package labeler

import (
	"database/sql"
	"testing"
	"time"

	_ "github.com/tursodatabase/go-libsql"
)

func newTestCache(t *testing.T) *Cache {
	t.Helper()
	db, err := sql.Open("libsql", ":memory:")
	if err != nil {
		t.Fatalf("open in-memory db: %v", err)
	}
	t.Cleanup(func() { _ = db.Close() })

	c, err := NewCache(db)
	if err != nil {
		t.Fatalf("NewCache: %v", err)
	}
	return c
}

func TestCacheSetAndIsTakenDown(t *testing.T) {
	c := newTestCache(t)
	uri := "at://did:plc:alice/io.atcr.manifest/abc"
	cts := time.Now().UTC().Add(-time.Hour)

	if _, ok := c.IsTakenDown(uri); ok {
		t.Fatalf("expected not taken down before Set")
	}
	if err := c.Set(uri, "did:web:labeler", cts); err != nil {
		t.Fatalf("Set: %v", err)
	}

	got, ok := c.IsTakenDown(uri)
	if !ok {
		t.Fatalf("expected taken down after Set")
	}
	if !got.Equal(cts) {
		t.Fatalf("cts = %v, want %v", got, cts)
	}
}

func TestCacheNegateRemovesEntry(t *testing.T) {
	c := newTestCache(t)
	uri := "at://did:plc:alice/io.atcr.manifest/abc"
	if err := c.Set(uri, "did:web:labeler", time.Now()); err != nil {
		t.Fatal(err)
	}
	if err := c.Negate(uri); err != nil {
		t.Fatalf("Negate: %v", err)
	}
	if _, ok := c.IsTakenDown(uri); ok {
		t.Fatalf("expected not taken down after Negate")
	}
}

func TestCacheUserLevelTakedownAppliesToAllManifests(t *testing.T) {
	c := newTestCache(t)
	userURI := "at://did:plc:alice"
	cts := time.Now().UTC()

	if err := c.Set(userURI, "did:web:labeler", cts); err != nil {
		t.Fatal(err)
	}

	manifestURI := "at://did:plc:alice/io.atcr.manifest/anything"
	got, ok := c.IsTakenDown(manifestURI)
	if !ok {
		t.Fatalf("user-level takedown should apply to manifest URI")
	}
	if !got.Equal(cts) {
		t.Fatalf("cts = %v, want %v", got, cts)
	}

	otherURI := "at://did:plc:bob/io.atcr.manifest/x"
	if _, ok := c.IsTakenDown(otherURI); ok {
		t.Fatalf("user-level takedown for alice must not affect bob")
	}
}

func TestCacheChoosesEarliestCtsAcrossSources(t *testing.T) {
	c := newTestCache(t)
	earlier := time.Now().UTC().Add(-2 * time.Hour)
	later := time.Now().UTC()

	manifestURI := "at://did:plc:alice/io.atcr.manifest/x"
	userURI := "at://did:plc:alice"

	// Per-manifest later, user-level earlier — IsTakenDown should report the earlier one.
	if err := c.Set(manifestURI, "did:web:labeler", later); err != nil {
		t.Fatal(err)
	}
	if err := c.Set(userURI, "did:web:labeler", earlier); err != nil {
		t.Fatal(err)
	}

	got, ok := c.IsTakenDown(manifestURI)
	if !ok {
		t.Fatalf("expected taken down")
	}
	if !got.Equal(earlier) {
		t.Fatalf("cts = %v, want earliest (%v)", got, earlier)
	}
}

func TestCachePersistsAcrossInstances(t *testing.T) {
	db, err := sql.Open("libsql", ":memory:")
	if err != nil {
		t.Fatalf("open: %v", err)
	}
	t.Cleanup(func() { _ = db.Close() })

	first, err := NewCache(db)
	if err != nil {
		t.Fatalf("first NewCache: %v", err)
	}
	uri := "at://did:plc:alice/io.atcr.manifest/abc"
	cts := time.Now().UTC()
	if err := first.Set(uri, "did:web:labeler", cts); err != nil {
		t.Fatal(err)
	}

	// New cache instance, same DB — should warm-load entry.
	second, err := NewCache(db)
	if err != nil {
		t.Fatalf("second NewCache: %v", err)
	}
	if _, ok := second.IsTakenDown(uri); !ok {
		t.Fatalf("second cache should see persisted takedown")
	}
}

func TestCacheCursorRoundTrip(t *testing.T) {
	c := newTestCache(t)
	const labeler = "did:web:labeler"

	got, err := c.GetCursor(labeler)
	if err != nil {
		t.Fatal(err)
	}
	if got != 0 {
		t.Fatalf("initial cursor = %d, want 0", got)
	}

	if err := c.SetCursor(labeler, 42); err != nil {
		t.Fatal(err)
	}
	got, err = c.GetCursor(labeler)
	if err != nil {
		t.Fatal(err)
	}
	if got != 42 {
		t.Fatalf("cursor = %d, want 42", got)
	}

	if err := c.SetCursor(labeler, 100); err != nil {
		t.Fatal(err)
	}
	got, err = c.GetCursor(labeler)
	if err != nil {
		t.Fatal(err)
	}
	if got != 100 {
		t.Fatalf("cursor after upsert = %d, want 100", got)
	}
}

func TestIsExpired(t *testing.T) {
	tests := []struct {
		name    string
		cts     time.Time
		grace   time.Duration
		expired bool
	}{
		{"in-window", time.Now().Add(-time.Hour), 24 * time.Hour, false},
		{"past-window", time.Now().Add(-48 * time.Hour), 24 * time.Hour, true},
		{"zero grace expires immediately", time.Now(), 0, true},
		{"negative grace expires immediately", time.Now(), -time.Hour, true},
	}
	for _, tt := range tests {
		t.Run(tt.name, func(t *testing.T) {
			if got := IsExpired(tt.cts, tt.grace); got != tt.expired {
				t.Fatalf("IsExpired = %v, want %v", got, tt.expired)
			}
		})
	}
}