package codec_test

import (
	"errors"
	"fmt"
	"math"
	"reflect"
	"testing"

	"github.com/cosmos/gogoproto/proto"
	"github.com/stretchr/testify/require"
	"google.golang.org/grpc/codes"
	"google.golang.org/grpc/encoding"
	"google.golang.org/grpc/status"

	"github.com/cosmos/cosmos-sdk/codec"
	"github.com/cosmos/cosmos-sdk/codec/types"
	"github.com/cosmos/cosmos-sdk/testutil/testdata"
	banktypes "github.com/cosmos/cosmos-sdk/x/bank/types"
)

func createTestInterfaceRegistry() types.InterfaceRegistry {
	interfaceRegistry := types.NewInterfaceRegistry()
	interfaceRegistry.RegisterInterface("testdata.Animal",
		(*testdata.Animal)(nil),
		&testdata.Dog{},
		&testdata.Cat{},
	)

	return interfaceRegistry
}

func TestProtoMarsharlInterface(t *testing.T) {
	cdc := codec.NewProtoCodec(createTestInterfaceRegistry())
	m := interfaceMarshaler{cdc.MarshalInterface, cdc.UnmarshalInterface}
	testInterfaceMarshaling(require.New(t), m, false)
	m = interfaceMarshaler{cdc.MarshalInterfaceJSON, cdc.UnmarshalInterfaceJSON}
	testInterfaceMarshaling(require.New(t), m, false)
}

func TestProtoCodec(t *testing.T) {
	cdc := codec.NewProtoCodec(createTestInterfaceRegistry())
	testMarshaling(t, cdc)
}

type lyingProtoMarshaler struct {
	codec.ProtoMarshaler
	falseSize int
}

func (lpm *lyingProtoMarshaler) Size() int {
	return lpm.falseSize
}

func TestEnsureRegistered(t *testing.T) {
	interfaceRegistry := types.NewInterfaceRegistry()
	cat := &testdata.Cat{Moniker: "Garfield"}

	err := interfaceRegistry.EnsureRegistered(*cat)
	require.ErrorContains(t, err, "testdata.Cat is not a pointer")

	err = interfaceRegistry.EnsureRegistered(cat)
	require.ErrorContains(t, err, "testdata.Cat does not have a registered interface")

	interfaceRegistry.RegisterInterface("testdata.Animal",
		(*testdata.Animal)(nil),
		&testdata.Cat{},
	)

	require.NoError(t, interfaceRegistry.EnsureRegistered(cat))
}

func TestProtoCodecMarshal(t *testing.T) {
	interfaceRegistry := types.NewInterfaceRegistry()
	interfaceRegistry.RegisterInterface("testdata.Animal",
		(*testdata.Animal)(nil),
		&testdata.Cat{},
	)
	cdc := codec.NewProtoCodec(interfaceRegistry)

	cartonRegistry := types.NewInterfaceRegistry()
	cartonRegistry.RegisterInterface("testdata.Cartoon",
		(*testdata.Cartoon)(nil),
		&testdata.Bird{},
	)
	cartoonCdc := codec.NewProtoCodec(cartonRegistry)

	cat := &testdata.Cat{Moniker: "Garfield", Lives: 6}
	bird := &testdata.Bird{Species: "Passerina ciris"}
	require.NoError(t, interfaceRegistry.EnsureRegistered(cat))

	var (
		animal  testdata.Animal
		cartoon testdata.Cartoon
	)

	// sanity check
	require.True(t, reflect.TypeOf(cat).Implements(reflect.TypeOf((*testdata.Animal)(nil)).Elem()))

	bz, err := cdc.MarshalInterface(cat)
	require.NoError(t, err)

	err = cdc.UnmarshalInterface(bz, &animal)
	require.NoError(t, err)

	bz, err = cdc.MarshalInterface(bird)
	require.ErrorContains(t, err, "does not have a registered interface")

	bz, err = cartoonCdc.MarshalInterface(bird)
	require.NoError(t, err)

	err = cdc.UnmarshalInterface(bz, &cartoon)
	require.ErrorContains(t, err, "no registered implementations")

	err = cartoonCdc.UnmarshalInterface(bz, &cartoon)
	require.NoError(t, err)

	// test typed nil input shouldn't panic
	var v *banktypes.QueryBalanceResponse
	bz, err = grpcServerEncode(cartoonCdc.GRPCCodec(), v)
	require.NoError(t, err)
	require.Empty(t, bz)
}

// Emulate grpc server implementation
// https://github.com/grpc/grpc-go/blob/b1d7f56b81b7902d871111b82dec6ba45f854ede/rpc_util.go#L590
func grpcServerEncode(c encoding.Codec, msg interface{}) ([]byte, error) {
	if msg == nil { // NOTE: typed nils will not be caught by this check
		return nil, nil
	}
	b, err := c.Marshal(msg)
	if err != nil {
		return nil, status.Errorf(codes.Internal, "grpc: error while marshaling: %v", err.Error())
	}
	if uint(len(b)) > math.MaxUint32 {
		return nil, status.Errorf(codes.ResourceExhausted, "grpc: message too large (%d bytes)", len(b))
	}
	return b, nil
}

func TestProtoCodecUnmarshalLengthPrefixedChecks(t *testing.T) {
	cdc := codec.NewProtoCodec(createTestInterfaceRegistry())

	truth := &testdata.Cat{Lives: 9, Moniker: "glowing"}
	realSize := len(cdc.MustMarshal(truth))

	falseSizes := []int{
		100,
		5,
	}

	for _, falseSize := range falseSizes {
		falseSize := falseSize

		t.Run(fmt.Sprintf("ByMarshaling falseSize=%d", falseSize), func(t *testing.T) {
			lpm := &lyingProtoMarshaler{
				ProtoMarshaler: &testdata.Cat{Lives: 9, Moniker: "glowing"},
				falseSize:      falseSize,
			}
			var serialized []byte
			require.NotPanics(t, func() { serialized = cdc.MustMarshalLengthPrefixed(lpm) })

			recv := new(testdata.Cat)
			gotErr := cdc.UnmarshalLengthPrefixed(serialized, recv)
			var wantErr error
			if falseSize > realSize {
				wantErr = fmt.Errorf("not enough bytes to read; want: %d, got: %d", falseSize, realSize)
			} else {
				wantErr = fmt.Errorf("too many bytes to read; want: %d, got: %d", falseSize, realSize)
			}
			require.Equal(t, gotErr, wantErr)
		})
	}

	t.Run("Crafted bad uvarint size", func(t *testing.T) {
		crafted := []byte{0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0xff, 0x7f}
		recv := new(testdata.Cat)
		gotErr := cdc.UnmarshalLengthPrefixed(crafted, recv)
		require.Equal(t, gotErr, errors.New("invalid number of bytes read from length-prefixed encoding: -10"))

		require.Panics(t, func() { cdc.MustUnmarshalLengthPrefixed(crafted, recv) })
	})
}

func mustAny(msg proto.Message) *types.Any {
	any, err := types.NewAnyWithValue(msg)
	if err != nil {
		panic(err)
	}
	return any
}

func BenchmarkProtoCodecMarshalLengthPrefixed(b *testing.B) {
	pCdc := codec.NewProtoCodec(types.NewInterfaceRegistry())
	msg := &testdata.HasAnimal{
		X: 1000,
		Animal: mustAny(&testdata.HasAnimal{
			X: 2000,
			Animal: mustAny(&testdata.HasAnimal{
				X: 3000,
				Animal: mustAny(&testdata.HasAnimal{
					X: 4000,
					Animal: mustAny(&testdata.HasAnimal{
						X: 5000,
						Animal: mustAny(&testdata.Cat{
							Moniker: "Garfield",
							Lives:   6,
						}),
					}),
				}),
			}),
		}),
	}

	b.ResetTimer()
	b.ReportAllocs()

	for i := 0; i < b.N; i++ {
		blob, err := pCdc.MarshalLengthPrefixed(msg)
		if err != nil {
			b.Fatal(err)
		}
		b.SetBytes(int64(len(blob)))
	}
}