SizeBytes:  10,
		State:      state,
		CreatedAt:  createdAt,
		LastUsedAt: createdAt,
	}
}

func insertTestCacheEntry(t *testing.T, d *DB, entry CacheEntry) {
	t.Helper()
	if err := d.InsertCacheEntry(context.Background(), entry); err != nil {
		t.Fatalf("InsertCacheEntry(%s): %v", entry.ID, err)
	}
}
func TestInsertCacheEntryWithinQuota(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	now := time.Now()

	first := testCacheEntry("first", "a", "pending", now)
	inserted, err := d.InsertCacheEntryWithinQuota(ctx, first, 1)
	if err != nil || !inserted {
		t.Fatalf("first quota insert = (%t, %v)", inserted, err)
	}

	second := testCacheEntry("second", "b", "pending", now)
	inserted, err = d.InsertCacheEntryWithinQuota(ctx, second, 1)
	if err != nil {
		t.Fatal(err)
	}
	if inserted {
		t.Fatal("entry quota accepted a second object for the same owner")
	}

	second.OwnerDID = "did:plc:other"
	inserted, err = d.InsertCacheEntryWithinQuota(ctx, second, 1)
	if err != nil || !inserted {
		t.Fatalf("other owner quota insert = (%t, %v)", inserted, err)
	}
}

func genericAllocation(t *testing.T, d *DB, id string) (int64, bool) {
	t.Helper()
	var amount int64
	err := d.QueryRow(`select amount from quota_allocations where kind = ? and key = ?`, quota.KindGenericCache, id).Scan(&amount)
	if errors.Is(err, sql.ErrNoRows) {
		return 0, false
	}
	if err != nil {
		t.Fatal(err)
	}
	return amount, true
}

func cacheEntryState(t *testing.T, d *DB, id string) string {
	t.Helper()
	var state string
	if err := d.QueryRow(`select state from cache_entries where id = ?`, id).Scan(&state); err != nil {
		t.Fatal(err)
	}
	return state
}

func TestMarkCacheEntryReadyEvictsLeastRecentlyUsedOverTotal(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	base := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)

	pinned := testCacheEntry("pinned", "p", "ready", base)
	pinned.OwnerDID, pinned.RestoreCount, pinned.SizeBytes = "did:plc:a", 1, 10
	cold := testCacheEntry("cold", "c", "ready", base.Add(time.Minute))
	cold.OwnerDID, cold.SizeBytes = "did:plc:b", 40
	warm := testCacheEntry("warm", "w", "ready", base.Add(2*time.Minute))
	warm.OwnerDID, warm.SizeBytes = "did:plc:c", 40
	reserved := testCacheEntry("reserved", "r", "pending", base.Add(3*time.Minute))
	reserved.OwnerDID, reserved.SizeBytes = "did:plc:d", 1000
	pending := testCacheEntry("pending", "n", "pending", base.Add(3*time.Minute))
	pending.OwnerDID, pending.SizeBytes = "did:plc:e", 0
	for _, entry := range []CacheEntry{pinned, cold, warm, reserved, pending} {
		insertTestCacheEntry(t, d, entry)
	}

	evicted, err := d.MarkCacheEntryReadyWithChecksum(ctx, pending.ID, 30, "", nil, 100, base.Add(4*time.Minute))
	if err != nil {
		t.Fatalf("save over the total should evict instead of failing: %v", err)
	}
	if len(evicted) != 1 || evicted[0].ID != cold.ID {
		t.Fatalf("evicted %v, want only %q", evicted, cold.ID)
	}
	for id, want := range map[string]string{
		pinned.ID: "ready", cold.ID: "deleting", warm.ID: "ready", reserved.ID: "pending", pending.ID: "ready",
	} {
		if got := cacheEntryState(t, d, id); got != want {
			t.Fatalf("%s state = %q, want %q", id, got, want)
		}
	}
}

func TestMarkCacheEntryReadyRefusesWhatCannotFitTheTotal(t *testing.T) {
	for _, tt := range []struct {
		name     string
		restores int64
		size     int64
	}{
		{name: "larger than the total", size: 60},
		{name: "room held by a restore", restores: 1, size: 20},
	} {
		t.Run(tt.name, func(t *testing.T) {
			ctx := context.Background()
			d := newTestDB(t)
			now := time.Now()
			existing := testCacheEntry("existing", "a", "ready", now)
			existing.OwnerDID, existing.RestoreCount, existing.SizeBytes = "did:plc:other", tt.restores, 40
			insertTestCacheEntry(t, d, existing)
			pending := testCacheEntry("pending", "b", "pending", now)
			pending.SizeBytes = 0
			insertTestCacheEntry(t, d, pending)

			if _, err := d.MarkCacheEntryReadyWithChecksum(ctx, pending.ID, tt.size, "", nil, 50, now); !errors.Is(err, sql.ErrNoRows) {
				t.Fatalf("MarkCacheEntryReady error = %v, want sql.ErrNoRows", err)
			}
			if got := cacheEntryState(t, d, existing.ID); got != "ready" {
				t.Fatalf("refused save left existing entry %q, want ready", got)
			}
			if got := cacheEntryState(t, d, pending.ID); got != "pending" {
				t.Fatalf("refused save state = %q, want pending", got)
			}
		})
	}
}

func TestRefusedSaveInBatchKeepsOldCache(t *testing.T) {
	for _, tt := range []struct {
		name              string
		userLimit, maxTot int64
		size              int64
	}{
		{name: "bigger than the user limit", userLimit: 30, size: 40},
		{name: "over the total cap", userLimit: 30, maxTot: 50, size: 25},
	} {
		t.Run(tt.name, func(t *testing.T) {
			ctx := context.Background()
			d := newTestDB(t)
			base := time.Date(2026, 1, 2, 3, 4, 5, 0, time.UTC)
			victim := testCacheEntry("victim", "v", "ready", base)
			old := testCacheEntry("old", "a", "ready", base.Add(time.Minute))
			pinned := testCacheEntry("pinned", "p", "ready", base)
			pinned.OwnerDID, pinned.RestoreCount, pinned.SizeBytes = "did:plc:other", 1, 45
			pending := testCacheEntry("pending", "a", "pending", base.Add(2*time.Minute))
			pending.SizeBytes = 0
			for _, entry := range []CacheEntry{victim, old, pinned, pending} {
				insertTestCacheEntry(t, d, entry)
			}

			if err := d.ApplyEventBatch(nil, func(tx *EventBatchTx) error {
				superseded, ready, err := tx.MarkCacheEntryReadyWithChecksum(ctx, pending.ID, tt.size, "", NewQuotaStore(d, cacheDefaults(tt.userLimit, 0)), tt.maxTot, base.Add(3*time.Minute))
				if err != nil {
					return err
				}
				if ready || len(superseded) != 0 {
					t.Fatalf("refused save = (%v, %t), want nothing ready or superseded", superseded, ready)
				}
				return nil
			}); err != nil {
				t.Fatal(err)
			}

			for id, want := range map[string]string{victim.ID: "ready", old.ID: "ready", pinned.ID: "ready", pending.ID: "pending"} {
				if got := cacheEntryState(t, d, id); got != want {
					t.Fatalf("%s state = %q, want %q", id, got, want)
				}
			}
			found, err := d.FindCacheEntry(ctx, old.RepoDID, old.Engine, old.CacheKey, old.CacheHash)
			if err != nil || found.ID != old.ID {
				t.Fatalf("restore lookup = %+v, %v; want %q", found, err, old.ID)
			}
			if _, ok := genericAllocation(t, d, pending.ID); ok {
				t.Fatal("a refused save committed in the batch kept its charge")
			}
		})
	}
}

func TestCacheEntryLookup(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	base := time.Date(2026, 1, 2, 3, 4, 5, 6, time.UTC)

	insertTestCacheEntry(t, d, testCacheEntry("exact-old", "requested", "ready", base))
	insertTestCacheEntry(t, d, testCacheEntry("exact-new", "requested", "ready", base.Add(time.Second)))
	insertTestCacheEntry(t, d, testCacheEntry("exact-pending", "requested", "pending", base.Add(2*time.Second)))
	insertTestCacheEntry(t, d, testCacheEntry("fallback-old", "old-a", "ready", base.Add(3*time.Second)))
	insertTestCacheEntry(t, d, testCacheEntry("fallback-new", "old-b", "ready", base.Add(4*time.Second)))
	insertTestCacheEntry(t, d, testCacheEntry("fallback-pending", "old-c", "pending", base.Add(5*time.Second)))

	exact, err := d.FindCacheEntry(ctx, "did:plc:repo", "microvm", "dependencies", "requested")
	if err != nil {
		t.Fatalf("FindCacheEntry: %v", err)
	}
	if exact.ID != "exact-new" {
		t.Fatalf("FindCacheEntry returned %q, want exact-new", exact.ID)
	}
	if !exact.CreatedAt.Equal(base.Add(time.Second)) || !exact.LastUsedAt.Equal(base.Add(time.Second)) {
		t.Fatalf("timestamps = (%v, %v), want %v", exact.CreatedAt, exact.LastUsedAt, base.Add(time.Second))
	}

	fallback, err := d.FindFallbackCacheEntry(ctx, "did:plc:repo", "microvm", "dependencies", "requested")
	if err != nil {
		t.Fatalf("FindFallbackCacheEntry: %v", err)
	}
	if fallback.ID != "fallback-new" {
		t.Fatalf("FindFallbackCacheEntry returned %q, want fallback-new", fallback.ID)
	}

	if _, err := d.FindCacheEntry(ctx, "did:plc:repo", "microvm", "missing", "requested"); !errors.Is(err, sql.ErrNoRows) {
		t.Fatalf("missing FindCacheEntry error = %v, want sql.ErrNoRows", err)
	}
}

func TestMarkCacheEntryReadySupersedesMatchingReady(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	base := time.Date(2026, 1, 3, 4, 5, 6, 7, time.UTC)
	first := testCacheEntry("first-completion", "same-hash", "pending", base)
	second := testCacheEntry("second-completion", "same-hash", "pending", base.Add(time.Second))
	insertTestCacheEntry(t, d, first)
	insertTestCacheEntry(t, d, second)

	superseded, err := d.MarkCacheEntryReady(ctx, first.ID, 100, nil, base.Add(2*time.Second))
	if err != nil {
		t.Fatalf("mark first ready: %v", err)
	}
	if len(superseded) != 0 {
		t.Fatalf("first completion superseded %d entries, want none", len(superseded))
	}
	superseded, err = d.MarkCacheEntryReady(ctx, second.ID, 200, nil, base.Add(3*time.Second))
	if err != nil {
		t.Fatalf("mark second ready: %v", err)
	}
	if len(superseded) != 1 || superseded[0].ID != first.ID || superseded[0].State != "deleting" {
		t.Fatalf("second completion superseded %+v, want deleting %s", superseded, first.ID)
	}

	ready, err := d.FindCacheEntry(ctx, second.RepoDID, second.Engine, second.CacheKey, second.CacheHash)
	if err != nil {
		t.Fatalf("find surviving ready entry: %v", err)
	}
	if ready.ID != second.ID || ready.SizeBytes != 200 || !ready.LastUsedAt.Equal(base.Add(3*time.Second)) {
		t.Fatalf("surviving entry = %+v, want %s (200 bytes)", ready, second.ID)
	}
}

func TestMarkCacheEntryReadyConcurrentCompletions(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	base := time.Date(2026, 1, 4, 5, 6, 7, 8, time.UTC)
	first := testCacheEntry("concurrent-a", "same-hash", "pending", base)
	second := testCacheEntry("concurrent-b", "same-hash", "pending", base.Add(time.Second))
	insertTestCacheEntry(t, d, first)
	insertTestCacheEntry(t, d, second)

	type result struct {
		superseded []CacheEntry
		err        error
	}
	start := make(chan struct{})
	results := make(chan result, 2)
	for _, entry := range []CacheEntry{first, second} {
		entry := entry
		go func() {
			<-start
			superseded, err := d.MarkCacheEntryReady(ctx, entry.ID, 100, nil, base.Add(2*time.Second))
			results <- result{superseded: superseded, err: err}
		}()
	}
	close(start)

	var superseded []CacheEntry
	for range 2 {
		result := <-results
		if result.err != nil {
			t.Fatalf("concurrent MarkCacheEntryReady: %v", result.err)
		}
		superseded = append(superseded, result.superseded...)
	}
	if len(superseded) != 1 || superseded[0].State != "deleting" {
		t.Fatalf("concurrent completions superseded %+v, want one deleting entry", superseded)
	}

	var readyCount, deletingCount int
	if err := d.QueryRowContext(ctx, `
		select sum(state = 'ready'), sum(state = 'deleting')
		from cache_entries
		where repo_did = ? and engine = ? and cache_key = ? and cache_hash = ?`,
		first.RepoDID, first.Engine, first.CacheKey, first.CacheHash).Scan(&readyCount, &deletingCount); err != nil {
		t.Fatalf("count completion states: %v", err)
	}
	if readyCount != 1 || deletingCount != 1 {
		t.Fatalf("completion states = %d ready, %d deleting; want one each", readyCount, deletingCount)
	}
}

func TestCacheEntryReadyTouchAndExpiry(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	base := time.Date(2026, 2, 3, 4, 5, 6, 7, time.UTC)

	readyOld := testCacheEntry("ready-old", "a", "ready", base)
	readyFresh := testCacheEntry("ready-fresh", "b", "ready", base)
	pendingOld := testCacheEntry("pending-old", "c", "pending", base)
	pendingFresh := testCacheEntry("pending-fresh", "d", "pending", base)
	pendingFresh.LastUsedAt = base.Add(20 * time.Minute)
	deletingOld := testCacheEntry("deleting-old", "e", "deleting", base)
	deletingFresh := testCacheEntry("deleting-fresh", "f", "deleting", base)
	deletingFresh.LastUsedAt = base.Add(20 * time.Minute)
	for _, entry := range []CacheEntry{readyOld, readyFresh, pendingOld, pendingFresh, deletingOld, deletingFresh} {
		insertTestCacheEntry(t, d, entry)
	}

	touchedAt := base.Add(30 * time.Minute)
	if err := d.TouchCacheEntry(ctx, readyFresh.ID, touchedAt); err != nil {
		t.Fatalf("TouchCacheEntry: %v", err)
	}

	expired, err := d.ExpiredCacheEntries(ctx, base.Add(10*time.Minute), base.Add(10*time.Minute), 10)
	if err != nil {
		t.Fatalf("ExpiredCacheEntries: %v", err)
	}
	got := make(map[string]bool, len(expired))
	for _, entry := range expired {
		got[entry.ID] = true
	}
	if len(got) != 3 || !got[readyOld.ID] || !got[pendingOld.ID] || !got[deletingOld.ID] {
		t.Fatalf("expired IDs = %v, want ready-old, pending-old, and deleting-old", got)
	}

	limited, err := d.ExpiredCacheEntries(ctx, base.Add(10*time.Minute), base.Add(10*time.Minute), 1)
	if err != nil {
		t.Fatalf("limited ExpiredCacheEntries: %v", err)
	}
	if len(limited) != 1 {
		t.Fatalf("limited expiry count = %d, want 1", len(limited))
	}
}

func TestCacheEntryClaim(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	base := time.Date(2026, 2, 4, 5, 6, 7, 8, time.UTC)
	entry := testCacheEntry("claim-me", "hash", "ready", base)
	insertTestCacheEntry(t, d, entry)

	touchedAt := base.Add(time.Minute)
	if err := d.TouchCacheEntry(ctx, entry.ID, touchedAt); err != nil {
		t.Fatalf("TouchCacheEntry: %v", err)
	}
	claimed, err := d.ClaimCacheEntry(ctx, entry.ID, "ready", base)
	if err != nil {
		t.Fatalf("stale ClaimCacheEntry: %v", err)
	}
	if claimed {
		t.Fatal("stale ClaimCacheEntry claimed a touched entry")
	}
	claimed, err = d.ClaimCacheEntry(ctx, entry.ID, "ready", touchedAt)
	if err != nil {
		t.Fatalf("ClaimCacheEntry: %v", err)
	}
	if !claimed {
		t.Fatal("ClaimCacheEntry did not claim unchanged entry")
	}

	if err := d.TouchCacheEntry(ctx, entry.ID, base.Add(2*time.Minute)); err != nil {
		t.Fatalf("TouchCacheEntry while deleting: %v", err)
	}
	if _, err := d.MarkCacheEntryReady(ctx, entry.ID, 999, nil, base.Add(3*time.Minute)); !errors.Is(err, sql.ErrNoRows) {
		t.Fatalf("MarkCacheEntryReady while deleting error = %v, want sql.ErrNoRows", err)
	}
	var state string
	var lastUsedAt int64
	var sizeBytes int64
	if err := d.QueryRowContext(ctx, `
		select state, last_used_at, size_bytes from cache_entries where id = ?`, entry.ID).Scan(&state, &lastUsedAt, &sizeBytes); err != nil {
		t.Fatalf("query claimed entry: %v", err)
	}
	if state != "deleting" || lastUsedAt != touchedAt.UnixNano() || sizeBytes != entry.SizeBytes {
		t.Fatalf("claimed entry = state %q, last used %d, size %d; want deleting, %d, %d",
			state, lastUsedAt, sizeBytes, touchedAt.UnixNano(), entry.SizeBytes)
	}

	if err := d.RestoreCacheEntryState(ctx, entry.ID, "ready"); err != nil {
		t.Fatalf("RestoreCacheEntryState: %v", err)
	}
	restored, err := d.FindCacheEntry(ctx, entry.RepoDID, entry.Engine, entry.CacheKey, entry.CacheHash)
	if err != nil {
		t.Fatalf("find restored entry: %v", err)
	}
	if restored.State != "ready" || !restored.LastUsedAt.Equal(touchedAt) {
		t.Fatalf("restored entry = state %q, last used %v", restored.State, restored.LastUsedAt)
	}
}

func TestCacheEntryDelete(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	entry := testCacheEntry("delete-me", "hash", "ready", time.Now())
	insertTestCacheEntry(t, d, entry)

	if err := d.DeleteCacheEntry(ctx, entry.ID); err != nil {
		t.Fatalf("DeleteCacheEntry: %v", err)
	}
	if err := d.DeleteCacheEntry(ctx, entry.ID); err != nil {
		t.Fatalf("second DeleteCacheEntry: %v", err)
	}
	if _, err := d.FindCacheEntry(ctx, entry.RepoDID, entry.Engine, entry.CacheKey, entry.CacheHash); !errors.Is(err, sql.ErrNoRows) {
		t.Fatalf("find deleted error = %v, want sql.ErrNoRows", err)
	}
}

func TestUpgradeChargesExistingCacheEntries(t *testing.T) {
	path := filepath.Join(t.TempDir(), "spindle.db")
	ctx := context.Background()
	d, err := Make(ctx, path)
	if err != nil {
		t.Fatal(err)
	}
	now := time.Now()
	for _, entry := range []CacheEntry{
		testCacheEntry("ready", "a", "ready", now),
		testCacheEntry("deleting", "b", "deleting", now),
		testCacheEntry("pending", "c", "pending", now),
	} {
		entry.SizeBytes = 100
		insertTestCacheEntry(t, d, entry)
	}
	if _, err := d.Exec(`delete from migrations where name = 'generic-cache-allocations'`); err != nil {
		t.Fatal(err)
	}
	d.Close()

	d, err = Make(ctx, path)
	if err != nil {
		t.Fatal(err)
	}
	defer d.Close()
	for id, want := range map[string]bool{"ready": true, "deleting": true, "pending": false} {
		if amount, ok := genericAllocation(t, d, id); ok != want || ok && amount != 100 {
			t.Fatalf("%s charged (%d, %t), want %t", id, amount, ok, want)
		}
	}
	usage, err := NewQuotaStore(d, nil).ListUsage(ctx)
	if err != nil {
		t.Fatal(err)
	}
	var user int64
	for _, u := range usage {
		if u.Scope == quota.ScopeUser && u.DID == "did:plc:owner" && u.Resource == quota.ResourceCacheStorageBytes {
			user = u.Used
		}
	}
	if user != 200 {
		t.Fatalf("owner cache usage = %d, want 200", user)
	}
}

func TestCacheEntryDeletesDropTheirCharge(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	qs := NewQuotaStore(d, nil)
	now := time.Now()
	for _, id := range []string{"by-id", "by-key", "kept"} {
		insertTestCacheEntry(t, d, testCacheEntry(id, id, "pending", now))
		if _, err := d.MarkCacheEntryReady(ctx, id, 10, qs, now); err != nil {
			t.Fatal(err)
		}
	}
	if _, err := d.Exec(`
		insert into quota_allocations (repo_did, resource, kind, key, amount) values (?, ?, ?, ?, 7)`,
		"did:plc:repo", quota.ResourceCacheStorageBytes, quota.KindNixCache, "by-id"); err != nil {
		t.Fatal(err)
	}

	if err := d.DeleteCacheEntry(ctx, "by-id"); err != nil {
		t.Fatal(err)
	}
	if err := d.DeleteCacheEntriesByStorageKey(ctx, "objects/by-key"); err != nil {
		t.Fatal(err)
	}
	for id, want := range map[string]bool{"by-id": false, "by-key": false, "kept": true} {
		if _, ok := genericAllocation(t, d, id); ok != want {
			t.Fatalf("%s charged = %t, want %t", id, ok, want)
		}
	}
	var nix int
	if err := d.QueryRow(`select count(*) from quota_allocations where kind = ?`, quota.KindNixCache).Scan(&nix); err != nil || nix != 1 {
		t.Fatalf("nix allocations = %d (%v), want the one with the same key kept", nix, err)
	}
}

func TestMillCacheCapabilitiesAreLeaseScopedAndConsumable(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	lease := MillLease{
		LeaseID:    "lease-1",
		NodeID:     "node-1",
		Epoch:      "epoch-1",
		Engine:     "microvm",
		PipelineID: "r",
		Workflow:   "build",
		State:      "running",
	}
	if err := d.SaveMillLease(lease); err != nil {
		t.Fatal(err)
	}
	capability := MillCacheCapability{
		Action:     "save",
		CacheID:    "cache-1",
		StorageKey: "objects/did:web:example.com/cache-1",
	}
	if err := d.SaveMillCacheCapabilities(lease.LeaseID, []MillCacheCapability{capability}); err != nil {
		t.Fatal(err)
	}
	if err := d.ApplyEventBatch(nil, func(tx *EventBatchTx) error {
		storageKey, consumed, err := tx.ConsumeMillCacheCapability(
			ctx,
			lease.LeaseID,
			capability.Action,
			capability.CacheID,
		)
		if err != nil {
			return err
		}
		if !consumed {
			t.Fatal("planned capability was not consumed")
		}
		if storageKey != capability.StorageKey {
			t.Fatalf("consumed storage key = %q, want %q", storageKey, capability.StorageKey)
		}
		return nil
	}); err != nil {
		t.Fatal(err)
	}
	if err := d.ApplyEventBatch(nil, func(tx *EventBatchTx) error {
		_, consumed, err := tx.ConsumeMillCacheCapability(
			ctx,
			"another-lease",
			capability.Action,
			capability.CacheID,
		)
		if err != nil {
			return err
		}
		if consumed {
			t.Fatal("foreign lease consumed capability")
		}
		return nil
	}); err != nil {
		t.Fatal(err)
	}
}

func TestCacheObjectDeletionQueuePersistsUntilCompleted(t *testing.T) {
	ctx := context.Background()
	d := newTestDB(t)
	key := "objects/did:web:example.com/orphan"
	if err := d.ApplyEventBatch(nil, func(tx *EventBatchTx) error {
		return tx.QueueCacheObjectDeletion(ctx, key, time.Now())
	}); err != nil {
		t.Fatal(err)
	}
	keys, err := d.PendingCacheObjectDeletions(ctx, 10)
	if err != nil {
		t.Fatal(err)
	}
	if len(keys) != 1 || keys[0] != key {
		t.Fatalf("pending deletions = %v, want %q", keys, key)
	}
	if err := d.CompleteCacheObjectDeletion(ctx, key); err != nil {
		t.Fatal(err)
	}
	keys, err = d.PendingCacheObjectDeletions(ctx, 10)
	if err != nil {
		t.Fatal(err)
	}
	if len(keys) != 0 {
		t.Fatalf("completed deletion remained queued: %v", keys)
	}
}

func TestReplacingACacheEntryChargesOnlyTheNewOne(t *testing.T) {
	for _, tt := range []struct {
		name      string
		unrelated int64
		allowed   bool
	}{
		{name: "fits once the old entry is gone", unrelated: 40, allowed: true},
		{name: "past twice the limit even without the old entry", unrelated: 60, allowed: false},
	} {
		for _, batch := range []bool{false, true} {
			t.Run(fmt.Sprintf("%s batch=%t", tt.name, batch), func(t *testing.T) {
				ctx := context.Background()
				d := newTestDB(t)
				qs := NewQuotaStore(d, cacheDefaults(50, 0))
				now := time.Now()
				old := testCacheEntry("old", "same", "pending", now)
				insertTestCacheEntry(t, d, old)
				if _, err := d.MarkCacheEntryReady(ctx, old.ID, 45, qs, now); err != nil {
					t.Fatal(err)
				}
				if _, err := d.Exec(`
					insert into quota_allocations (repo_did, resource, kind, key, amount) values (?, ?, ?, 'unrelated', ?)`,
					old.RepoDID, quota.ResourceCacheStorageBytes, quota.KindNixCache, tt.unrelated); err != nil {
					t.Fatal(err)
				}
				pending := testCacheEntry("new", "same", "pending", now.Add(time.Second))
				insertTestCacheEntry(t, d, pending)

				var ready bool
				if batch {
					if err := d.ApplyEventBatch(nil, func(tx *EventBatchTx) error {
						var err error
						_, ready, err = tx.MarkCacheEntryReadyWithChecksum(ctx, pending.ID, 50, "", qs, 0, now)
						return err
					}); err != nil {
						t.Fatal(err)
					}
				} else {
					_, err := d.MarkCacheEntryReady(ctx, pending.ID, 50, qs, now)
					if err != nil && !errors.Is(err, sql.ErrNoRows) {
						t.Fatal(err)
					}
					ready = err == nil
				}
				if ready != tt.allowed {
					t.Fatalf("replacement ready = %t, want %t", ready, tt.allowed)
				}
				oldCharge, oldCharged := genericAllocation(t, d, old.ID)
				_, newCharged := genericAllocation(t, d, pending.ID)
				if tt.allowed && (oldCharged || !newCharged) {
					t.Fatalf("old charged %t, new charged %t; want only the new one", oldCharged, newCharged)
				}
				if !tt.allowed && (!oldCharged || oldCharge != 45 || newCharged || cacheEntryState(t, d, old.ID) != "ready") {
					t.Fatalf("refused replacement left old charged (%d, %t) in %s and new charged %t; want the old entry as it was", oldCharge, oldCharged, cacheEntryState(t, d, old.ID), newCharged)
				}
				if err := d.DeleteCacheEntry(ctx, old.ID); err != nil {
					t.Fatalf("deleting the replaced entry: %v", err)
				}
			})
		}
	}
}