package storage

import (
	"context"
	"fmt"
	"io/ioutil"
	"log"
	"os"
	"reflect"
	"testing"

	"github.com/matrix-org/dendrite/keyserver/api"
	"github.com/matrix-org/dendrite/keyserver/types"
	"github.com/matrix-org/dendrite/setup/config"
)

var ctx = context.Background()

func MustCreateDatabase(t *testing.T) (Database, func()) {
	tmpfile, err := ioutil.TempFile("", "keyserver_storage_test")
	if err != nil {
		log.Fatal(err)
	}
	t.Logf("Database %s", tmpfile.Name())
	db, err := NewDatabase(&config.DatabaseOptions{
		ConnectionString: config.DataSource(fmt.Sprintf("file://%s", tmpfile.Name())),
	})
	if err != nil {
		t.Fatalf("Failed to NewDatabase: %s", err)
	}
	return db, func() {
		os.Remove(tmpfile.Name())
	}
}

func MustNotError(t *testing.T, err error) {
	t.Helper()
	if err == nil {
		return
	}
	t.Fatalf("operation failed: %s", err)
}

func TestKeyChanges(t *testing.T) {
	db, clean := MustCreateDatabase(t)
	defer clean()
	_, err := db.StoreKeyChange(ctx, "@alice:localhost")
	MustNotError(t, err)
	deviceChangeIDB, err := db.StoreKeyChange(ctx, "@bob:localhost")
	MustNotError(t, err)
	deviceChangeIDC, err := db.StoreKeyChange(ctx, "@charlie:localhost")
	MustNotError(t, err)
	userIDs, latest, err := db.KeyChanges(ctx, deviceChangeIDB, types.OffsetNewest)
	if err != nil {
		t.Fatalf("Failed to KeyChanges: %s", err)
	}
	if latest != deviceChangeIDC {
		t.Fatalf("KeyChanges: got latest=%d want %d", latest, deviceChangeIDC)
	}
	if !reflect.DeepEqual(userIDs, []string{"@charlie:localhost"}) {
		t.Fatalf("KeyChanges: wrong user_ids: %v", userIDs)
	}
}

func TestKeyChangesNoDupes(t *testing.T) {
	db, clean := MustCreateDatabase(t)
	defer clean()
	deviceChangeIDA, err := db.StoreKeyChange(ctx, "@alice:localhost")
	MustNotError(t, err)
	deviceChangeIDB, err := db.StoreKeyChange(ctx, "@alice:localhost")
	MustNotError(t, err)
	if deviceChangeIDA == deviceChangeIDB {
		t.Fatalf("Expected change ID to be different even when inserting key change for the same user, got %d for both changes", deviceChangeIDA)
	}
	deviceChangeID, err := db.StoreKeyChange(ctx, "@alice:localhost")
	MustNotError(t, err)
	userIDs, latest, err := db.KeyChanges(ctx, 0, types.OffsetNewest)
	if err != nil {
		t.Fatalf("Failed to KeyChanges: %s", err)
	}
	if latest != deviceChangeID {
		t.Fatalf("KeyChanges: got latest=%d want %d", latest, deviceChangeID)
	}
	if !reflect.DeepEqual(userIDs, []string{"@alice:localhost"}) {
		t.Fatalf("KeyChanges: wrong user_ids: %v", userIDs)
	}
}

func TestKeyChangesUpperLimit(t *testing.T) {
	db, clean := MustCreateDatabase(t)
	defer clean()
	deviceChangeIDA, err := db.StoreKeyChange(ctx, "@alice:localhost")
	MustNotError(t, err)
	deviceChangeIDB, err := db.StoreKeyChange(ctx, "@bob:localhost")
	MustNotError(t, err)
	_, err = db.StoreKeyChange(ctx, "@charlie:localhost")
	MustNotError(t, err)
	userIDs, latest, err := db.KeyChanges(ctx, deviceChangeIDA, deviceChangeIDB)
	if err != nil {
		t.Fatalf("Failed to KeyChanges: %s", err)
	}
	if latest != deviceChangeIDB {
		t.Fatalf("KeyChanges: got latest=%d want %d", latest, deviceChangeIDB)
	}
	if !reflect.DeepEqual(userIDs, []string{"@bob:localhost"}) {
		t.Fatalf("KeyChanges: wrong user_ids: %v", userIDs)
	}
}

// The purpose of this test is to make sure that the storage layer is generating sequential stream IDs per user,
// and that they are returned correctly when querying for device keys.
func TestDeviceKeysStreamIDGeneration(t *testing.T) {
	var err error
	db, clean := MustCreateDatabase(t)
	defer clean()
	alice := "@alice:TestDeviceKeysStreamIDGeneration"
	bob := "@bob:TestDeviceKeysStreamIDGeneration"
	msgs := []api.DeviceMessage{
		{
			Type: api.TypeDeviceKeyUpdate,
			DeviceKeys: &api.DeviceKeys{
				DeviceID: "AAA",
				UserID:   alice,
				KeyJSON:  []byte(`{"key":"v1"}`),
			},
			// StreamID: 1
		},
		{
			Type: api.TypeDeviceKeyUpdate,
			DeviceKeys: &api.DeviceKeys{
				DeviceID: "AAA",
				UserID:   bob,
				KeyJSON:  []byte(`{"key":"v1"}`),
			},
			// StreamID: 1 as this is a different user
		},
		{
			Type: api.TypeDeviceKeyUpdate,
			DeviceKeys: &api.DeviceKeys{
				DeviceID: "another_device",
				UserID:   alice,
				KeyJSON:  []byte(`{"key":"v1"}`),
			},
			// StreamID: 2 as this is a 2nd device key
		},
	}
	MustNotError(t, db.StoreLocalDeviceKeys(ctx, msgs))
	if msgs[0].StreamID != 1 {
		t.Fatalf("Expected StoreLocalDeviceKeys to set StreamID=1 but got %d", msgs[0].StreamID)
	}
	if msgs[1].StreamID != 1 {
		t.Fatalf("Expected StoreLocalDeviceKeys to set StreamID=1 (different user) but got %d", msgs[1].StreamID)
	}
	if msgs[2].StreamID != 2 {
		t.Fatalf("Expected StoreLocalDeviceKeys to set StreamID=2 (another device) but got %d", msgs[2].StreamID)
	}

	// updating a device sets the next stream ID for that user
	msgs = []api.DeviceMessage{
		{
			Type: api.TypeDeviceKeyUpdate,
			DeviceKeys: &api.DeviceKeys{
				DeviceID: "AAA",
				UserID:   alice,
				KeyJSON:  []byte(`{"key":"v2"}`),
			},
			// StreamID: 3
		},
	}
	MustNotError(t, db.StoreLocalDeviceKeys(ctx, msgs))
	if msgs[0].StreamID != 3 {
		t.Fatalf("Expected StoreLocalDeviceKeys to set StreamID=3 (new key same device) but got %d", msgs[0].StreamID)
	}

	// Querying for device keys returns the latest stream IDs
	msgs, err = db.DeviceKeysForUser(ctx, alice, []string{"AAA", "another_device"})
	if err != nil {
		t.Fatalf("DeviceKeysForUser returned error: %s", err)
	}
	wantStreamIDs := map[string]int{
		"AAA":            3,
		"another_device": 2,
	}
	if len(msgs) != len(wantStreamIDs) {
		t.Fatalf("DeviceKeysForUser: wrong number of devices, got %d want %d", len(msgs), len(wantStreamIDs))
	}
	for _, m := range msgs {
		if m.StreamID != wantStreamIDs[m.DeviceID] {
			t.Errorf("DeviceKeysForUser: wrong returned stream ID for key, got %d want %d", m.StreamID, wantStreamIDs[m.DeviceID])
		}
	}
}