package proto_test

import (
	"math"
	"math/rand"
	"testing"

	"git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/util/proto/test"
	generated "git.frostfs.info/TrueCloudLab/frostfs-api-go/v2/util/proto/test/custom"
	"github.com/stretchr/testify/require"
	"google.golang.org/protobuf/encoding/protojson"
	goproto "google.golang.org/protobuf/proto"
)

type protoInt interface {
	~int32 | ~uint32 | ~int64 | ~uint64
}

func nonZero[T protoInt]() T {
	var r T
	for r == 0 {
		r = T(rand.Uint64())
	}
	return r
}

func TestStableMarshalSingle(t *testing.T) {
	t.Run("empty", func(t *testing.T) {
		input := &generated.Primitives{}
		require.Zero(t, input.StableSize())

		r := input.MarshalProtobuf(nil)
		require.Empty(t, r)
	})

	marshalCases := []struct {
		name  string
		input *generated.Primitives
	}{
		{name: "bytes", input: &generated.Primitives{FieldA: []byte{1, 2, 3}}},
		{name: "string", input: &generated.Primitives{FieldB: "123"}},
		{name: "bool", input: &generated.Primitives{FieldC: true}},
		{name: "int32", input: &generated.Primitives{FieldD: -10}},
		{name: "uint32", input: &generated.Primitives{FieldE: nonZero[uint32]()}},
		{name: "int64", input: &generated.Primitives{FieldF: nonZero[int64]()}},
		{name: "uint64", input: &generated.Primitives{FieldG: nonZero[uint64]()}},
		{name: "uint64", input: &generated.Primitives{FieldI: nonZero[uint64]()}},
		{name: "float64", input: &generated.Primitives{FieldJ: math.Float64frombits(12345677890)}},
		{name: "fixed32", input: &generated.Primitives{FieldK: nonZero[uint32]()}},
		{name: "enum, positive", input: &generated.Primitives{FieldH: generated.Primitives_POSITIVE}},
		{name: "enum, negative", input: &generated.Primitives{FieldH: generated.Primitives_NEGATIVE}},
	}
	for _, tc := range marshalCases {
		t.Run(tc.name, func(t *testing.T) {
			t.Run("proto", func(t *testing.T) {
				r := tc.input.MarshalProtobuf(nil)
				require.Equal(t, len(r), tc.input.StableSize())
				require.NotEmpty(t, r)

				var actual test.Primitives
				require.NoError(t, goproto.Unmarshal(r, &actual))

				var actualFrostfs generated.Primitives
				require.NoError(t, actualFrostfs.UnmarshalProtobuf(r))
				require.Equal(t, tc.input, &actualFrostfs)

				primitivesEqual(t, tc.input, &actual)
			})
			t.Run("json", func(t *testing.T) {
				r, err := tc.input.MarshalJSON()
				require.NoError(t, err)
				require.NotEmpty(t, r)

				var actual test.Primitives
				require.NoError(t, protojson.Unmarshal(r, &actual))

				var actualFrostfs generated.Primitives
				require.NoError(t, actualFrostfs.UnmarshalJSON(r))
				require.Equal(t, tc.input, &actualFrostfs)

				primitivesEqual(t, tc.input, &actual)
			})
		})
	}
}

func primitivesEqual(t *testing.T, a *generated.Primitives, b *test.Primitives) {
	// Compare each field directly, because proto-generated code has private fields.
	require.Equal(t, a.FieldA, b.FieldA)
	require.Equal(t, a.FieldB, b.FieldB)
	require.Equal(t, a.FieldC, b.FieldC)
	require.Equal(t, a.FieldD, b.FieldD)
	require.Equal(t, a.FieldE, b.FieldE)
	require.Equal(t, a.FieldF, b.FieldF)
	require.Equal(t, a.FieldG, b.FieldG)
	require.Equal(t, a.FieldI, b.FieldI)
	require.Equal(t, a.FieldJ, b.FieldJ)
	require.Equal(t, a.FieldK, b.FieldK)
	require.EqualValues(t, a.FieldH, b.FieldH)
}

func repPrimitivesEqual(t *testing.T, a *generated.RepPrimitives, b *test.RepPrimitives) {
	// Compare each field directly, because proto-generated code has private fields.
	require.Equal(t, a.FieldA, b.FieldA)
	require.Equal(t, a.FieldB, b.FieldB)
	require.Equal(t, a.FieldC, b.FieldC)
	require.Equal(t, a.FieldD, b.FieldD)
	require.Equal(t, a.FieldE, b.FieldE)
	require.Equal(t, a.FieldF, b.FieldF)
	require.Equal(t, a.FieldFu, b.FieldFu)
}

func randIntSlice[T protoInt](n int, includeZero bool) []T {
	r := make([]T, n)
	if n == 0 {
		return r
	}
	for i := range r {
		r[i] = T(rand.Uint64())
	}
	if includeZero {
		r[0] = 0
	}
	return r
}

func TestStableMarshalRep(t *testing.T) {
	t.Run("empty", func(t *testing.T) {
		marshalCases := []struct {
			name  string
			input *generated.RepPrimitives
		}{
			{name: "default", input: &generated.RepPrimitives{}},
			{name: "bytes", input: &generated.RepPrimitives{FieldA: [][]byte{}}},
			{name: "string", input: &generated.RepPrimitives{FieldB: []string{}}},
			{name: "int32", input: &generated.RepPrimitives{FieldC: []int32{}}},
			{name: "uint32", input: &generated.RepPrimitives{FieldD: []uint32{}}},
			{name: "int64", input: &generated.RepPrimitives{FieldE: []int64{}}},
			{name: "uint64", input: &generated.RepPrimitives{FieldF: []uint64{}}},
			{name: "uint64", input: &generated.RepPrimitives{FieldFu: []uint64{}}},
		}

		for _, tc := range marshalCases {
			t.Run(tc.name, func(t *testing.T) {
				require.Zero(t, tc.input.StableSize())

				r := tc.input.MarshalProtobuf(nil)
				require.Empty(t, r)
			})
		}
	})

	marshalCases := []struct {
		name  string
		input *generated.RepPrimitives
	}{
		{name: "bytes", input: &generated.RepPrimitives{FieldA: [][]byte{{1, 2, 3}}}},
		{name: "string", input: &generated.RepPrimitives{FieldB: []string{"123"}}},
		{name: "int32", input: &generated.RepPrimitives{FieldC: randIntSlice[int32](1, true)}},
		{name: "int32", input: &generated.RepPrimitives{FieldC: randIntSlice[int32](2, true)}},
		{name: "int32", input: &generated.RepPrimitives{FieldC: randIntSlice[int32](2, false)}},
		{name: "uint32", input: &generated.RepPrimitives{FieldD: randIntSlice[uint32](1, true)}},
		{name: "uint32", input: &generated.RepPrimitives{FieldD: randIntSlice[uint32](2, true)}},
		{name: "uint32", input: &generated.RepPrimitives{FieldD: randIntSlice[uint32](2, false)}},
		{name: "int64", input: &generated.RepPrimitives{FieldE: randIntSlice[int64](1, true)}},
		{name: "int64", input: &generated.RepPrimitives{FieldE: randIntSlice[int64](2, true)}},
		{name: "int64", input: &generated.RepPrimitives{FieldE: randIntSlice[int64](2, false)}},
		{name: "uint64", input: &generated.RepPrimitives{FieldF: randIntSlice[uint64](1, true)}},
		{name: "uint64", input: &generated.RepPrimitives{FieldF: randIntSlice[uint64](2, true)}},
		{name: "uint64", input: &generated.RepPrimitives{FieldF: randIntSlice[uint64](2, false)}},
		{name: "uint64", input: &generated.RepPrimitives{FieldFu: randIntSlice[uint64](1, true)}},
		{name: "uint64", input: &generated.RepPrimitives{FieldFu: randIntSlice[uint64](2, true)}},
		{name: "uint64", input: &generated.RepPrimitives{FieldFu: randIntSlice[uint64](2, false)}},
	}
	for _, tc := range marshalCases {
		t.Run(tc.name, func(t *testing.T) {
			t.Run("proto", func(t *testing.T) {
				r := tc.input.MarshalProtobuf(nil)
				require.Equal(t, len(r), tc.input.StableSize())
				require.NotEmpty(t, r)

				var actual test.RepPrimitives
				require.NoError(t, goproto.Unmarshal(r, &actual))
				repPrimitivesEqual(t, tc.input, &actual)
			})
			t.Run("json", func(t *testing.T) {
				r, err := tc.input.MarshalJSON()
				require.NoError(t, err)
				require.NotEmpty(t, r)

				var actual test.RepPrimitives
				require.NoError(t, protojson.Unmarshal(r, &actual))
				repPrimitivesEqual(t, tc.input, &actual)
			})
		})
	}
}